Name: genome-wide analysis of hdac inhibitor-mediated modulation of micrornas and mrnas in b cells induced to undergo class-switch dna recombination and plasma cell differentiation
Uploaded: 2017-09-20T12:30:00
Description: Watch this Scientific Journal Video about Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell

This work was supported by NIH grants AI 105813 and AI 079705 (to PC), the Alliance for Lupus Research Target Identification in Lupus Grant ALR 295955 (to PC), and the Arthritis National Research Foundation research grant (to HZ). TS was supported by the Pediatrics Medical Center, Second Xiangya Hospital, Central South University, Changsha, China, in the context of the Xiangya-UT School of Medicine San Antonio medical student visiting program.

The protocol follows the animal care guidelines of The Institutional Animal Care and Use Committees of the University of Texas Health Science Center at San Antonio.
1. Stimulation of Mouse B Cells for CSR, Plasma Cell Differentiation, and HDI Treatment
<ol>
	<li>Preparation of spleen cell suspensions 
	NOTE: Perform all steps in a laminar flow hood except for mouse euthanasia and dissection.
	<ol>
		<li>Euthanize the specific pathogen-free C57BL/6J mouse (8-12 weeks of ...

<ol>
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This protocol provides comprehensive approaches to induce B cell class switching and plasma cell differentiation; to analyze their impact by epigenetic modulators, namely HDI; and to detect the effect of HDI on mRNA and miRNA expression in these cells. Most of these approaches can also be used to analyze the impact of epigenetic factor on human B-cell function and mRNA/miRNA expression. The qRT-PCR and mRNA-seq/miRNA-seq approaches can also be used to analyze B cells isolated from mice treated with epigenetic modulators,...

Epigenetic marks or factors, such as DNA methylation, histone posttranslational modifications, and non-coding RNAs (including microRNAs), modulate cell function by altering gene expression1. Epigenetic modifications regulate B lymphocyte function, such as immunoglobulin class-switch DNA recombination (CSR), somatic hypermutation (SHM), and differentiation to memory B cells or plasma cells, thereby modulating the antibody and autoantibody responses2,3. CSR and SHM critically require activation-induced cytidine deaminase (AID, encoded as Aicda), which is highly induced in B cells in response to T-dependent and T-independent antigens4. Class-switched/hypermutated B cells further differentiate into plasma cells, which secrete large volumes of antibodies in a fashion critically dependent upon B lymphocyte-induced maturation protein 1 (Blimp1, encoded as Prdm1)5. Abnormal epigenetic changes in B cells may result in aberrant antibody/autoantibody responses, which can lead to allergic response or autoimmunity1,4. Understanding how epigenetic factors, such as miRNAs, modulate B cell-intrinsic gene expression is not only important for vaccine development, but is also essential to reveal the mechanisms of potential abnormal antibody/autoantibody responses.
Histone acetylation and deacetylation are modifications of the lysine residues on histone proteins typically catalyzed by histone acetyltransferase (HAT) and histone deacetylase (HDAC). These modifications lead to the increasing or decreasing accessibility of chromatin and further allow or prevent the binding of transcription factors or proteins to DNA and the alteration of gene expression5,6,7,8. HDAC inhibitors (HDI) are a class of compounds that interfere with the function of HDACs. Here, we used HDI (VPA) to address the regulation of HDAC on the intrinsic gene expression profile of B cells and on its mechanism.
miRNAs are small, non-coding RNAs approximately 18 to 22 nucleotides in length that are generated through several stages. miRNA host genes are transcribed and form hairpin primary microRNAs (pri-miRNAs). They are exported to the cytoplasm, where pri-miRNAs are further processed into precursor miRNAs (pre-miRNAs). Finally, mature miRNAs are formed through the cleavage of the pre-miRNAs. miRNAs recognize the complementary sequences within the 3&#39; untranslated region of their target mRNAs6,7. Through post-transcriptional silencing, miRNAs regulate cellular activity, such as proliferation, differentiation, and apoptosis10,11. Since multiple miRNAs can target the same mRNA, and one single miRNA can potentially target multiple mRNAs, it is important to have an in-context view of the miRNA expression profile to understand the value of the individual and the collective effect of miRNAs. miRNAs have been shown to be involved in B-cell development and peripheral differentiation, as well as B-cell stage-specific differentiation, antibody response, and autoimmunity1,4,9. In the 3&#39; UTR of Aicda and Prdm1, there are several validated or predicted evolutionarily conserved sites that can be targeted by miRNAs8.
Epigenetic modulation, including histone post-transcription modification and miRNAs, display a cell-type and cell stage-specific regulation pattern of gene expression9. Here, we describe methods to define the HDI-mediated modulation of miRNA and mRNA expression, CSR, and plasma cell differentiation. These include protocols for inducing B cells to undergo CSR and plasma cell differentiation; for treating the B cells with HDI; and for analyzing miRNA and mRNA expression by qRT-PCR, miRNA-seq, and mRNA-seq10,11,12,8,13.

<table border="0" cellpadding="0" cellspacing="0" width="854">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:528px;">C57BL/6 mice</td>
			<td style="width:152px;">Jackson Labs</td>
			<td align="right" style="width:111px;">664</td>
			<td style="width:64px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Corning cellgro RPMI 1640 Medium (Mod.) 1X with L-Glutamine (Size: 6 x 500mL; With L-Glutamine)</td>
			<td>Fisher Scientific</td>
			<td>MT 10-040-CV&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FBS</td>
			<td>Hyclone</td>
			<td>SH300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HyClone Antibiotic Antimycotic Solution 100 mL</td>
			<td>Fisher Scientific - Hyclone</td>
			<td>SV3007901&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#946;-Mercaptoethanol</td>
			<td>Fisher Scientific</td>
			<td>44-420-3250ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Falcon Cell Strainers</td>
			<td>Fisher Scientific</td>
			<td>21008-952&#160;&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Trypan Blue Stain 0.04%</td>
			<td>GIBCO/Life Technologies/Inv</td>
			<td align="right">15250</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ACK Lysis Buffer&#160;</td>
			<td>Fisher Scientific</td>
			<td>BW10-548E&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Hausser Scientific Bright-Line Counting Chamber</td>
			<td>Fisher Scientific</td>
			<td>02-671-51B</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:528px;">EasySep Magnet</td>
			<td>Stem Cell Technologies</td>
			<td align="right">18000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Falcon Round-Bottom Polystyrene Tubes with Cap</td>
			<td>Fisher Scientific</td>
			<td>14-959-1A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">EasySep Mouse B cell Isolation Kit</td>
			<td>Stem Cell Tech</td>
			<td align="right">19854</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BD Needle Only 18 Gauge 1.5 inch SHORT BEVEL 100/box&#160;</td>
			<td>BD Biosciences</td>
			<td>&#160;305199</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PE/Cy7 anti-mouse CD138 (Syndecan-1) Antibody</td>
			<td>BioLegend&#160;</td>
			<td>142513 (25 ug)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PE-Cy7 B220 antibody</td>
			<td>BioLegend</td>
			<td align="right">103222</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">7-AAD (1 mg)</td>
			<td>Sigma Aldrich</td>
			<td>A9400-1MG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">APC anti-mouse/human CD45R/B220 antibody</td>
			<td>Biolegend</td>
			<td align="right">103212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mouse APC-IgG1 200 &#181;g</td>
			<td>Biolegend</td>
			<td align="right">406610</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FITC anti-mouse IgM Antibody</td>
			<td>Biolegend</td>
			<td align="right">406506</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FITC anti-mouse/human CD45R/B220 Antibody</td>
			<td>Biolegend</td>
			<td align="right">103206</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PE Anti-Human/Mouse CD45R (B220) (RA3-6B2)</td>
			<td>Biolegend</td>
			<td align="right">103208</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HBSS 1X</td>
			<td>Fisher Scientific</td>
			<td>MT-21-022-CM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bovine Serum Albumin, Fraction V, Heat Shock Treated&#160;</td>
			<td>Fisher Scientific</td>
			<td>BP1600-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">LPS 25mg (Lipopolysaccharides from Escherichia coli 055:B5)</td>
			<td>Sigma Aldrich</td>
			<td>L2880-25MG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Recombinant mouse IL-4 (carrier-free)</td>
			<td>BioLegend</td>
			<td>574302 (size: 10 ug)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Valproic acid sodium salt</td>
			<td>Sigma Aldrich</td>
			<td>P4543</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SterilGARD e3 Class II Type A2 Biosafety Cabinet</td>
			<td>The Baker Company</td>
			<td>SG404</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">Large-Capacity Reach-In CO2 Incubator&#160;</td>
			<td>Thermo Scientific</td>
			<td align="right">3950</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isotemp Digital-Control Water Baths: Model 205</td>
			<td>Fisher Scientific</td>
			<td>15-462-5Q</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5mL Round Bottom Polystyrene Test Tube</td>
			<td>Fisher Scientific</td>
			<td>&#160;14-959-5</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Corning CentriStar 15ml Centrifuge Tubes&#160;</td>
			<td>Fisher Scientific&#160;</td>
			<td>05-538-59A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1.7 mL Microtube, clear</td>
			<td>Genesee</td>
			<td>22-282</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Higher-Speed Easy Reader Plastic Centrifuge Tubes 50ml</td>
			<td>Fisher Scientific</td>
			<td>06-443-18</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ELMI SkySpin CM-6MT</td>
			<td>ELMI</td>
			<td>CM-6MT</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rotor 6M</td>
			<td>ELMI</td>
			<td>6M</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rotor 6M.06</td>
			<td>ELMI</td>
			<td>6M.06</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Drummond Portable Pipet-Aid XP Pipet Controller</td>
			<td>Drummond Scientific</td>
			<td>4-000-101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">25 mL serological pipette tips</td>
			<td>Fisher Scientific</td>
			<td>89130-900</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10 mL serological pipette tips</td>
			<td>Fisher Scientific</td>
			<td>89130-898</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5 mL serological pipette tips</td>
			<td>Fisher Scientific</td>
			<td>898130-896</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">48-well plates</td>
			<td>Fisher Scientific</td>
			<td>07-200-86</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Allegra 6 Benchtop Centrifuge, Non-Refrigerated</td>
			<td>Beckman Coulter</td>
			<td align="right">366802</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">GH-3.8A Rotor, Horizontal, ARIES Smart Balance</td>
			<td>Beckman Coulter</td>
			<td align="right">366650</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Allegra 25R Benchtop Centrifuge, Refrigerated</td>
			<td>Beckman Coulter</td>
			<td align="right">369434</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TA-15-1.5 Rotor, Fixed Angle</td>
			<td>Beckman Coulter</td>
			<td align="right">368298</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fisher Scientific AccuSpin Micro 17</td>
			<td>Fisher Scientific</td>
			<td>13-100-675</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fisher Scientific Analog Vortex Mixer&#160;</td>
			<td>Fisher Scientific</td>
			<td>02-215-365</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">miRNeasy Mini Kit (50)</td>
			<td>Qiagen</td>
			<td align="right">217004</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Direct-zol RNA MiniPrep kit</td>
			<td>Zymo Research</td>
			<td>R2050</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Chloroform (Approx. 0.75% Ethanol as Preservative/Molecular Biology)</td>
			<td>Fisher Scientific</td>
			<td>BP1145-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rnase-Free Dnase set (50)</td>
			<td>QIAGEN</td>
			<td align="right">79254</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NanoDrop 2000 Spectrophotometers</td>
			<td>Thermo Scientific</td>
			<td>ND-2000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Superscript III First-strand Synthesis System RT-PCR</td>
			<td>Invitrogen</td>
			<td align="right">175013897</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">iTaq Universal SYBR Green Supermix</td>
			<td>Bio-rad&#160;</td>
			<td>172-5121</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fisherbrand 96-Well Semi-Skirted PCR Plates, case of 25</td>
			<td>Fisher</td>
			<td style="width:111px;">14-230-244</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microseal &#39;B&#39; Adhesive Seals</td>
			<td>Bio-Rad</td>
			<td>MSB-1001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MyiQ Optics Module</td>
			<td>Bio-Rad</td>
			<td>170-9744</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">iCycler Chassis</td>
			<td>Bio-Rad</td>
			<td>170-8701</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Optical Kit</td>
			<td>Bio-Rad</td>
			<td>170-9752</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BD LSR II Flow Cytometry Analyzer</td>
			<td>BD Biosciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FACSDiva software</td>
			<td>BD Biosciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">FlowJo 10</td>
			<td>BD Biosciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2100 Bioanalyzer</td>
			<td>Agilent Technologies</td>
			<td>G2943CA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">S200 Focused-ultrasonicator</td>
			<td>Covaris</td>
			<td>S200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SPRIworks Fragment Library System I for Illumina</td>
			<td>Beckman Coulter</td>
			<td>A288267</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">cBot Cluster Generation Station</td>
			<td>illumina</td>
			<td>SY-312-2001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HiSeq 2000 Genome Sequencer</td>
			<td>Illumina</td>
			<td>SY-401-1001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TruSeq RNA Library Prep Kit v2</td>
			<td>Illumina</td>
			<td>RS-122-2001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TruSeq Small RNA Library Prep Kit</td>
			<td>Illumina</td>
			<td>RS-200-0012</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NEXTflex Illumina Small RNA Sequencing Kit v3</td>
			<td>Bioo Scientific</td>
			<td>5132-05</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2200 TapeStation</td>
			<td>Agilent</td>
			<td>G2964AA</td>
			<td></td>
		</tr>
	</tbody>
</table>

genome-wide analysis of hdac inhibitor-mediated modulation of micrornas and mrnas in b cells induced to undergo class-switch dna recombination and plasma cell differentiation

Antibody responses are accomplished through several critical B cell-intrinsic processes, including somatic hypermutation (SHM), class-switch DNA recombination (CSR), and plasma cell differentiation. In recent years, epigenetic modifications or factors, such as histone deacetylation and microRNAs (miRNAs), have been shown to interact with B-cell genetic programs to shape antibody responses, while the dysfunction of epigenetic factors has been found to lead to autoantibody responses. Analyzing genome-wide miRNA and mRNA expression in B cells in response to epigenetic modulators is important for understanding the epigenetic regulation of B-cell function and antibody response. Here, we demonstrate a protocol for inducing B cells to undergo CSR and plasma cell differentiation, treating these B cells with histone deacetylase (HDAC) inhibitors (HDIs), and analyzing mRNA and microRNA expression. In this protocol, we directly analyze complementary DNA (cDNA) sequences using next-generation mRNA sequencing (mRNA-seq) and miRNA-seq technologies, mapping of the sequencing reads to the genome, and quantitative reverse transcription (qRT)-PCR. With these approaches, we have defined that, in B cells induced to undergo CSR and plasma cell differentiation, HDI, an epigenetic regulator, selectively modulates miRNA and mRNA expression and alters CSR and plasma cell differentiation.

Using our protocol, purified B cells placed with LPS (3 &#181;g/mL) and IL-4 (5 ng/mL) for 96 h can induce 30-40% of CSR to IgG1 and ~10% of plasma cell differentiation. After treatment with HDI (500&#181;M VPA), the CSR to IgG1 decreased to 10-20%, while plasma cell differentiation decreased to ~2% (Figure 1). HDI-mediated inhibition of CSR was further confirmed by decreased numbers of post-recombination I&#956;-C&#947;1 and mature VHDJH-C&#947;1 tr...

Watch this Scientific Journal Video about Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell

Genome-wide Analysis of HDAC Inhibitor-mediated Modulation of microRNAs and mRNAs in B Cells Induced to Undergo Class-switch DNA Recombination and Plasma Cell Differentiation

Epigenetic factors can interact with genetic programs to modulate gene expression and regulate B cell function. By combining in vitro B-cell stimulation, qRT-PCR, and high-throughput microRNA-sequence and mRNA-sequence approaches, we can analyze the epigenetic modulation of miRNA and gene expression in B cells.

Antibody responses are accomplished through several critical B cell-intrinsic processes, including somatic hypermutation (SHM), class-switch DNA ...

The overall goal of this experiment is to induce B lymphocytes to undergo antibody class-switching and plasma cell differentiation and analyze the modulation as well as epigenetic regulation by the expression of HDAC inhibitor mRNA and microRNA in B-cells. This method can help answer key questions in the B-cell antibody response field such as, epigenetic modulation of immunoglobulin class-switching and plasma cell differentiation. The main advantage of this technique is to provide a simple method to modulate B-cell functions and to define the alteration of microRNAs and mRNAs by epigenetic regulators.After euthanizing a specific pathogen-free C57BL6J mouse and sterilizing the skin according to the text protocol, use autoclaved forceps and dissecting scissors to cut through the skin just below the ribcage to visualize the spleen on the left side of the abdomen, just below the liver. Gently clamp the spleen and cut off all the connecting tissue before extracting the organ. Then place the spleen into a 1.5 milliliter microcentrifuge tube containing 1, 000 microliters of complete RPMI 1640 medium.Next, insert a 70 micron cell strainer into a 50 milliliter polypropylene conical centrifuge tube and pour the spleen from the microcentrifuge tube onto the cell strainer. Use the tip of a 15 milliliter polypropylene conical centrifuge tube to gently mesh the spleen through the strainer. Then with 15 to 20 milliliters of complete medium, rinse the strainer.Spin down the cells at 350 x G for five minutes. Discard the supernatant. Use one milliliter of ACK lysis buffer to re-suspend the cell pellet and incubate for one minute.Then add four milliliters of ACK and incubate the suspension to remove red blood cells from the spleen suspension for an additional four minutes at room temperature with occasional shaking. Then add 25 milliliters of complete medium to quench the lysis reaction. Spin down the cells at 350 x G for five minutes.Discard the supernatant and add one milliliters of complete medium to re-suspend the cell pellet. Then using a hemocytometer, count the viable cells. In a sterile five milliliter polystyrene round bottom tube, prepare a 0.25 to two milliliter cell suspension of 1 x 10 to the 8th cells per milliliter in complete medium.Add normal rat serum to the sample. Next, add 50 microliters per milliliter of isolation cocktail to the tube. Then mix the cells by gently pipetting up and down two to three times and incubate the sample at room temperature for 10 minutes.Add 75 microliters per milliliter of streptavidin encoated magnetic particles to the tube. Gently pipette up and down two to three times and incubate the sample at room temperature for two and a half minutes. Bring the volume up to 2.5 milliliters using complete RPMI 1640 medium and gently pipette two to three times to mix.Place the opened tube into the magnet and incubate it at room temperature for two and a half minutes. Then pour off the supernatant containing untouched B-cells into a new 15 milliliter conical tube. Use trypan blue and a hemocytometer to count the cells.Re-suspend the purified B-cells in complete RPMI 1640 medium at a final concentration of 0.3 x 10 to the 6th cells per milliliter. Then, to the wells of a 48 well plate, add one milliliter of purified B-cells at a 0.3 x 10 to the 6th cells per milliliter three microgram per milliliter of LPS from E.Coli, five nanogram per milliliter of IL4 and either zero or 500 micromolar HDI. Incubate the cells at 37 degree celsius and 5%carbon dioxide for 60 hours for QRT PCR and high throughput mRNA and miRNA sequencing analysis or 96 hours for flow cytometry analysis.After 96 hours of culture, detach the cells from each well by pipetting them up and down several times. Transfer the cell suspension into a 1.5 milliliter microcentrifuge tube. Then, using a bench top centrifuge, spin down the cells at 350 x G for five minutes.Then, discard the supernatant. Mix a cocktail of HBSS buffer and the following reagents, 1%BSA, 0.5 nanograms per milliliter of conjugated goat anti-mouse IgM antibody, 0.2 nanograms per milliliter of conjugated rat anti-mouse IgG1 monoclonal antibody, 0.2 nanograms per milliliter of conjugated rat anti-mouse B220 monoclonal antibody, 0.2 nanograms per milliliter of PE-Cy7-conjugated rat anti-mouse CD138 monoclonal antibody and two nanograms per milliliter of 7-AAD. Incubate the cells in the dark at room temperature for 30 minutes.Then use one milliliter of HBSS with 1%BSA to wash the cells. Use a bench top centrifuge to spin down the cells at 1, 500 x G for five minutes. After discarding the supernatant, use 300 microliters of HBSS with 1%BSA to re-suspend the cells and transfer the cell suspension to a round bottom polystyrene tube.Cover the tube with foil to avoid light exposure. To carry out QRT PCR analysis of mRNA, include the DNAse 1 treatment step. Then, use a commercial total RNA isolation kit that can recover small RNA to extract RNA from 0.2 to 5 x 10 to the 6th cells, following the manufacturer's instructions.After synthesizing cDNA and performing QRT PCR on the mRNA, carry out RT PCR for microRNA using a cyber green real time PCR master mix by thawing at room temperature, 2x PCR master mix, 250 nanomolar miRNA specific forward primer and a universal reverse primer. After preparing a 25 microliter reaction mix according to the text protocol, add 22.5 microliter aliquots per well to a 96 well PCR plate. Then, add 2.5 microliters of template cDNA to the individual wells.Tightly seal the plate film. Then centrifuge the plate at 1, 000 x G at room temperature for one minute. Place the plate in the real time cycler and start the cycling program found in the text protocol.Using the protocol demonstrated in this video, purified B-cells incubated without PS NIL4 for 96 hours can induce 30 to 40%of CSR to IgG1 and approximately 10%of plasma cell differentiation. After treatment with HDI, the CSR to IgG1 decreased to 10 to 20%while plasma cell differentiation decreased to approximately 2%HDI mediated inhibition of CSR was further confirmed by decreased numbers of post-recombination I mu C gamma 1 and mature VHDJHC gamma 1 transcripts. As measured by QRT PCR, the expression of Aicda which is critical for CSR SHM and Prdm1 and Xbp1, which are important for plasma cell differentiation were shown to be inhibited by VPA.As measured by mRNA sequencing of B-cells stimulated without PS Nil4, only 0.3%of these highly expressed mRNAs were upregulated by HDI more than two fold and only 0.36%of the highly expressed mRNAs, including Aicda, Prdm1 and Xbp1 were reduced by HDI more than 50%The miRNA sequencing analysis of miRNA profiling in B-cells treated with HDI or Nil, showed that HDIs selectively upregulate Aicda and Prdm1 targeting miRNAs. Once mastered, this technique can be done in four and half to five hours. While attempting this procedure, it is important to remember to keep a sterile work environment.After watching this video, you should have a good understanding of how to induce B-cells to undergo class-switching and plasma cell differentiation and to modulate these functions by epigenetic regulators.

genome-wide-analysis-hdac-inhibitor-mediated-modulation-micrornas

Research

JoVE Journal

Immunology and Infection

Induction and Assessment of Class Switch Recombination in Purified Murine B Cells

Humoral immunity is the branch of the immune system maintained by B cells and mediated through the secretion of antibodies. Upon B cell activation, the immunoglobulin locus undergoes a series of genetic modifications to alter the binding capacity and effector function of secreted antibodies. This process is highlighted by a genomic recombination event known as class switch recombination (CSR) in which the default IgM antibody isotype is substituted for one of IgG, IgA, or IgE. Each isotype possesses distinct effector functions thereby making CSR crucial to the maintenance of immunity. Diversification of the immunoglobulin locus is mediated by the enzyme activation-induced cytidine deaminase (AID). A schematic video describing this process in detail is available online (http://video.med.utoronto.ca/videoprojects/immunology/aam.html). AID's activity and the CSR pathway are commonly studied in the assessment of B cell function and humoral immunity in mice. The protocol outlined in this report presents a method of B cell isolation from murine spleens and subsequent stimulation with bacterial lipopolysaccharide (LPS) to induce class switching to IgG3 (for other antibody isotypes see Table 1). In addition, the fluorescent cell staining dye Carboxyfluorescein succinimidyl ester (CFSE) is used to monitor cell division of stimulated cells, a process crucial to isotype switching 1, 2. The regulation of AID and the mechanism by which CSR occurs are still unclear and thus in vitro class switch assays provide a reliable method for testing these processes in various mouse models. These assays have been previously used in the context of gene deficiency using knockout mice 3. Furthermore, in vitro switching of B cells can be preceded by viral transduction to modulate gene expression by RNA knockdown or transgene expression 4-6. The data from these types of experiments have impacted our understanding of AID activity, resolution of the CSR reaction, and antibody-mediated immunity in the mouse.

Following antigen exposure, subpopulations of activated B cells undergo a process known as class switch recombination (CSR) to produce antibody isotypes with distinct effector functions. The protocol outlined in this report explains how CSR can be induced and analyzed in vitro for the purposes of studying B cell function.

Humoral immunity is the branch of the immune system maintained by B cells and mediated through the secretion of antibodies. Upon B cell activation, the ...

Directed Differentiation of Induced Pluripotent Stem Cells towards T Lymphocytes

Adoptive cell transfer (ACT) of antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) is a promising treatment for a variety of malignancies 1. CTLs can recognize malignant cells by interacting tumor antigens with the T cell receptors (TCR), and release cytotoxins as well as cytokines to kill malignant cells. It is known that less-differentiated and central-memory-like (termed highly reactive) CTLs are the optimal population for ACT-based immunotherapy, because these CTLs have a high proliferative potential, are less prone to apoptosis than more differentiated cells and have a higher ability to respond to homeostatic cytokines 2-7. However, due to difficulties in obtaining a high number of such CTLs from patients, there is an urgent need to find a new approach to generate highly reactive Ag-specific CTLs for successful ACT-based therapies.
TCR transduction of the self-renewable stem cells for immune reconstitution has a therapeutic potential for the treatment of diseases 8-10. However, the approach to obtain embryonic stem cells (ESCs) from patients is not feasible. Although the use of hematopoietic stem cells (HSCs) for therapeutic purposes has been widely applied in clinic 11-13, HSCs have reduced differentiation and proliferative capacities, and HSCs are difficult to expand in in vitro cell culture 14-16. Recent iPS cell technology and the development of an in vitro system for gene delivery are capable of generating iPS cells from patients without any surgical approach. In addition, like ESCs, iPS cells possess indefinite proliferative capacity in vitro, and have been shown to differentiate into hematopoietic cells. Thus, iPS cells have greater potential to be used in ACT-based immunotherapy compared to ESCs or HSCs.
Here, we present methods for the generation of T lymphocytes from iPS cells in vitro, and in vivo programming of antigen-specific CTLs from iPS cells for promoting cancer immune surveillance. Stimulation in vitro with a Notch ligand drives T cell differentiation from iPS cells, and TCR gene transduction results in iPS cells differentiating into antigen-specific T cells in vivo, which prevents tumor growth. Thus, we demonstrate antigen-specific T cell differentiation from iPS cells. Our studies provide a potentially more efficient approach for generating antigen-specific CTLs for ACT-based therapies and facilitate the development of therapeutic strategies for diseases.

Generation of T lymphocytes from induced pluripotent stem (iPS) cells gives an alternative approach of using embryonic stem cells for T cell-based immunotherapy. The method shows that by utilizing either in vitro or in vivo induction system, iPS cells are able to differentiate into both conventional and antigen-specific T lymphocytes.

Adoptive cell transfer (ACT) of antigen-specific CD8+  cytotoxic T lymphocytes (CTLs) is a promising treatment for a variety of  malignancies 1. CTLs can  ...

Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages

A cell culture model system, if a close mimic of host environmental conditions, can serve as an inexpensive, reproducible and easily manipulatable alternative to animal model systems for the study of a specific step of microbial pathogen infection. A human monocytic cell line THP-1 which, upon phorbol ester treatment, is differentiated into macrophages, has previously been used to study virulence strategies of many intracellular pathogens including Mycobacterium tuberculosis. Here, we discuss a protocol to enact an in vitro cell culture model system using THP-1 macrophages to delineate the interaction of an opportunistic human yeast pathogen Candida glabrata with host phagocytic cells. This model system is simple, fast, amenable to high-throughput mutant screens, and requires no sophisticated equipment. A typical THP-1 macrophage infection experiment takes approximately 24 hr with an additional 24-48 hr to allow recovered intracellular yeast to grow on rich medium for colony forming unit-based viability analysis. Like other in vitro model systems, a possible limitation of this approach is difficulty in extrapolating the results obtained to a highly complex immune cell circuitry existing in the human host. However, despite this, the current protocol is very useful to elucidate the strategies that a fungal pathogen may employ to evade/counteract antimicrobial response and survive, adapt, and proliferate in the nutrient-poor environment of host immune cells.

Establishment of an In vitro System to Study Intracellular Behavior of Candida glabrata in Human THP-1 Macrophages

The current article outlines a protocol to establish an in vitro cell culture model system to study the interaction of a facultative intracellular human fungal pathogen Candida glabrata with human macrophages which will be a useful tool to advance our knowledge of fungal virulence mechanisms.

A cell culture model system, if a close mimic of host environmental conditions, can serve as an inexpensive, reproducible and easily manipulatable ...

Rapid Molecular Detection and Differentiation of Influenza Viruses A and B

Influenza is a contagious respiratory illness caused by influenza viruses A and B in humans and causes a significant amount of morbidity and mortality every year. The Influenza A and B assay was the first CLIA-waived molecular rapid flu test available. The Influenza A and B test works by employing isothermal amplification with influenza-specific primers followed by target detection with molecular beacon probes. Here, the performance of the Influenza A and B assay on frozen, archived nasopharyngeal swab (NPS) specimens stored in viral transport medium (VTM) were compared to a respiratory panel assay.
The performance of the Influenza A and B assay was evaluated by comparing the results to the respiratory panel reference method. The sensitivity for total influenza virus A was 67.5% (95% CI (CI), 56.6-78.5) and the specificity was 86.9% (CI, 71.0-100). For influenza virus B testing, the sensitivity and specificity were 90.2% (CI, 68.5-100) and 98.8% (CI, 68.5-100), respectively.
This system has the advantage of a significantly shorter test time than any other currently available molecular assay and the simple, pipette-free procedure runs on a fully integrated, closed, small-footprint system. Overall, the Influenza A and B assay evaluated in this study has the potential to serve as a point-of-care rapid influenza diagnostic test.

We describe a rapid, molecular-based Influenza A and B assay. The Influenza assay detects each target within 15 min by employing isothermal amplification with influenza-specific primers followed by target detection with molecular beacon probes. The Influenza A and B assay is user-friendly and required minimal hands-on time to perform.

Influenza is a contagious respiratory illness caused by influenza viruses A and B in humans and causes a significant amount of morbidity and mortality ...

Detection and Enrichment of Rare Antigen-specific B Cells for Analysis of Phenotype and Function

B cells reactive with a specific antigen usually occur at a frequency of &lt;0.05% of lymphocytes. For decades researchers have sought methods to isolate and enrich these rare cells for studies of their phenotype and biology. Approaches are inevitably based on the principle that B cells recognize native antigen by virtue of cell surface receptors that are representative in specificity of antibodies that will eventually be secreted by their differentiated daughters. Perhaps the most obvious approach to the problem involves use of fluorochrome-conjugated antigens in conjunction with fluorescence-activated cell sorting (FACS). However, the utility of these methods is limited by cell frequency and the achievable rate of analysis and isolation by electronic sorting. A novel method to enrich rare antigen-specific B cells using magnetic nanoparticles that results in high yield enrichment of antigen-reactive B cells from large starting cell populations is described. This method enables improved monitoring of the phenotype and biology of antigen reactive cells before and following in vivo antigen encounter, such as after immunization or during development of autoimmunity.

A simple yet effective method that employs magnetic nanoparticles to detect and enrich antigen-reactive B cells for functional and phenotypic analysis is described.

B cells reactive with a specific antigen usually occur at a frequency of &lt;0.05% of lymphocytes. For decades researchers have sought methods to isolate ...

An In Vivo Mouse Model to Measure Na&#239;ve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

Quantification of na&#239;ve CD4 T cell activation, proliferation, and differentiation to T helper 1 (Th1) cells is a useful way to assess the role played by T cells in an immune response. This protocol describes the in vitro differentiation of bone marrow (BM) progenitors to obtain granulocyte macrophage colony-stimulating factor (GM-CSF) derived-dendritic cells (DCs). The protocol also describes the adoptive transfer of ovalbumin peptide (OVAp)-loaded GM-CSF-derived DCs and na&#239;ve CD4 T cells from OTII transgenic mice in order to analyze the in vivo activation, proliferation, and Th1 differentiation of the transferred CD4 T cells. This protocol circumvents the limitation of purely in vivo methods imposed by the inability to specifically manipulate or select the studied cell population. Moreover, this protocol allows studies in an in vivo environment, thus avoiding alterations to functional factors that may occur in vitro and including the influence of cell types and other factors only found in intact organs. The protocol is a useful tool for generating changes in DCs and T cells that modify adaptive immune responses, potentially providing important results to understand the origin or development of numerous immune associated diseases.

An &lt;em&gt;In Vivo&lt;/em&gt; Mouse Model to Measure Na&amp;#239;ve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

Here, we present a protocol for the in vivo determination of na&#239;ve CD4 T cell (T cell) activation, proliferation, and Th1 differentiation induced by GM-CSF bone marrow (BM)-derived dendritic cells (DCs). In addition, this protocol describes BM and T-cell isolation, DC generation, and DC and T-cell adoptive transfer.

Quantification of na&#239;ve CD4 T cell activation, proliferation, and differentiation to T helper 1 (Th1) cells is a useful way to assess the role played ...

Analysis of Shear Flow-induced Migration of Murine Marginal Zone B Cells In Vitro

Marginal zone B cells (MZBs) are a population of B cells that reside in the mouse splenic marginal zones that envelop follicles. To reach the follicles, MZBs must migrate up the shear force of blood flow. We present here a method for analyzing this flow-induced MZB migration in vitro. First, MZBs are isolated from the mouse spleen. Second, MZBs are settled on integrin ligands in flow chamber slides, exposed to shear flow, and imaged under a microscope while migrating. Third, images of the migrating MZBs are processed using the MTrack2 automatic cell tracking plugin for ImageJ, and the resulting cell tracks are quantified using the Ibidi chemotaxis tool. The migration data reveal how fast the cells move, how often they change direction, whether the shear flow vector affects their migration direction, and which integrin ligands are involved. Although we use MZBs, the method can easily be adapted for analyzing migration of any leukocyte that responds to the force of shear flow.

Marginal zone B cells (MZBs) respond to the force of shear flow by re-orienting their migration path up the flow. This protocol shows how to record and analyze the migration using a fluidics unit, pump, microscope imaging system, and free software.

Marginal zone B cells (MZBs) are a population of B cells that reside in the mouse splenic marginal zones that envelop follicles. To reach the follicles, ...

In Vitro Differentiation Model of Human Normal Memory B Cells to Long-lived Plasma Cells

Plasma cells (PCs) secrete large amounts of antibodies and develop from B cells that have been activated. PCs are rare cells located in the bone marrow or mucosa and ensure humoral immunity. Due to their low frequency and location, the study of PCs is difficult in human. We reported a B to PC in vitro differentiation model using selected combinations of cytokines and activation molecules that allow to reproduce the sequential cell differentiation occurring in vivo. In this in vitro model, memory B cells (MBCs) will differentiate into pre-plasmablasts (prePBs), plasmablasts (PBs), early PCs and finally, into long-lived PCs, with a phenotype close to their counterparts in healthy individuals.&#160;We also built an open access bioinformatics tools to analyze the most prominent information from GEP data related to PC differentiation. These resources can be used to study human B to PC differentiation and in the current study, we investigated the gene expression regulation of epigenetic factors during human B to PC differentiation.

Using multi-step culture systems, we report an in vitro B cell to plasma cell differentiation model.

Plasma cells (PCs) secrete large amounts of antibodies and develop from B cells that have been activated. PCs are rare cells located in the bone marrow or ...

Studying Organelle Dynamics in B Cells During Immune Synapse Formation

Recognition of surface-tethered antigens&#160;by the B cell receptor (BCR)&#160;triggers the formation of an immune synapse (IS), where both signaling&#160;and antigen uptake are coordinated. IS formation involves dynamic actin remodeling accompanied by the polarized recruitment to the synaptic membrane of the centrosome and associated intracellular organelles such as lysosomes and the Golgi apparatus. Initial stages of actin remodeling allow B cells to increase their cell surface and maximize the quantity of antigen-BCR complexes gathered at the synapse. Under certain conditions, when B cells recognize antigens associated to rigid surfaces, this process is coupled to the local recruitment and secretion of lysosomes, which can facilitate antigen extraction. Uptaken antigens&#160;are internalized into specialized endo-lysosome compartments for processing into peptides, which are loaded onto major histocompatibility complex II (MHC-II) molecules for further presentation to T helper cells. Therefore, studying organelle dynamics associated with the formation of an IS is crucial to understanding how B cells are activated. In the present article we will discuss both imaging and a biochemical technique used to study changes in intracellular organelle positioning and cytoskeleton rearrangements that are associated with the formation of an IS in B cells.

Herein we describe two approaches to characterize cell polarization events in B lymphocytes during the formation of an IS. The first, involves quantification of organelle recruitment and cytoskeleton rearrangements at the synaptic membrane. The second is a biochemical approach, to characterize changes in composition of the centrosome, which undergoes polarization to the immune synapse.

Recognition of surface-tethered antigens&#160;by the B cell receptor (BCR)&#160;triggers the formation of an immune synapse (IS), where both ...

Induced Differentiation of M Cell-like Cells in Human Stem Cell-derived Ileal Enteroid Monolayers

M (microfold) cells of the intestine function to transport antigen from the apical lumen to the underlying Peyer&#8217;s patches and lamina propria where immune cells reside and therefore contribute to mucosal immunity in the intestine. A complete understanding of how M cells differentiate in the intestine as well as the molecular mechanisms of antigen uptake by M cells is lacking. This is because M cells are a rare population of cells in the intestine and because in vitro models for M cells are not robust. The discovery of a self-renewing stem cell culture system of the intestine, termed enteroids, has provided new possibilities for culturing M cells. Enteroids are advantageous over standard cultured cell lines because they can be differentiated into several major cell types found in the intestine, including goblet cells, Paneth cells, enteroendocrine cells and enterocytes. The cytokine RANKL is essential in M cell development, and addition of RANKL and TNF-&#945; to culture media promotes a subset of cells from ileal enteroids to differentiate into M cells. The following protocol describes a method for the differentiation of M cells in a transwell epithelial polarized monolayer system of the intestine using human ileal enteroids. This method can be applied to the study of M cell development and function.

This protocol describes how to induce the differentiation of M cells in human stem cell-derived ileal monolayers and methods to assess their development.

M (microfold) cells of the intestine function to transport antigen from the apical lumen to the underlying Peyer&#8217;s patches and lamina propria where ...