N.G. is the recipient of fellowships from the French &#8220;Fondation pour la Recherche M&#233;dicale FRM&#8221; and the Philipp Foundation; R.S. is supported by the Lucile Packard Foundation for Children&#8217;s Health and the Stanford NIH/NCRR CTSA award number UL1 RR025744; P.S. is supported by a Max Kade Fellowship of the Max Kade Foundation and the Austrian Academy of Sciences and a Schroedinger Fellowship of the Austrian Science Fund (FWF): J3399-B21; S.J.G. acknowledges support from National Institutes of Health grants U19 AI104209, NS 080062 and from Tobacco-Related Disease Research Program at University of California; L.L.R. acknowledges support from the Arthritis National Research Foundation (ANRF) and National Institutes of Health grant K99AI110645.

All animal care and experimentation were conducted in compliance with the guidelines of the National Institutes of Health and with the specific approval of the Institutional Animal Care and Use Committee of Stanford University.
1. Generation and Characterization of Bone Marrow-derived Cultured Mast Cells (BMCMCs).
Note: Donor BMCMCs should be generated from bone marrow cells of the same genetic background as the recipient MC-deficient mice. Male-derived donor BMCMCs a...

Almost 30 years after its initial description38, the &#8216;mast cell knock-in&#8217; approach continues to provide valuable information about what MCs can do or can&#8217;t do in vivo. The functions of MCs were long thought to be limited to their role in allergy. Data generated using the &#8216;mast cell knock-in&#8217; approach have changed this view, by providing evidence that MCs can, among other functions, play critical roles in host defense against certain pathogens4,39</s...

Mast cells (MCs) are hematopoietic cells that arise from pluripotent bone marrow progenitors1-3. Following bone marrow egression, MCs progenitors migrate into various tissues where they develop into mature MCs under the influence of local growth factors1-3. Tissue-resident MCs are strategically located at host-environment interfaces, such as the skin, the airways and the gastrointestinal tract, where they behave as a first line of defense against external insults3-6. MCs are often sub-classified based on their &#8220;baseline&#8221; phenotypic characteristics and their anatomic locations. In mice, two types of MCs have been described: &#8220;connective tissue-type&#8221; MCs (CTMCs) and mucosal MCs (MMCs)1-3,7,8. CTMCs are often located around venules and near nerve fibers, and reside in serosal cavities, while MMCs occupy intraepithelial locations in the gut and respiratory mucosa1-3.
Numerous methodologies have been applied to study biological functions of MCs9-13. Many groups have focused on in vitro approaches using either cell lines (such as the human MC lines HMC114 or LAD215,16), in vitro derived MCs (such as human peripheral blood-derived MCs17, or mouse bone marrow-derived cultured MCs [BMCMCs]18, fetal skin-derived cultured MCs [FSCMCs]19 and peritoneal cell-derived MCs [PCMCs]20) or ex vivo isolated MCs from different anatomical sites. All these models are widely used to study molecular details of MC biology, such as signaling pathways involved in MC activation. However, an important aspect of MCs biology is that their phenotypic and functional characteristics (e.g., cytoplasmic granule protease content or response to different stimuli) can be modulated by anatomical location and microenvironment2,7. Since the exact mixture of such factors that are encountered in vivo may be difficult to reproduce in vitro, we favor using in vivo approaches to gain insights into MCs functions9.
Several mouse strains with genetic MC deficiency exist, such as the widely used WBB6F1-Kit W/W-v or C57BL/6-Kit W-sh/W-sh mice. These mice lack expression and/or activity of KIT (CD117), the receptor for the main MC growth factor stem cell factor (SCF)21,22. As a result, these mice have a profound MC deficiency but also have additional phenotypic abnormalities related to their c-kit mutations (in the WBB6F1-Kit W/W-v mice) or to the effects of the large chromosomal inversion that results in reduced c-kit expression (in the C57BL/6-Kit W-sh/W-sh mice)9,10,12,23. More recently, several strains of mice with c-kit-independent constitutive MC deficiency have been reported24-26. All these mice and some additional new types of inducible MC-deficient mice have been recently reviewed in detail9,10,13.
Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This so-called &#8216;mast cell knock-in&#8217; method can be used to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>1% Antibiotic-Antimycotic Solution</td>
			<td>Corning cellgro</td>
			<td>30-004-Cl</td>
			<td></td>
		</tr>
		<tr>
			<td>3 ml Syringe</td>
			<td>Falcon</td>
			<td>309656</td>
			<td></td>
		</tr>
		<tr>
			<td>35 mm x 10 mm Dish</td>
			<td>Corning cellgro</td>
			<td>430588</td>
			<td></td>
		</tr>
		<tr>
			<td>5 ml Polystyrene Round Bottom Tube</td>
			<td>Falcon</td>
			<td>352058</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic Acid Glacial</td>
			<td>Fisher Scientific</td>
			<td>A35-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Alcian Blue 8GX</td>
			<td>Rowley Biochemical Danver</td>
			<td>33864-99-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Allegra 6R Centrifuge</td>
			<td>Beckman</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-mouse CD16/32 (clone 93) Purified</td>
			<td>eBioscience</td>
			<td>14-0161-81</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Mercaptoethanol</td>
			<td>Sigma Aldrich</td>
			<td>M7522</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 1 ml TB Syringe</td>
			<td>BD Syringe</td>
			<td>309659</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 22G x1 (0.7 mm x 25 mm) Needles</td>
			<td>BD Precision Glide Needle</td>
			<td>205155</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 25G 5/8 Needles</td>
			<td>BD Syringe</td>
			<td>305122</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 30G x1/2 Needles</td>
			<td>BD Precision Glide</td>
			<td>305106</td>
			<td></td>
		</tr>
		<tr>
			<td>Blue MAX Jr, 15 ml Polypropylene Conical Tube</td>
			<td>Falcon</td>
			<td>352097</td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Fisher Scientific</td>
			<td>C298-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Cytoseal 60 Mounting Medium</td>
			<td>Richard-Allan Scientific</td>
			<td>8310-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Cytospin3</td>
			<td>Shandon</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>DakoCytomation pen</td>
			<td>Dako</td>
			<td>S2002</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco Modified Eagle Medium (DMEM) 1x</td>
			<td>Corning cellgro</td>
			<td>15-013-CM</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sigma Aldrich</td>
			<td>E 7023-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum Heat Inactivated</td>
			<td>Sigma Aldrich</td>
			<td>F4135-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>FITC Conjugated IgG2b K Rat Isotype Control</td>
			<td>eBioscience</td>
			<td>14-4031-82</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescein Isotiocyanate (FITC) Conjugated Anti-mouse KIT (CD117; clone 2B8)</td>
			<td>eBioscience</td>
			<td>11-1171-82</td>
			<td></td>
		</tr>
		<tr>
			<td>Formaldehyde</td>
			<td>Fisher Scientific</td>
			<td>F79-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Giemsa Stain Modified</td>
			<td>Sigma Aldrich</td>
			<td>GS-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Isothesia</td>
			<td>Henry Schein Animal Health</td>
			<td>29405</td>
			<td></td>
		</tr>
		<tr>
			<td>May-Grunwald Stain</td>
			<td>Sigma Aldrich</td>
			<td>MG-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Multiwell 6 well plates</td>
			<td>Falcon</td>
			<td>35 3046</td>
			<td></td>
		</tr>
		<tr>
			<td>Olympus BX60 Microscope</td>
			<td>Olympus</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraplast Plus Tissue Embedding Medium</td>
			<td>Fisher Brand</td>
			<td>23-021-400</td>
			<td></td>
		</tr>
		<tr>
			<td>PE Conjugated IgG Armenian Hamster Isotype Control</td>
			<td>eBioscience</td>
			<td>12-4888-81</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate-Buffered-Saline (PBS) 1x</td>
			<td>Corning cellgro</td>
			<td>21-040-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Phycoerythrin (PE) Conjugated Anti-mouse FceRIa (clone MAR-1)</td>
			<td>eBioscience</td>
			<td>12-5898-82</td>
			<td></td>
		</tr>
		<tr>
			<td>Propidium Iodide Staining Solution</td>
			<td>eBioscience</td>
			<td>00-6990-50</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Mouse IL-3</td>
			<td>Peprotech</td>
			<td>213-13</td>
			<td></td>
		</tr>
		<tr>
			<td>Safranin-o Certified</td>
			<td>Sigma Aldrich</td>
			<td>S8884</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue culture flasks T25 25 cm2</td>
			<td>Beckton Dickinson</td>
			<td>353109</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue culture flasks T75 75 cm2</td>
			<td>Beckton Dickinson</td>
			<td>353110</td>
			<td></td>
		</tr>
		<tr>
			<td>Toluidine Blue 1 % Aqueous</td>
			<td>LabChem-Inc</td>
			<td>LC26165-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Mouse SCF</td>
			<td>Peprotech</td>
			<td>250-03</td>
			<td></td>
		</tr>
	</tbody>
</table>

analyzing the functions of mast cells in vivo using 'mast cell knock-in' mice

Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such as skin, airways and gastrointestinal tract. Best known for their detrimental role in IgE-dependent allergic reactions, MCs have also emerged as important players in host defense against venom and invading bacteria and parasites. MC phenotype and function can be influenced by microenvironmental factors that may differ according to anatomic location and/or based on the type or stage of development of immune responses. For this reason, we and others have favored in vivo approaches over in vitro methods to gain insight into MC functions. Here, we describe methods for the generation of mouse bone marrow-derived cultured MCs (BMCMCs), their adoptive transfer into genetically MC-deficient mice, and the analysis of the numbers and distribution of adoptively transferred MCs at different anatomical sites. This method, named the &#8216;mast cell knock-in&#8217; approach, has been extensively used over the past 30 years to assess the functions of MCs and MC-derived products in vivo. We discuss the advantages and limitations of this method, in light of alternative approaches that have been developed in recent years.

An overview of the &#8216;mast cell knock-in&#8217; approach is shown in Figure 1, and includes the generation of BMCMCs, the number of cells that should be engrafted i.p., i.d. or i.v. into MC-deficient mice (the number can be varied if indicated based on the experimental design) and the interval between engraftment and experiment depending on the injection site (this interval also can vary, if indicated; e.g., the content of stored mediators in MC cytoplasmic granules increases steadi...

Watch this Scientific Journal Video about Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice at JoVE.com

Analyzing the Functions of Mast Cells In Vivo Using &#039;Mast Cell Knock-in&#039; Mice

We describe a method for the generation of in vitro derived mast cells, their engraftment into mast cell-deficient mice, and the analysis of the phenotype, numbers and distribution of engrafted mast cells at different anatomical sites. This protocol can be used to assess the functions of mast cells in vivo.

Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice

Mast cells (MCs) are hematopoietic cells which reside in various tissues, and are especially abundant at sites exposed to the external environment, such ...

analyzing-functions-mast-cells-vivo-using-mast-cell-knock

Research

JoVE Journal

Immunology and Infection

10.1K ビュー.  Stanford University School of Medicine. イン ビトロ 由来肥満細胞の生成方法、肥満細胞欠損マウスへのそれらの生着、異なる解剖学的部位における生着マスト細胞の表現型、数および分布の分析について述べた。このプロトコルは、 生体内のマストセルの機能を評価するために使用することができます。

ビデオ: Analyzing the Functions of Mast Cells In Vivo Using 'Mast Cell Knock-in' Mice

We describe a method for the generation of in vitro derived mast cells, their engraftment into mast cell-deficient mice, and the analysis of the phenotype, numbers and distribution of engrafted mast cells at different anatomical sites. This protocol can be used to assess the functions of mast cells in...

an ex vivo mast cell degranulation assay using crude peritoneal exudate cells and natural antigen stimulation

An Ex vivo Mast Cell Degranulation Assay using Crude Peritoneal Exudate Cells and Natural Antigen Stimulation

We have established an ex vivo mast cell degranulation assay carried out by incubating crude peritoneal exudate cells isolated from the mice, treated with a pharmacological agent of interest and administered anti-dinitrophenol (DNP) IgE beforehand, with DNP on a carrier...

an in vitro technique to visualize exocytosis of secretory granules in mast cells

This video demonstrates a technique to visualize exocytosis in mast cells. The cells are incubated with FITC-dextran &#8212; a fluorescent reporter &#8212; which is taken up by cells inside secretory granules (SGs), where the acidic pH quenches its fluorescence. Upon stimulation of granule exocytosis, the medium&#39;s higher pH induces reporter fluorescence inside the fused SGs, which is visualized using a fluorescence...

An In Vitro Technique to Visualize Exocytosis of Secretory Granules in Mast Cells

investigating mast cell secretory granules; from biosynthesis to exocytosis

Investigating Mast Cell Secretory Granules; from Biosynthesis to Exocytosis

The goal of the present&#160;protocol was to develop a method that will allow functional genomic analyses of mast cell secretion. The protocol is based on quantitative assessment of the release of a fluorescent reporter gene cotrasfected with the gene of interest and real time&#160;analyses of the secretory granule&#39;s...

mast cell degranulation assay to study the effect of a target chemical

This video demonstrates a colorimetric assay to determine the degranulation activity of mast cells. The enzyme released by the mast cells hydrolyzes the substrate and produces a colored product. The degranulation activity of the mast cells was measured as the percentage release of enzymes outside the cell normalized with the total enzyme content in the...

Mast Cell Degranulation Assay to Study the Effect of a Target Chemical

Dissolve ammonium chloride powder in Tyrode&#39;s buffer to create a 400-millimolar ammonium chloride solution. Next, aspirate the media from the chambered coverglass, and replace it with 300 microliters of pre-warmed Tyrode&#39;s buffer. After repeating the washing process two times, replenish the chamber with 300 microliters of Tyrode&#39;s...

mast cells in the microenvironment of hepatocellular carcinoma confer favorable prognosis: a retrospective study using qupath image analysis software

Author Spotlight: Investigating Immune Cell Dynamics in the Tumor Microenvironment &amp;#8212; Challenges and Innovations in Cancer Prognosis

The presence of mast cells in the inner margin and peritumor areas of hepatocellular carcinoma after resection confers a favorable prognosis. This study endorses QuPath image analysis software as a promising platform that could meet the need for reproducibility, consistency, and accuracy in digital pathology.

Mast Cells in the Microenvironment of Hepatocellular Carcinoma Confer Favorable Prognosis: A Retrospective Study using QuPath Image Analysis Software

Transfer 120 microliters of the supernatant to a flat-bottom 96-well plate, and place it on ice. Carefully avoid touching the cell pellets, but completely aspirate the supernatant. Next, add 125 microliters of lysis buffer to the cell pellets. Incubate the cell pellets for 5 minutes at room temperature, and resuspend them after the incubation by repeated...

measuring mast cell exocytosis via neuropeptide y monomeric red fluorescent protein release

This video demonstrates mast cell exocytosis induced by an activating reagent that includes a calcium ionophore, initiating the release of secretory granules containing the fluorescent reporter protein NPY-mRFP. Subsequently, we quantitatively assess the exocytosis by measuring the released NPY-mRFP using a fluorescence plate...

Measuring Mast Cell Exocytosis via Neuropeptide Y Monomeric Red Fluorescent Protein Release

a technique to isolate primary mast cells from a murine peritoneal cavity

This video demonstrates a peritoneal lavage method for isolating mature connective tissue-type mast cells from the peritoneal cavity of adult mice. Upon isolating a mixture of primary immune cells from the peritoneal cavity, selective proliferation of mast cells is performed under appropriate culture...

A Technique to Isolate Primary Mast Cells from a Murine Peritoneal Cavity

assessment of perigenital sensitivity and prostatic mast cell activation in a mouse model of neonatal maternal separation

Assessment of Perigenital Sensitivity and Prostatic Mast Cell Activation in a Mouse Model of Neonatal Maternal Separation

We are measuring perigenital mechanical sensitivity and mast cell activation in the prostate of male C57BL/6 mice that underwent an early life stress paradigm &#8211; neonatal maternal separation, in order to induce a preclinical model of chronic prostatitis/chronic pelvic pain...

isolation of peritoneum-derived mast cells and their functional characterization with ca2+-imaging and degranulation assays

Isolation of Peritoneum-derived Mast Cells and Their Functional Characterization with Ca2+-imaging and Degranulation Assays

Here, we present a protocol to isolate and cultivate murine peritoneal mast cells. We also describe two protocols for their functional characterization: a fluorescent imaging of intracellular free Ca2+ concentration and a degranulation assay based on colorimetric quantification of the released...

Isolation of Peritoneum-derived Mast Cells and Their Functional Characterization with Ca2+-imaging and Degranulation Assays

analyzing in vivo cell migration using cell transplantations and time-lapse imaging in zebrafish embryos

Analyzing In Vivo Cell Migration using Cell Transplantations and Time-lapse Imaging in Zebrafish Embryos

Combining cell transplantation, cytoskeletal labeling and loss/gain of function approaches, this protocol describes how the migrating zebrafish prospective prechordal plate can be used to analyze the function of a candidate gene in in vivo cell migration.

Analyzing In Vivo Cell Migration using Cell Transplantations and Time-lapse Imaging in Zebrafish Embryos

fabrication of a crystalline nanocellulose embedded agarose biomaterial ink for bone marrow-derived mast cell culture

Fabrication of a Crystalline Nanocellulose Embedded Agarose Biomaterial Ink for Bone Marrow-Derived Mast Cell Culture

This protocol highlights a method to rapidly assess the biocompatibility of a crystalline nanocellulose (CNC)/agarose composite hydrogel biomaterial ink with mouse bone marrow-derived mast cells in terms of cell viability and phenotypic expression of the cell surface receptors, Kit (CD117) and high-affinity IgE receptor...

Carefully transfer the supernatants of each well to a 96-well plate. Place the plate on ice, and protect from light. The supernatants contain the chimeric peptide NPY-mRFP that was released from the...

Next, inject 7 milliliters of ice-cold RPMI medium in the peritoneal cavity by inserting a 27-gauge needle carefully in the peritoneum. Do not perforate any organs and use a spot in the region of the epididymal fat to reduce the risk of an organ...

zygote microinjection for creating gene cassette knock-in and flox alleles in mice

Zygote Microinjection for Creating Gene Cassette Knock-in and Flox Alleles in Mice

The present protocol describes zygote microinjection of CRISPR-Cas9 and donor DNA to efficiently produce gene cassette knock-in and floxed...

in vivo photolabeling of cells in the colon to assess migratory potential of hematopoietic cells in neonatal mice

In Vivo Photolabeling of Cells in the Colon to Assess Migratory Potential of Hematopoietic Cells in Neonatal Mice

The protocol described here utilizes a photolabeling approach in newborn mice to specifically identify immune cells that emigrate from the colon to extra-intestinal sites. This strategy will be useful to study host-microbiome interactions in early...

In Vivo Photolabeling of Cells in the Colon to Assess Migratory Potential of Hematopoietic Cells in Neonatal Mice

in vivo calcium imaging of granule cells in the dentate gyrus of hippocampus in mice 

Author Spotlight: Investigating Neural Activity of Dentate Gyrus Granule Cells with Miniature Microscope

The dentate gyrus of the hippocampus carries out essential and distinct functions in learning and memory. This protocol describes a set of robust and efficient procedures for in vivo calcium imaging of granule cells in the dentate gyrus in freely moving...

In Vivo Calcium Imaging of Granule Cells in the Dentate Gyrus of Hippocampus in Mice 

a microplate assay to assess chemical effects on rbl-2h3 mast cell degranulation: effects of triclosan without use of an organic solvent

A Microplate Assay to Assess Chemical Effects on RBL-2H3 Mast Cell Degranulation: Effects of Triclosan without Use of an Organic Solvent

Mast cell degranulation, the release of allergic mediators, is important in allergy, asthma, and parasite defense. Here we demonstrate techniques1 for assessing effects of drugs and toxicants on degranulation, methodology recently utilized to exhibit the powerful inhibitory effect of antibacterial agent...

Following Cell-fate in E. coli After Infection by Phage Lambda

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the simultaneous infection of the cell by a number of phages, one of two pathways is chosen: lytic (virulent) or lysogenic (dormant)3,4. We recently developed a method for fluorescently labeling individual phages, and were able to examine the post-infection decision in real-time under the microscope, at the level of individual phages and cells5. Here, we describe the full procedure for performing the infection experiments described in our earlier work5. This includes the creation of fluorescent phages, infection of the cells, imaging under the microscope and data analysis. The fluorescent phage is a "hybrid", co-expressing wild- type and YFP-fusion versions of the capsid gpD protein. A crude phage lysate is first obtained by inducing a lysogen of the gpD-EYFP (Enhanced Yellow Fluorescent Protein) phage, harboring a plasmid expressing wild type gpD. A series of purification steps are then performed, followed by DAPI-labeling and imaging under the microscope. This is done in order to verify the uniformity, DNA packaging efficiency, fluorescence signal and structural stability of the phage stock. The initial adsorption of phages to bacteria is performed on ice, then followed by a short incubation at 35&deg;C to trigger viral DNA injection6. The phage/bacteria mixture is then moved to the surface of a thin nutrient agar slab, covered with a coverslip and imaged under an epifluorescence microscope. The post-infection process is followed for 4 hr, at 10 min interval. Multiple stage positions are tracked such that ~100 cell infections can be traced in a single experiment. At each position and time point, images are acquired in the phase-contrast and red and green fluorescent channels. The phase-contrast image is used later for automated cell recognition while the fluorescent channels are used to characterize the infection outcome: production of new fluorescent phages (green) followed by cell lysis, or expression of lysogeny factors (red) followed by resumed cell growth and division. The acquired time-lapse movies are processed using a combination of manual and automated methods. Data analysis results in the identification of infection parameters for each infection event (e.g. number and positions of infecting phages) as well as infection outcome (lysis/lysogeny). Additional parameters can be extracted if desired.

Following Cell-fate in E. coli After Infection by Phage Lambda

This article describes the procedure for preparing a fluorescently-labeled version of bacteriophage lambda, infection of E. coli bacteria, following the infection outcome under the microscope, and analysis of infection results.

The system comprising bacteriophage (phage) lambda and the bacterium E. coli has long served as a paradigm for cell-fate determination1,2. Following the ...

Induction of Graft-versus-host Disease and In Vivo T Cell Monitoring Using an MHC-matched Murine Model

Graft-versus-host disease (GVHD) is the limiting barrier to the broad use of bone marrow transplant as a curative therapy for a variety of hematological deficiencies. GVHD is caused by mature alloreactive T cells present in the bone marrow graft that are infused into the recipient and cause damage to host organs. However, in mice, T cells must be added to the bone marrow inoculum to cause GVHD. Although extensive work has been done to characterize T cell responses post transplant, bioluminescent imaging technology is a non-invasive method to monitor T cell trafficking patterns in vivo. 
Following lethal irradiation, recipient mice are transplanted with bone marrow cells and splenocytes from donor mice. T cell subsets from L2G85.B6 (transgenic mice that constitutively express luciferase) are included in the transplant. By only transplanting certain T cell subsets, one is able to track specific T cell subsets in vivo, and based on their location, develop hypotheses regarding the role of specific T cell subsets in promoting GVHD at various time points. At predetermined intervals post transplant, recipient mice are imaged using a Xenogen IVIS CCD camera. Light intensity can be quantified using Living Image software to generate a pseudo-color image based on photon intensity (red = high intensity, violet = low intensity). 
Between 4-7 days post transplant, recipient mice begin to show clinical signs of GVHD. Cooke et al.1 developed a scoring system to quantitate disease progression based on the recipient mice fur texture, skin integrity, activity, weight loss, and posture. Mice are scored daily, and euthanized when they become moribund. Recipient mice generally become moribund 20-30 days post transplant. 
Murine models are valuable tools for studying the immunology of GVHD. Selectively transplanting particular T cell subsets allows for careful identification of the roles each subset plays. Non-invasively tracking T cell responses in vivo adds another layer of value to murine GVHD models.

Induction of Graft-versus-host Disease and In Vivo T Cell Monitoring Using an MHC-matched Murine Model

Murine bone marrow transplantation is a widely used technique to study immunological mechanisms governing graft-versus-host disease in humans. The ability to monitor T cell trafficking patterns in vivo allows for detailed analysis of the development and perpetuation of T cell responses during graft-versus-host disease.

Graft-versus-host disease (GVHD) is the limiting barrier to the broad use of bone marrow transplant as a curative therapy for a variety of hematological ...

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a process that results in the exocytosis of allergic mediators. Modulation of mast cell degranulation by drugs and toxicants may have positive or adverse effects on human health. Mast cell function has been dissected in detail with the use of rat basophilic leukemia mast cells (RBL-2H3), a widely accepted model of human mucosal mast cells3-5. Mast cell granule component and the allergic mediator &#946;-hexosaminidase, which is released linearly in tandem with histamine from mast cells6, can easily and reliably be measured through reaction with a fluorogenic substrate, yielding measurable fluorescence intensity in a microplate assay that is amenable to high-throughput studies1. Originally published by Naal et al.1, we have adapted this degranulation assay for the screening of drugs and toxicants and demonstrate its use here.
Triclosan is a broad-spectrum antibacterial agent that is present in many consumer products and has been found to be a therapeutic aid in human allergic skin disease7-11, although the mechanism for this effect is unknown. Here we demonstrate an assay for the effect of triclosan on mast cell degranulation. We recently showed that triclosan strongly affects mast cell function2. In an effort to avoid use of an organic solvent, triclosan is dissolved directly into aqueous buffer with heat and stirring, and resultant concentration is confirmed using UV-Vis spectrophotometry (using &#949;280 = 4,200 L/M/cm)12. This protocol has the potential to be used with a variety of chemicals to determine their effects on mast cell degranulation, and more broadly, their allergic potential.

Mast cell degranulation, the release of allergic mediators, is important in allergy, asthma, and parasite defense. Here we demonstrate techniques1 for assessing effects of drugs and toxicants on degranulation, methodology recently utilized to exhibit the powerful inhibitory effect of antibacterial agent triclosan2.

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a ...

Mast Cells (MC) are secretory cells of the immune system that accomplish their physiological and pathological functions by releasing pre-formed and newly synthesized allergic, inflammatory and immunoregulatory mediators. MCs&#8217; mediators affect multiple tissues and organs culminating in allergic and immune responses. The synthesis, storage and release of the MC mediators are highly regulated. The pre-formed mediators are packed in cytoplasmic secretory granules&#160;(SG) that fuse with the plasma membrane and release their content by regulated exocytosis. We present a protocol, based on the co-expression of a gene of interest with a reporter gene that is targeted to the SGs and is released in a regulated fashion alongside the endogenous SG mediators. The protocol enables high resolution four dimensional confocal analyses of the MC SGs and monitoring their timeline from biogenesis to triggered exocytosis. Thus, using this protocol for screening genes of interest for their phenotypic and functional impact allows deciphering the molecular mechanisms that govern the biogenesis and exocytosis of the MC SGs and identifying the regulators involved. Thereby, further insights into the cellular mechanisms that account for MCs function in health and disease should be provided.

The goal of the present&#160;protocol was to develop a method that will allow functional genomic analyses of mast cell secretion. The protocol is based on quantitative assessment of the release of a fluorescent reporter gene cotrasfected with the gene of interest and real time&#160;analyses of the secretory granule&#39;s morphology.

Mast Cells (MC) are secretory cells of the immune system that accomplish their physiological and pathological functions by releasing pre-formed and newly ...

Assessing Retinal Microglial Phagocytic Function In Vivo Using a Flow Cytometry-based Assay

Microglia are the tissue resident macrophages of the central nervous system (CNS) and they perform a variety of functions that support CNS homeostasis, including phagocytosis of damaged synapses or cells, debris, and/or invading pathogens. Impaired phagocytic function has been implicated in the pathogenesis of diseases such as Alzheimer's and age-related macular degeneration, where amyloid-&#946; plaque and drusen accumulate, respectively. Despite its importance, microglial phagocytosis has been challenging to assess in vivo. Here, we describe a simple, yet robust, technique for precisely monitoring and quantifying the in vivo phagocytic potential of retinal microglia. Previous methods have relied on immunohistochemical staining and imaging techniques. Our method uses flow cytometry to measure microglial uptake of fluorescently labeled particles after intravitreal delivery to the eye in live rodents. This method replaces conventional practices that involve laborious tissue sectioning, immunostaining, and imaging, allowing for more precise quantification of microglia phagocytic function in just under six hours. This procedure can also be adapted to test how various compounds alter microglial phagocytosis in physiological settings. While this technique was developed in the eye, its use is not limited to vision research.

Assessing Retinal Microglial Phagocytic Function In Vivo Using a Flow Cytometry-based Assay

Microglial phagocytosis is critical for the maintenance of tissue homeostasis and inadequate phagocytic function has been implicated in pathology. However, assessing microglia function in vivo is technically challenging. We have developed a simple but robust technique for precisely monitoring and quantifying the phagocytic potential of microglia in a physiological setting.

Microglia are the tissue resident macrophages of the central nervous system (CNS) and they perform a variety of functions that support CNS homeostasis, ...

Mast cells (MCs), as a part of the immune system, play a key role in defending the host against several pathogens and in the initiation of the allergic immune response. The activation of MCs via the cross-linking of surface IgE bound to high affinity IgE receptor (Fc&#949;RI), as well as through the stimulation of several other receptors, initiates the rise of the free intracellular Ca2+ level ([Ca2+]i) that promotes the release of inflammatory and allergic mediators. The identification of molecular constituents involved in these signaling pathways is crucial for understanding the regulation of MC function. In this article, we describe a protocol for the isolation of murine connective tissue type MCs by peritoneal lavage and cultivation of peritoneal MCs (PMCs). Cultures of MCs from various knockout mouse models by this methodology represent a useful approach to the identification of proteins involved in MC signaling pathways. In addition, we also describe a protocol for single cell Fura-2 imaging as an important technique for the quantification of Ca2+ signaling in MCs. Fluorescence-based monitoring of [Ca2+]i is a reliable and commonly used approach to study Ca2+ signaling events, including store-operated calcium entry, which is of utmost importance for MC activation. For the analysis of MC degranulation, we describe a &#946;-hexosaminidase release assay. The amount of &#946;-hexosaminidase released into the culture medium is considered as a degranulation marker for all three different secretory subsets described in MCs. &#946;-hexosaminidase can easily be quantified by its reaction with a colorigenic substrate in a microtiter plate colorimetric assay. This highly reproducible technique is cost-effective and requires no specialized equipment. Overall, the provided protocol demonstrates a high yield of MCs expressing typical MC surface markers, displaying typical morphological and phenotypic features of MCs, and demonstrating highly reproducible responses to secretagogues in Ca2+-imaging and degranulation assays.

Here, we present a protocol to isolate and cultivate murine peritoneal mast cells. We also describe two protocols for their functional characterization: a fluorescent imaging of intracellular free Ca2+ concentration and a degranulation assay based on colorimetric quantification of the released &#946;-hexosaminidase.

Mast cells (MCs), as a part of the immune system, play a key role in defending the host against several pathogens and in the initiation of the allergic ...

Characterization of Thymus-dependent and Thymus-independent Immunoglobulin Isotype Responses in Mice Using Enzyme-linked Immunosorbent Assay

Antibodies, also termed as immunoglobulins (Ig), secreted by differentiated B lymphocytes, plasmablasts/plasma cells, in humoral immunity provide a formidable defense against invading pathogens via diverse mechanisms. One major goal of vaccination is to induce protective antigen-specific antibodies to prevent life-threatening infections. Both thymus-dependent (TD) and thymus-independent (TI) antigens can elicit robust antigen-specific IgM responses and can also induce the production of isotype-switched antibodies (IgG, IgA and IgE) as well as the generation of memory B cells with the help provided by antigen presenting cells (APCs). Here, we describe a protocol to characterize TD and TI Ig isotype responses in mice using enzyme-linked immunosorbent assay (ELISA). In this protocol, TD and TI Ig responses are elicited in mice by intraperitoneal (i.p.) immunization with hapten-conjugated model antigens TNP-KLH (in alum) and TNP-polysaccharide (in PBS), respectively. To induce TD memory response, a booster immunization of TNP-KLH in alum is given at 3 weeks after the first immunization with the same antigen/adjuvant. Mouse sera are harvested at different time points before and after immunization. Total serum Ig levels and TNP-specific antibodies are subsequently quantified using Ig isotype-specific Sandwich and indirect ELISA, respectively. In order to correctly quantify the serum concentration of each Ig isotype, the samples need to be appropriately diluted to fit within the linear range of the standard curves. Using this protocol, we have consistently obtained reliable results with high specificity and sensitivity. When used in combination with other complementary methods such as flow cytometry, in vitro culture of splenic B cells and immunohistochemical staining (IHC), this protocol will allow researchers to gain a comprehensive understanding of antibody responses in a given experimental setting.

In this paper, we describe a protocol to characterize T-dependent and T-independent immunoglobulin (Ig) isotype responses in mice using ELISA. This method used alone or in combination with flow cytometry will allow researchers to identify differences in B cell-mediated Ig isotype responses in mice following T-dependent and T-independent antigen immunization.

Antibodies, also termed as immunoglobulins (Ig), secreted by differentiated B lymphocytes, plasmablasts/plasma cells, in humoral immunity provide a ...

Generation of Knock-out Primary and Expanded Human NK Cells Using Cas9 Ribonucleoproteins

CRISPR/Cas9 technology is accelerating genome engineering in many cell types, but so far, gene delivery and stable gene modification have been challenging in primary NK cells. For example, transgene delivery using lentiviral or retroviral transduction resulted in a limited yield of genetically-engineered NK cells due to substantial procedure-associated NK cell apoptosis. We describe here a DNA-free method for genome editing of human primary and expanded NK cells using Cas9 ribonucleoprotein complexes (Cas9/RNPs). This method allowed efficient knockout of the TGFBR2 and HPRT1 genes in NK cells. RT-PCR data showed a significant decrease in gene expression level, and a cytotoxicity assay of a representative cell product suggested that the RNP-modified NK cells became less sensitive to TGF&#946;. Genetically modified cells could be expanded post-electroporation by stimulation with irradiated mbIL21-expressing feeder cells.

Here, we present a protocol to genetically modify primary or expanded human natural killer (NK) cells using Cas9 Ribonucleoproteins (Cas9/RNPs). By using this protocol, we generated human NK cells deficient for transforming growth factor&#8211;b receptor 2 (TGFBR2) and hypoxanthine phosphoribosyltransferase 1 (HPRT1).

CRISPR/Cas9 technology is accelerating genome engineering in many cell types, but so far, gene delivery and stable gene modification have been challenging ...

Adoptive Immunotherapy of iNKT Cells in Glucose-6-Phosphate Isomerase (G6PI)-Induced RA Mice

Rheumatoid arthritis (RA) is a complex chronic inflammatory autoimmune disease. The pathogenesis of the disease is related to invariant natural killer T (iNKT) cells. Patients with active RA present fewer iNKT cells, defective cell function, and excessive polarization of Th1. In this study, an RA animal model was established using a mixture of hGPI325-339 and hGPI469-483 peptides. The iNKT cells were obtained by in vivo induction and in vitro purification, followed by infusion into RA mice for adoptive immunotherapy. The in vivo imaging system (IVIS) tracking revealed that iNKT cells were mainly distributed in the spleen and liver. On day 12 after cell therapy, the disease progression slowed down significantly, the clinical symptoms were alleviated, the abundance of iNKT cells in the thymus increased, the proportion of iNKT1 in the thymus decreased, and the levels of TNF-&#945;, IFN-&#947;, and IL-6 in the serum decreased. Adoptive immunotherapy of iNKT cells restored the balance of immune cells and corrected the excessive inflammation of the body.

Adoptive Immunotherapy of iNKT Cells in Glucose-6-Phosphate Isomerase G6PI-Induced RA Mice

This protocol uses G6PI mixed peptides to construct rheumatoid arthritis models that are closer to that of human rheumatoid arthritis in CD4+ T cells and cytokines. High purity invariant natural killer T cells (mainly iNKT2) with specific phenotypes and functions were obtained by in vivo induction and in vitro purification for adoptive immunotherapy.

Rheumatoid arthritis (RA) is a complex chronic inflammatory autoimmune disease. The pathogenesis of the disease is related to invariant natural killer T ...

Evaluation of T Follicular Helper Cells and Germinal Center Response During Influenza A Virus Infection in Mice

T Follicular Helper (Tfh) cells are an independent CD4+&#160;T cell subset specialized in providing help for germinal center (GC) development and generation of high-affinity antibodies. In influenza virus infection, robust Tfh and GC B cell responses are induced to facilitate effective virus eradication, which confers a qualified mouse model for Tfh-associated study. In this paper, we described protocols in detection of basic Tfh-associated immune response during influenza virus infection in mice. These protocols include: intranasal inoculation of influenza virus; flow cytometry staining and analysis of polyclonal and antigen-specific Tfh cells, GC B cells and plasma cells; immunofluorescence detection of GCs; enzyme-linked immunosorbent assay (ELISA) of influenza virus-specific antibody in serum. These assays basically quantify the differentiation and function of Tfh cells in influenza virus infection, thus providing help for studies in elucidating differentiation mechanism and manipulation strategy.

This paper describes protocols of evaluating Tfh and GC B response in mouse model of influenza virus infection.