National Institutes of Health Kirchstein Fellowship predoctoral fellowship AI-64128 (MPM), GM-41514 (MDC), GM-48071 (I.P.)

1) Remove both femur bones from one mouse
<ol>
<li>Use dissection scissors to cut away muscle and expose the femur bone above and below the joints (knee and hip). Grasp the center of the femur with dissection tweezers and cut above and below the joints to leave as much of the epiphysis intact as possible.</li>
<li>Clean off as much muscle as possible using small dissection scissors. Transfer the femur into a dish of RPMI.</li>
<li>All procedures should be carried out in the hood from this point on, using only sterile media, instruments, pipette tips and culture dishes.</li>
</ol>
2) Sterilize Femur bones:
<ol>
<li>In the hood, transfer bones from the RPMI to a small culture dish filled with 70% ethanol on ice.</li>
<li>Allow bones to soak in ethanol for 5 minutes on ice.</li>
</ol>
3) Collect Bone marrow under sterile conditions:
<ol>
<li>Transfer bones to a small culture dish containing sterile filtered Primary DC culture media.</li>
<li>With sterile tweezers, hold the bone over a discard dish or tube, and with sterile scissors, cut each epiphesis (ends of the bone) off. The cut should expose bone marrow which is bright red in the center of the bone.</li>
<li>With a sterile syringe (26-28 gauge needle), suck up about 100-200 mL of sterile media.</li>
<li>Hold the bone with the sterile tweezers over a fresh dish of sterile media and insert the needle into one side of the bone. Position the tip of the needle near the top of the bone and slowly wash the bone out with the sterile media. If you are in the center of the bone, the needle should slide in easily.</li>
<li>The bone marrow washes out, either in small pieces or as a single piece. It&nbsp;should be flushed out of the bone and into the dish of sterile media.</li>
<li>Repeat this step as needed to completely wash the marrow out of the bone.</li>
<li>When the bone is clean, it will be white and translucent.</li>
<li>Repeat this procedure with the other femur bone. Discard each femur bone once it is clean.</li>
</ol>
4) Re-suspend and Spin down Bone Marrow cells:
<ol>
<li>Transfer cells to a sterile falcon tube.</li>
<li>If marrow is still intact, very gently pipette media up and down in the dish, to break up the marrow into a single cell suspension. This may take several minutes and should be done slowly to avoid killing cells by sheer force.</li>
<li>Centrifuge cells as you would any other mammalian cells. </li>
</ol>
5) Cell Lysis:
<ol>
<li>Remove the tube from the centrifuge after the spin is done and pour media off (decant) into a small waste (50 mL falcon tube) in the hood. </li>
<li>Resuspend pellet by gently flicking the bottom of the tube. </li>
<li>Using sterile filtered water and 10x DPBS or 10x PBS, carry out a water lysis to remove the red blood cells (RBCs) using the following volumes: 
<ul>
<li>900 mL sterile filtered water</li>
<li>100 mL 10x DPBS or 10x PBS</li>
</ul>
</li>
<li>Add 100 mL of 10x PBS 5-10 seconds after adding the water. It is very important do this immediately so that only the RBCs are lysed. It is a good idea to have both pipettes filled and ready.</li>
<li>Add 5 mL &ndash; 10 mL of sterile DC basic media.</li>
</ol>
6) Count Cells:
<ol>
<li>In the hood, mix the 6 to 11 mL of bone marrow cells by gently swirling the tube with a slight inversion, a&nbsp;45 degree tilt (not so that the media touches the top of the tube)</li>
<li>Remove 10 mL of media into a sterile tube for counting. </li>
<li>Re-cap the cells and centrifuge again.</li>
</ol>
7) Plating Dendritic cells:
<ol>
<li>Cells should be plated at a density of 1 x 106/mL. </li>
<li>Remove cells from centrifuge, decant media and re-suspend cells in the appropriate amount of Primary DC Media for plating.</li>
<li>Place in tissue culture incubator.&nbsp; </li>
</ol>
8) Culture Care and Maturation:
Always check cultures before adding more media or using in any experiments. Check the general health of cells and look for potential contamination.
DAY 0: Dendritic cells plated.
DAY 3: Remove 75% of the media and non-adherant cells and add back Primary DC media.
DAY 6: After Initial Cell Plating: Re-plate the cells using the following procedure:
<ol>
<li>Remove media, which should contain some non-adherant DCs at this point, and place in a sterile 50 mL falcon tube, leaving plates very slightly wet (you don&rsquo;t want the adherent cells to dry out) </li>
<li>Add 3 mM EDTA in PBS to each plate and allow&nbsp;to sit for 5 minutes. </li>
<li>Hold the plate at a 45 degree angle and gently pipette media up and down against the bottom of the plate to gently dislodge non-adherant cells.</li>
<li>EDTA/PBS should become thicker indicating cells are being collected from the bottom of the plate. </li>
<li>After several minutes of this, cell mixture can be transferred to the 50 mL falcon tube. </li>
<li>Spin all cells after performing this procedure for each plate.</li>
<li>Count and plate the cells at a density of 1 x 10^6 per plate in Secondary DC Media in new sterile 10 cm culture dishes. Return cells to tissue culture incubator.</li>
</ol>
DAY 10-11
Mature DCs ready for stimulation/antigen loading.
9) Dendritic Cell Stimulation:
<ol>
<li>Use LPS (lipopolyscaccharide) in combination with desired peptide for activation and peptide loading. Depending on your source of LPS, different stimulation conditions may give better results. Additionally, the desired amount of peptide for DC presentation should be optimized. Stimulation conditions in this protocol were 100 ng/mL LPS and 100 ug/mL OVA (ovalbumin).&nbsp;</li>
<li>Load antigen/treat with LPS for 18-24 hours prior to harvest/use. </li>
</ol>
Dendritic Cell Media: Sterile filter after everything has been added
Please see the discussion section for a review of different dendritic cell culture conditions and for the resulting dendritic cell phenotype. These culture conditions are designed to produce mature dendritic cells that rapidly home to draining lymph nodes, 18-24 hours after subcutaneous injection and present antigen efficiently.
Primary DC Media: Sterile filter after everything has been added
<ul>
<li>500 mL IMDM (remove 55-60 mL for 500mL final volume)</li>
<li>50 mL heat inactivated FBS</li>
<li>5 mL of 200 mM L-Gln, final concentration of 2 mM</li>
<li>100 IU/mL Penicillin and 100 mg/mL streptomycin (5 mL of 10,000 IU/mL Pen and 10,000 mg/mL Strep stock)</li>
<li>50 uM B-Me (14.3 M B-Me stock, dilute 1:100 in chemical hood, use 35 ul per 100 mL media for 50 micromolar concentration)</li>
<li>20-30 ng/mL GM-CSF</li>
<li>100-400 IU/mL IL-4 roughly 10- 40 ng/mL</li>
</ul>
SecondaryDC media for maturation* 
100 ng/mL TNF-alpha (add to Primary DC media) * Note: GM-CSF + IL-4 should produce immature dendritic cells. Using GM-CSF + IL4 (400 IU/ul) + TNF-alpha (100 ug/mL) will create cells that resemble mature monocyte derived dendritic cells. Mature dendritic cells are known not to take up antigen as efficiently as immature dendritic cells and cultures may have endogenous TNF-a released from stromal cells4.

<ol>
	<li>Miller, M. J., Safrina, O., Parker, I., Cahalan, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+single+cell+dynamics+of+CD4++T+cell+activation+by+dendritic+cells+in+lymph+nodes.">Imaging the single cell dynamics of CD4+ T cell activation by dendritic cells in lymph nodes.</a> J Exp Med. 200, 847-856 (2004).</li><li>Henrickson, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T+cell+sensing+of+antigen+dose+governs+interactive+behavior+with+dendritic+cells+and+sets+a+threshold+for+T+cell+activation.">T cell sensing of antigen dose governs interactive behavior with dendritic cells and sets a threshold for T cell activation.</a> Nat Immunol. 9, 282-291 (2008).</li><li>Jefford, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+comparison+of+DCs+generated+in+vivo+with+Flt3+ligand+or+in+vitro+from+blood+monocytes:+differential+regulation+of+function+by+specific+classes+of+physiologic+stimuli.">Functional comparison of DCs generated in vivo with Flt3 ligand or in vitro from blood monocytes: differential regulation of function by specific classes of physiologic stimuli.</a> Blood. 102, 1753-1763 (2003).</li><li>Inaba, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+large+numbers+of+dendritic+cells+from+mouse+bone+marrow+cultures+supplemented+with+granulocyte/macrophage+colony-stimulating+factor.">Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor.</a> J Exp Med. 176, 1693-1702 (1992).</li><li>Lutz, M. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+functions+of+IL-4+receptor+types+I+and+II+for+dendritic+cell+maturation+and+IL-12+production+and+their+dependency+on+GM-CSF.">Differential functions of IL-4 receptor types I and II for dendritic cell maturation and IL-12 production and their dependency on GM-CSF.</a> J Immunol. 169, 3574-3580 (2002).</li><li>Xu, Y., Zhan, Y., Lew, A. M., Naik, S. H., Kershaw, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+development+of+murine+dendritic+cells+by+GM-CSF+versus+Flt3+ligand+has+implications+for+inflammation+and+trafficking.">Differential development of murine dendritic cells by GM-CSF versus Flt3 ligand has implications for inflammation and trafficking.</a> J Immunol. 179, 7577-7584 (2007).</li><li>Inaba, K., Swiggard, W. J., Steinman, R. M., Romani, N., Schuler, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+dendritic+cells.">Isolation of dendritic cells.</a> Curr Protoc Immunol. 3, (2001).</li><li>Winzler, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maturation+stages+of+mouse+dendritic+cells+in+growth+factor-dependent+long-term+cultures.">Maturation stages of mouse dendritic cells in growth factor-dependent long-term cultures.</a> J Exp Med. 185, 317-328 (1997).</li><li>Koch, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+necrosis+factor+alpha+maintains+the+viability+of+murine+epidermal+Langerhans+cells+in+culture,+but+in+contrast+to+granulocyte/macrophage+colony-stimulating+factor,+without+inducing+their+functional+maturation.">Tumor necrosis factor alpha maintains the viability of murine epidermal Langerhans cells in culture, but in contrast to granulocyte/macrophage colony-stimulating factor, without inducing their functional maturation.</a> J Exp Med. 171, 159-171 (1990).</li><li>Miller, M. J., Hejazi, A. S., Wei, S. H., Cahalan, M. D., Parker, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T+cell+repertoire+scanning+is+promoted+by+dynamic+dendritic+cell+behavior+and+random+T+cell+motility+in+the+lymph+node.">T cell repertoire scanning is promoted by dynamic dendritic cell behavior and random T cell motility in the lymph node.</a> Proc Natl Acad Sci U S A. 101, 998-1003 (2004).</li><li>Wei, S. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2++signals+in+CD4++T+cells+during+early+contacts+with+antigen-bearing+dendritic+cells+in+lymph+node.">Ca2+ signals in CD4+ T cells during early contacts with antigen-bearing dendritic cells in lymph node.</a> J Immunol. 179, 1586-1594 (2007).</li><li>Castellino, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemokines+enhance+immunity+by+guiding+naive+CD8++T+cells+to+sites+of+CD4++T+cell-dendritic+cell+interaction.">Chemokines enhance immunity by guiding naive CD8+ T cells to sites of CD4+ T cell-dendritic cell interaction.</a> Nature. 440, 890-895 (2006).</li></ol>

Dendritic cells are key mediators of the adaptive immune response and the most efficient antigen presenting cell characterized to date. Methods for human and mouse dendritic cell culture in the literature differ in the type of cytokines used to influence the development of different dendritic cell types. Notably, GM-CSF, flt3L, IL4, IL13, TNF-alpha and IFN-gamma are used in different combinations to produce mature, immature, inflammatory and steady-state like murine bone marrow derived dendritic cells in vitro3-7</s...

generation of bone marrow derived murine dendritic cells for use in 2-photon imaging

Several methods for the preparation of murine dendritic cells can be found in the literature. Here, we present a method that produces greater than 85% CD11c high dendritic cells in culture that home to the draining lymph node after subcutaneous injection and present antigen to antigen specific T cells (see video). Additionally, we use Essen Instruments Incucyte to track dendritic cell maturation, where, at day 10, the morphology of the cultured cells is typical of a mature dendritic cell and &lt;85% of cells are CD11chigh. The study of antigen presentation in peripheral lymph nodes by 2-photon imaging revealed that there are three distinct phases of dendritic cell and T cell interaction1, 2. Phase I consists of brief serial contacts between highly motile antigen specific T cells and antigen carrying dendritic cells1, 2. Phase two is marked by prolonged contacts between antigen-specific T cell and antigen bearing dendritic cells1, 2. Finally, phase III is characterized by T cells detaching from dendritic cells, regaining motility and beginning to divide1, 2. This is one example of the type of antigen-specific interactions that can be analyzed by two-photon imaging of antigen-loaded cell tracker dye-labeled dendritic cells.

Watch this Scientific Journal Video about Generation of Bone Marrow Derived Murine Dendritic Cells for Use in 2-photon Imaging at JoVE.com

Generation of Bone Marrow Derived Murine Dendritic Cells for Use in 2-photon Imaging

Antigen presentation in secondary lymphoid organs by dendritic cells is crucial for the initiation of the T cell mediated adaptive immune response. Here we demonstrate the culture of bone marrow derived murine dendritic cells, activation, and labeling for 2-photon imaging.

Several methods for the preparation of murine dendritic cells can be found in the literature. Here, we present a method that produces greater than 85% ...

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31.0K Views.  University of California, Irvine (UCI). Antigen presentation in secondary lymphoid organs by dendritic cells is crucial for the initiation of the T cell mediated adaptive immune response. Here we demonstrate the culture of bone marrow derived murine dendritic cells, activation, and labeling for 2-photon imaging. 

Video: Generation of Bone Marrow Derived Murine Dendritic Cells for Use in 2-photon Imaging

Dissection and 2-Photon Imaging of Peripheral Lymph Nodes in Mice

Two-photon imaging has revealed an elegant choreography of motility and cellular interactions within the lymph node under basal conditions and at the initiation of an immune response 1. Here, we present methods for adoptive transfer of labeled T cells, isolation of lymph nodes, and imaging motility of CD4+ T cells in the explanted lymph node as first described in 2002 2. Two-photon imaging of immune cells requires that the cells are fluorescently labeled, either by staining with a cell tracker dye or by expressing a fluorescent protein. We demonstrate the adoptive transfer procedure of injecting cells derived from donor mice into the tail vein of a recipient animal, where they home to lymphoid organs within approximately 15-30 min. We illustrate the isolation of a lymph node and describe methods to ensure proper mounting of the excised lymph node. Other considerations such as proper oxygenation of perfused media, temperature, and laser power are discussed. Finally, we present 3D video images of naive CD4+ T cells exhibiting steady state motility at 37&deg;C.

Two-photon imaging has uncovered lymphocyte motility and cellular interactions within the lymph node under basal conditions and durring an immune response 1. Here, we demonstrate adoptive transfer of T cells, isolation of lymph nodes, and imaging motility of CD4+ T cells in the explanted lymph node.

Two-photon imaging has revealed an elegant choreography of motility and cellular interactions within the lymph node under basal conditions and at the ...

In situ Imaging of the Mouse Thymus Using 2-Photon Microscopy

Two-photon Microscopy (TPM) enables us to image deep into the thymus and document the events that are important for thymocyte development. To follow the migration of individuals in a crowd of thymocytes , we generate neonatal chimeras where less than one percent of the thymocytes are derived from a donor that is transgenic for a ubiquitously express fluorescent protein. To generate these partial hematopoetic chimeras, neonatal recipients are injected with bone marrow between 3-7 days of age. After 4-6 weeks, the mouse is sacrificed and the thymus is carefully dissected and bissected preserving the architecture of the tissue that will be imaged. The thymus is glued onto a coverslip in preparation for ex vivo imaging by TPM. During imaging the thymus is kept in DMEM without phenol red that is perfused with 95% oxygen and 5% carbon dioxide and warmed to 37&deg;C. Using this approach, we can study the events required for the generation of a diverse T cell repertoire.

We present step-by-step instructions for the generation of neonatal chimeras as well as the dissection and preparation of the thymus for ex vivo imaging by 2-Photon Microscopy.

Two-photon Microscopy (TPM) enables us to image deep into the thymus and document the events that are important for thymocyte development.  To follow the ...

A Method for 2-Photon Imaging of Blood Flow in the Neocortex through a Cranial Window

The ability to image the cerebral vasculature (from large vessels to capillaries) and record blood flow dynamics in the intact brain of living rodents is a powerful technique. Using in vivo 2-photon microscopy through a cranial window it is possible to image fluorescent dyes injected intravenously. This permits one to image the cortical vasculature and also to obtain measurements of blood flow. This technique was originally developed by David Kleinfeld and Winfried Denk. The method can be used to study blood flow dynamics during or after cerebral ischemia, in neurodegenerative disorders, in brain tumors, or in normal brain physiology. For example, it has been used to study how stroke causes shifts in blood flow direction and changes in red blood cell velocity or flux in and around the infarct. Here we demonstrate how to use 2-photon microscopy to image blood flow dynamics in the neocortex of living mice using fluorescent dyes injected into the tail vein.

Cortical blood flow dynamics can be studied in vivo by imaging fluorescent dextran dyes injected into the tail vein of rodents with 2-photon microscopy. This video shows how to image blood flow dynamics in neocortex of mice through a glass-covered cranial window preparation.

The ability to image the cerebral vasculature (from large vessels to capillaries) and record blood flow dynamics in the intact brain of living rodents is ...

In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution . The method consists in implanting a cranial imaging window, injecting a fluorescent calcium indicator dye that can be taken up by large numbers of neurons and finally recording the activity of neurons with time lapse calcium imaging using an in-vivo two photon microscope. Co-injection of astrocyte-specific dyes allows one to differentiate neurons from astrocytes. The technique can be performed in mice expressing fluorescent molecules in specific subpopulations of neurons to better understand the network interactions of different groups of cells.

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons . In-vivo two-photon calcium imaging is the only method that allows one to record the activity of a dense neuronal population with single-cell resolution .

To understand network dynamics of microcircuits in the neocortex, it is essential to simultaneously record the activity of a large number of neurons .  ...

Culture of myeloid dendritic cells from bone marrow precursors

Myeloid dendritic cells (DCs) are frequently used to study the interactions between innate and adaptive immune mechanisms and the early response to infection. Because these are the most potent antigen presenting cells, DCs are being increasingly used as a vaccine vector to study the induction of antigen-specific immune responses. In this video, we demonstrate the procedure for harvesting tibias and femurs from a donor mouse, processing the bone marrow and differentiating DCs in vitro. The properties of DCs change following stimulation: immature dendritic cells are potent phagocytes, whereas mature DCs are capable of antigen presentation and interaction with CD4+ and CD8+ T cells. This change in functional activity corresponds with the upregulation of cell surface markers and cytokine production. Many agents can be used to mature DCs, including cytokines and toll-like receptor ligands. In this video, we demonstrate flow cytometric comparisons of expression of two co-stimulatory molecules, CD86 and CD40, and the cytokine, IL-12, following overnight stimulation with CpG or mock treatment. After differentiation, DCs can be further manipulated for use as a vaccine vector or to generate antigen-specific immune responses by in vitro pulsing using peptides or proteins, or transduced using recombinant viral vectors. 

This video demonstrates the procedure for differentiating myeloid dendritic cells from mouse bone marrow. Isolation of mouse tibia and femur, and processing of bone marrow are demonstrated. Pictures demonstrating cell morphology before and after differentiation, and figures depicting cell phenotype and IL-12 production following maturation using CpG are shown.

Myeloid dendritic cells (DCs) are frequently used to study the interactions between innate and adaptive immune mechanisms and the early response to ...

The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell  electroporation system and Gene Pulser  electroporation buffer were specifically developed to transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells.This video demonstrates how to establish primary hematopoietic cell cultures from murine bone marrow, and then prepare them for electroporation in the MXcell system. We begin by isolating femur and tibia. Bone marrow from both femur and tibia are then harvested and cultures are established. Cultured bone marrow cells are then transfected and analyzed.

This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation system.

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...

Homing of Hematopoietic Cells to the Bone Marrow

Homing is the phenomenon whereby transplanted hematopoietic cells are able to travel to and engraft or establish residence in the bone marrow. Various chemomkines and receptors are involved in the homing of hematopoietic stem cells. [1, 2]
This paper outlines the classic homing protocol used in hematopoietic stem cell studies. In general this involves isolating the cell population whose homing needs to be investigated, staining this population with a dye of interest and injecting these cells into the blood stream of a recipient animal. The recipient animal is then sacrificed at a pre-determined time after injection and the bone marrow evaluated for the percentage or absolute number of cells which are positive for the dye of interest. In one of the most common experimental schemes, the homing efficiency of hematopoietic cells from two genetically distinct animals (a wild type animal and the corresponding knock-out) is compared. This article describes the hematopoietic cell homing protocol in the framework of such as experiment.

This article describes a protocol used to study the homing of hematopoietic cells to their niches in the bone marrow.

Homing is the phenomenon whereby transplanted hematopoietic cells are able to travel to and engraft or establish residence in the bone marrow.  Various ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Osteoclast Derivation from Mouse Bone Marrow

Osteoclasts are highly specialized cells that are derived from the monocyte/macrophage lineage of the bone marrow. Their unique ability to resorb both the organic and inorganic matrices of bone means that they play a key role in regulating skeletal remodeling. Together, osteoblasts and osteoclasts are responsible for the dynamic coupling process that involves both bone resorption and bone formation acting together to maintain the normal skeleton during health and disease.
As the principal bone-resorbing cell in the body, changes in osteoclast differentiation or function can result in profound effects in the body. Diseases associated with altered osteoclast function can range in severity from lethal neonatal disease due to failure to form a marrow space for hematopoiesis, to more commonly observed pathologies such as osteoporosis, in which excessive osteoclastic bone resorption predisposes to fracture formation.
An ability to isolate osteoclasts in high numbers in vitro has allowed for significant advances in the understanding of the bone remodeling cycle and has paved the way for the discovery of novel therapeutic strategies that combat these diseases. 
Here, we describe a protocol to isolate and cultivate osteoclasts from mouse bone marrow that will yield large numbers of osteoclasts.

Osteoclasts are the principal bone-resorbing cell in the body. An ability to isolate osteoclasts in large numbers has resulted in significant advances in the understanding of osteoclast biology. In this protocol, we describe a method for isolation, cultivating and quantifying osteoclast activity in vitro.

Osteoclasts are highly specialized cells that are derived from the monocyte/macrophage lineage of the bone marrow. Their unique ability to resorb both the ...

Expression of Fluorescent Fusion Proteins in Murine Bone Marrow-derived Dendritic Cells and Macrophages

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation of an adaptive immune response. Experimental work with these cells is rather challenging. Their abundance in organs and tissues is relatively low. As a result, they cannot be isolated in large numbers. They are also difficult to transfect with cDNA constructs. In the murine model, these problems can be partially overcome by in vitro differentiation from bone marrow progenitors in the presence of M-CSF for macrophages or GM-CSF for dendritic cells. In this way, it is possible to obtain large amounts of these cells from very few animals. Moreover, bone marrow progenitors can be transduced with retroviral vectors carrying cDNA constructs during early stages of cultivation prior to their differentiation into bone marrow derived dendritic cells and macrophages. Thus, retroviral transduction followed by differentiation in vitro can be used to express various cDNA constructs in these cells. The ability to express ectopic proteins substantially extends the range of experiments that can be performed on these cells, including live cell imaging of fluorescent proteins, tandem purifications for interactome analyses, structure-function analyses, monitoring of cellular functions with biosensors and many others. In this article, we describe a detailed protocol for retroviral transduction of murine bone marrow derived dendritic cells and macrophages with vectors coding for fluorescently-tagged proteins. On the example of two adaptor proteins, OPAL1 and PSTPIP2, we demonstrate its practical application in flow cytometry and microscopy. We also discuss the advantages and limitations of this approach.

In this article, we provide a detailed protocol for the expression of fluorescent fusion proteins in murine bone marrow derived dendritic cells and macrophages. The method is based on the transduction of bone marrow progenitors with retroviral constructs followed by differentiation into macrophages and dendritic cells in vitro.

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation ...