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 vistas.  Stanford University School of Medicine. Describimos un método para la generación de células de mástil derivadas in vitro, su engraftment en ratones célula-deficientes del mástil, y el análisis del fenotipo, de los números y de la distribución de las células de mástil engrafted en diversos sitios anatómicos. Este protocolo se puede utilizar para evaluar las funciones de los mastocitos in vivo.