Choosing an immunodeficient mouse model

JAX NotesMarch 20, 2006

Immunodeficient mouse models, particularly severe combined immunodeficient (Prkdc^scid and Rag1^null) mice, are very useful models for immunology, infectious disease, cancer, stem cell biology and other research. As the number, diversity and specialized research applications of these models increase, so does the difficulty of choosing the most appropriate ones for a particular study. The purpose of this article is to help you make those choices.

To choose the most appropriate immunodeficient mouse model for your research, you will have to consider many factors. Some of the major ones are listed below (Tables 1, 2, and 3 summarize how these factors apply to selected JAX® Mice models):

Background features. Consider important features of the background strain, such as H2 haplotype, behavior and disease susceptibility. For example, the NOD strain is susceptible to diabetes and is deficient in natural killer (NK), macrophage, antigen presenting cell (APC) and complement activity (Table 1).
Functionality of various endogenous immune system components. Consider the activity of the mutant's endogenous B cells, T cells, NK cells, APCs and complement (Table 1).
Leakiness. As applied to Prkdc^scid mice, leakiness refers to their tendency (on certain backgrounds) to produce some functional B and T cells as they age. It is higher in mice housed under non-specific pathogen free (SPF) conditions, and it is generally high on the C57BL/6J and BALB/cByJ backgrounds, low on the C3H/HeSnJSmn background, and very low on the NOD/LtSzJ background (Table 1).
Lifespan. Some immunodeficient mice die young because they are susceptible to thymic lymphomas (Table 3). This limits their use for long-term experiments.
Radiosensitivity. Prkdc^scid mice are sensitive to radiation and therefore cannot be as thoroughly irradiated as other immunodeficient models before being engrafted.
Breeding performance. Female nude mice are poor breeders: they begin to ovulate late, when 2.5 months old, and stop early, when 4 months old.
Gene features. Consider how the gene of interest functions, and where it is expressed (Table 2).
Mutant gene effects. Consider how the mutant gene affects immune responses (such as NK cell, macrophage and complement activity) and interacts with the genetic background of a mutant. For example, the beta 2 microglobulin and perforin mutations lower NK cell activity, the interleukin 2 receptor, gamma chain mutation completely eliminates it, and the scid mutation renders NOD mice resistant to diabetes (Tables 2 and 3).
Availability. Consider whether the mutant you want is readily available in the quantities you need. If it is not, consider requesting a Dedicated Supply contract with JAX® Services.
Husbandry. Nude, Rag1^null and Pkrdc^scid mice should be housed in specific pathogen-free (SPF) environments.
Research type. Consider the kind of research you are conducting (allograft, xenograft, immunology, cancer, etc.) and how your research will relate to previous and future research.

Table 1. Major features of selected backgrounds for JAX® Mice immunodeficient models and the names of selected models on those backgrounds

Background	Background Features			Selected Immunodeficient JAX® Mice Models (stock number)	Availability Levels
Background	Innate Immunity(NK, B, APC cells; complement activity)	Scid-associated leakiness	H2 haplotype		Availability Levels
BALB Substrains	Normal	High	d	CByJ.Cg-Foxn1^nu/J(000711)	4
				CBySmn.CB17-Prkdc^scid/J (001803)	2
C57BL/6J	Normal	High	b	B6;129S7-Rag1^tm1Mom/J (002096)	3
				B6.129S7-Rag1^tm1Mom/J (002216)	2
				B6.CB17-Prkdc^scid/SzJ (001913)	2
NOD/LtSzJ	Impaired	Low	g⁷	NOD.129S7(B6)-Rag1^tm1Mom/J (003729)	RL
				NOD.Cg-Rag1^tm1Mom Prf1^tm1Sdz/Sz (004848)	RL
				NOD.CB17-Prkdc^scid/SzJ (001303)	1
				NOD.Cg-Prkdc^scid B2m^tm1Unc/J (002570)	3
				NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (005557)	RL
NU/J*	Normal	na	q	NU/J (002019)	4

na = not applicable
*Harbors the Foxn1^nu mutation

Table 2. Gene names and functions for models in Table 1.

Gene names	Function
B2m beta-2 microglobulin	B2m is required for normal expression of major histocompatibility class I proteins (displaying viral and self antigens to potentially responsive T cells) and for CD8+ T cell maturation and NK cell development
Foxn1 forkhead box N1, formerly Hfh11	The Foxn1^nu mutation is commonly known as nude. Homozygous mutants lack a thymus and therefore are T cell deficient; they respond very poorly to thymus-dependent antigens, are unable to reject allogeneic and xenogeneic grafts, and have greatly increased susceptibility to infection.
*Il2rg* interleukin 2 receptor, gamma chain	Il2rg is indispensable for IL2, IL4, IL7, IL9, IL15, and IL21 high-affinity binding and signaling; in mice, it is also thought to play a key role in mediating susceptibility to thymic lymphomas. Thus, NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ mice do not develop thymic lymphomas characteristic of aging NOD.CB17-Prkdc^scid/SzJ mice. Most importantly, Il2rg deficiency blocks the development of NK cells and causes other defects in innate immunity.
Prf1 perforin 1 (pore-forming protein)	Prf1 is a critical component of the lytic pathway by which NK and CD8+ lymphocytes kill targeted cells.
Prkdc protein kinase, DNA-activated, catalytic polypeptide	The scid mutation in the Prkdc gene stands for severe combined immunodeficient. Prkdc is instrumental in repairing double-stranded DNA breaks and in recombining the variable (V), diversity (D), and joining (J) segments of immunoglobulin and T-cell receptor genes. Homozygous mutants have no mature T and B cells, cannot mount cell-mediated and humoral adaptive immune responses, do not reject allogeneic and xenogeneic grafts, and are useful cancer research models. The scid mutation renders NOD mice diabetes-free and thereby makes them useful for adoptive transfer of diabetes by T cells. (Note: the NOD.NON-Thy1^a/1Lt (004483) strain provides an allotypically marked T cell population and develops diabetes at the same rate and frequency as does the standard NOD/LtJ (Thy1^b) strain. Thus, it is useful as a T cell donor source.)
Rag1 recombination activating gene 1	Rag1 is essential for the V(D)J gene rearrangements that generate functional antigen receptors in T and B cells; homozygous Rag1^tm1Mom mutants have no mature, functional T and B cells. The Rag1^tm1Mom mutation on the NOD background renders NOD mice diabetes-free. Aging NOD.129S7(B6)-Rag1^tm1Mom/J mice develop B cell lymphomas at a high frequency.

Table 3. Major characteristics of featured severely immunodeficient JAX® mouse models.

Model (stock number)	Availability	Lifespan (in months)	Primary References
NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (005557)	3	>16	Ishikawa et al. 2005; Shultz et al. 2005; Shultz et al. 2003
Advantages:
Our most useful and versatile model no functional B and T cells no leakiness with age no NK cell activity lymphoma-resistant and long-lived enables long-term experiments superior ability to be humanized: excellent engraftment and differentiation of human hematopoietic stem cells (HSCs) into mature human lymphoid and myeloid cells superior for HIV and other infectious disease research: can essentially be engrafted with a human immune system adoptive transfer of diabetic T cells without irradiation superior for transplantation research
Disadvantages:
characterization in progress Significantly slower rate of adoptive transfer of diabetes by splenic T cells from diabetic donors or beta cell autoreactive T cells from TCR transgenic donors (JAX Prof. Dr. Leiter, personal communication)
Model (stock number)	Availability	Lifespan	Primary References
NOD.CB17-Prkdc^scid/SzJ (001303)	1	8.5	Shultz et al. 1995
Advantages:
no functional B and T cells due to NOD background, low NK cell activity, no hemolytic complement activity, defects in myeloid development, and poor APC functions well characterized very low leakiness with age supports human hematolymphoid engraftment better than CBySmn.CB17-Prkdc^scid/J and B6.CB17-Prkdc^scid/SzJ
Disadvantages:
high incidence of thymic lymphomas (largely responsible for reduced lifespan) radiosensitive: tolerates up to 4 Gy suboptimal reconstitution with human HSCs
Model (stock number)	Availability	Lifespan	Primary References
NOD.Cg-Rag1^tm1Mom Prf1^tm1Sd^z/Sz (004848)	RL	8.5	Shultz et al. 2003; Minamiguchi et al. 2005
Advantages:
no functional B and T cells no leakiness with age no NK cell activity more lymphoma-resistant and longer-lived than NOD.Cg-Prkdc^scid B2m^tm1Unc/J radiation resistant: survive 8 Gy - optimizes radiation preconditioning for engraftment supports engraftment of human PBMCs and HSCs at about 10 fold higher levels than do NOD.CB17-Prkdc^scid/SzJ and NOD.129S7(B6)-Rag1^tm1Mom/J human PBMC engraftment results in high levels of CD4+ T cells and normalization of CD4:CD8 ratio engrafted human HSCs that differentiate into myeloid, erythroid and B cell lineages, but not T cells breeds better than NOD.CB17-Prkdc^scid B2m^tm1Unc/SzJ mice
Disadvantages:
characterization in progress shorter lifespan than NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ (due to thymic lymphomagenesis) less efficient reconstitution with human cells and tissues than NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ
Model (stock number)	Availability	Lifespan	Primary References
NOD.Cg-Prkdc^scid B2m^tm1Unc/J (002570)	3	6.3	Christianson et al. 1997
Advantages:
no functional B and T cells very low leakiness with age does not express MHC class I molecules, resulting in virtually no NK cell activity supports engraftment of human PBMCs and HSCs at about 10-fold higher levels than do NOD.CB17-Prkdc^scid/SzJ and NOD.129S7(B6)-Rag1^tm1Mom/J human PBMC engraftment results in higher levels of CD4+ T cells and normalization of CD4:CD8 ratio engrafts human HSCs that differentiate into myeloid, erythroid and B cell lineages, but not T cells
Disadvantages:
shortened lifespan due to thymic lymphomagenesis more radiosensitive than NOD.CB17-Prkdc^scid/SzJ develops severe hemochromatosis PBMC engraftment results in high levels of T cells, but does not support increased levels of human B cell engraftment less efficient reconstitution with human cells and tissues than NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ
Model (stock number)	Availability	Lifespan	Primary References
NOD.129S7(B6)-Rag1^tm1Mom/J (003729)	RL	10.5	Shultz et al. 2000
Advantages:
no functional B and T cells no leakiness with age low NK cell activity more resistant to radiation and thymic lymphomas, and longer-lived than NOD.CB17-Prkdc^scid/SzJ engrafts human lymphoid cells and HSCs at high levels due to total inability to functionally rearrange T and B cell receptors, this strain is the best host for adoptive transfer of diabetogenic NOD lymphoid cells.
Disadvantages:
characterization in progress develops high frequency of pre-B cell lymphomas with age
Model (stock number)	Availability	Lifespan	Primary References
B6.129S7-Rag1^tm1Mom/J (002216)	2	ND	Mombaerts et al. 1992
Advantages:
no functional B and T cells no leakiness with age more severely immunodeficient than are Foxn1^nu mutants supports enhanced engraftment of allogeneic and xenogeneic cells, tissues and tumors compared to Foxn1^nu mutants for certain experiments, this strain is preferable: e.g., when it is necessary to match MHC with MHC restriction of a T cell receptor
Disadvantages:
high NK cell activity normal complement activity normal APC functions
Model (stock number)	Availability	Lifespan	Primary References
B6;129S7-Rag1^tm1Mom/J (002096)	3	ND	Mombaerts et al. 1992
Advantages:
no functional B and T cells no leakiness with age more severely immunodeficient than are Foxn1^nu mutants supports enhanced engraftment of allogeneic and xenogeneic cells, tissues, and tumors compared to Foxn1^nu mutants
Disadvantages:
high NK cell activity normal complement activity normal APC functions
Model (stock number)	Availability	Lifespan	Primary References
B6.CB17-Prkdc^scid/SzJ (001913)	2	ND	Christianson et al. 1996
Advantages:
no functional B and T cells more severely immunodeficient than are Foxn1^nu mutants support better engraftment of allogeneic and xenogeneic cells, tissues, and tumors than do Foxn1^nu mutants
Disadvantages:
very leaky with age elevated NK cell activity elevated complement activity normal APC functions
Model (stock number)	Availability	Lifespan	Primary References
CBySmn.CB17-Prkdc^scid/J (001803)	2	ND	Custer et al. 1985
Advantages:
no functional B and T cells more severely immunodeficient than are Foxn1^numutants Incidence of thymomas about three-fold less than NOD.CB17-Prkdc^scid/SzJ supports better engraftment of allogeneic and xenogeneic cells, tissues and tumors compared to Foxn1^numutants for certain experiments, their MHC haplotype may be more appropriate than are those of NOD.CB17-Prkdc^scid/SzJ
Disadvantages:
leaky with age normal complement activity normal numbers and functions of macrophages, NK cells and APCs radiosensitive reduced lifespan due to thymic lymphomagenesis engraftment of human cells and tissues significantly less efficient than with NOD.CB17-Prkdc^scid/SzJ, NOD.Cg-Prkdc^scid B2m^tm1Unc/J, and NOD.Cg-Rag1^tm1Mom Prf1^tm1Sd^z/Sz
Model (stock number)	Availability	Lifespan	Primary References
NU/J (002019)	4	ND	Kelland 2004
Advantages:
homozygous Foxn1^nu mutants are well characterized and widely used NU/J mice, developed from the NIH outbred nude stock and inbred at The Jackson Laboratory, are more robust and breed better than do CByJ.Cg-Foxn1^nu/J mice supports growth of many types of cells and tumors, especially those from mice support engraftment of many human tumors hairless: subcutaneously transplanted tumors are easily visible athymic: no need for thymectomy
Disadvantages:
has normal B cells develops extrathymic T cell function with age normal numbers and functions of macrophages, NK cells and APCs normal complement activity
Model (stock number)	Availability	Lifespan	Primary References
CByJ.Cg-Foxn1^nu/J (000711)	4	ND	Committee 1989
Advantages:
homozygous Foxn1^nu mutants are well characterized and widely used widely used and well characterized in many experimental systems, especially as host for various human tumors supports growth of many types of cells and tumors, especially those from mice supports engraftment of many human tumors hairless, so subcutaneously transplanted tumors are easily visible athymic, so no need for thymectomy
Disadvantages:
breeds less well than do NU/J mice has normal B cells develops extrathymic T cell function with age normal numbers and functions of macrophage, NK cells and APCs normal complement activity

References

Christianson SW, Greiner DL, Hesselton RA, Leif JH, Wagar EJ, Schweitzer IB, Rajan TV, Gott B, Roopenian DC, Shultz LD. 1997. Enhanced human CD4+ T cell engraftment in beta2-microglobulin-deficient NOD-scid mice. J Immunol 158:3578-86.

Christianson SW, Greiner DL, Schweitzer IB, Gott B, Beamer GL, Schweitzer PA, Hesselton RM, Shultz LD. 1996. Role of natural killer cells on engraftment of human lymphoid cells and on metastasis of human T-lymphoblastoid leukemia cells in C57BL/6J-scid mice and in C57BL/6J-scid bg mice. Cell Immunol 171:186-199.

Committee on Immunologically Compromised Rodents 1989. Hereditary immunodeficiencies. Immunodeficient Rodents, a Guide to their Immunobiology, Husbandry, and Use, National Academy Press. 69-71.

Custer RP, Bosma GC, Bosma MJ. 1985. Severe combined immunodeficiency (SCID) in the mouse. Pathology, reconstitution, neoplasms. Am J Pathol 120:464-77.

Ishikawa F, Yasukawa M, Lyons B, Yoshida S, Miyamoto T, Yoshimoto G, Watanabe T, Akashi K, Shultz LD, Harada M. 2005. Development of functional human blood and immune systems in NOD/SCID/IL2 receptor {gamma} chain null mice. Blood 106:1565-73.

Kelland LR. 2004. Of mice and men: values and liabilities of the athymic nude mouse model in anticancer drug development. Eur J Cancer 40:827-36.

Minamiguchi H, Wingard JR, Laver JH, Mainali ES. Shultz LD, Ogawa M. 2005. An assay for human hematopoietic stem cells based on transplantation into nonobese diabetic recombination activating gene-null perforin-null mice. Biol Blood Marrow Transplant 11:487-494.

Mombaerts P, Iacomini J, Johnson RS, Herrup K, Tonegawa S, Papaioannou VE. 1992. RAG-1-deficient mice have no mature B and T lymphocytes. Cell 68:869-77.

Shultz LD. Lyons BL, Burzenski LM, Gott B, Chen X, Chaleff S, Kotb M, Gillies SD, King M, Mangada J, et al. 2005. Human lymphoid and myeloid cell development in NOD/LtSz-scid IL2R_null mice engrafted with mobilized human hemopoietic stem cells. J Immunol 174:6477?89.

Shultz LD, Banuelos S, Lyons B, Samuels R, Burzenski L, Gott B, Lang P, Leif J, Appel M, Rossini A, Greiner DL. 2003. NOD/LtSz-Rag1^nullPfp^null mice: a new model system with increased levels of human peripheral leukocyte and hematopoietic stem-cell engraftment. Transplantation 76:1036-42.

Shultz LD, Lang PA, Christianson SW, Gott B, Lyons B, Umeda S, Leiter E, Hesselton R, Wagar EJ, Leif JH, Kollet O, Lapidot T, Greiner DL. 2000. NOD/LtSz-Rag1^null mice: an immunodeficient and radioresistant model for engraftment of human hematolymphoid cells, HIV infection, and adoptive transfer of NOD mouse diabetogenic T cells. J Immunol 164:2496-507.

Shultz LD, Schweitzer PA, Christianson SW, Gott B, Schweitzer IB, Tennent B, McKenna S, Mobraaten L, Rajan TV, Greiner DL, Leiter EH. 1995. Multiple defects in innate and adaptive immunologic function in NOD/LtSz-scid mice. J Immunol 154:180-91.

Choosing an immunodeficient mouse model

Table 1. Major features of selected backgrounds for JAX® Mice immunodeficient models and the names of selected models on those backgrounds

Table 2. Gene names and functions for models in Table 1.

Table 3. Major characteristics of featured severely immunodeficient JAX® mouse models.

References

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