Our readily available NRG mice may be useful for cell or tissue transplantation studies, particularly as a model for human lymphohematopoietic cell engraftment studies that require a radioresistant host.
Below are common questions and answers for maintaining and using NSG™ mice in biomedical research. The questions are organized under the following sections:
Neutrophils and monocytes constitute most of the remaining mouse immune cells detectable in peripheral blood. Dendritic cells and macrophages are also present in the mouse, although they are defective because of alleles in the NOD/ShiLt genetic background.
The gene Prkdc, mutated by scid, enocodes a DNA protein kinase that participates in DNA double strain break repair throughout the body, and not just in developing immune cells. Consequently, mice that carry the Prkdcscid mutation have increased sensitivity to chemical or physical agents that damage DNA, such as cancer chemotherapies and irradiation. Mice expressing scid require a lower dose of preconditioning irradiation, compared with mice harboring the Rag1 knockout. On the other hand, they do not tolerate very high doses of radiation. NSG™ mice tolerate radiation doses up to 400 cGy (4 Gy). The radiation sensitivity of NSG™ mice might become an issue when studying the response of an engrafted tumor to high-dose radiation treatment. Furthermore, chemotherapies that act by causing DNA damage can have higher toxicity in scid mice, compared to Rag1 or Rag2 knockouts. A maximum tolerated dose study is advisable before dosing NSG™ mice with any chemotherapy.
Yes, NSG™ mice are susceptible to STZ. STZ is an alkylating agent that kills the insulin producing beta cells in the pancreas, resulting in a state that resembles the end stage of type 1 diabetes.
A “scid beige” mouse expresses the same scid mutation found in NSG™, along with the “beige” mutation that impairs NK cells by reduces the degranulation capabilities. The genetic background is congenic with BALB/c. The level of immunodeficiency of a scid-beige is probably similar to NOD-scid, but not as high as NSG™. NSG™ is a better host for humanized immune systems than scid-beige. scid beige mice are not available from The Jackson Laboratory.
Most direct comparisons pertain to “humanized mice”. NSG™ is superior over other models for human CD34+ (stem cell) and PBMC (mature immune cell) engraftment. Inferior models include:
Mice with a knockout of either Rag1 or Rag2 have a very similar phenotype in the immune system (elimination of T and B cells), but they do not have the side effect of radiation/chemotherapy sensitivity. Rag1 and Rag2 knockout mice have essentially the same phenotype, and a knockout of either gene suffices to eliminate the adaptive immune system.
NSG™ and NRG (NOD.Cg-Rag1tm1Mom Il2rgtm1Wjl/SzJ, 007799) are very similar strains. NRG mice substitute the Rag1 knockout mutation for the scid mutation. The Rag1 knockout has a very similar phenotype in the immune system (elimination of T and B cells), but it does not have the scid side effect of radiation/chemotherapy sensitivity.
There is one publication comparing NSG™ to NRG in a humanized immune system model created by injection of human CD34+ stem cells. The recovery of mature human immune cells is essentially the same.
NRG mice do not have the same sensitivity to DNA damage that NSG™ mice do. NRG could be used in any application that requires especially high doses of radiation. Note that NSG™ mice do tolerate the radiation doses necessary for human hematopoietic stem cell engraftment. NSG™ mice do not tolerate radiation doses at or above 400cGy (4 Gy), while NRG mice tolerate radiation at doses up to 650 cGy. Many chemotherapies act by damaging DNA, and the scid mutation also makes a mouse more sensitive to the side effects of chemotherapies. Although In Vivo Pharmacology Services has successfully dosed NSG™ mice with many different chemotherapies (cisplatin, carboplatin, araC, and others), there may be some instances when NRG mice are preferred if the treatment remains persistently toxic to the mouse.
NSG™ mice are severely immunodeficient and unable to fight off infections. They are susceptible to infections by normal mouse pathogens, opportunistic pathogens, and even their own intestinal flora. They can become infected from injection sites, bite wounds, and any insult that punctures the skin. The most common type of infection is an ascending urinary tract infection.
Proper aseptic handling techniques are essential when working with NSG™ mice. For more details, please see the “Housing and breeding considerations for NSG™ mice” the FAQ section on this page.
Yes, assuming that they are maintained in a sufficiently clean environment. Poor breeding performance can indicate an infection. For more details, please see the “Housing and breeding considerations for NSG™ mice” the FAQ section on this page.
We do not maintain NSG™ mice on antibiotics at The Jackson Laboratory. We find that strict adherence to proper husbandry and handling practices can prevent the introduction of pathogens to the mice, and ensure their long-term survival.
PBMCs (“peripheral blood mononuclear cells”) include mature lymphocytes (B, T, NK cells), monocytes and macrophages. When injected in the NSG™ mouse, PBMCs either remain in circulation (T cells), or die/migrate to other tissues (all other cell types). They are collected from a blood donation, usually from healthy donors, but can be from diseased or sick patients.
Treatment with radiation (usually from an X-irradiator or a cesium source) is a prerequisite for efficient colonization of mouse bone marrow by human hematopoietic stem cells. Irradiation works by killing the mouse stem cells and opening the bone marrow niche, and also by inducing expression of cytokines like Kit ligand (also known as stem cell factor, or SCF). The preconditioning irradiation dose depends on the age of the mouse and often needs to be optimized in every laboratory. Newborn mice tolerate lower doses than juvenile or adult mice.
Yes, through In Vivo Pharmacology Services.
CD45+ cells (mature white blood cells) have been detected in the peripheral blood as long as one year after injection with CD34+ hematopoietic stem cells. In the experience of JAX In Vivo Pharmacology Services, there are no signs of graft-versus-host disease when T-cell-depleted stem cells are sourced from cord blood in mice for up to one year post-engraftment.
The different cell types that make up the lymphoid and myeloid lineages are present within humanized NSG™ mice, and there is a significant amount of effort going into understanding how functional they are. Here’s a summary of some key findings:
To function in a vaccine model, the human T cells in the mouse must be able to interact efficiently with human antigen presenting cells, such as dendritic cells. This phenomenon is known as “HLA restriction” (HLA is the human counterpart to the mouse MHC). Unless the human T cells have developed in a transgenic mouse expressing human HLA, or in a mouse with a human thymus implant, then the interactions are not efficient, and the humanized immune system is probably not capable of mounting an efficient immune response to a vaccination.
Expression of human MHC (“HLA”) class I improves the function of cytotoxic T cells (CD8+ cells). This is useful for studies involving infectious diseases that infect human immune cells (Epstein-Barr virus, for example), because this response is largely control by cytotoxic T cells. NOD.Cg-Prkdcscid Il2rgtm1Wjl Tg(HLA-A2.1)1Enge/SzJ (Stock # 009617) and NOD.Cg-Prkdcscid Il2rgtm1Wjl Tg(HLA-A/H2-D/B2M)1Dvs/SzJ (Stock # 014570) are two strains that express the HLA-A2.1 class I haplotype.
Expression of human MHC (“HLA”) class II improves the function of helper T cells (CD4+ cells). This should be useful for vaccine studies. NOD.Cg-Prkdcscid Il2rgtm1Wjl Tg(HLA-DRA*0101,HLA-DRB1*0101)1Dmz/GckRolyJ (Stock # 012479) and NOD.Cg-Prkdcscid Il2rgtm1Wjl H2-Ab1tm1Gru Tg(HLA-DRB1)31Dmz/SzJ (Stock # 017637) are two examples. The second strain does not express the endogenous mouse MHC class2 complex.
No. Only hematopoietic stem cells require preconditioning irradiation for efficient engraftment. Irradiation accelerates the GVHD response.
Below is a list of publications that describe protocols and considerations for creating humanized NSG™ mice. Pearson, et al. 2008 is especially recommended.
From the most highly immunodeficient mouse available— NSG™ (005557) - to nude mice (002019), the JAX immunodeficient suite of mice are powerful xenograft models for studying solid and hematopoietic tumors, cancer stem cells, hematopoeisis, humanized mice and infectious disease.
|Name & Stock Number||
Il2rgtm1Wjl Tg(CMV-IL3,CSF2,KITLG)1Eav/MloySzJ (013062)
|Common name||NSG™, NOD scid gamma||NRG, NOD Rag gamma||NSGS, NOD scid gamma Il3- GM-SF (NSG-SGM3)||NOD scid|
|Mature B cells||Absent||Absent||Absent||Absent|
|Mature T cells||Absent||Absent||Absent||Absent|
|Natural killer cells||Absent||Absent||Absent||Defective|
|Lymphoma incidence||Low||Low||Low||High (thymic lymphoma)|
|Median survival||> 89 weeks||Not determined||Not determined||36 weeks|
|References||Shultz et al. 1995|
|Name & Stock Number||
||B6.129S7-Rag1tm1Mom/J (002216)||J:NU (007850)||NU/J (002019)|
|Common name||BALB scid||B6 Rag1||Nude||Nude|
|Mature B cells||Absent||Absent||Present||Present|
|Mature T cells||Absent||Absent||Absent||Absent|
|Natural killer cells||Present||Present||Present||Present|
|Lymphoma incidence||High (thymic lymphoma)||Low||Low||Low|
|Median survival||Not determined||Not determined||Not determined||Not determined|
|References||Nonoyama et al. 1993||Mombaerts et al. 1992||Kelland LR. 2004||Kelland LR. 2004|
NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (005557)
The most powerful immunodeficient model that has changed the face of oncology, stem cell and infectious disease research.