NKG-MHC I/II dKO Mice

Catalog Number: C001559

Strain Name: NOD.Cg-Prkdcscid Il2rgem1cyaB2mem1cyaH2-Ab1em1cya/Cya

Genetic Background: NKG

Reproduction: Homozygote x Homozygote

 

Strain Description

NKG mice are a type of severe immunodeficient mouse developed by Cyagen by deleting the Il2rg gene from the NOD-Scid strain. This strain lacks mature T, B, and NK cells, has reduced complement activity, and weak macrophage phagocytosis of human cells. As a result, NKG mice can efficiently engraft human hematopoietic stem cells (HSC), peripheral blood mononuclear cells (PBMC), patient-derived xenografts (PDX), or adult stem cells and tissues.

In the field of immunology research, there are differences between humans and mice in terms of physiology and immune systems, so research conducted directly on mice cannot fully reflect the human situation. By transplanting human peripheral blood mononuclear cells (PBMC) or human hematopoietic stem cells (HSC) into immunodeficient mice, the mouse’s immune system is partially or completely replaced by the human immune system, allowing for the simulation of human immune system function in vivo. PBMC transplantation into NKG mice has the advantages of high immune reconstitution efficiency and fast speed. However, due to the mismatch between human immune cells and mouse MHC molecules, graft-versus-host disease (GvHD) occurs, where transplanted human immune cells (including T cells, B cells, and NK cells) attack mouse tissues, causing inflammation and tissue damage, ultimately leading to rapid death of the mouse.

The B2M gene encodes β2-microglobulin, a serum protein that exists on the surface of almost all nucleated cells in conjunction with the major histocompatibility complex (MHC) class I heavy chain. It is an essential component for the transport of MHC class I proteins to the cell surface. Studies have shown that knocking out the B2m gene in immunodeficient mice can lead to a lack of MHC class I molecule expression, thereby reducing graft-versus-host disease (GvHD) [1-2]. In mice, MHC is commonly referred to as the H-2 complex. The H2-Ab1 gene encodes a part of the mouse MHC class II molecules. This complex is primarily present on the surface of antigen-presenting cells such as macrophages, dendritic cells, and B cells. It plays a crucial role in presenting fragments of foreign substances, such as bacteria or viruses, to helper T cells (CD4+ T cells). This antigen presentation is a fundamental step in initiating adaptive immune responses. Studies have shown that transplanting PBMCs into MHC II-deficient mice can prevent lethal graft-versus-host disease (GvHD) caused by CD4+ T cells [3-4].

NKG-MHC I/II dKO mice were obtained by crossing NKG B2m KO mice (catalog No. C001416) with NKG-H2-Ab1 KO mice (catalog No. C001498), which were effective in delaying the onset of graft-versus-host disease (GvHD). This model can be used for long-term studies of PBMC immune system reconstitution.

Strain Strategy

Obtained by crossing NKG B2m KO mice (catalog No. C001416) with NKG-H2-Ab1 KO mice (catalog No. C001498).

Application

  • Establishment of humanized immune system mouse model;
  • Research on graft-versus-host disease (GvHD);
  • Research on the immune system, hematopoietic system, and blood disease;
  • Cell line-derived xenograft (CDX) and drug screening and efficacy evaluation;
  • Patient-derived xenograft (PDX) and drug screening and efficacy evaluation.

Validation Data

1. Body weight changes in NKG-MHC I/II dKO mice after PBMC transplantation


Figure 1. Weight change curves of NKG mice and NKG-MHC I/II dKO mice after PBMC transplantation. NKG-MHC I/II dKO mice showed longer lifespan and better growth status after transplantation compared with NKG mice.


2. GvHD scores in NKG-MHC I/II dKO mice after PBMC transplantation in vivo


Figure 2. Comparison of GvHD scores between NKG mice and NKG-MHC I/II dKO mice after PBMC transplantation. Compared with NKG mice, NKG-MHC I/II dKO mice significantly delayed the onset and reduced the severity of GvHD, and prolonged the experimental window after transplantation.


3. Reconstitution of human-derived CD45 and T cells after PBMC transplantation


Figure 3. Proportion of human CD45+ cells and human CD3 cells in NKG mice and NKG-MHC I/II dKO mice after PBMC transplantation. The FACS results showed that the average proportion of human CD45+ cells in NKG-MHC I/II dKO mice exceeds 40% in the 3rd week after transplantation*, and the content of human CD45+ cells gradually declined in the later stage. The reconstruction of the immune system on NKG mice and NKG-MHC I/II dKO mice after PBMC transplantation were both dominated by T cells and the T cell reconstruction trends were consistent.

*The rate of reconstitution of human CD45+ cells was affected by the individual variability of donor cells, and the reconstitution efficiency varied among PBMC donors.


4. Reconstitution of human CD4+ T cells and CD8+ T cells after PBMC transplantation


Figure 4. Distribution of human T cell subsets in NKG mice and NKG-MHC I/II dKO mice after PBMC transplantation. NKG mice and NKG-MHC I/II dKO mice could successfully reconstitute CD4+ T cells and CD8+ T cells after PBMC transplantation, and the reconstruction trends were consistent.

 

 

References

[1] Yaguchi T, Kobayashi A, Inozume T, Morii K, Nagumo H, Nishio H, Iwata T, Ka Y, Katano I, Ito R, Ito M, Kawakami Y. Human PBMC-transferred murine MHC class I/II-deficient NOG mice enable long-term evaluation of human immune responses. Cell Mol Immunol. 2018 Nov;15(11):953-962.
[2] Cogels MM, Rouas R, Ghanem GE, Martinive P, Awada A, Van Gestel D, Krayem M. Humanized Mice as a Valuable Pre-Clinical Model for Cancer Immunotherapy Research. Front Oncol. 2021 Nov 18;11:784947.
[3] Koyama M, Mukhopadhyay P, Schuster IS, Henden AS, Hülsdünker J, Varelias A, Vetizou M, Kuns RD, Robb RJ, Zhang P, Blazar BR, Thomas R, Begun J, Waddell N, Trinchieri G, Zeiser R, Clouston AD, Degli-Esposti MA, Hill GR. MHC Class II Antigen Presentation by the Intestinal Epithelium Initiates Graft-versus-Host Disease and Is Influenced by the Microbiota. Immunity. 2019 Nov 19;51(5):885-898.e7.
[4] L Covassin, J Laning, R Abdi, D L Langevin, N E Phillips, L D Shultz, M A Brehm, Human peripheral blood CD4 T cell-engrafted non-obese diabetic-scid IL2rγnull H2-Ab1 tm1Gru Tg (human leucocyte antigen D-related 4) mice: a mouse model of human allogeneic graft-versus-host disease, Clinical and Experimental Immunology, Volume 166, Issue 2, November 2011, Pages 269–280.