B-hPVRIG mice

Basic Information

mRNA expression analysis

Species-specific PVRIG gene expression analysis in wild-type and humanized B-hPVRIG mice by RT-PCR. Murine Pvrig mRNA was detected in splenocytes isolated from wild-type (+/+) mice, while human PVRIG mRNA was exclusively detected in homozygous B-hPVRIG (H/H) mice.

Protein expression analysis

Species-specific PVRIG protein expression analysis in wild-type and humanized B-hPVRIG mice. Cardiac tissue was isolated from wild-type C57BL/6 (+/+) and homozygous B-hPVRIG (H/H) mice and analyzed by western blot using an anti-m/hPVRIG antibody. Murine and human PVRIG protein was detected in wild-type and B-hPVRIG mice.

Analysis of spleen leukocytes

Analysis of spleen leukocyte subpopulations. Splenocytes were isolated from female C57BL/6 and B-hPVRIG mice (n=3, 8-week-old). Flow cytometry analysis of the splenocytes was performed to assess leukocyte subpopulations. (A) Representative flow cytometry plots. Single live cells were gated on CD45+ cells and used for further analysis as indicated. (B) Percent of T cells, B cells, NK cells, dendritic cells, granulocytes, monocytes and macrophages in homozygous B-hPVRIG mice were similar to those in the C57BL/6 mice, demonstrating that introduction of hPVRIG in place of its mouse counterpart dose not change the overall development, differentiation or distribution of these spleen cell types. Values are expressed as mean ± SEM.

Analysis of spleen T cells

Analysis of spleen T cells. Splenocytes were isolated from female C57BL/6 and B-hPVRIG mice (n=3, 8-week-old).  Flow cytometry analysis of the splenocytes was performed to assess leukocyte subpopulations. (A) Representative flow cytometry plots. Single live CD45+ cells were gated on CD3+ T cells and used for further analysis as indicated. (B) Percent of CD4+ T cells, CD8+ T cells and Treg cells in homozygous B-hPVRIG mice were similar to those in the C57BL/6 mice, demonstrating that introduction of hPVRIG in place of its mouse counterpart does not change the overall development, differentiation or distribution of these spleen T cell subtypes. Values are expressed as mean ± SEM.

In vivo Efficacy of Anti-Human PVRIG Antibodies

Antitumor activity of anti-human PVRIG antibodies in B-hPVRIG mice. Murine colon cancer MC38 cells were subcutaneously implanted into homozygous B-hPVRIG (H/H) mice (female, 6-week-old, n=5). Mice were grouped when tumor volume reached ~100 mm³, at which time they were treated with anti-human PVRIG antibodies (COM-701, SRF-813, in house). (A) COM-701 and SRF-813 antibodies controlled tumor growth in B-hPVRIG mice, (B) without negatively impacting body weight changes. Values are expressed as mean ± SEM.

Poster

AACR 2022: Humanized PVRIG Mice: A Novel Tool for Evaluating Anti-PVRIG Immunotherapies