Basic Information

Strain Name
C57BL/6-CTLA4tm1(CTLA4)Bcgen/Bcgen
Stock Number
110011
Common Name
B-hCTLA4 Mice
Source/Investigator
Bcgen (Beijing Biocytogen Co., Ltd)
Related Genes
Ctla4 (cytotoxic T-lymphocyte-associated protein 4)
Species
C57BL/6
Appearance
Black
Genotypes
Homozygous

Description

CTLA4 (cytotoxic T-lymphocyte-associated protein 4), also known as CD152, competitively binds to B7-1 (CD80) and B7-2 (CD86) on Antigen-Presenting Cells (APCs) to block the T cell activating signal by B7 and CD28 (on T cells) interaction. The inhibition of CTLA4 by its inhibitory antibodies enhances T cell activity. The CTLA4 antibody is the first FDA- approved antibody to treat advanced melanoma.

Targeting Strategy

Details

Phenotype

mRNA Expression Analysis

B-hCTLA4-Mice-mrna-expression-analysis

RT-PCR analysis of CTLA4 gene. The hCTLA4, but not mCTLA4, mRNA was detected in splenocytes of the homozygous B-hCTLA4 mice.

 

Protein Expression Analysis

Splenocytes from both wild type (WT)C57BL/6 and homozygous B-hCTLA-4 mice were analyzed by flow cytometry for the expression of CTLA4. Mouse CTLA4+ T cells were detectable in the WT mice, while human CTLA4+ T cells were detectable in the homozygous B-hCTLA4 mice.

Phenotypic analysis

Analysis of spleen leukocytes cell subpopulations in B-hCTLA4 mice

Analysis of spleen leukocyte subpopulations by FACS Splenocytes were isolated from female C57BL/6 and B-hCTLA4 mice (n=3, 6 week-old) Flow cytometry analysis of the splenocytes was performed to assess leukocyte subpopulations. A. Representative FACS plots. Single live cells were gated for CD45 population and used for further analysis as indicated here. B. Results of FACS analysis. Percent of T, B, NK, Monocyte, DC and macrophage cells in homozygous B-hCTLA4 mice were similar to those in the C57BL/6 mice, demonstrating that introduction of hCTLA4 in place of its mouse counterpart does not change the overall development, differentiation or distribution of these cell types in spleen.

Analysis of spleen T cell subpopulations in B-hCTLA4 mice

Analysis of spleen T cell subpopulations by FACS Splenocytes were isolated from female C57BL/6 and B-hCTLA4 mice (n=3, 6 week-old). Flow cytometry analysis of the splenocytes was performed to assess leukocyte subpopulations. A. Representative FACS plots. Single live CD45+ cells were gated for CD3 T cell population and used for further analysis as indicated here. B. Results of FACS analysis. Percent of CD8, CD4, and Treg cells in homozygous B-hCTLA4 mice were similar to those in the C57BL/6 mice, demonstrating that introduction of hCTLA4 in place of its mouse counterpart does not change the overall development, differentiation or distribution of these T cell sub types in spleen. Values are expressed as mean ± SEM (please confirm)

Blood routine test in B-hCTLA4 mice

Complete blood count (CBC). Blood from female C57BL/6 and B-hCTLA4 mice (n=3, 6 week-old) was collected and analyzed for CBC. There was no differences among any measurement between C57BL/6 and B-hCTLA4 mice, indicating that introduction of hCTLA4 in place of its mouse counterpart does not change blood cell composition and morphology. Values are expressed as mean ± SEM.

Blood chemistry of B-hCTLA4 mice

Blood chemistry tests of B-hCTLA4 mice. Serum from the C57BL/6 and B-hCTLA4 mice (n=3, 6 week-old) was collected and analyzed for levels of ALT and AST. There was no differences on either measurement between C57BL/6 and B-hCTLA4 mice, indicating that introduction of hCTLA4 in place of its mouse counterpart does not change ALT and AST levels or health of liver. Values are expressed as mean ± SEM.

Application

In vivo efficacy of anti-human CTLA4 antibody

Antitumor activity of anti-human CTLA4 antibody in B-hCTLA4 mice. (A) Anti-human CTLA4 antibody inhibited MC38 tumor growth in B-hCTLA4 mice. Murine colon cancer MC38 cells were subcutaneously implanted into homozygous B-hCTLA4 mice (female, 6-7 week-old, n=5). Mice were grouped when tumor volume reached approximately 100 mm3, at which time they were treated with ipilimumab with doses and schedules indicated in panel (B) Body weight changes during treatment. As shown in panel A, ipilimumab was efficacious in controlling tumor growth in B-hCTLA4 mice, demonstrating that the B-hCTLA4 mice provide a powerful preclinical model for in vivo evaluation of anti-human CTLA4 antibody. Values are expressed as mean ± SEM.

 

 

 

References

1. Cell Research (2018) 0:1–15; doi: 10.1038/s41422-018-0012-z
2. Blood.2005;106:3127-3133
3. Scientific Reports volume7, 42913 (2017) doi: 10.1038/srep42913

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