Targeted disruption of the MHC class II Aa gene in C57BL/6 mice.

摘要: The MHC class II gene Aa was disrupted by targeted mutation in embryonic stem (ES) cells derived from C57BL/6 mice to prevent expression of molecules. Contrary previous reports, the effect null-mutation on T cell development investigated mice, which provide a defined genetic background. complete lack surface molecules B6-Aa0/Aa0 homozygous mutant directly demonstrated cytofluorometric analysis using anti-Ab and anti-Ia specific mAbs. Development CD4+CD8- thymus largely absent except for small population thymocytes expressing high levels CD4 together with low amounts CD8. majority these express TCR at density. Although mature were undetectable thymus, some CD4+CD8-TCRhigh phenotype found lymph nodes spleen. Peripheral can be polyclonally activated vitro mitogen concanavalin A. However, they could not stimulated staphylococcal enterotoxin B autologous lymphocyte reactions, thereby demonstrating absence mice. mutants functional responded independent antigen levan production antigen-specific IgM antibodies similar wild-type cells. described this study represent an important tool investigate involvement maturation immune response.