Methods: We isolated the CD4+ T cells from C57BL/6 mice using magnetic bead column to investigate the function of B7-H3 on murine CD4+ T cells. The CD4+T cells were activated on 0.6 μg/ml CD3 antibody coated cell culture plate and treated with B7-H3 peptide. Cell proliferation was measured by MTT assay and the mRNA level of IL-2 (Interleukin-2) was determined by PCR analysis. And then, to profile the promising target genes of B7-H3 activity, we performed the microarray analysis.
Results: CD3-activated CD4+ T lymphocyte showed the increases in proliferation and IL-2 mRNA level, however, treatment of B7-H3 on activated T lymphocyte reduced the cell proliferation and increased IL-2 mRNA level. In microarray analysis, 4 common genes were altered by treatment of B7-H3 on T lymphocyte and the expression levels of 4 common genes were confirmed by quantitative Real-time PCR. The mRNA expression levels of 2 genes were decreased, but another 2 common genes were increased by B7-H3 in T lymphocyte.
Conclusions: These results shows B7-H3 can modulate the T lymphocyte immune responses in vitro and we need further studies to verify the mechanism of the effect of B7-H3 on T lymphocyte.
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