Cd28 (CD28 antigen)
CD28 (Cluster of Differentiation 28) is one of the proteins expressed on T cells that provide co-stimulatory signals required for T cell activation and survival. T cell stimulation through CD28 in addition to the T-cell receptor (TCR) can provide a potent signal for the production of various interleukins (IL-2 and IL-6 in particular). CD28 is the only B7 receptor constitutively expressed on naive T cells. Association of the TCR of a naive T cell with MHC: antigen complex without CD28:B7 interaction results in a T cell that is anergic. Agonistic antibodies targeting CD28 have entered clinical trials.
Protein expression analysis
Fig 1. Splenocytes from both wild type (WT) C57BL/6 and heterozygous B-hCD28 mice were analyzed by flow cytometry.
Mouse CD28+ T cells were detected in both WT C57BL/6 and heterozygous B-hCD28 mice, while human CD28+ T cells were only detected in the heterozygous B-hCD28 mice.
B-hCD28 model evalution
Fig2. C57BL/6 and B-hCD28 mice were immuned by hPDL1 recombination protein with CFA . No significant difference was detected, indicating that the B7-1/CD28 co-stimulating signaling pathway was normal in hCD28 mice. Chimera of CD28 had efficient activity.