CD40 (cluster of differentiation 40) is a tumor necrosis factor receptor superfamily member expressed on APC such as dendritic cells (DC), B cells, and monocytes as well as many non-immune cells and a wide range of tumors. Interaction with its trimeric ligand CD154 on activated T helper cells results in APC activation, which has been found to be essential in mediating a broad variety of immune and inflammatory responses including T cell-dependent immunoglobulin class switching, memory B cell development, and germinal center formation. Agonistic CD40 mAb have been shown to activate APC and promote anti-tumor T cell responses and to foster cytotoxic myeloid cells with the potential to control cancer in the absence of T-cell immunity. Thus, agonistic CD40 mAb may serves as a new antitumor drugs which are fundamentally different from mAb which block negative immune checkpoint such as anti-CTLA-4 or anti-PD-1.
mRNA expression analysis:
Fig 1. RT-PCR analysis of the CD40 gene. The mCD40 mRNA was detected in both wild type C57BL/6 and heterozygous B-hCD40 mice, while the hCD40 mRNA was detected only in the heterozygous B-hCD40 mice.
Protein expression analysis:
Fig 2. Splenocytes from both wild type (WT) C57BL/6 and heterozygous B-hCD40 mice were analyzed by flow cytometry. Mouse CD40+ B cells were detected in both WT C57BL/6 and heterozygous B-hCD40 mice, while human CD40+ B cells were only detected in the heterozygous B-hCD40 mice.