Suppression of mouse skin allograft rejection by protein A-Yersiniae V antigen fusion peptide

V antigen is an established virulence factor of Yersinia pestis, the causative agent of bubonic plague. Injection of homogenous staphylococcal protein A-V antigen fusion peptide into mice was previously found to suppress tumor necrosis factor-α and interferon-γ necessary for generation of protective granulomas. Here, we show that BALB/c mice receiving daily intraperitoneal injections of 100 μg of control protein A initiated rejection of C57BL/6 mouse tail skin grafts after 6.2±1.1 days. This time doubled to 12.2±1.4 days upon similar administration of protein A-V antigen fusion peptide (P<0.001); times of total allograft retention remained constant. This finding indicates that V antigen can postpone inflammation known to be associated with recognition and destruction of foreign tissue by T lymphocytes.