Dendritic Cells Internalize More Efficiently than , but Do Not Differ in Induction of Antigen-Specific T Cell Proliferation.

and are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation of anti-staphylococcal T cell responses. Therefore, we aimed to compare the ability of and to influence the essential steps in human DC activation and subsequent antigen-specific CD4 T cell proliferation, and to investigate the underlying mechanisms. Using multiple strains of both species, we observed that was internalized more effectively than by DCs but that both species were equally potent in activating these host cells, as evidenced by similar induction of DC maturation marker expression and antigen loading onto MHC-II molecules. The DCs stimulated by strains not harboring superantigen (SAg) genes or by any of the strains, induced low, likely physiological levels of T cell proliferation. Only DCs stimulated with strains harboring SAg genes induced high levels of T cell proliferation. Taken together, and do not differently affect DC activation and ensuing antigen-specific T cell proliferation, unless a strain has the capacity to produce SAgs.