Campylobacter_A_showae_A_mgs_3545 from the genus Campylobacter_A on the dorsal tongue and unclassified_mgs_2621 from the genus Granulicatella in saliva Infection with the two flora can result in local and systemic immune responses, including the activation and differentiation of CD4 + naive T cells, which, upon encountering Campylobacter_A_showae antigens displayed by antigen-presenting cells, further differentiate into helper T cells (Th1, Th2, Th17) and regulatory T cells that regulate the immune response. The gene discussed is CD4; the disease is infection.