Plasmodium falciparum stimuli for human gamma delta T cells are related to phosphorylated antigens of mycobacteria

The presence in Plasmodium falciparum of a mitogenic factor for the major human blood gamma delta T-cell subset has been known for years. These gamma delta T cells bearing T-cell receptor V gamma 9 and V delta 2 variable regions also respond to Mycobacterium tuberculosis, through recognition of several phosphorylated nonpeptidic antigens. In this study, we undertook a better characterization of the malarial stimulus and show that the polyclonal activation of V gamma 9/V delta 2 gamma delta T cells by P. falciparum schizonts is also and exclusively attributable to two phosphorylated malarial compounds. The finding of such stimuli in eukaryotic cells evidence an antigenic link between intracellular parasites as different as Plasmodium and Mycobacterium species. Hence, phosphorylated antigens could be involved in a common pattern of transdisease T-cell responses against various human pathogens.