Monocytes and gammadelta T cells: close encounters in microbial infection.
gammadelta T cells comprise an evolutionarily conserved yet poorly understood subset of T cells. Numerous features place these unconventional lymphocytes at the branching point between antigen-presenting cells and natural killer cells of the innate immune system and major-histocompatibility-complex-restricted alphabeta T cells of the adaptive immune system. We propose a role for human Vgamma9/Vdelta2 T cells in the generation of monocyte-derived inflammatory dendritic cells during infection. Our model incorporates the peculiar innate-like specificity of Vgamma9/Vdelta2 T cells for the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), co-recruitment of monocytes and Vgamma9/Vdelta2 T cells to sites of infection, and their crosstalk, with profound consequences for the initiation of antigen-specific alphabeta T-cell responses. Vgamma9/Vdelta2 T cells act thus as a cellular switch between innate and adaptive defence mechanisms.
Department of Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom. eberlm@cf.ac.uk
Matthias
M
Eberl
Bernhard
B
Moser
D056704:Adaptive Immunity; D001424:Bacterial Infections / Q000276:immunology* / Q000473:pathology; D002450:Cell Communication / Q000276:immunology*; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000378:metabolism / Q000473:pathology; D011756:Diphosphates / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
C443995:4-hydroxy-3-methylbut-2-enyl pyrophosphate; D011756:Diphosphates; D016692:Receptors, Antigen, T-Cell, gamma-delta