Direct presentation of nonpeptide prenyl pyrophosphate antigens to human gamma delta T cells.
Human V gamma 2V delta 2+ T cells recognize mycobacterial nonpeptide antigens, such as isopentenyl pyrophosphate, and their synthetic analogs, such as monoethyl phosphate, through a TCR-dependent process. Here, we examine the presentation of these antigens. V gamma 2V delta 2+ T cells recognized secreted prenyl pyrophosphate antigens in the absence of other accessory cells but, under such conditions, required T cell-T cell contact. Recognition required neither the expression of classical MHC class I, MHC class II, or CD1a, CD1b, and CD1c molecules, nor MHC class I or class II peptide loading pathways. Fixed accessory cells also presented the prenyl pyrophosphate antigens to gamma delta T cells. Thus, in contrast with the presentation of conventional peptide antigens, protein antigens, and superantigens to alpha beta T cells, prenyl pyrophosphate antigens are presented to gamma delta T cells through a novel extracellular pathway that does not require antigen uptake, antigen processing, or MHC class I or class II expression. This pathway allows for the rapid recognition of bacteria by gamma delta T cells and suggests that gamma delta T cells play a role in the early response to bacterial infection.
Morita
C T
CT
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Beckman
E M
EM
Bukowski
J F
JF
Tanaka
Y
Y
Band
H
H
Bloom
B R
BR
Golan
D E
DE
Brenner
M B
MB
D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000276:immunology*; D002460:Cell Line; D011756:Diphosphates / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D000942:Antigens, Bacterial; D011756:Diphosphates; D016692:Receptors, Antigen, T-Cell, gamma-delta