A predominance of the T cell receptor V gamma 2/V delta 2 subset in human mycobacteria-responsive T cells suggests germline gene encoded recognition.
Little is known about the nature of Ag recognition by the TCR-gamma delta. The recent observation that gamma delta T cells preferentially recognize mycobacterial Ag provides a model to examine the molecular basis of gamma delta-TCR recognition. Here, examination of the Mycobacteria-stimulated peripheral blood T cells with TCR-specific mAb revealed a predominance of T cells bearing V gamma 2/V delta 2 gene products. PCR cloning and sequence analysis of the TCR chains demonstrated extensive junctional diversity indicating that the response was polyclonal. The marked in vitro gamma delta T cell response to Mycobacteria was also detected in newborns before encounters with foreign Ag and exclusively involved the same V-gene usage observed in adults. Together, these results suggest that a major mechanism of gamma delta T cell reactivity involves recognition mediated by germline-encoded segments of the TCR.
Panchamoorthy
G
G
Laboratory of Immunochemistry, Dana-Farber Cancer Institute, Boston, MA 02115.
McLean
J
J
Modlin
R L
RL
Morita
C T
CT
Ishikawa
S
S
Brenner
M B
MB
Band
H
H
D000328:Adult; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000276:immunology*; D001483:Base Sequence; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; D006801:Humans; D007231:Infant, Newborn; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology
D000942:Antigens, Bacterial; D016692:Receptors, Antigen, T-Cell, gamma-delta; D014373:Tuberculin