Human lymphocytes bearing T cell receptor gamma/delta are phenotypically diverse and evenly distributed throughout the lymphoid system.
A direct quantitative and phenotypic cytofluorographic analysis of TCR-gamma/delta+ lymphocytes as well as an immunohistologic study of their tissue distribution and microanatomy was made possible by the availability of two mAbs (anti-TCR-delta 1 and anti-C gamma M1) specific for framework determinants on human TCR gamma and delta chains, respectively. TCR-gamma/delta+ lymphocytes, ranging between greater than 0.5 and 16% of CD3+ cells, were found in fetal and postnatal thymus, fetal and adult peripheral lymphoid organs, and adult peripheral blood. While TCR-gamma/delta+ lymphocytes comprised a small subpopulation of T cells (mean, approximately 4%) occasionally greater than 10-16% of CD3+ cells expressed TCR-gamma/delta. Virtually all TCR-gamma/delta+ thymocytes/lymphocytes expressed CD7, CD2, and CD5 but were heterogeneous with respect to their expression of CD1, CD4, CD8, CD28, CD11b, CD16, and Leu-7. Human TCR-gamma/delta+ cells populate both organized lymphoid tissues (thymus, tonsil, lymphnode, and spleen) as well as the gut- and skin-associated lymphoid systems at similar frequencies without obvious tropism for epithelial microenvironments. TCR-gamma/delta+ lymphocytes tend to be located within a given organ wherever TCR-alpha/beta+ lymphocytes are found. This study shows that TCR-gamma/delta+ lymphocytes constitute a small but numerically important, phenotypically diverse T cell population distributed throughout the body. These results support the concept that TCR-gamma/delta+ cells comprise a distinct, functionally heterogeneous, mature T cell sublineage that may substantially broaden the T cell repertoire at all immunologically relevant sites.
Groh
V
V
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Porcelli
S
S
Fabbi
M
M
Lanier
L L
LL
Picker
L J
LJ
Anderson
T
T
Warnke
R A
RA
Bhan
A K
AK
Strominger
J L
JL
Brenner
M B
MB
D000911:Antibodies, Monoclonal / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D007958:Leukocyte Count; D008221:Lymphoid Tissue / Q000166:cytology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta