Differential expression of CD8 epitopes amongst porcine CD8-positive functional lymphocyte subsets.
The swine is a useful model for immunobiological studies as it has a highly heterogeneous lymphocyte pool, containing several subsets not easily accessible in humans and rodents. In particular, the CD8-positive (CD8+) cells contain a variety of lymphocyte subsets, such as alpha beta-T cells, gamma delta-T cells, CD4 CD8 double-positive (DP) cells and natural killer (NK) cells. In order to define these subsets further, we have selected four monoclonal antibodies (mAb) with differential reactivity on CD8+ cells. Thus, mAb CD8.1 (PPT20) bound to CD8hi and CD8lo subpopulations in a similar way to the conventional anti-CD8. The mAb CD8.2 (PPT21), though binding to all of the CD8+ cells, reacted preferably with CD8hi. Two other mAb, CD8.3 (PPT22) and CD8.4 (PPT23), were specific for CD8hi alpha beta-T-cell subpopulation. These results, complemented by immunoprecipitation, co-modulation and enzyme-linked immunosorbent assay experiments, suggest that CD8.1 and CD8.2 react putatively with the CD8 alpha-chain and CD8.3 and CD8.4 with the CD8 beta-chain. Tissue distribution studies revealed that CD8+ thymocytes and peripheral CD8hi alpha beta-T cells expressed both putative CD8 alpha- and beta-chains while peripheral CD4+ CD8+ alpha beta-T cells, CD8lo gamma delta-T cells and NK cells expressed only putative CD8 alpha-chain. Functional studies indicated that the CD8hi alpha beta-T and CD8lo gamma delta-T cells were effector cells in the CD3-redirected cytotoxicity.
Yang
H
H
Immunology Division, BBSRC Institute for Animal Health, Pirbright, Surrey, UK.
Parkhouse
R M
RM
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D000939:Epitopes / Q000032:analysis*; D005260:Female; D008297:Male; D011233:Precipitin Tests; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis; D013552:Swine / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta