Functional characteristics of 197+ CD4- CD8- sheep T lymphocytes: expansion and differentiation of peripheral T cells.
This report describes the results of functional studies on the CD3+ 197+ CD4- CD8- TCR gamma/delta + peripheral T lymphocyte of sheep. Cell types were identified by immunofluorescent and immunoenzymic staining and separated by fluorescence activated flow cytometry. Newly synthesized DNA was labelled in vivo by incorporation of 5-bromo-2-deoxyuridine (BrdU), and total DNA by in vitro incubation with propidium iodide. Cells were challenged in vivo with alloantigens, in vitro with alloantigens or a range of mitogens, and activation/differentiation was assessed by determination of cell number, phenotype, and thymidine incorporation. In normal lambs the 197+ cells showed no in vivo DNA synthesis except at a low level in the ileocaecal lymph node. A similarly low level of synthesis in the prescapular node was induced by local allogeneic challenge. A higher proportion of 197+ cells than of other T cells isolated from blood and lymph had G2/M phase DNA content, while very few had S phase DNA content. The response of 197+ cells in terms of change in relative numbers following in vivo allogeneic challenge was quite different to that of CD4+ or CD8+ cells. Instead of rising to a peak at 5-8 days after challenge and then declining, the percentage of 197+ cells rose steadily with no evidence of decline by 14 days. Purified 197+ cells were activated in vitro by phytohaemagglutinin (PHA) and concanavalin-A (Con-A) but not by B cell mitogens; such activation was dependent on the inclusion of feeder cells or interleukin-2 (IL-2).(ABSTRACT TRUNCATED AT 250 WORDS)
McClure
S J
SJ
Basel Institute for Immunology, Switzerland.
Hein
W R
WR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002453:Cell Cycle; D002454:Cell Differentiation; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D007519:Isoantigens / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008934:Mitogens / Q000276:immunology; D010641:Phenotype; D012756:Sheep; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D007519:Isoantigens; D008934:Mitogens; D004247:DNA; D001973:Bromodeoxyuridine