Cytolytic function for pseudorabies virus-stimulated porcine CD4+ CD8dull+ lymphocytes.
We previously observed that pseudorabies (PRV) virus-specific killing in vitro was mediated by CD6+ CD8+ lymphocytes. Also a high percentage of CD4+ lymphocytes, among these CD6+ CD8+ lymphocytes, was observed. The purpose of this study was, therefore, to further characterize the killing ability of PRV-stimulated CD4+ CD8+ lymphocytes. Peripheral blood mononuclear cells (PBMC) were isolated from blood of PRV-immune pigs and were stimulated in vitro with PRV. After 6 days, the frequency of CD4+ CD8+ lymphocytes in peripheral blood was determined by flow cytometry analyses. Lymphocytes were separated using a magnet-activated cell sorter or a FACSVantage SE, and the cytolytic activity of the isolated populations was determined. Flow cytometry analyses demonstrated that PRV stimulation of immune PBMC resulted in the occurrence of 26% +/- 4% CD4+ CD8dull+ lymphocytes. We further demonstrated that killing by PRV-stimulated PBMC was mediated by CD4+ CD8dull+ T lymphocytes and CD4- CD8+ T lymphocytes (classic cytolytic T lymphocytes and natural killer cells). The CD4+ CD8dull+ T lymphocytes showed major histocompatibility complex (MHC) II-restricted PRV-specific killing. The CD4- CD8+ T lymphocytes showed both PRV-specific and natural killing. The CD4+ CD8dull+ lymphocytes, which are unique in the pig, seemed to have a more heterogeneous function than was earlier demonstrated. In conclusion, we demonstrated that PRV-specific CD4+ CD8dull+ lymphocytes are able to kill PRV-infected target cells in a MHC II-restricted manner.
De Bruin
T G
TG
Department of Mammalian Virology, Institute for Animal Science and Health, Lelystad, The Netherlands. m.g.m.debruin@ID.WAG-UR.NL
Van Rooij
E M
EM
De Visser
Y E
YE
Bianchi
A T
AT
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002461:Cell Line, Transformed; D002469:Cell Separation; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D011558:Herpesvirus 1, Suid / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology; D013552:Swine; D013556:Swine, Miniature; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II