In vitro cytotoxic activity of equine lymphocytes on equine herpesvirus-1 infected allogenic fibroblasts.
The objectives of this study were to: (1) develop a technique to analyze the in vitro cytotoxic activity of lymphocytes from adult horses against equine herpesvirus-1 (EHV-1) infected allogenic equine dermal fibroblasts (EDF); (2) evaluate the ability of a 72-h in vitro incubation with interleukin-2 (IL-2) to enhance the lymphocytic cytolytic activity against EHV-1 infected EDF; (3) compare the cytotoxic activity of lymphocytes isolated from pregnant mares and non-pregnant mares against EHV-1 infected EDF; (4) ascertain if any correlations existed between the percent cytotoxicity and percentage of lymphocytes phenotypically identified by five different mouse-anti-equine monoclonal antibodies; and (5) determine if any correlation existed between virus-neutralizing antibody titers and the percent cytotoxicity. Results of the study indicate that in vitro cytotoxic activity of equine lymphocytes against EHV-1 infected allogenic fibroblasts can be measured with a standard 4-h 51Cr release assay. This activity was enhanced by an in vitro incubation with IL-2. The cytolytic activity of freshly isolated lymphocytes was greater for non-pregnant than pregnant mares. However, after IL-2 stimulation the cytolytic activity was greater for lymphocytes from pregnant mares. A positive correlation was not detected between the percentage of phenotypically identified cells and the percent cytotoxicity, although several negative correlations were present. This suggests that the cytotoxic activity was either not mediated by any of the phenotypically identified cell populations or that the activity was
Edens
L M
LM
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
Crisman
M V
MV
Toth
T E
TE
Ahmed
S A
SA
Murray
M J
MJ
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic / Q000662:veterinary*; D005260:Female; D004861:Herpesvirus 1, Equid / Q000276:immunology*; D006736:Horses; D007376:Interleukin-2 / Q000494:pharmacology*; D016131:Lymphocyte Subsets / Q000276:immunology; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D009500:Neutralization Tests / Q000662:veterinary; D011247:Pregnancy
D000914:Antibodies, Viral; D007376:Interleukin-2