Antigens of activated rat T lymphocytes including a molecule of 50,000 Mr detected only on CD4 positive T blasts.
Mouse monoclonal antibodies (MAbs) have been prepared against rat T cell blasts. One MAb called MRC OX-40 recognized an antigen that differed from any previously described in that its expression was detected only on T blasts that also expressed the CD4 antigen. The OX-40 MAb did not detect an activation determinant of CD2 or CD4 molecules but recognized a distinct chain of mol. wt 50,000. The OX-40 MAb augmented T cell proliferation at late stages on in vitro responses. Other MAbs without obvious counterparts in other species were MRC OX-48 and MRC OX-49,50 which recognized cell surface molecules of mol. wts of about 95,000 and 90,000, respectively. The OX-48 antigen was not expressed on resting lymphocytes but was found on a subset of T and B blasts and also on other leucocytes. The OX-49,50 antigen was found on most haemopoietic cells but was expressed at greatly increased levels after lymphocyte activation and this was also the case for MRC OX-47 antigen which is of unknown Mr. The MRC OX-39 MAb was found to bind the rat IL-2 receptor; expression of this antigen was detected on thymic dendritic cells as well as on T blasts. The phenotype of rat T blasts compared to resting cells was also examined and changes in expression of L-CA, Thy-1, OX-2 and CD8 antigens were seen in addition to the changes found with the above MAbs.
Paterson
D J
DJ
MRC Cellular Immunology Unit, Sir William Dunn School of Pathology, University of Oxford, U.K.
Jefferies
W A
WA
Green
J R
JR
Brandon
M R
MR
Corthesy
P
P
Puklavec
M
M
Williams
A F
AF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis*; D002455:Cell Division; D003208:Concanavalin A / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D007124:Immunoenzyme Techniques; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D003208:Concanavalin A