Antigens of activated rat T lymphocytes including a molecule of 50,000 Mr detected only on CD4 positive T blasts

Mol Immunol. 1987 Dec;24(12):1281-90. doi: 10.1016/0161-5890(87)90122-2.


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.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Antigens, Surface / analysis*
  • Cell Division
  • Concanavalin A / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Immunoenzyme Techniques
  • Lymphocyte Activation*
  • Mice
  • Mice, Inbred BALB C
  • Molecular Weight
  • Rats
  • Rats, Inbred Strains
  • T-Lymphocytes / immunology*
  • Tumor Necrosis Factor Receptor Superfamily, Member 7


  • Antibodies, Monoclonal
  • Antigens, Surface
  • Tumor Necrosis Factor Receptor Superfamily, Member 7
  • Concanavalin A