MITOGENIC RESPONSE OF T-CELL SUBCLASSES TO AGAROSE-LINKED AND TO FREE RIBONUCLEOTIDES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (3) , 451-457
Abstract
Thymocytes [from mice] incubated with ATP or GTP exhibit a brief period of enhanced DNA synthesis in contrast to the prolonged period of enhanced synthesis observed when thymocytes were incubated with concanavalin A. The cells responding to nucleotides represent a sub-population of .theta. antigen-bearing T cells comprising approximately 2% of the total thymocyte population as judged by a combined immunofluorescent/autoradiographic analysis. Thymocytes responsive to ATP and GTP are sensitive to cortisone, suggesting that they are relatively immature T cells. ATP-responsible cells also preferentially aggregate with immature T cells when incubated with peanut agglutinin. GTP-responsive cells do not. Nucleotides rendered insoluble by linkage to agarose via the ribose moiety are more active mitogenically at lower concentrations than soluble nucleotides or nucleotides linked to agarose via the nucleic acid base. The mitogenic response of thymocytes to nucleotides may be limited to as little as a single round of DNA synthesis; such mitogenesis is probably stimulated at a site located on the plasma membrane.