TY - JOUR
T1 - Antigen-specific T lymphocyte clones. II. Purification and biological characterization of an antigen-specific suppressive protein synthesized by cloned T cells
AU - Fresno, M.
AU - McVay-Boudreau, L.
AU - Nabel, G.
AU - Cantor, H.
PY - 1981
Y1 - 1981
N2 - We have generated an antigen-specific T suppressor clone that synthesizes 70,000-mol wt peptides that have antigen-specific-binding activity. Although these data also indicated that antigen-binding peptides completely inhibited the in vitro primary response to a complex antigen, suppression might reflect the combined biologic activities of many different 70-mol wt polypeptides or polypeptides associated with the 70,000-mol wt material by noncovalent interactions. The protein responsible for antigen-specific suppression was therefore purified to virtual homogeneity after sequential separation of internally labeled supernate peptides on Sephacryl S-200 and DEAE-cellulose columns followed by isoelectrofocusing. The resulting protein is >95% homogenous according to sodium dodecyl sulfate-polyacrylamide electrophoresis and represents two peptides having two very close but distinguishable isoelectric point values of ~5.0. The purified molecules are retained by columns coated with lentil lectin or antigen but not by columns coated with antisera specific for immunoglobulins, the I region of the major histocompatibility complex or Ly-1 or Ly-2 antigens. Less than 50 pg of the purified glycoprotein specifically and completely suppresses production of anti-sheep erythrocyte plaque-forming cell by mixtures of 106 Ly-1 cells and B cells and this is a result of inactivation of Ly-1-mediated helper function. Specific inactivation of T (Th) cells by the 70,000-mol wt molecule is rapid, specific, and requires the presence of antigen. The mechanism of specific suppression of Th function may depend upon two functionally distinct regions of the 70,000-mol wt molecule: one that binds antigen and a second that mediates suppression.
AB - We have generated an antigen-specific T suppressor clone that synthesizes 70,000-mol wt peptides that have antigen-specific-binding activity. Although these data also indicated that antigen-binding peptides completely inhibited the in vitro primary response to a complex antigen, suppression might reflect the combined biologic activities of many different 70-mol wt polypeptides or polypeptides associated with the 70,000-mol wt material by noncovalent interactions. The protein responsible for antigen-specific suppression was therefore purified to virtual homogeneity after sequential separation of internally labeled supernate peptides on Sephacryl S-200 and DEAE-cellulose columns followed by isoelectrofocusing. The resulting protein is >95% homogenous according to sodium dodecyl sulfate-polyacrylamide electrophoresis and represents two peptides having two very close but distinguishable isoelectric point values of ~5.0. The purified molecules are retained by columns coated with lentil lectin or antigen but not by columns coated with antisera specific for immunoglobulins, the I region of the major histocompatibility complex or Ly-1 or Ly-2 antigens. Less than 50 pg of the purified glycoprotein specifically and completely suppresses production of anti-sheep erythrocyte plaque-forming cell by mixtures of 106 Ly-1 cells and B cells and this is a result of inactivation of Ly-1-mediated helper function. Specific inactivation of T (Th) cells by the 70,000-mol wt molecule is rapid, specific, and requires the presence of antigen. The mechanism of specific suppression of Th function may depend upon two functionally distinct regions of the 70,000-mol wt molecule: one that binds antigen and a second that mediates suppression.
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M3 - Article
C2 - 6166714
AN - SCOPUS:0019473392
SN - 0022-1007
VL - 153
SP - 1260
EP - 1274
JO - Journal of Experimental Medicine
JF - Journal of Experimental Medicine
IS - 5
ER -