Production and characterization of monoclonal anti-Thy-1 antibodies that stimulate lymphokine production by cytolytic T cell clones.
In an effort to derive monoclonal antibodies (mAb) which can induce production of macrophage-activating factor (MAF) by cloned murine cytolytic T lymphocyte (CTL) lines, we have fused spleen cells from a rat immunized with a CTL clone with the nonsecreting mouse myeloma X63-Ag8.653. Three mAb (designated I-22, III-5 and V-8) were found to stimulate MAF production by the immunizing CTL clone and (with a single exception) two other unrelated CTL clones. However, none of these mAb inhibited the cytolytic activity of the clones. Immunoprecipitation studies indicated that the three mAb reacted primarily with a 25-30-kDa protein which could not be distinguished from that precipitated by either a reference anti-Thy-1.2 mAb or a polyclonal rabbit anti-Thy-1 antiserum. Moreover, competition binding experiments demonstrated that the three mAb competed with each other and with the reference anti-Thy-1.2 mAb. Flow cytofluorometric analysis of the strain distribution of the molecules defined by the mAb revealed that two of the antibodies (I-22 and III-5) were directed against nonpolymorphic determinants of Thy-1, whereas V-8 mAb reacted only with Thy-1.2+ lymphocytes. One of the mAb (III-5) was also able to stimulate proliferation and interleukin 2 secretion by normal splenic T cells. Since mAb directed against a number of other surface structures on CTL clones did not stimulate MAF production, it thus appears that Thy-1 (or molecules associated with Thy-1) may play a functional role in T lymphocyte triggering.
MacDonald
H R
HR
Bron
C
C
Rousseaux
M
M
Horvath
C
C
Cerottini
J C
JC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000954:Antigens, Surface / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis*; D016215:Macrophage-Activating Factors; D051379:Mice; D051381:Rats; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D018800:Thy-1 Antigens
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D007376:Interleukin-2; D008222:Lymphokines; D016215:Macrophage-Activating Factors; D018800:Thy-1 Antigens