Recognition of the beta-2 microglobulin-B molecule by a CTL clone.

In this report we offer evidence that the beta-2 microglobulin-B (beta 2M-B) molecule is recognized by a cytotoxic T lymphocyte (CTL). Production of GA5, a CTL clone reactive against a membrane antigen with the same strain distribution pattern as beta 2M-B, is described. This clone lysed syngeneic target cells in which native beta 2M-A molecules had been exchanged with beta 2M-B molecules by incubating the cells in serum from beta 2M-B-positive mouse strains. Conversely, the CTL clone GA5 failed to lyse its specific target when beta 2M-B molecules had been exchanged with beta 2M-A molecules by incubating the cells in serum from beta 2M-A-positive, beta 2M-B-negative mouse strains. Strain combinations were chosen so as to limit reactivity to beta 2M and to preclude reactivity to H-3 antigens, thus indicating CTL clone GA5 to be reacting specifically with beta 2M-B.