Studies of murine lymphocytes and alloantigens: I. Ly-6 mitogen and MLR responses

Antisera to the mouse lymphocyte surface alloantigens Ly-6.1 and Ly-6.2 were used to further study the functional distribution of these antigens. After selective depletion with antiserum + rabbit complement (RC), lymph node or spleen cells from Ly-6 congenic (C3H and C3H.B6-Ly-6^b) and noncongenic strains of mice were tested for: (a) their proliferative responses to T- and B-cell mitogens; and (b) their proliferative responses to alloantigens, or ability to stimulate in the MLR. Lymphoid cells required in the proliferative responses to the mitogens leucoagglutinin, concanavalin A (Con A), lipopolysaccharide (LPS), and pokeweed mitogen (PWM) were Ly-6⁺. Lymph node responder cells in the mixed lymphocyte reaction (MLR) were also Ly-6⁺, whereas spleen stimulator cells were Ly-6^?. Treatment of lymph node cells with anti-Ly-6 sera in the absence of RC had no specific blocking effect on the response to any of these mitogens. The studies indicate that the Ly-6 antigen is a potentially valuable marker for distinguishing between functionally distinct Ly-1⁺ T-cell subsets.