Interferences between dinitrophenyl and azobenzenearsonate determinant on in vitro binding to lymphoid cells I. Effect of the heterologous conjugate on the specific binding to a population of spleen cells from normal or immunized mice

Abstract

Specific binding of dinitrophenyl (DNP) and azobenzenearsonate (ARS) determinants in vitro on the surface of spleen cells from normal and immunized mice of strains CBA and BALB/c, were determined by using hapten-coupled bacteriophage T 4 (DNP-T 4 and ARS-T 4). Derivatives of ARS with poly- L-tyrosine, ARS-P (Tyr), and with human serum albumin (ARS-HSA), partially inhibited the binding of DNP-T 4 when added to the cells either before or concomitantly with the DNP-coupled bacteriophage. In a “reverse situation,” a conjugate of DNP with HSA and DNP-epsilon aminocaproic acid inhibited the binding of ARS-T 4 to the cells when added to the cell-phage mixture. Inhibition of hapten-T 4 binding by a heterologous conjugate (ARS or DNP) was found to occur in spleen cell populations derived either from normal or immunized mice. The conjugates ARS 65-HSA and ARS-p(Tyr) were also able to release a certain proportion of DNP-T 4 already bound to the cells derived from normal mice (elution effect). Alternatively, the DNP derivatives released a certain amount of ARS-T 4 bound to spleen cells from normal mice. However, the elution effect was not observed in the case of spleen cells from mice immunized with either DNP or ARS conjugate. HSA alone had no effect on the binding of hapten T 4 (DNP or ARS) or on dissociation of bound hapten-T 4 from the cells. No such inhibitory effect by a heterologous conjugate was exerted on free-circulating antibodies; the development of anti-DNP titers was not affected by the addition of an ARS-conjugate to the mixture of mouse anti-DNP serum and the corresponding antigen.