A new approach to obtain Lyb5-specific antiserum.

A new approach to obtain antiserum specific for Lyb5.2 allotype, was developed. Mice of DBA/2 inbred strain, bearing Lyb5.1 allotype, were made unresponsive to cellular antigens of Lyb5-CBA/N mice by specific tolerance induction. These tolerant recipients were further immunized with suspensions of splenocytes from CBA mice which contain Lyb5.2 + B lymphocytes. Thus obtained Lyb5.2-specific antiserum was cytotoxic for 25-30% of CBA or BALB/c (both Lyb5.2 + allotype) but not for CBA/N spleen cells. When splenocytes of BALB/c mice preimmunized with polyvinylpyrrolidone (T-independent type 2 antigen) were treated with this antiserum, 50% decrease in numbers of antibody-forming and antigen-induced non-specific immunoglobulin-forming cells was documented. We conclude that, during humoral immune response to T-independent type 2 antigen, not only antibody-forming cells but also non-specific immunoglobulin-forming cells are recruited from the Lyb5 + B cell pool.