Idiotypic Lymphocytes in the Rabbit: Occurrence and Nature of Idiotypic Lymphocytes in Normal and Hyperimmunized Rabbits

Abstract

Rabbits were hyperimmunized with Micrococcus Pysodeicticus, leading to homogeneous antibody responses. Peripheral blood lymphocytes were taken from the rabbits before and monthly (during 3 months) after the start of the immunization. The cells were stored frozen. Lymphocytes were tested with anti-idiotypic conjugates for the presence of surface idiotypic structures. The nature of the idiotype-positive cells was determined with respect to the presence of IgM or T-cell antigenic determinants on their surface. A sharp rise and fall in the percentage of idiotypic lymphocytes was found, ranging between 1/40,000 and 1/1,000. Initially almost all idiotypic lymphocytes were IgM-positive. In the blood taken 2 months after the start of the immunization 20% of the idiotypic cells belonged to the T-cell population and 10% were negative for both IgM and T-cell antigenic determinants.

Cellular expression of idiotopes defined by monoclonal antibodies

“…Id' but hapten (NP) nonbinding antibodies have also been reported by Takemori et al [14]. Our results compare favorably with respect to the frequency of Id-bearing lymphocytes in adult rabbits [15] and in mice investigated by both direct lymphocyte surface expression or in functional assays [16-191. Our panel of mAb do not appear to express specificities directed to putative rnitogen receptors of B cells which are not clonally restricted [20]. Theoretically, positive IF staining might be caused by antigen-binding B or T cells, recognizing the Id of the mAb used or by anti-anti-Id antibodies (Ab3).…”