IgG Anti-tetanus Toxoid Antibody Research Articles

A restricted component of T cell help in pokeweed mitogen-stimulated humans peripheral blood cell cultures.

Limiting dilution analyses using human T and B cells from the peripheral blood of individuals recently (2 to 5 weeks) boosted with tetanus toxoid or a combination of diphtheria and tetanus toxoids were performed in order to investigate the specificity of T cell help during in vitro pokeweed mitogen (PWM) stimulation. Limiting numbers of irradiated T cells were added to an excess of B cells and their ability to help 1) IgG anti-tetanus toxoid antibody or 2) IgG anti-tetanus toxoid and IgG antidiphtheria toxoid antibody production were compared. The helper activity for anti-tetanus toxoid antibody production did not dilute out at the same point as help for total IgG production. Cultures were observed at limiting dilutions of added helper T cells that produced anti-tetanus toxoid IgG or anti-diphtheria toxoid IgG but not both even though a sufficient number of potential specific IgG-producing B cells were present. A distribution analysis of the IgG anti-tetanus and IgG anti-diphtheria helper T cells indicated that the two subpopulations did not segregate together. Thus in the presence of PWM, individual helper T cells appeared capable of supplying help for a restricted number of B cells.

Differential synthesis of IgM and IgG anti-tetanus toxoid antibody in vitro following in vivo booster immunization of humans

The in vitro syntheses of IgM and IgG anti-tetanus toxoid antibody by human peripheral blood leukocytes were compared prior to and at various intervals following in vivo booster immunization with soluble tetanus toxoid. Prior to booster immunization, the in vitro synthesis of IgG anti-tetanus toxoid antibody by combinations of B cells and irradiated T lymphocytes was negligible following pokeweed mitogen stimulation. Within 2 weeks after booster immunization, the quantity of IgG anti-tetanus toxoid antibody synthesized in vitro increased 5- to 20-fold. There was no comparable increase in total IgG synthesis. In contrast to the synthesis of IgG antibody, in vitro synthesis of IgM anti-tetanus toxoid antibody occurred prior to booster immunization and did not increase significantly following booster immunization. This dichotomy in anti-tetanus antibody production was further demonstrated in an individual with common variable hypogammaglobulinemia whose lymphocytes synthesized normal quantities of total IgG, IgM, and IgM anti-tetanus toxoid antibody in vitro, but failed to synthesize IgG anti-tetanus antibody following in vivo booster immunization.

Characterization of a Circulating Subpopulation of Spontaneous Antitetanus Toxoid Antibody Producing B Cells Following in Vivo Booster Immunization

Abstract The appearance of circulating B lymphocyte subpopulations responsible for the in vitro synthesis of IgG or IgM antitetanus toxoid antibody after in vivo booster immunization has been analyzed. Before booster immunization, only background levels of IgG antitetanus toxoid antibody were synthesized by B lymphocytes alone, or in combination with T cells and pokeweed mitogen, as measured by quantitative radioimmunoassay. Within 5 days after booster immunization, a population of B lymphocytes appeared within the circulation that had the capacity to synthesize IgG antitetanus toxoid antibody in the absence of T lymphocytes or pokeweed mitogen. These cells could be detected in the circulation until 10 to 12 days after immunization, and the antibody synthesized was inhibited by the inclusion of 50 µg/ml cyclohexamide in the culture medium. At the peak of this response, between 10 and 60% of the total IgG synthesized was IgG directed against tetanus toxoid. The cells responsible had a precursor frequency of up to 10-3 in the non-E-rosetting cell fraction obtained from peripheral blood and sedimented at 1 × G with velocities ranging from 4 to 11 mm/hr. The synthesis of IgM antitetanus toxoid antibody by this cell fraction was not detected. In contrast to the above B cells, lymphocytes capable of responding to pokeweed mitogen and T lymphocytes with the synthesis of IgG antitetanus toxoid antibody did not appear in the circulation until 10 days after immunization. Limiting dilution analysis of the pokeweed mitogen responsive B lymphocytes 2 to 4 weeks after booster immunization gave a precursor frequency of 1 × 10-4. In the presence of T cells and PWM, the synthesis of IgM anti-Tet remained at constant levels before and for 3 weeks post-booster immunization. These results indicate that multiple subsets of circulating B cells can be functionally defined in humans.

Anti-Idiotypic Antisera in Man

Abstract Antisera were raised in rabbits against immunosorbent-purified F(ab′)2 fragments of IgG antitetanus toxoid (TT) antibodies obtained from three different donors. The antisera were rendered idiotype specific by absorption with insolubilized TT-nontreactive F(ab′)2. The resulting anti-idiotypic antisera precipitated more than 85% of 125I-radiolabeled F(ab′)2 anti-TT and were shown to be individual specific in that they reacted only with the immunizing F(ab′)2 anti-TT and not with F(ab′)2 anti-TT derived from other donors. Anti-idiotypic antiserum inhibited binding of 125I-TT but not of 125I-DT to IgG derived from the donor of the immunizing F(ab′)2 anti-TT, but did not inhibit 125I-TT binding to IgG derived from other donors. Binding of radiolabeled TT to IgM and IgE was significantly inhibited by the anti-idiotypic antiserum, demonstrating the presence of shared idiotypic determinants on anti-TT antibody molecules belonging to the IgG, IgM, and IgE classes of immunoglobulin. Finally, binding of 125I-F(ab′)2 anti-TT to the antiidiotypic antiserum was completely inhibited by IgG derived from the same donor but only partially inhibited by a great excess of TT antigen, suggesting that the antiidiotypic antiserum is recognizing nonantigen-binding idiotypic determinants on F(ab′)2 anti-TT. The data presented demonstrate that anti-idiotypic heteroantisera can be successfully raised against human antibodies to TT, indicate minimal cross-reactivity of idiotypic determinants between unrelated individuals, and suggest the presence of nonantigen binding-idiotypic determinants on the antibody molecule.