Regulatory functions of hapten-reactive helper and suppressor T lymphocytes. II. Selective inactivation of hapten-reactive suppressor T cells by hapten-nonimmunogenic copolymers of D-amino acids, and its application to the study of suppressor T-cell effect on helper T-cell development.
An experimental condition was established in vivo for selectively eliminating hapten-reactive suppressor T-cell activity generated in mice primed with a para-azobenzoate (PAB)-mouse gamma globulin (MGG)-conjugate and treated with PAB-nonimmunogenic copolymer of D-amino acids (D- glutamic acid and D-lysine; D-GL). The elimination of suppressor T-cell activity with PAB-D-GL treatment from the mixed populations of hapten- reactive suppressor and helper T cells substantially increased apparent helper T-cell activity. Moreover, the inhibition of PAB-reactive suppressor T-cell generation by the pretreatment with PAB-D-GL before the PAB-MGG-priming increased the development of PAB-reactive helper T-cell activity. The analysis of hapten-specificity of helper T cells revealed that the reactivity of helper cells developed in the absence of suppressor T cells was more specific for primed PAB-determinants and their cross-reactivities to structurally related determinants such as meta-azobenzoate (MAB) significantly decreased, as compared with the helper T-cell population developed in the presence of suppressor T lymphocytes. In addition, those helper T cells generated in the absence of suppressor T cells were highly susceptible to tolerogenesis by PAB-D- GL. Similarly, the elimination of suppressor T lymphocytes also enhanced helper T-cell activity in a polyclonal fashion in the T-T cell interactions between benzylpenicilloyl (BPO)-reactive T cells and PAB- reactive T cells after immunization of mice with BPO-MGG-PAB. Thus inhibition of BPO-reactive suppressor T-cell development by the BPO-v-GL- pretreatment resulted in augmented generation of PAB-reactive helper T cells with higher susceptibility of tolerogenesis to PAB-D-GL. Thus, these results support the notion that suppressor T cells eventually suppress helper T-cell activity and indicate that the function of suppressor T cells related to helper T-cell development is to inhibit the increase in the specificity and apparent affinity of helper T cells in the primary immune response. The hapten-reactive suppressor and helper T lymphocytes are considered as a model system of T cells that regulate the immune response, and the potential applicability of this system to manipulating various T cell-mediated immune responses is discussed in this context.
D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D001391:Azo Compounds / Q000276:immunology; D001565:Benzoates / Q000276:immunology; D004140:Dinitrophenols / Q000276:immunology; D005971:Glutamates / Q000276:immunology; D006241:Haptens; D006433:Hemocyanins / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007108:Immune Tolerance; D007114:Immunization; D008239:Lysine / Q000276:immunology; D051379:Mice; D010400:Penicillin G / Q000031:analogs & derivatives / Q000276:immunology; D013489:Suppression, Genetic; D013601:T-Lymphocytes / Q000276:immunology*; D005719:gamma-Globulins / Q000276:immunology
D001391:Azo Compounds; D001565:Benzoates; D004140:Dinitrophenols; D005971:Glutamates; D006241:Haptens; D005719:gamma-Globulins; D006433:Hemocyanins; D008239:Lysine; D010400:Penicillin G