Characterization of rat T helper cell clones specific for Bacteroides gingivalis antigen

Abstract

During the past several years, much interest has been directed towards delineating and characterizing different subsets of T helper (Th) cells in order to understand their roles in immune processes. In this study, we report the generation of antigen-specific rat Th cell clones and their characterization in terms of phenotype, function, and lymphokine production. The clones were derived by culturing purified splenic T cells from rats immunized with the pathogen Bacteroides gingivalis with equivalent numbers of irradiated spleen cells from nonimmune rats and B. gingivalis whole-cell antigen. The clones required antigen stimulation but not exogenously added interleukin-2 for growth and were maintained in culture for approximately 6 months. The cloned T cells proliferated in response to the mitogen concanavalin A and to B. gingivalis whole-cell antigen but not to other microbial antigens. Phenotypic characterization of the cloned T cells for cell surface markers demonstrated that these cells were OX19+ W3/25+ OX8- OX22- and therefore probably represented a mature subpopulation of CD4+ Th cells. These cloned T cells were positive for interleukin-2 receptor expression. Culture supernatants from the Th cell clones which were collected at various times after antigen stimulation exhibited low interleukin-2 activity and high gamma interferon activity. This in vitro study provides evidence of a rat Th cell subset that could represent an important population in regulating immune responses to microbial antigens.

Vaccine-specific T cells in human peripheral blood after oral immunization with an inactivated enterotoxigenic Escherichia coli vaccine

“…The cytokine pattern observed, i.e., no IL-2 and large quantities of IFN-y, is in keeping with findings described by other investigators. Thus, Katz et al (17) have shown that splenic murine T-helper cell clones specific for Bacteroides gingivalis exhibited low IL-2 activity and high IFN--y activity. Similarly, Autenrieth et al (3) reported the isolation of splenic murine T-cell clones specific for Yersinia enterocolitica, producing small or nondetectable quantities of IL-2 and considerable quantities of IFN-y (500 mU/ml), comparable to the amounts of IFN--y detected in this study.…”

Effect of host responses on the pathogenicity of strains of Porphyromonas gingivalis

“…Numerous animaJ models have been developed which have been extremely valuable in providing information important to our understanding of virulence properties of P. gingivalis (1,3,4,10,11,13,17,18,21,22). For instance.…”

Cloning, characterization, and antigen specificity of T-lymphocyte subsets extracted from gingival tissue of chronic adult periodontitis patients

“…Along with several other oral bacteria, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia have been implicated in the initiation and progression of different forms of this disease (18). The immunopathogenic mechanism involved in periodontitis is not understood, although the interaction between bacterial antigens and T lymphocytes in inflamed oral lesions has been suggested to be of importance in the pathogenesis of the disease in human (12,39) and experimental rat (16,44,50) models. In addition to bacterial antigens, autoantigens have also been considered to play a role in the pathogenesis of periodontitis (1,4).…”