Inactivation of suppressor T cell activity by the nontoxic lipopolysaccharide of Rhodopseudomonas sphaeroides

Abstract

Antibody responses of mice immunized with type III pneumococcal polysaccharide were examined with and without treatment with nontoxic lipopolysaccharide from Rhodopseudomonas sphaeroides (Rs-LPS). The results obtained were similar to those described previously for mice treated with monophosphoryl lipid A (MPL) except that lower amounts of Rs-LPS were needed. Both were without effect when given at the time of immunization with type III pneumococcal polysaccharide but elicited significant enhancement when given 2 to 3 days later. Such enhancement was T cell dependent and not due to polyclonal activation of immunoglobulin M synthesis by B cells. Treatment with either Rs-LPS or MPL abolished the expression but not induction of low-dose paralysis, a form of immunological unresponsiveness known to be mediated by suppressor T cells (Ts). The in vitro treatment of cell suspensions containing Ts with extremely small amounts of Rs-LPS or MPI completely eliminated the capacity of such cells to transfer suppression to other mice. These findings indicate that the immunomodulatory effects of both MPL and Rs-LPS are mainly the result of eliminating the inhibitors effects of Ts; this permits the positive effects of amplifier T cells to be more fully expressed, thereby resulting in an increased antibody response. The significance of these and other findings to the use of Rs-LPS as a pharmacotherapeutic agent for gram-negative bacterial sepsis is discussed.

Effect of Rhodopseudomonas sphaeroides–Treated Wastewater on Yield, Digestive Enzymes, Antioxidants, Nonspecific Immunity, and Intestinal Microbiota of Common Carp

“…Adeoye et al (2016) and Zhao et al (2018) found that intestinal microbiota, especially probiotics, played an important role in the nonspecific immune system, antioxidant system, and disease resistance and digestive system. Figure 2 and Jagielo et al (1998) and Baker et al (1990) support the finding that R. sphaeroides in effluent inhibited or killed pathogenic bacteria (Flavobacterium and Acinetobacter) and promoted the growth of probiotics in Common Carp intestine. Moreover, R. sphaeroides themselves were probiotics.…”

“…Jagielo et al (1998) described that R. sphaeroides cell walls contained 3-hydroxy-sebacic acid and diphosphonic acid lipoid A. Baker et al (1990) observed that R. sphaeroides contained antiviral, antigen (Ag1, Ag2, Ag3), and immune factors and even secreted antibiotics. The above bioactive substances could inhibit or kill pathogenic bacteria (Baker et al 1990;Jagielo et al 1998).…”

“…Baker et al (1990) observed that R. sphaeroides contained antiviral, antigen (Ag1, Ag2, Ag3), and immune factors and even secreted antibiotics. The above bioactive substances could inhibit or kill pathogenic bacteria (Baker et al 1990;Jagielo et al 1998). Moreover, R. sphaeroides dominated when competing for nutrition and space with pathogenic microbes.…”

“…In this study, higher gene expression in the NF-kB signaling pathway was induced in the ER and WR groups and then immunerelated enzyme activities were enhanced in the ER and WR groups. Jagielo et al (1998) and Baker et al (1990) thought that R. sphaeroides contained the antigens Ag1, Ag2, and Ag3 and the nonmethylation dinucleotide sequence CpG-DNA. Further, Baker et al (1990) and Morales-Nebreda et al (2019) observed that antigens Ag1, Ag2, and Ag3 and CpG-DNA had very strong immune stimulation and induced the release of immune factors and the differentiation of immune cells.…”

Differential effects of monophosphoryl lipid A on expression of suppressor T cell activity in lipopolysaccharide-responsive and lipopolysaccharide-defective strains of C3H mice

“…The magnitude of the antibody response to type III pneumococcal polysaccharide (SSS-III) is regulated in a negative and positive manner by the competitive interaction of thymus-derived CD8+ CD4suppressor T cells (Ts) and CD8-CD4+ amplifier T cells, respectively (reviewed in reference 2). Treatment with monophosphoryl lipid A (MPL) abolishes expression of Ts activity without adversely effecting expression of amplifier and helper T cell functions; this permits the positive effects of amplifier T cells on antigen-stimulated B cells to be more fully expressed, thereby resulting in either an increased antibody response to SSS-III or abrogation of Ts-mediated immunological unresponsiveness (6,7,13).…”