Enrichment of suppressor T cells by means of binding to monophosphoryl lipid A

Abstract

The binding and elution of spleen cells from plastic dishes coated with monophosphoryl lipid A (MPL) resulted in a greater than 1,000-fold enrichment of antigen-specific suppressor T-cell (TS) activity when spleen cells from mice 18 to 24 h after exposure to a low dose of type III pneumonococcal polysaccharide (SSS-III) were used. The removal of MPL-adherent TS cells resulted in an increase in the degree of amplifier T-cell (TA) activity present in the remaining MPL-nonadherent cell fraction; however, both TS and TA activities were found in the MPL-adherent cell fraction when spleen cells from mice 4 days after immunization with an optimal dose of SSS-III were examined. These findings, as well as others, suggest that both TS and TA, once activated, acquire a cell surface receptor that enables them to bind to MPL. Because of differences in the kinetics for the activation of TS and TA during the course of the antibody response and the fact that TS, but not TA, activity appears as early as 18 to 24 h after exposure to SSS-III, it is possible to use this experimental approach to obtain cell suspensions greatly enriched in TS activity.

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

“…(ii) By using highly purified populations of splenic T cells, it has been shown that only a small percentage (about 3%) of T cells are able to bind and respond directly to LPS (21). (iii) MPL acts preferentially on activated, rather than resting (or precursor), Ts to abolish Ts function (6); although the frequency of splenic Ts activated after exposure to SSS-III is not known, the results of enrichment studies (5) indicate that they represent a very small fraction of the total number of CD8+ CD4-T cells present. In view of these considerations, it is evident that unless one (i) circumvents the problem of nonspecific binding and (ii) uses cell populations greatly enriched for activated Ts, it may not be possible to discriminate between LPSr and LPSd strains of C3H mice with respect to their binding characteristics for MPL.…”

Antigen-specific suppressor T cells respond to recombinant interleukin-2 and other lymphokines

“…Previous studies have consistently shown that spleen cells harvested 16 to 24 h after priming with SSS-111 are rich in Ts activity (3)(4)(5)(20)(21)(22). Suppression can be transferred with at least 20 x 106 whole spleen cells or 105 purified T cells recovered from plates treated with monophosphoryl lipid A (4). We observed in the present studies, as well as in the past (4), that 5 x 106 or 2 x 106 primed spleen cells not treated with recombinant IL-2 (rIL-2) did not transfer significant suppression.…”

“…In earlier studies, we observed that because of the low frequency of putative Ts cells, approximately 20 x 106 spleen cells from SSS-III-primed mice were required to transfer suppression. In fact, only under conditions of enrichment, such as use of monophosphoryl lipid A-adherent T cells, was it possible to transfer suppression with such small numbers of cells (4,5). These studies therefore suggest that precursor Ts cells, once activated, express IL-2 receptors that are capable of binding available IL-2; this results in clonal expansion of precursor Ts cells, as reflected by an increase in Ts-cell activity.…”

“…A number of studies have demonstrated that suppressor T (Ts) cells are capable of down-regulating the antibody response to pneumococcal polysaccharide type III (SSS-III) (1)(2)(3)(4)(5)(6)(7)(21)(22)(23)(24) and that Ts cells function mainly to limit the expansion of antigen-stimulated B cells. These studies have also shown that Ts cells are activated during the course of a normal immune response not by antigen but by cell-associated antibody on the surfaces of immune B cells (12,14,23).…”

Abrogation of suppression of delayed hypersensitivity induced by Candida albicans-derived mannan by treatment with monophosphoryl lipid A

“…nonadherent cells as previously described (31). Other cell suspensions were panned on petri dishes coated with affinity-purified anti-mouse immunoglobulin M (IgM) (,u-chain specific; Sigma Chemical Co., Ltd., Dorset, England) as previously described (2). Erythrocytes were removed by treatment with Gey's solution (40).…”