Plaque-forming Cell Response In Mice Research Articles

Enhancement by Tea Catechin of in vitro and in vivo Plaque-forming Cell Response in Mice

Enhancement by Tea Catechin of in vitro and in vivo Plaque-forming Cell Response in Mice

Differences between rats and mice in the immunosuppressive activity of 2-methoxyethanol and 2-methoxyacetic acid

Previous studies from this laboratory have demonstrated that 2-methoxyethanol (ME) and its principal metabolite 2-methoxyacetic acid (MAA) are immunosuppressive in young adult male Fischer 344 rats. In the present study, the immunosuppressive potential of ME and MAA was evaluated in young adult female Fischer 344 rats and C57BL/6J mice. Rats and mice were dosed by gavage with either ME or MAA in water, at dosages ranging from 50–400 mg/kg/day, for 10 consecutive days. Rats and mice were examined for alterations in body, spleen and thymus weights and mitogen-induced proliferation of splenic lymphocytes in vitro; separate groups were employed for the antibody plaque-forming cell (PFC) response to trinitrophenyl-lipopolysaccharide (TNP-LPS). Rats dosed at 100–400 mg/kg/day ME and rats dosed at 50–400 mg/kg/day MAA had decreased thymus weights in the absence of decreased body or spleen weights. Lymphoproliferative (LP) responses to concanavalin A (Con A), phytohemagglutinin (PHA), pokeweed mitogen (PWM) and Salmonella typhimurium mitogen (STM) were all reduced in rats treated with all dosages of ME. Rats treated with MAA displayed similar reductions in these LP responses except that the responses to PWM and STM in rats dosed at 50 mg/kg/day were not reduced. In contrast to the effects of ME and MAA on these end points in the rat, no thymic involution or suppression of LP responses were observed in mice dosed at 50–400 mg/kg/day. The PFC response to TNP-LPS was suppressed in rats dosed with either ME or MAA at dosages of 100–400 mg/kg/day. ME and MAA, however, failed to suppress the PFC response in mice immunized with TNP-LPS. These results indicate that unlike Fischer 344 rats, C57BL/6J mice are insensitive to the immunosuppressive effects of ME and MAA at the dosages employed in this study. Whether the different sensitivities of these two rodent species to ME- and MAA-induced immunosuppression are due to immunologic, pharmacokinetic or metabolic differences within each species remains to be determined.

Effect of diisopropylfluorophosphate on the antibody response

The impact of the in-vivo administration of diisopropylfluorophosphate (DFP) on the antibody response in mice was examined. The antigen-specific plaque-forming cell (PFC) response of mice injected with DFP (4 mg/kg) at the time of immunization with a macrophage-dependent T-cell antigen, trinitrophenylated keyhole limpet hemocyanin (TNP-KLH) or sheep red blood cells (SRBC), was significantly depressed. In contrast, the injection of a similar dose of DFP had no effect on the PFC response of mice immunized with a macrophage-independent B-cell antigen, lipopolysaccharide (LPS). This differential effect suggests a possible detrimental effect of DFP on cells involved in antigen processing and/or presentation which are required for the antibody response to SRBC and TNP-KLH. These results, however, do not exclude T cells as a possible target and the cellular targets of DFP action remain to be established. The DFP-mediated depression of the PFC response to SRBC was still evident when DFP was given as early as 1 day before, but not 1 day after, the injection of antigen, suggesting that DFP may well affect an early event of the antibody response. For the secondary TNP-specific IgM PFC response, a significant depression was observed only when DFP was administered at the time of antigen challenge. The injection of DFP at the time of antigen priming, however, was effective in depressing the IgG, but not the IgM, PFC response. Therefore, DFP may also interfere with the generation of antigen-specific memory cells for the secondary IgG response.

Immunopharmacologic studies of D-penicillamine-L-cysteine disulfide.

Effects of D-penicillamine-L-cysteine disulfide (P-C) on some immunological parameters were examined in normal and immunity-impaired mice and rats. P-C enhanced the DNA synthesis in concanavalin A-stimulated mouse spleen cell cultures in vitro. In vivo, administration of P-C produced either enhancement or depression of plaque forming cell (PFC) response and delayed type hypersensitivity (DTH) to sheep red blood cells (SRBC) in low responder mice to SRBC, depending on the dose of P-C. P-C restored the impaired PFC response in hydrocortisone-pretreated mice. The enhancing effect of P-C was not shown in high responder mice to SRBC, but an inhibiting effect was observed. P-C inhibited the suppressor cell induction on PFC response in mice immunized with a supraoptimum dose of antigen. In adjuvant arthritic rats, P-C induced severe arthritis by eliminating the suppressor cells regulating this disease process. The relevance of these findings and mode of action of D-penicillamine in rheumatoid arthritis is discussed.

IMMUNOPHARMACOLOGIC STUDIES OF D-PENICILLAMINE-L-CYSTEINE DISULFIDE

Effects of D-penicillamine-L-cysteine disulfide (P-C) on some immunological parameters were examined in normal and immunity-impaired mice and rats. P-C enhanced the DNA synthesis in concanavalin A-stimulated mouse spleen cell cultures in vitro. In vivo, administration of P-C produced either enhancement or depression of plaque forming cell (PFC) response and delayed type hypersensitivity (DTH) to sheep red blood cells (SRBC) in low responder mice to SRBC, depending on the dose of P-C. P-C restored the impaired PFC response in hydrocortisone-pretreated mice. The enhancing effect of P-C was not shown in high responder mice to SRBC, but an inhibiting effect was observed. P-C inhibited the suppressor cell induction on PFC response in mice immunized with a supraoptimum dose of antigen. In adjuvant arthritic rats, P-C induced severe arthritis by eliminating the suppressor cells regulating this disease process. The relevance of these findings and mode of action of D-penicillamine in rheumatoid arthritis is discussed.

Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides.

Pneumococcal type 19F polysaccharide, contained in the current U.S. licensed pneumococcal vaccine, is a poor immunogen in young children. Capsular polysaccharides of Klebsiella, reported to be cross-reactive with the pneumococcal type 19F, were isolated. Immunochemical relations between pneumococcal group 19 and Klebsiella capsular polysaccharides were studied by immunodiffusion with hyperimmune typing antisera, immune passive hemolysis, and plaque-forming cell response in mice following injection of polysaccharides. Klebsiella K2, K9, K32, K47, and K48 polysaccharides were reported to cross-react with horse pneumococcal type 19 antiserum by direct precipitation. However, these Klebsiella polysaccharides did not react in immunodiffusion with horse or with rabbit pneumococcal 19F and 19A typing antisera. Furthermore, pneumococcal type 19F and 19A polysaccharides did not precipitate with rabbit K2, K9, K32, K47, and K49 typing antisera. The cross-reactivity of the Klebsiella and pneumococcal polysaccharides was studied by 2 other methods. Rabbit pneumococcal 19F antiserum induced by low passive hemolysis of sheep erythrocytes coated with Klebsiella polysaccharides. In contrast, Klebsiella typing antisera exhibited higher hemolytic activity with erythrocytes coated with type 19F polysaccharides. The cross-reactivity of K2 and pneumococcal 19F polysaccharides was also exhibited by the direct IgM plaque-forming cell response. The cross-reactivity, determined by precipitin reactions using animal antisera, may not predict the cross-immunogenicity of purified polysaccharides in humans.

Suppressor cells in contact sensitivity: Effect on T cells helping antibody production to picryl chloride

T cells from mice injected with picryl sulfonic acid have previously been shown to suppress the effector and possibly other phases of contact hypersensitivity reactions to picryl chloride. In this report we examine their effect on T cells helping the early direct anti-TNP plaque-forming cell response of mice painted with picryl chloride. They did not directly inhibit the activity of the helper cells but did inhibit the ability of mice to generate helper cells after skin painting. The suppressor cells were T cells as tested by passage through nylon wool columns and sensitivity to anti-θ serum. Viable syngeneic cells were required for suppression and their effect was specific. The suppressor cells could not be generated in adult thymectomized mice but could be produced in mice treated with high doses (200 mg/kg) of cyclophosphamide. These properties are distinct from those of suppressor T cells produced following immunization with picryl chloride but are the same as those of other suppressor cells induced by PSA which inhibit contact hypersensitivity.

Serum-Derived Immunosuppressive Substances

Suppression of the plaque-forming cell response in mice following injection of substances fractionated from pooled normal serum α-globulin was investigated. The dose-response relationship for fractions obtained by ion-exchange chromatography show that a single preparation has both enhancing and suppressive activities which are revealed at different doses. Whether this observation reflects the sum of activities of a number of molecular species remains to be determined. The immune responses to both thymus-dependent (heterologous erythrocytes) and thymus-independent (DNP-ficoll) antigens are suppressed while the response to the thymus-independent antigen lipopolysaccharide is enhanced. Thus, the cellular locus for immunosuppression cannot be exclusively on the T cell, and the magnitude of the action on each of the two populations (T and B cells) remains unclear.

Immunosuppression by hydroxystilbamidine isethionate, a lysosome-stabilizing, anti-proteolytic, antifungal drug.

Hydroxystilbamidine (HSB) is a potent suppressor of the plaque-forming cell response of mice injected with heterologous erythrocytes. HSB, given in varying doses and injection schedules, suppressed both the primary and secondary immune responses to bovine serum albumin. Apparently the effect is not simply a toxic effect on spleen cells, because there was no appreciable difference in cell numbers between control and HSB-treated mice. The effect of HSB was most apparent in the early phase of the immune respone.

Application of Transformations to Normalize the Distribution of Plaque-Forming Cells

Abstract In the past, it has been tacitly assumed that the distribution of the plaque-forming cell response in mice is approximately normal; that is, it would provide the usual bell-shaped normal distribution curve if enough replicate samples were collected. We address this point directly, by using the plaque-forming cell response generated in a total of five in situ, in vivo, and in vitro experimental systems. The Gaussian distribution assumption was tested on the untransformed data and on the same observations transformed by logarithms or square roots. We conclude that the log transformation provides a close approximation to normality for all the systems studied.

Regulation of T Lymphocyte Function by Immunoregulatory Alphaglobulin (IRA)

Abstract Immunoregulatory alphaglobulin, IRA, has been shown to suppress T cell-dependent immune responses. The present studies were to determine the effect of IRA on B cell-mediated immune responses. IRA-protein, and a more purified species, IRA peptide were shown to inhibit the T cell-mediated responses of spontaneous rosette formation between human peripheral lymphocytes and sheep red blood cells (SRBC) and the plaque-forming cell response in mice injected with SRBC. The same IRA preparations were ineffective in suppressing rosette formation between human peripheral lymphocytes and EAC-SRBC and the plaque-forming cell response to Escherichia coli lipopolysaccharide, both of which are B cell-mediated, T cell-independent immune responses. Therefore, we believe that IRA is effective in nonspecific suppression of only immune responses dependent on T cell function.

Effects of Sublethal Irradiation on the Plaque-Forming Cell Response in Mice

Abstract X-ray (440 R) administered 4 days after a primary injection of 1 × 108 sheep red blood cells (SRBC) into normal BALB/c mice resulted in increased numbers of indirect plaque-forming cells per million spleen cells (PFC/106) 3 days after a secondary challenge of 1 × 108 SRBC. The results were compared to control, non-x-rayed mice. The time of x-ray in relation to SRBC injection was critical as x-ray 3, 5, or 6 days after primary SRBC injection did not increase the number of PFC/106 cells. The state of increased responsiveness induced by x-ray was dependent on the dose of SRBC used for primary injection and could not be transferred by spleen cells to syngeneic recipient mice. The number of primary direct PFC/106 cells was increased when the response was measured 8 days after injection of SRBC and mice x-rayed 48 hr after antigen injection when compared to control non-x-rayed mice; this increase was probably due to a delay in the response induced by x-ray.

The effect of cysteine on the immunosuppressive activity of busulphan, cyclophosphamide and nitrogen mustard.

The effect of cysteine on the immunosuppressive activity of three alkylating agents was tested. Cysteine strongly inhibited the ability of cyclophosphamide and nitrogen mustard to depress the direct plaque-forming cell response of mice to sheep red cells. In contrast, the activity of busulphan was usually potentiated by administration of cysteine. This throws doubt on the hypothesis that busulphan exerts its cytotoxic effects by alkylating thiol groups.