Miconazole Influence on Both Cellular Immune Response and Hepatic Drug Metabolism in Mice

Miconazole was found to exert a biphasic influence on both cellular immune response and hepatic drug metabolism in adult Swiss mice. Indeed, at the dose of 2.5 or 12.5 ma/kg/twice daily via intraperitoneal route, miconazole depressed delayed-type hypersensitivity (DTH) to sheep red blood cells and hepatic drug metabolism as determined from barbiturate sleeping time, following one-day treatment. By contrast, at the same dose level, miconazole enhanced DTH and hepatic drug metabolism after a five-day administration schedule. Primary humoral response and colloidal carbon clearance were not affected. Although the underlying mechanism remains to be fully elucidated, these findings clearly suggest a close relation between modulation of the cellular immune response and activity of liver drug metabolizing enzymes.     

The Immune Response to a Schistosomacidel, Amoscanate, I. Serum Antibody Responses

A potent antischistosomal drug, Amoscanate, was found to be immunogenic to mice and Cebus apella monkeys. The drug was readily haptenated to proteins under relatively mild conditions. The Amoscanate-protein conjugates were observed to be immunogenic when injected into the footpads of several strains of mice. However, such protein conjugates were not found to raise IgE antibody to the drug in high-responder strains using several procedures. When the formulated drug (dissolved in oil) was fed to CD 1 mice, a rise in serum antibody against the drug was noted 1 week following the primary dose. This is preliminary evidence that the drug, or a cross-reactive metabolite, becomes covalently bound to proteins in vivo. Cebus apella monkeys fed the drug exhibited a rise in anti-Amoscanate antibody one month after a second oral dose. These data suggest that the immunogenicity of Amoscanate is readily detected; furthermore, since there is no lasting immunity to schistosomiasis, thus necessitating multiple administration of the drug, the possibility that serum antibody titers to Amoscanate may interfere with its therapeutic efficacy cannot be overlooked.     

Drug Induced Modulation of Immune Responses in Mice: Effects of 5-(3,3-Dimethyl-1-Triazeno)-Imidazole-4-Carboxamide (DTIC) and Cyclophosphayide (CY)

Graded doses of Cyclophosphamide (Cy) or 5-(3,3-dimethyl-l-triazeno)-imidazole-4-carboxamide (DTIC) were given to CD2F₁ or C57B1/6 mice. One, 45 or 60 days later the animals were tested for allograft responses, competence of producing cytotoxic lymphocytes and lethal graft-versus-host disease (GVHD) in vivo, delayed-type hypersensitivity (DTH) and humoral antibody responses against sheep red blood cells (SRBC).

Both agents produced strong inhibitory effects, except for DTH, when given 1 day before the antigenic stimulus. However immunodepression lasted for at least 60 days after DTIC, whereas relatively rapid recovery of immune responsiveness was detected in mice treated with Cy. hen Cy or DTIC were given to allo-geneic donor mice 1 day before spleen cell transfer, immunodepressed recipients did not undergo GVHD. However when drugs were administered to recipient mice inoculated with allogeneic spleen cells, lethal GVHD occurred when Cy but not DTIC was given to the hosts. DTH responses were potentiated by Cy when the drug was given 1 day before sensitization. In contrast hypersensitivity reactions were not affected by DTIC treatment.

It was concluded that DTIC is a potent and long-lasting immunodepressive agent, capable of affecting various T-cell subpopulations and possibly B lymphocytes in mice. Since the drug inhibits immune response when given before the antigenic stimulation, it was suggested that DTIC acts through a mechanism similar to that of alkylating non phase-specific agents.     

Cyclosporin A can switch the immune response induced by antigen from a humoral to a cell-mediated mode.

Cyclosporin A (CsA) is known as a nontoxic inhibitor of the immune response that is primarily employed in humans to prevent the rejection of allografts. We report here on a novel activity for this drug as an immunomodulator. CsA can either inhibit or facilitate the induction of delayed-type hypersensitivity (DTH) depending on the class of immune response that would be induced in the absence of the drug. The drug inhibits the in vivo and in vitro induction of DTH when antigen is given under conditions that normally result in the induction of this response. The same concentration or dose of CsA inhibits the in vitro and in vivo induction of an antibody response and the antigen induces DTH instead. An explanation for these different effects of CsA on the induction of DTH is proposed. This novel activity of CsA in modulating the immune response from an antibody to a cell-mediated mode may have clinical applications.     

Effects of contact sensitization and delayed hypersensitivity reactions on immune responses to non-related antigens. Modulation of Immune responses.

Guinea pigs were immunized intracutaneously into the ears with sheep red blood cells (SRBC). Application of a sensitizing dose of the contact allergen dinitrochlorobenzene (DNCB) onto the same ears was shown to suppress or enhance the humoral response to SRBC depending on the time of application. When guinea pigs were sensitized to a contact allergen, application of a sensitizing dose of a non-related allergen on the same ears either had no effect or caused a clear enhancement of the development of delayed type hypersensitivity (DTH). Strongest enhancement was found when both sensitizations were performed on the same day. Further experiments on the effects of a concomitant DTH reaction elicited at the site of application of a contact allergen showed a strong potentiation of DTH when B-cell suppression was minimized by pretreatment with cyclophosphamide (CY). It was considered that CY-DTH-immunopotentiation might be a useful tool for achieving a higher level of sensitivity after epicutaneous sensitization.     

Preferential induction of memory T cells for delayed-type hypersensitivity with reduced and alkylated human serum albumin in mice.

Reduction and alkylation of human serum albumin (HSA) resulted in molecular aggregation of the protein. The reduced and alkylated antigen (RA-HSA) was lacking in the ability to induce delayed-type hypersensitivity (DTH) response as well as antibody response to native HSA in mice, although native HSA induced both responses. On the other hand, RA-HSA could stimulate a priming function that accelerated and enhanced the DTH response to native HSA, which, however, failed to stimulate the function. Thus, DTH-related memory activity was dissociated from DTH-related effector activity. The DTH-related memory activity, manifested by the accelerated an enhanced response in RA-HSA-primed mice, could be transferred antigen-specifically by their spleen cells and T-cell enriched fraction, but not by their T-cell depleted spleen cells. The RA-HSA-primed T cells, however, failed to transfer the effector function for DTH response. These results suggested that DTH-related memory T cells belong to different subset(s) of T cells from effector T cells for a DTH response.     

Effects of cyclosporin A on the cells responsible for the anticryptococcal cell-mediated immune response and its regulation.

Cyclosporin A (CsA), a potent immunosuppressive drug, was used to explore further the induction, expression, and regulation of lymphoid cells involved in the delayed-type hypersensitivity (DTH) response to cryptococcal antigen(s). We found that the induction of the cells responsible for DTH (TDH cells) was not affected by CsA, but their expression was inhibited in CsA-treated mice. The inhibition of expression of the TDH cells could not be attributed to the Cryptococcus neoformans-specific suppressor T (Ts) cells, even though the Ts cells were induced in CsA-treated mice. Instead, the suppressed expression of the TDH cells in CsA-treated mice was a direct effect of CsA or its products. Our studies with CsA also resulted in the first identification of a population of cells that significantly amplify the anticryptococcal DTH response. The amplifier cells were induced in mice that were given a primary immunizing dose of cryptococcal antigen in complete Freund adjuvant, and they amplified the anticryptococcal DTH response in recipient mice when they were transferred at the time of immunization of the recipient. The amplifier cell population was distinct from the TDH cells in that CsA inhibited the production of the amplifying cells but did not affect the induction of TDH cells. Amplification of the DTH response was a cell-mediated event, since cells but not serum from immunized mice mediated the amplified response in recipient mice. Thus, CsA enabled us to characterize anticryptococcal TDH and Ts cells further and to add to the immune cell circuit of the cryptococcal system a distinct population of cells that amplifies the anticryptococcal DTH response.     

The effects of cyclosporin A on the induction, expression and regulation of the immune response to herpes simplex virus.

Investigations were conducted to determine the effect of cyclosporin A (CsA) on the delayed type hypersensitivity (DTH) and antibody response of mice to Herpes simplex virus (HSV). Given only at the time of priming, the drug had little effect on the subsequent DTH response in mice receiving a 'DTH immunogenic' inoculation regime. However, CsA restored normal responsiveness in groups receiving a 'DTH tolerogenic' regime implying the abrogation of T suppressor (Ts) cells. Ts cell induction was insensitive to cyclophosphamide. Antibody responses were not suppressed after giving CsA with either of these regimes and enhancement was shown in some groups. DTH was substantially reduced by CsA when the drug was given repeatedly between the time of priming and challenge, or when previously primed mice received the drug shortly before challenge.     

Modification of Immune Response by Cinnarizine

Effects of cinnarizine on immune response in mice were investigated. Mice were orally administered with cinnarizine and were immunized with sheep red blood cells (SRBC) intravenously. Numbers of plaque forming cells (PFC) to SRBC in spleen of these mice were assayed and delayed-type hypersensitivity (DTH) response to SRBC was measured. 1) PFC response in immunization with 5 × 10⁶ cells/mouse of SRBC was enhanced by administration of 25 mg/kg of cinnarizine, while the response in immunization with 5 × 10⁸ cells/mouse was suppressed by 25 to 200 mg/kg of cinnarizine. 2) From study on timing of administration, suppression of PFC response by 6.25 to 200 mg/kg of cinnarizine was observed at 24 hr. after the immunization. 3) 12.5 to 200 mg/kg of cinnarizine suppressed polyclonal B cell activation induced by lipopolysaccharide (LPS). 4) Colchicine induced suppressor T cell inactivation was prevented by administration of 50 mg/kg of cinnarizine and it was suggested that cinnarizine may induce suppressor T cells from the study of adoptive cell transfer system. 5) 50 mg/kg of cinnarizine showed the suppression of DTH response in expression phase, but not in induction phase. It was concluded that immune responses in mice were modified by cinnarizine.     

Priming of systemic and local delayed-type hypersensitivity responses by feeding low doses of ovalbumin to mice.

We have examined the effects on both systemic and intestinal immunity of feeding different doses of ovalbumin (OVA) to mice. A single feed of doses of more than 1 mg OVA produced significant suppression of subsequent delayed-type hypersensitivity (DTH) and IgG antibody responses. Feeding 100 micrograms-1 mg OVA had no net effect on systemic immunity, but mice fed 10-50 micrograms OVA had consistently enhanced systemic DTH responses when immunized subsequently with OVA in adjuvant. Oral challenge of these mice with OVA produced alterations in mucosal architecture and in intra-epithelial lymphocyte counts, consistent with the presence of an intestinal DTH response. Similar changes were not found in mice fed tolerogenic doses of OVA. Although feeding low doses of OVA primed both systemic and intestinal DTH responses, this had no effect on serum IgG responses and very little systemic DTH could be revealed in OVA-fed mice without systemic challenge with OVA in adjuvant. We conclude that feeding certain low doses of protein antigens can induce priming of local and systemic DTH responses rather than the immune tolerance which is normally found. The development of clinical food hypersensitivities may be highly dependent on the dose of dietary antigen at the time of first encounter.     

Studies on the immunomodulatory effects of anthracycline antibiotics in mice: effects on immune responses and graft immunogenicity

The immunomodulatory effects of adriamycin, a clinically used tumor antibiotic, were studied. A 5-day course of adriamycin therapy in mice led to a suppression of the primary but not of the secondary humoral response to sheep erythrocytes without significant alterations in peripheral blood leukocyte subsets or lymphocyte subpopulations in the spleen. The delayed type hypersensitivity (DTH) response to ovalbumin or alloantigens was not inhibited. Adriamycin-treated spleen cells were unable to stimulate an allogeneic mixed leukocyte reaction, which shows that antigen presentation is inhibited by this drug. Adriamycin-treated murine skin grafts show a prolonged survival after allotransplantation despite their unimpaired ability to induce DTH. The possible cellular mechanisms of these effects and clinical relevance of adriamycin are discussed.     

Immune function in patients with rheumatoid arthritis treated with etanercept

Etanercept, a recombinant human tumor necrosis factor (TNF) inhibitor that binds both soluble and cell-bound TNF, has been shown to reduce disease activity and inhibit joint destruction when administered to patients with rheumatoid arthritis (RA). Because TNF receptors are found on many types of cells that modulate the immune response, we evaluated the general immune function of a subset of RA patients in a blinded clinical study. No significant differences were seen between patients treated with etanercept or placebo in the surface antigen phenotypes of peripheral blood leukocytes, T cell proliferative responses, neutrophil function, delayed-type hypersensitivity (DTH) reactions, serum immunoglobulin levels, or incidence of infections. Although this observational study was relatively small and could detect only major changes in immunological status, the stability of immune function over time in patients receiving etanercept corroborates the findings in clinical studies, which suggest that etanercept does not alter overall global immune function.     

Modification of Immune Response by Cinnarizine

Abstract

Effects of cinnarizine on immune response in mice were investigated. Mice were orally administered with cinnarizine and were immunized with sheep red blood cells (SRBC) intravenously. Numbers of plaque forming cells (PFC) to SRBC in spleen of these mice were assayed and delayed-type hypersensitivity (DTH) response to SRBC was measured. 1) PFC response in immunization with 5 × 10⁶ cells/mouse of SRBC was enhanced by administration of 25 mg/kg of cinnarizine, while the response in immunization with 5 × 10⁸ cells/mouse was suppressed by 25 to 200 mg/kg of cinnarizine. 2) From study on timing of administration, suppression of PFC response by 6.25 to 200 mg/kg of cinnarizine was observed at 24 hr. after the immunization. 3) 12.5 to 200 mg/kg of cinnarizine suppressed polyclonal B cell activation induced by lipopolysaccharide (LPS). 4) Colchicine induced suppressor T cell inactivation was prevented by administration of 50 mg/kg of cinnarizine and it was suggested that cinnarizine may induce suppressor T cells from the study of adoptive cell transfer system. 5) 50 mg/kg of cinnarizine showed the suppression of DTH response in expression phase, but not in induction phase. It was concluded that immune responses in mice were modified by cinnarizine.     

Differential regulation of effector responses of cell mediated immunity in experimental salmonellosis.

Delayed type hypersensitivity (DTH) and protective cell mediated immunity showed different profiles with respect to time following intraperitoneal immunization with live Salmonella enteritidis. Whereas the DTH response decreased with time the Protection Index increased. The decline in DTH response was found to be associated with suppressor cells generated by intraperitoneal immunization and could be prevented by cyclophosphamide treatment prior to immunization. It was concluded that the two effector responses of cell mediated immunity were under differential regulation.     

Glutathione depletion inhibits dendritic cell maturation and delayed-type hypersensitivity: implications for systemic disease and immunosenescence

BACKGROUND: Dendritic cells (DCs) play a key role as antigen-presenting cells in the immune system. There is growing evidence that the redox equilibrium of these cells influences their ability to induce T-cell activation and to regulate the polarity of the immune response. This could affect the outcome of the immune response during systemic diseases and aging. OBJECTIVE: Our aim was to elucidate the mechanism by which the redox equilibrium of antigen-presenting DCs affects the delayed-type hypersensitivity (DTH) response during experimental modification of glutathione levels, as well as during aging. METHODS: We looked at the effect of glutathione depletion by diethyl maleate in DCs as well as during systemic administration on the DTH response to the contact-sensitizing antigens, oxazolone, and 2,4-dinitro-1-fluorobenzene. We also determined whether glutathione repletion with N-acetyl cysteine could influence the decline of the DTH response in aged mice. RESULTS: Glutathione depletion in bone marrow-derived DCs interfered in their ability to mount a DTH response on adoptive transfer into recipient mice. Glutathione depletion interfered in IL-12 production and costimulatory receptor expression in DCs, leading to decreased IFN-gamma production in the skin of recipient mice. Systemic diethyl maleate treatment exerted similar effects on the DTH response and IFN-gamma production, whereas N-acetyl cysteine administration reversed the decline of the DTH response in aged animals. CONCLUSION: Glutathione depletion downregulates T(H)1 immunity through a perturbation of DC maturation and IL-12 production. CLINICAL IMPLICATIONS: These data show that the induction of oxidative stress in the immune system, under disease conditions and aging, interferes in T(H)1 immunity.     

A cardiac myosin-specific autoimmune response is induced by immunization with Trypanosoma cruzi proteins

Trypanosoma cruzi is the protozoan parasite that causes Chagas' heart disease, a potentially fatal cardiomyopathy prevalent in Central and South America. Infection with T. cruzi induces cardiac myosin autoimmunity in susceptible humans and mice, and this autoimmunity has been suggested to contribute to cardiac inflammation. To address how T. cruzi induces cardiac myosin autoimmunity, we investigated whether immunity to T. cruzi antigens could induce cardiac myosin-specific autoimmunity in the absence of live parasites. We immunized A/J mice with a T. cruzi Brazil-derived protein extract emulsified in complete Freund's adjuvant and found that these mice developed cardiac myosin-specific delayed-type hypersensitivity (DTH) and autoantibodies in the absence of detectable cardiac damage. The induction of autoimmunity was specific since immunization with extracts of the related protozoan parasite Leishmania amazonensis did not induce myosin autoimmunity. The immunogenetic makeup of the host was important for this response, since C57BL/6 mice did not develop cardiac myosin DTH upon immunization with T. cruzi extract. Perhaps more interesting, mice immunized with cardiac myosin developed T. cruzi-specific DTH and antibodies. This DTH was also antigen specific, since immunization with skeletal myosin and myoglobin did not induce T. cruzi-specific immunity. These results suggest that immunization with cardiac myosin or T. cruzi antigen can induce specific, bidirectionally cross-reactive immune responses in the absence of detectable cardiac damage.     

Distinction between suppressors of the delayed-type hypersensitivity and the humoral response to sheep erythrocytes.

Suppressors for both delayed-type hypersensitivity (DTH) and the humoral immune response could be simultaneously induced in the spleens of mice by immunization with a high dose of SRBC. Normal recipient mice of the spleen cells from donors immunized 5 days previously elicited depressed DTH or humoral response when immunized with SRBC. The suppressive activity was found to reside in T not B enriched fraction. Four hundred rad irradiation of the primed spleen cells resulted in complete loss of DTH suppressor activity, but only in some reduction of the suppressor activity for the humoral response. In contrast, hydrocortisone treatment of the donor mice caused no loss of DTH suppressor activity while approximately half of the suppressive activity for anti-SRBC PFC response was lost. Adult thymectomy prevented completely the induction of the DTH suppressor in contrast to little loss of the suppressor activity for the humoral response. DTH suppression was antigen-specific for the induction, but nonspecific for the expression. However the suppression of the humoral response was antigen-specific not only for the induction but also for the expression. In addition, DTH suppressor was capable of suppressing both the induction and expression of DTH while the humoral response was suppressed only in the induction stage by the suppressor.     

Immune privilege in the anterior chamber of the eye: alloantigens and tumour-specific antigens presented into the anterior chamber simultaneously induce suppression and activation of delayed hypersensitivity to the respective antigens.

Allografts placed into the anterior chamber of the eye enjoy prolonged and sometimes permanent survival while similar grafts are promptly rejected if transplanted to non-privileged sites. The immunological privilege of the anterior chamber is due, in large part, to the systemic suppression of delayed-type hypersensitivity (DTH) that is induced by anterior chamber presentation of alloantigens and is termed anterior chamber-associated immune deviation (ACAID). Although many categories of antigens elicit ACAID, strong tumour-specific transplantation antigens (TSTA) do not induce ACAID and instead, provoke potent DTH responses following anterior chamber presentation. The present study sought to determine if the anterior chamber were simultaneously confronted with these two categories of antigens, which systemic immune response would prevail: DTH or suppression of DTH? The results show that inoculation of minor histocompatibility alloantigens and TSTA into the anterior chamber induced both afferent and efferent suppression of specific anti-alloantigen DTH responses, yet simultaneously induced normal anti-TSTA DTH responses. Both responses (i.e. DTH and suppression) were transferable with lymphoid cells.     

Suppressor T cells for delayed-type hypersensitivity to Japanese encephalitis virus.

The delayed-type hypersensitivity (DTH) to Japanese encephalitis virus (JEV) and the suppressor cells controlling it and the antibody-forming cells in inbred Swiss mice have been studied. JEV induces DTH, with a peak response at day 7 following infection which persists at low levels at least up to 119 days. Suppressor activity appeared on day 18. It was transferable by immune spleen cells. Treatment of spleen cells with anti-Thy-1.2 antisera and complement abrogated the suppressor activity. The homogenate of the spleen was equally effective in mediating suppression of DTH and the humoral response as measured by direct antibody plaque-forming cell (IgM-PFC) assay. The suppressor activity was antigen-specific both on DTH and T helper for antibody response as the immune responses against SRBC or Coxsackie B4 virus were not suppressed. The suppressor cells were sensitive to cyclophosphamide treatment when the drug was given 48 hr before their appearance. It is, therefore, concluded that in JEV infection of mice, antigen-specific suppressor T cells are generated, both for DTH and IgM antibody, which are cyclophosphamide-sensitive and mediate suppression through soluble product(s).