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.     

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.     

Immunostimulating properties of the complexes of inosine derivatives

The effects of the complexes of inosine (Ino) analogues of isoprinosine on the immune response to sheep red blood cells (SRBC), in plaque-forming cells assay (PFC), in mice spleen, and on the Fc-dependent SRBC phagocytosis in mice peritoneal macrophages were investigated. Molar ratios of 1:3 of the complexes of inosine with N,N-dimethylaminopropanol-2-p-acetaminobenzoate (isoprinosine), and 8-thioinosine with N,N-dimethylaminopropanol-2-p-acetaminobenzoate (OSI-177), inosine with l-arginine butyrate (OSI-2655), and 8-thioinosine with l-arginine butyrate (OSI-3648) were administered. The administered doses were 0.5, 5 and 50 mg/kg body weight. The compound OSI-2655 exceeded isoprinosine in PFC stimulation and phagocytosis activation. The compound OSI-3648 exceeded isoprinosine only in PFC stimulation in the case of immunization with a suboptimal SRBC dose. OSI-3648 stimulated the immune response in PFC better than isoprinosine, OSI177, or OSI-2655, and maintained the ability to stimulate capture, but lost the ability to stimulate destruction processes of captured SRBC. l-Arginine butyrate in the doses equivalent to its content in the complexes did not affect the number of PFC. l-Arginine butyrate was able to stimulate the processes of destruction but its stimulation degree was inferior to the compound OSI-2655.     

Immunomodulatory effect of a newly synthesized compound, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo [2,1-b]thiazole-2-carboxamide) on antibody production in vivo and delayed-type hypersensitivity in mice

The immunopharmacological effects of a newly synthesized compound in vivo, TOK-8801 (N-(2-phenylethyl)-3,6,6-trimethyl-5,6-dihydroimidazo[2,1-b]thi azo le-2- carboxamide), on the anti-SRBC plaque-forming cell (PFC) response and delayed-type hypersensitivity (DTH) reaction were investigated. Oral administration of TOK-8801 (0.1-10 mg/kg) resulted in the suppression of the PFC responses to varying doses of antigen (5 x 10(6), 2 x 10(7), 1 x 10(8)) in C3H/He strain mice (7 W) which are high responders to SRBC antigen. On the other hand, the compound augmented the PFC response in aged mice (8-9 months) in which the PFC response was markedly depressed compared with that in young mice. In the experiment of the methylated human serum albumin-induced DTH reaction, TOK-8801 augmented the reaction in low responder (C57BL/6) mice by oral administrations of 0.1-1 mg/kg for 5 days from the sensitization, whereas suppressed the reaction in high responder (ICR) mice. These immunopharmacological actions of TOK-8801 were compared in dose and activity with those of lobenzarit and bucillamine. Thus, these results suggest that TOK-8801 may act as an immunomodulating agent and would be expected to be a useful agent for autoimmune diseases such as rheumatoid arthritis.     

Effect of in utero exposure to hexachlorocyclohexane on the developing immune system of mice.

Gestational exposure to 10 and 100 mg/kg body weight (m.b.w.) hexachlorocyclohexane throughout the gestation period was done to Swiss albino mice. HCH (alpha, beta and gamma isomers) residue analysis in pups showed a higher contamination in the lymphoid organs (Spleen, Thymus and Kidney) than liver in dose dependent manner. Immune functions of the offsprings of these dams along with the offsprings of vehicle treated or untreated control dams were assessed using selected parameters of both the cellular and humoral immune responses. The delayed hypersensitivity (DTH) response to sheep erythrocytes (SRBC) was significantly higher (p less than 0.01) in pups of the dams exposed to 10 mg/kg b.w. HCH and significantly impaired in pups of the dams exposed to 100 mg/kg m.b.w. HCH as compared to controls. Mitogenic responsiveness of the spleen cells in response to Concanavalin A (Con A) and Lipopolysaccharide (LPS) was almost two fold and eight fold higher respectively and antibody response to SRBC, as measured by plaque forming cells (PFC) assay was two fold higher (p less than 0.001) in pups exposed to 10 mg/kg HCH. However, 100 mg/kg m.b.w. HCH did not affect either mitogenic response or PFC response of the pups. The results, therefore, suggest that lower dose of HCH is capable of modulating the development and function of developing immune system possibly by modulating the functional organization of the T-cell populations.     

Sodium Valproate Does not Alter Immune Competence in Mice

Spleen and thymus weight, delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC), contact hypersensitivity to picryl chloride, anti-sheep red blood cell hemagglutinin titers and plaque-forming cells (PFC), resistance against experimental toxoplasmosis as well as serum total and intestinal specific IgA were investigated in Swiss mice given sodium valproate (250 mg/kg/day) orally for 21 consecutive days. Sodium valproate (SV) did not exert marked effects as only DTH to SRBC and PFC numbers were found to be slightly altered. These results suggest that SV is unlikely to alter immune competence markedly.     

Regulation of delayed-type hypersensitivity. III. Effect of cyclophosphamide on the suppressor cells for delayed-type hypersensitivity to sheep erythrocytes in mice.

A previous study (Eur. J. Immunol. 1977. 7: 714) has shown that mice injected intravenously (i.v.) with 4 x10(9) sheep red blood cells (SRBC) produce cells which suppress delayed-type hypersensitivity (DTH). These suppressor cells are theta-positive, antigen-specific and act via a soluble factor which does not bear immunoglobulin determinants (Eur. J. Immunol. 1978. 8: 168). The present paper demonstrates that these suppressor cells are inhibitable by cyclophosphamide (CY). Mice injected with graded amounts of CY two days prior to SRBC injection, showed maximum augmentation of DTH at 200 mg/kg body weight, a dose which completely suppressed the appearance of splenic plaque-forming cells (PFC) to SRBC. In contrast, lower doses of CY enhanced both DTH and PFC responses. Time course studies showed that CY inhibited the precursors of suppressor cells and had little or no effect on suppressor cells which have already encountered antigens. This was further confirmed by passive transfer studies which showed tha- suppressor cells were inhibited if CY was administered at the same time or 2 days before SRBC injection, but were not affected if CY was given after antigen stimulation. Direct evidence for the effect of CY on suppressor cells was obtained by cell fractination with a Ficoll density gradient. The denser suppressor cell population was absent from the spleens of mice treated with 200 mg/kg of CY 2 days before i.v. injection with 1 x 10(9) SRBC.     

Resistance of helper T lymphocytes to cyclophosphamide

The effect of cyclophosphamide (Cy) on helper T lymphocytes using an adoptive transfer approach in athymic nude mice was investigated. The results indicated that Cy, at a dose (100 mg/kg) which virtually abolished anti-sheep erythrocyte (SRBC) antibody plaque forming cell (PFC) response of Balb/c mice, did not alter significantly the capacity of their splenic T cells to restore the anti-SRBC PFC response of nude mice. This resistance of T helper cells was observed in unimmunized mice and in mice injected with SRBC two days prior to Cy administration. It has been concluded that both resting and antigen stimulated T helper cells responsible for reconstituting anti-SRBC response of nude mice are resistant to Cy.     

Methyl inosine monophosphate: a potential immunotherapeutic for early human immunodeficiency virus (HIV) infection.

MIMP is a new thymomimetic purine under development for immunorestorative therapy. Lymphocytes were obtained from eight patients with acquired immunodeficiency disease (AIDS), eight with symptomatic pre-AIDS (ARC), and 22 normal controls and were stimulated in vitro with phytohemagglutinin (PHA). AIDS patients (mean CD4 counts of 40) showed PHA responses less than 10% of control while ARC patients (mean CD4 counts of 544) showed responses approximately 50% of the control responses. MIMP (0.1, 1, 10 and 100 micrograms/ml) progressively augmented the PHA responses in all these groups. The augmentation of the responses of the leukocytes of AIDS patients while statistically significant was minimal. The augmentation of the responses of ARC patients was significant and their maximal responses approached control levels. The effect of 1 micrograms/ml MIMP was comparable with that observed with indomethacin (10(-6) M) and interleukin-2 (IL2 - 4 units/ml) and was additive with each of these stimulants. In a parallel manner, MIMP restored the suppression of control lymphocytes induced by the immunosuppressive 17 amino acid fragment of the P41 peptide of HIV. In vivo experiments showed that MIMP significantly delayed death in a murine FLV AIDS model at a dose of 1 mg/kg by the oral or parenteral route. MIMP is under preclinical development for early HIV disease to forestall progression to AIDS by attenuating virus-induced immunosuppression.     

Influence of Arecoline on Immune System: II. Suppression of Thymus-Dependent Immune Responses and Parameter of Non-specific Resistance After Short-Term Exposure

Abstract

Arecoline, a major alkaloid of arecanut was screened to explore its modulatory influence on cell-mediated immune response in a murine model system. the in viva and in vitro effects were evaluated at subtoxic concentrations of arecoline. Delayed type hypersensitivity (DTH) reactions to sheep red blood cells (SRBC) were evaluated in male mice. When treated subcutaneously with 20 mg/kg bw (1/5 of LD50) dose of arecoline for 1, 2 or 3 weeks, the DTH reactions were significantly suppressed. At arecoline concentration of 10 mg/kg bw, there was a moderate reduction in DTH response, while no appreciable change was observed at a dosage of 5 mg/kg bw. the effects were not dependent on the duration of treatment. In contrast, treating with arecoline continuously for 4 days following SRBC immunization showed significant suppression in DTH reactions at both 10 and 20 mg/kg bw doses. When treated after 12 h following immunization with 20 mg/kg bw arecoline, significant reduction in DTH reactions were seen. While moderate reduction in response was observed with arecoline dosage of 10 mg/kg bw, there was no alteration in response at the dose level of 5mg/kg bw. Recovery experiments in mice revealed that arecoline mediated effects are of a reversible nature. Arecoline treatment did not appreciably alter the host resistance to endotoxin shock. In vitro experiments revealed both dose-dependent and time-dependent cytotoxic effects of arecoline when spleen cells were incubated with varying concentrations of arecoline. Concomitant exposure of arecoline at concentrations of 10–6–10–4 m with con A, markedly suppressed both 3H-thymidine incorporation and interleukin-2 production of splenic cells. In contrast, concomitant exposure of arecoline with IL-2 did not alter 3H-thymidine incorporation in the IL-2 dependent cytolytic T-lymphocyte line (CTLL), except at the concentration of 10–4 m arecoline. From these studies it is concluded that the dose-dependent suppressive effects of arecoline on DTH response to SRBC and on certain in vitro lymphocyte functions are more clear than the host resistance to endotoxin shock.     

Influence of Arecoline on Immune System: II. Suppression of Thymus-Dependent Immune Responses and Parameter of Non-specific Resistance After Short-Term Exposure

Arecoline, a major alkaloid of arecanut was screened to explore its modulatory influence on cell-mediated immune response in a murine model system. the in viva and in vitro effects were evaluated at subtoxic concentrations of arecoline. Delayed type hypersensitivity (DTH) reactions to sheep red blood cells (SRBC) were evaluated in male mice. When treated subcutaneously with 20 mg/kg bw (1/5 of LD50) dose of arecoline for 1, 2 or 3 weeks, the DTH reactions were significantly suppressed. At arecoline concentration of 10 mg/kg bw, there was a moderate reduction in DTH response, while no appreciable change was observed at a dosage of 5 mg/kg bw. the effects were not dependent on the duration of treatment. In contrast, treating with arecoline continuously for 4 days following SRBC immunization showed significant suppression in DTH reactions at both 10 and 20 mg/kg bw doses. When treated after 12 h following immunization with 20 mg/kg bw arecoline, significant reduction in DTH reactions were seen. While moderate reduction in response was observed with arecoline dosage of 10 mg/kg bw, there was no alteration in response at the dose level of 5mg/kg bw. Recovery experiments in mice revealed that arecoline mediated effects are of a reversible nature. Arecoline treatment did not appreciably alter the host resistance to endotoxin shock. In vitro experiments revealed both dose-dependent and time-dependent cytotoxic effects of arecoline when spleen cells were incubated with varying concentrations of arecoline. Concomitant exposure of arecoline at concentrations of 10-6-10-4 m with con A, markedly suppressed both 3H-thymidine incorporation and interleukin-2 production of splenic cells. In contrast, concomitant exposure of arecoline with IL-2 did not alter 3H-thymidine incorporation in the IL-2 dependent cytolytic T-lymphocyte line (CTLL), except at the concentration of 10-4 m arecoline. From these studies it is concluded that the dose-dependent suppressive effects of arecoline on DTH response to SRBC and on certain in vitro lymphocyte functions are more clear than the host resistance to endotoxin shock.     

黄芪多糖对去T细胞小鼠促进抗体产生机理的探讨

黄芪多糖(APS)100mg/kgx6天 ip 可以增加正常小鼠脾脏重量,而对去胸腺与抗胸腺细胞血清处理过的小鼠(T_x-ATS)的作用明显降低。APS 能够显著提高正常小鼠 SRBC 免疫后脾细胞直接溶血空斑(d-PFC)和间接溶血空斑(i-PFC)数量,但对 T_x-ATS 小鼠不能促进d-PFC 数升高。APS 可以提高 T_x-ATS 小鼠在 LPS 免疫后 d-PFC 数,这个作用同 APS 对正常小鼠 SRBC 免疫后的效应相比显著降低。这些结果提示,APS 促进抗体形成作用机理可能是通过 T 细胞介导的。     

Cyclosporin A prevents suppression of delayed-type hypersensitivity in mice immunized with high-dose sheep erythrocytes.

When administered intraperitoneally to mice 2 days before immunization with a tolerogenic dose (10(9)) of sheep red blood cells (SRBC), cyclosporin A (CsA; 200 mg/kg) strikingly augmented 4-day delayed-type hypersensitivity (DTH) footpad reactions. These enhanced responses were similar in magnitude to those seen in animals sensitized with an immunogenic, low-dose (10(6)) SRBC. The stimulatory effect of CsA was observed over the dose range of 5-200 mg/kg and was obtained in animals given the drug in one injection, up to 7 days before sensitization. The augmentation of DTH was characterized by footpad swelling, intense mononuclear cell infiltration and increased deposition of 125I-fibrinogen within the challenge site. In addition, increased expression of procoagulant activity by spleen cells in response to antigen was observed. Cell transfer experiments showed that the CsA-enhanced DTH could be adoptively transferred to naive recipients. Additional transfers conducted at the time of antigen challenge suggested that, under the conditions described, CsA inhibited the action of a population of suppressor cells normally effective during DTH reactions.     

The Dose-Dependent Influence of Mechloretamine on the Response to Sheep Erythrocytes in Mice. Comparison of Immunostimulating Properties of Mechloretamine with Levamisole

The effect of the following doses of mechloretamine: 1, 5, 10, 25, 50, 100, 250 and 500 μg^/kg on the immunological response in mice immunized with sheep red blood cells (SRBC) was investigated. the number of plaque forming cells (PFC) to SRBC, the serum hemagglutinins level and the number of lymphocytes forming E or EAC-rosettes were determined. Depending on mechloretamine dose the following effects on the tested parameters were obtained : (i) only stimulating -1 and 5 pg/kg, (ii) stimulating or suppressive according to the test -10-100 pg/kg, (iii) only suppressive -250 and 500 μg/kg. Mechloretamine (5 μg/kg) induced the increase in PFC in comparison with levamisole (2 mg/kg). the difference between the action of mechloretamine and levamisole used in immunostimulating doses on the increased anti-SKBC antibodies or on the E-rosette forming lymphocytes was revealed.     

西咪替丁对小鼠骨髓细胞的抑制作用

本文用小鼠骨髓移植模型研究了西咪替丁对骨髓细胞的毒性作用.结果表明,在100mg/kg/天的剂量下,连续用药50天,免疫重建小鼠脾细胞对Con A和LPS的增殖反应明显受到抑制;对TNP-Ba特异的PFC反应以及对BSA诱导的DTH反应也较对照组明显降低。CFU-S的检测结果表明,西咪替丁对小鼠造血干细胞有明显抑制作用。     

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.     

Methyl inosine monophosphate (MIMP) augments T-lymphocyte mitogen responses and reverses various immunosuppressants

Methyl inosine monophosphate (MIMP) augments preferentially the in vitro responses of human and murine lymphocytes to a T-cell mitogen such as phytohemagglutinin (PHA) and inconsistently to a B-cell mitogen such as pokeweed or lipopolysaccharide (LPS). In a normal interleukin-2-dependent cell line (CTLL), MIMP showed little or no effect on IL-2 action; however, in a murine CTLL line exhibiting impaired responses to IL-2, MIMP stimulated thymidine incorporation and restored the response to IL-2. MIMP augments the PHA responses of both CD4⁺ and CD8⁺ human peripheral blood T-cells. The effect of MIMP to augment the PHA response of human lymphocytes is paralleled by the parent molecule, IMP. MIMP, but not IMP, is resistant to hydrolysis by 5'nucleotidase; thus, MIMP appears to be a protected analogue of IMP which is capable of in vivo action. MIMP (100 μg/ml) augments the PHA responses of 15 of 24 elderly humans. MIMP also augments the PHA responses of eight HIV-infected pre-AIDS patients but not of eight AIDS patients. When PHA responses of human lymphocytes are suppressed in vitro by an HIV-derived immunosuppressive peptide, interferon α, or prostaglandin PGE₂, MIMP (0.1–100 μg/ml) progressively restores the depressed response; however, when the suppression is severe (greater than 50%), MIMP cannot restore the response. These data indicate that MIMP potentiates normal T-lymphocyte mitogen responses and restores those impaired by a variety of inflammatory and immunosuppressive influences.     

Dissociative effects of malarial infection on humoral and cell-mediated immunity in mice.

The effect of malarial infection on immune responses was studied in mice. When sheep red blood cells (SRBC) were injected 2 days before or at the same time as infection with Plasmodium berghei, there was a marked increase in the number of splenic plaque forming cells (PFC) induced by SRBC as compared with uninfected controls. When SRBC were injected 2 days or more after the infection, however, the PFC response was significantly reduced. On the other hand, cell-mediated immunity, as exemplified by delayed-type hypersensitivity (DTH) to a number of antigens, was suppressed whether the infection was introduced before or after antigen stimulation. A similar effect could be produced by injecting the host with the supernatant obtained following incubation in vitro of peripheral blood from heavily infected mice. When this supernatant was injected i.v. into normal mice at the same time as SRBC priming, it enhanced the humoral response to SRBC, but suppressed the DTH to SRBC. The coincident induction of this inverse relationship between humoral and cell-mediated immunities was clearly borne out by a dose response study using different dilutions of supernatant. The active component appeared to be of large molecular weight (greater than 150,000), thermostable and not present in the serum of infected mice.     

Modulation of the immune responses against SRBC after oestriol treatment in mice.

Delayed-type hypersensitivity (DTH), primary direct and indirect PFC, memory antibody response and suppressor cell induction against sheep red blood cells (SRBC) have been examined in oestriol (E3) pretreated mice. The results showed that DTH and primary direct and indirect PFC responses were suppressed by E3 treatment. These suppressive effects could, however, be overcome when oestrogenized mice were given supra-optimal doses of SRBC for each response. On the other hand, the memory antibody response was markedly enhanced when E3 was given prior to the primary antigen stimulation. Induction of the suppressor cells for the antibody response seemed not to be affected by E3 treatment, but the characterization of the suppressor cells revealed that those obtained from E3 treated mice were surface immunoglobulin positive (sIg+) cells whereas those from control mice were not. These results were discussed in terms of the altered antigen distribution due to the activated phagocytic activity of the reticuloendothelial system (RES) after E3 treatment.     

Evaluation of Antitrypanosomal and Anti Inflammatory Activities of Selected Nigerian Medicinal Plants in Mice

The extracts of nine selected Nigerian medicinal plants were investigated on Trypanosoma brucei brucei infected mice. The anti-inflammatory properties of hexane fraction of the most promising U. chamae extract was assessed by acute oedema of the mice paw model while the modulatory effect of the extract on Delayed-Type Hypersensitivity (DTH) response on in vivo leucocytes mobilization was evaluated. ‘Dose-probing acute toxicity tests’ established an oral and intraperitoneal LD₅₀ for T. ivorensis stem bark as >1600 < 5000 mg/kg and 100 mg/kg respectively, while the oral LD₅₀ of Uvaria. chamae was >5000 mg/kg. Extracts of Khaya senegalensis, Harungana madagascariensis, Terminalia ivorensis, Curcuma longa, Ocimum gratissimum and Alcornea cordifolia showed weak anti-trypanosomal effect and did not exhibit significant clearance in parasitemia at the test dose administered compared with the positive control (Diminal®). However, the leaf extract of U. chamae and its hexane fraction demonstrated a significant response (P < 0.01). The fraction at 1000 mg/kg inhibited oedema by 107%. Uvaria. chamae demonstrated both antitrypanosomal and anti-inflammatory properties by increasing the survival time of infected mice due to reduction in parasitemia caused by T. brucei brucei.