Inhibition of the neutrophilic infiltrate of experimental tubulointerstitial nephritis in the Brown-Norway rat by decomplementation

Anti-tubular basement membrane (TBM) antibody-associated tubulointerstitial nephritis (TIN) in Brown-Norway rats is induced by immunization with bovine TBM antigens and adjuvants. The lesion is characterized by linear deposition of IgG and C3 along the TBM with sequential neutrophil (Days 8-9)- and mononuclear (Day 10 and after)-dominated inflammatory infiltrates. To study the complement dependence of the infiltrative process, immunized rats were decomplemented with cobra venom factor (CVF). The CVF treatment did not affect the production or renal deposition of anti-TBM antibodies. CVF markedly reduced the neutrophilic inflammatory infiltrate. In rats immunized with suboptimal doses of soluble bovine TBM antigens to produce a mild lesion, decomplementation also decreased the mononuclear inflammatory infiltrates on Days 10-13. In rats immunized optimally with particulate TBM to induce maximally severe TIN, decomplementation did not affect the mild mononuclear cell infiltrate on Days 8 and 9 but did somewhat reduce the subsequent mononuclear infiltrate on Days 10 and 12. These results demonstrate that the anti-TBM antibody- and C3-associated neutrophilic inflammatory infiltrate is largely complement dependent. The early mononuclear cell infiltrate that was unmodified by CVF treatment may be dependent on complement-independent humoral events or related to cell-mediated immune events. A portion of the later mononuclear inflammatory infiltrate could be dependent on the preceding neutrophilic inflammatory phase.     

Suppression of nephrotoxic serum nephritis in rats by prostaglandin E1.

The ability of specific prostaglandins to modulate the development of nephrotoxic serum nephritis (NSN) in rats has been examined. The nephrotoxicity of one intravenous injection of antibodies directed against rat glomerular basement membrane (GBM) was markedly suppressed by treatment with a stable analog of prostaglandin E1 (15-(S)-15-methyl PGE1; 15-M-PGE1). Prostaglandin E1 treatment was shown to suppress both glomerular hypercellularity and proteinuria, while the binding of specific antibody to the GBM was not altered. These studies indicate that certain prostaglandins may play an important role in the regulation of Type II immune reactions. Further investigations of the role of arachidonic acid products undoubtedly will provide valuable information regarding the modulation of tissue injury as a result of various inflammatory reactions.     

Prevention of experimental autoimmune uveoretinitis and experimental autoimmune pinealitis in (Lewis x Brown-Norway) F1 rats by HgCl2 injections.

Mercuric chloride (HgCl2) induces in Brown-Norway (BN) and (Lewis x Brown-Norway) F1 hybrid rats a transient autoimmune disease characterized by the production of various antibodies to self and non-self antigens and by a dramatic increase of serum IgE. Experimental autoimmune uveoretinitis (EAU) can be induced in Lewis (LEW) and (LEW x BN) F1 hybrid rats by a single immunization with retinal S-antigen (S-Ag). Besides uveoretinitis, animals immunized with S-Ag develop an autoimmune pinealitis (EAP). We demonstrate in this study that (LEW x BN) F1 hybrid rats, injected with HgCl2 7 days before S-Ag immunization, are quite efficiently protected against EAU and EAP. We also show that HgCl2-induced protection is neither due to a cytotoxic effect of HgCl2 nor to CD8+ T-cell dependent mechanisms nor to the HgCl2-induced increase of serum IgE concentration. The role of other hypothetical mechanisms, such as anti-S-Ag anti-idiotypic antibodies and/or HgCl2-induced unbalance between T-helper cell subsets, is discussed.     

Sequential study of the histopathology and cellular and humoral immune response during the development of an autoimmune orchitis in Wistar rats

Wistar rats immunized with an homologous testicular homogenate (TH) and complete Freund's adjuvant, followed by i.v. injection of Bordetella pertussis, developed an autoimmune orchitis (EAO). Animals were studied at 7, 16, 30, 50, and 80 days (d) after the first immunization. An important lesion of the testis only appeared at 50 d, increasing in severity and incidence (77%) at 80 d. Lesions were characterized by a prevalent aspermatogenesis with tubular atrophy and mild interstitial mononuclear infiltrates. Delayed-type hypersensitivity response (DTH) against TH was detected early at 7 d and, except for 16 d, it increased with time, reaching a maximum at 80 d. A good temporal relationship between DTH and histopathology was found. Circulating antibodies to TH, detected by ELISA, were only present in 64% of the animals with testis lesion, while no deposits of IgG or C3 in the seminiferous tubules were seen. We describe a sequence of immunological events, concomitant with pathological changes of the testis, during the development of a severe EAO in Wistar rats.     

ACTH response induced in capsaicin-desensitized rats by intravenous injection of interleukin-1 or prostaglandin E.

1. We investigated whether afferent nerves are involved in the development of adrenocorticotrophic hormone (ACTH) responses induced either by systemic administration of interleukin-1 beta (IL-1 beta) and prostaglandin E2, or by psychological stress. The capsaicin desensitization method was used to impair afferent C fibres and we compared the ACTH responses between capsaicin desensitized and vehicle pretreated control rats. 2. The present results showed that the capsaicin desensitized rats had significantly smaller increases in plasma ACTH than the control rats in response to intravenous injection of IL-1 beta or prostaglandin E2. 3. There were no significant differences between the capsaicin desensitized and control rats in the ACTH responses induced by cage switch stress. 4. The capsaicin desensitized rats responded to intravenous injection of corticotrophin releasing factor (CRF) with a greater increase in the plasma level of ACTH than the control rats, indicating that capsaicin pretreatment resulted in augmentation of pituitary gland sensitivity to CRF. 5. These results suggest that afferent neurons play an important role in the ACTH responses induced by systemic injection of IL-1 beta or prostaglandin E2.     

Vitamin E supplementation suppresses prostaglandin E1(2) synthesis and enhances the immune response of aged mice

The potential for vitamin E to modulate prostaglandin metabolism and alter immune response in aged mice was studied. Semi-purified diets containing 30 ppm or 500 ppm dl-alpha-tocopheryl acetate (VitE) were fed for 6 weeks to young (3 months) and old (24 months) C57BL/6J mice. Delayed hypersensitivity skin test to DNFB and the proliferative response of splenocytes to T- and B-cell mitogens were assessed. Ex-vivo synthesis of Prostaglandin E2 (PGE2) was measured in spleen homogenates and serum vitamin E was measured by HPLC. Vitamin E supplementation of aged mice enhanced percent ear swelling to DNFB as well as the mitogenic response of splenocytes to Con A and LPS (P less than 0.05). Furthermore, spleen homogenates from old mice fed 30 ppm VitE had a significantly higher PGE2 level than young mice fed 30 ppm VitE and old mice fed 500 ppm VitE (3.20 +/- 0.07 micrograms/g vs. 2.60 +/- 0.08 and 2.3 +/- 0.10, respectively). Thus, the vitamin E enhanced immune response of aged mice appears to be mediated by decreased prostaglandin synthesis.     

Effect of the antitumor antibiotic chromomycin A3 on the humoral immune response in rats.

Chromomycin A3 (250 mug/kg) suppressed the humoral immune response in rats against sheep erythrocytes when administered 48 h or later after antigenic stimulus. The antibiotic at this dose enhanced immunity when given along with or before antigen administration. The natural heterohemagglutinin levels in rabbits and guinea pigs were not affected by the antibiotic (10 mug/kg per day x 7).     

Studies on the pathogenesis of experimental autoimmune renal tubulointerstitial disease in guinea-pigs. III. The role of adjuvants in the induction of disease.

Experimental renal tubulointerstitial disease is induced in guinea-pigs by anti-tubular basement membrane autoantibodies. The complete mechanism of mononuclear cell accumulation in the target organ is not known; however, in addition to antibody, complement and radiosensitive leucocytes are important. In the present experiments we explored the influence of adjuvant in the accumulation of mononuclear cells in kidneys of actively or passively immunized guinea-pigs. We found that renal disease could be induced without adjuvant, by multiple injections of rabbit tubular basement membrane. Lesions were comparable to those groups which received a single dose of antigen in Freund's complete or pertussis vaccine adjuvant. Passive transfer of nephritis confirmed that adjuvant is not necessary for either the accumulation of mononuclear cells or the formation of antibodies with particularly potent pathogenicity.     

小鼠自身免疫性心肌炎发病过程中4-1BB/4-1BBL和IL-15的表达及意义

目的： 探讨在小鼠自身免疫性心肌炎发病过程中4-1BB/4-1BBL、IL-15的表达和变化,及其免疫学活性对心肌炎的影响。方法：将提纯的猪心肌肌球蛋白和完全弗氏佐剂等体积混合成乳浊液在1 d、8 d及30 d免疫具有遗传易感性的BALB/c小鼠,建立实验性自身免疫性心肌炎（EAM）模型。对照组小鼠仅用完全弗氏佐剂皮下注射。分别于初次免疫后21 d、80 d进行心肌炎症评分及血清肌钙蛋白I(cTnI)测定,免疫组化检测心肌淋巴细胞活化诱导受体配体（4-1BBL）的表达,ELISA法检测血清白细胞介素-15(IL-15)的浓度,RT-PCR技术检测4-1BB/4-1BBL和IL-15 mRNA在小鼠心肌组织中的表达。结果：在急性期21 d,EAM组小鼠心肌组织见不同程度的炎性细胞浸润和心肌细胞变性坏死、血清cTnI水平升高（P<0.05）;80 d EAM组小鼠心肌组织炎症减弱伴有纤维化出现、cTnI较前期降低;心肌4-1BBL和血清IL-15在EAM组中表达明显,在对照组中少量表达（P<0.05）;21 d EAM组小鼠心肌组织中4-1BB/4-1BBL和IL-15基因表达水平均高于对照组(P<0.01),且与心肌炎症呈明显的正相关,80 d时表达仍然升高(P<0.05)。结论：4-1BB/4-1BBL和IL-15在EAM小鼠发病过程中的表达上调,4-1BB/4-1BBL共刺激通路和IL-15可能协同参与了自身免疫性心肌炎的发生发展过程。     

Assessment of the humoral immune response against Plasmodium falciparum rhoptry-associated proteins 1 and 2.

Naturally occurring antibody responses to Plasmodium falciparum rhoptry-associated proteins 1 and 2 (RAP-1 and RAP-2) were measured with recombinant and parasite-derived forms of the antigens. For comparative purposes, responses to multiple forms of three other malarial antigens were also examined. The sera of 100 Papua New Guineans were screened for antibodies. Eighty-six and 82% of individuals over 30 years of age had antibodies that recognized parasite-derived RAP-1 and RAP-2, respectively. Importantly, we found that recombinant and native antigens share linear epitopes seen by the human immune system; thus, the recombinant proteins may be adequate human immunogens. However, antibodies affinity purified on recombinant RAP-1 reacted with other antigens in addition to parasite-derived RAP-1. Thus, the antigenicity of RAP-1 may have been overestimated previously. The recognition of RAP-1 and RAP-2 correlated with age and with the recognition of recombinant forms of the ring-infected erythrocyte surface antigen, merozoite surface protein 1, and merozoite surface antigen 2 (MSA2) antigens. Antibodies to these antigens appear to be generated in response to the total exposure to malaria of the host. Antibodies to conserved regions of MSA2 had stronger correlations with both age and the recognition of other antigens than did the full-length recombinant MSA2 molecule. In contrast to results with the other antigens, there was no significant difference in the ages of individuals with a certain antibody titer to the full-length recombinant or parasite-derived MSA2 molecule, but antibodies to these two antigens did correlate with parasitemia. For all antigens tested, antibody levels after two infections can approach the peak levels of antibodies obtained in immune individuals.     

Androgen sensitivity and autoimmune disease. I. Influence of sex and testosterone on the humoral immune response of autoimmune and non-autoimmune mouse strains to sheep erythrocytes.

Sheep erythrocytes sensitized with subagglutinating doses of haemolymph from Botrylloides leachii were found to bind strongly to mouse peritoneal macrophages in vitro. Erythrocytes sensitized with similar agglutinating doses of plant lectins or haemolymph from the fresh water crayfish Cherax destructor did not adhere. The adherence promoted by B. leachii haemolymph appears to be a heteroagglutination reaction mediated by a molecule which binds to lactose-like determinants on both erythrocytes and macrophages.     

Regulation of the immune response in experimental models of autoimmune disorders: resistance of (NZB X NZW)F1 mice to tolerance induction in vivo

Studies were carried out to test whether tolerance to alloantigens and to heterologous proteins could be induced in (NZB X NZW)F1 (B/W) female mice, compared with females of various other mouse strains, including BALB/c, C3H/eb, C57Bl/Ka and (BALB/c X C57Bl/6)F1. Untreated BALB/c and B/W mice were resistant to tolerance induction by deaggregated BSA, while all other strains were susceptible, as indicated by their lack of response to antigen challenge. Tolerance induction to BSA was further potentiated in all mouse strains including BALB/c with the exception of B/W, following prior conditioning of the mice with total lymphoid irradiation (TLI). Similarly, specific and permanent tolerance to H-2 incompatible alloantigens was successfully induced in TLI conditioned BALB/c, C3H/eb, (BALB/c X C57Bl/6)F1 injected with bone marrow cells, however, B/W mice were resistant. Stable chimeras could be established in TLI treated B/W mice only across a semi-allogeneic combination (BALB/c--greater than B/W). No graft vs host disease (GVHD) was observed in any of the chimeras including B/W mice. We conclude that B/W mice are resistant to tolerance induction to heterologous proteins and alloantigens, even after TLI conditioning. We postulate that this phenomenon is a function of both the intrinsic properties of the haemopoietic stem cells, including their differentiated progeny, as well as characteristics of their cellular microenvironment.     

The immune response in the hamster. 3. Selective induction of concomitant antibody formation and unresponsiveness in the 7S 1 - and 7S 2 -globulins with soluble hen egg albumin

Synthesis of antibody to hen egg albumin (HEA) was restricted to one of the 7S immunoglobulins (7Sγ₁-globulin) when hamsters were inoculated with soluble HEA (HEA—saline). This selective induction occurred regardless of the amount of HEA—saline injected (0.001–5.0 mg) or the route of inoculation. In contrast, HEA in Freund''s adjuvants induced synthesis of anti-HEA in both the 7Sγ₁- and 7Sγ₂-globulins, even when as little as 0.1 μg of HEA was used. Repeated inoculations of hamsters with HEA—saline increased or maintained 7Sγ₁-antibody, but did not induce anti-HEA synthesis in the 7Sγ₂-globulins. The results of cell transfer experiments indicated that cells from HEA—saline treated hamsters were primed to synthesize 7Sγ₁ anti-HEA and were specifically unresponsive for 7Sγ₂ anti-HEA synthesis. Selective induction of antibody production and unresponsiveness, concomitantly, within different immunoglobulin classes suggests that different antibody induction mechanisms are utilized by these two immunoglobulin classes.     

Involvement of cyclooxygenase-1 and -2 in the sciatic nerve of rats with experimental autoimmune neuritis

The expression of both cyclooxygenase (COX)-1 and COX-2, which are representative enzymes in prostaglandin synthesis, was evaluated in the sciatic nerve of rats with experimental autoimmune neuritis (EAN). Western blot analysis showed that both COX-1 and COX-2 were significantly increased in the sciatic nerve at the peak stage of EAN and declined during the recovery stage. Vascular endothelial cells in normal sciatic nerves immunostained for both COX-1 and COX-2. COX-1 was mainly detected in macrophages, and not in other cell types, while COX-2 was detected in Schwann cells and axons as well as inflammatory macrophages in EAN lesions. This suggests that COXs are involved in the pathogenesis of peripheral demyelinating disease, including EAN, and the major cellular source of both COXs in EAN lesions is inflammatory macrophages. Furthermore, COX-2 is enhanced in some Schwann cells and neural elements, possibly mediating peripheral nervous system inflammation.     

Fine specificity of the humoral immune response to HIV-1 GP160 in HIV-1 infected individuals from Tanzania.

A total of 160 sera from HIV-1 infected individuals from Tanzania were examined for their fine specificity characteristics relative to 9 synthetic peptides that define HIV-1 gp160 epitopes. Immunorecessive and immunodominant epitopes were identified in both gp120 and gp41 based on serologic reactivity of these HIV-1 infected sera. A significant difference in fine specificity among HIV-1 infected individuals from Tanzania and the United States was observed for an immunodominant gp41 epitope. No significant differences in reactivity among asymptomatic vs. symptomatic HIV-1 infected individuals were detected for the selected HIV-1 gp160 epitopes defined by these peptides. The majority of sera from HIV-1 infected Tanzanians contained antibodies that recognized a peptide corresponding to the V3 region of gp120 from the HIV-1 MN isolate. These data suggest that regional isolates of HIV-1 may exist in Tanzania that differ from HIV-1 isolated in the United States. However, based on serology, HIV-1 isolates exhibiting sequences with HIV-1 MN V3 similarity may also be prevalent in Tanzania. The results of this study may be useful for the design of more effective AIDS diagnostic and therapeutic products for use worldwide.     

Increased expression of caveolin-1 and -2 in the hearts of Lewis rats with experimental autoimmune myocarditis

The expression of caveolin-1, -2 and -3 was studied in the hearts of rats with experimental autoimmune myocarditis (EAM), to elucidate the involvement of caveolins in the pathogenesis of EAM. Western blot analysis showed that levels of caveolin-1 and -2 were significantly increased in the hearts of rats with EAM on day 14 post-immunization (pi), as compared to the hearts of normal controls (p < 0.05, normal controls vs. EAM). Caveolin-3 is already at a high level in control animals, so it does not increase further.

Immunohistochemistry showed that caveolin-1 was expressed mainly in ED1-positive macrophages and in some cardiomyocytes and vessels in the EAM lesions. Caveolin-2 was expressed constitutively in the vascular endothelial cells of normal hearts, and its expression was enhanced in EAM rats, as compared with the normal control group. Caveolin-3 was expressed constitutively in the plasma membranes of cardiomyocytes, but not in the vascular endothelial cells and inflammatory cells in the EAM lesions. Our results suggest that the expression of caveolin-1 and -2 is increased in EAM lesions and that the increased expression of caveolin-1 stimulates second signals in affected cells, such as macrophages and some cardiomyocytes, in EAM rats.     

Increased expression of caveolin-1 and -2 in the hearts of Lewis rats with experimental autoimmune myocarditis

The expression of caveolin-1, -2 and -3 was studied in the hearts of rats with experimental autoimmune myocarditis (EAM), to elucidate the involvement of caveolins in the pathogenesis of EAM. Western blot analysis showed that levels of caveolin-1 and -2 were significantly increased in the hearts of rats with EAM on day 14 post-immunization (pi), as compared to the hearts of normal controls (p < 0.05, normal controls vs. EAM). Caveolin-3 is already at a high level in control animals, so it does not increase further.Immunohistochemistry showed that caveolin-1 was expressed mainly in ED1-positive macrophages and in some cardiomyocytes and vessels in the EAM lesions. Caveolin-2 was expressed constitutively in the vascular endothelial cells of normal hearts, and its expression was enhanced in EAM rats, as compared with the normal control group. Caveolin-3 was expressed constitutively in the plasma membranes of cardiomyocytes, but not in the vascular endothelial cells and inflammatory cells in the EAM lesions. Our results suggest that the expression of caveolin-1 and -2 is increased in EAM lesions and that the increased expression of caveolin-1 stimulates second signals in affected cells, such as macrophages and some cardiomyocytes, in EAM rats.     

B-T lymphocyte interactions in experimental autoimmune myasthenia gravis: autoantibody mediated up-regulation of the response of acetylcholine receptor-specific T lymphocytes.

Twenty-six monoclonal antibodies of five different isotypes and reactive against distinct parts (alpha, beta, gamma, delta-subunits) of the nicotinic acetylcholine receptor (AChR) from Torpedo californica were screened for their capacity to enhance activation of AChR-specific CD4+ autoreactive T cells. The T-cell line (LR) used in this study recognized an epitope (98-116) on the alpha-subunit of Torpedo AChR. Four monoclonal antibodies bearing a gamma 2b isotype and recognizing an epitope on the Torpedo AChR alpha-subunit, especially the main immunogenic region (MIR), were able to enhance T-cell activation in a dose-response manner. Four further gamma 2b isotype monoclonal antibodies, recognizing epitopes other than the AChR alpha-subunit, had no effect. Monoclonal antibodies of other isotypes (IgM, IgG1, IgG2a, IgG2c), irrespective of their subunit specificity, were unable to influence the T-cell response. Thus, the enhancement requires a IgG2b isotype, and both the antibody and the T-cell recognize an epitope on the same subunit. We have previously shown that AChR-specific B cells are directly able to present antigen to AChR-specific T-cell lines in a privileged way. The present data demonstrate that B cells are also capable of enhancing indirectly the immunogenicity of autoantigens via their humoral antibodies.