Induction Of Experimental Allergic Orchitis Research Articles

1055 Effects of nitric oxide on the induction of experimental allergic orchitis in the mouse

1055 Effects of nitric oxide on the induction of experimental allergic orchitis in the mouse

Effects of Nitric Oxide on the Induction of Experimental Allergic Orchitis in Guinea Pig

Background: Production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathology of autoimmune disease. It is unknown whether iNOS expression is increased within testes and whether iNOS and NO have essential roles in the pathogenesis of EAO. Methods: EAO was induced in guinea pig testes at 17 days after secondary immunization by administration of crude extract (CE) and purified glycoprotein 1 (GP1) from normal guinea pig testes. iNOS gene expression was assessed by RT-PCR and Northern blot analysis in testes. Localization of iNOS and Mac-1 and the indicator of NO-mediated tissue injury, nitrotyrosine, were detected in the testicular lesion by immunohistochemistry. Results: In control testes, inflammation and iNOS gene expression were not detected, whereas, in CE- and GP1-injected testes, inflammation and marked iNOS gene expression were evident at day 17 after secondary immunization. Immunohistochemistry of Mac-1 showed the colocalization with iNOS protein and nitrotyrosyl proteins in intertubules, suggesting that NO produced by infiltrated macrophages may be involved in inflammatory lesions of intertubules. Intraperitoneal administration of aminoguanidine significantly prevented EAO with reduction of inflammation, iNOS expression and nitrotyrosine formation. Conclusion: These results suggest that NO production by macrophages may be important in the pathogenesis of CE- and GP1-induced EAO. Furthermore, this study demonstrated the therapeutic potential of iNOS inhibitor in the treatment of inflammatory and autoimmune mediated-diseases.

Experimental allergic orchitis in mice. V. Resistance to actively induced disease in BALB/cJ substrain mice is mediated by CD4 + T cells

Previous studies have shown that differential susceptibility to actively induced experimental allergic orchitis (EAO) exists among various BALB/c substrains. Of 13 substrains studied, BALB/cJ mice consistently exhibit greater resistance to disease induction. Such resistance is associated with a single recessive genotypic difference in an immunoregulatory locus which is unlinked to any of the known alleles distinguishing the BALB/cJ substrain. In this study, gene complementation protocols were used to study the genetics of susceptibility and resistance to EAO. The results indicate that resistance in BALB/cJ mice is not due to a mutation in the H-2Dd linked gene which governs the phenotypic expression of autoimmune orchitis. The mechanistic basis for disease resistance was examined using reciprocal bone marrow radiation chimeras generated between the disease-susceptible BALB/cByJ (ByJ) substrain and BALB/cJ (Jax) mice. All constructs, including Jax----Jax and Jax----ByJ, developed severe EAO following inoculation with mouse testicular homogenate (MTH) and adjuvants whereas control chimeras immunized with adjuvants alone did not. These results suggest that an active immunoregulatory mechanism rather than a passive one, such as the lack of T cells and/or B cells with receptors for the aspermatogenic autoantigens relevant in the induction of EAO, is responsible for disease resistance in BALB/cJ mice. The role of immunoregulatory cells was examined by pretreating BALB/cJ mice with either cyclophosphamide (20 mg/kg) or low-dose whole body or total lymphoid irradiation (350 rads) 2 days prior to inoculation. BALB/cJ mice immunized with MTH plus adjuvants generate immunoregulatory spleen cells (SpCs) that, when transferred to naive BALB/cByJ recipients, significantly reduce the severity of autoimmune orchitis observed during actively induced EAO. Treatment of such cells with either cytotoxic monoclonal anti-Thy-1.2 or anti-CD4 plus C' before transfer abrogates the ability of BALB/cJ spleen cells to inhibit disease. In contrast, neither SpCs from adjuvant-immunized BALB/cJ nor MTH plus adjuvant-primed BALB/cByJ donors significantly influenced the severity of disease observed in recipients. Taken together, these results suggest that genetically controlled resistance to EAO in BALB/cJ mice is associated with a mutation in an immunoregulatory locus whose effects appear to be mediated through a cyclophosphamide and low-dose radiation-sensitive CD4+ T-cell population.

Actively induced experimental allergic orchitis in lewis-resistant (Le-R) Rats: Reversibility of disease resistance by immunization with Bordetella pertussis

Differential susceptibility to the induction of experimental allergic orchitis (EAO) was examined in Lewis/NCr and Le-R subline rats. Lewis/NCr rats were found to be fully susceptible to the induction of EAO whereas Le-R subline rats were not. Disease resistance exhibited by Le-R rats could be overcome by including Bordetella pertussis in the immunization protocol. However, reversal of resistance with B. pertussis was dependent on the dose of rat testicular homogenate in the inoculum and found to be effective only at lower doses of antigen (10 mg/rat). Disease resistance in Le-R rats as well as B. pertussis-induced reversal of resistance did not appear to be associated with either (1) a significant difference in the number of mast cells in the ductus efferentes, the anatomic location of the earliest inflammatory infiltrates, or (2) an alteration in the phenotypic expression of either innate or B. pertussis-induced sensitivity to vasoactive amines. The results are discussed in the context of the role of B. pertussis in other animal models of organ-specific autoimmune diseases. It is proposed that the phenotypic expression of resistance to EAO in Le-R rats is a result of a mutation in a common regulatory locus affecting susceptibility to multiple autoimmune diseases and whose immunoregulatory action is normally exerted during the sensitization phase of the immune response.

Serum Testosterone (T) Levels in Balb/CBYJ and Balb/CJ Substrain Mice: Potential Relationship with Differential Susceptibility to Experimental Allergic Orchitis (EAO)

BALB/cByJ substrain mice are highly susceptible to the induction of EAO whereas BALB/cJ mice are resistant. BALB/cJ mice have been reported to have elevated levels of serum T, which may account for disease resistance in light of its purported immunosuppressive effects. Serum T levels were determined by radioimmunoassay on 40 BALB/cByJ and 41 BALB/cJ age matched male mice. Our results indicate that the two substrains do not differ significantly from each other in their mean serum T levels (BALB/cByJ-4.50 ng/ml and BALB/cJ-3.16 ng/ml; p = 0.601) suggesting that the EAO resistant phenotype exhibited by BALB/cJ mice is not a result of the immunosuppressive effects of T.

Experimental allergic orchitis in mice: III. Differential susceptibility and resistance among BALB/c sublines

Significant differences in susceptibility to the induction of experimental allergic orchitis (EAO) were found to exist among the various substrains of BALB/c mice. Substrains which were susceptible to disease induction include BALB/cKa, BALB/cByJ, BALB/cWtJ, BALB/cCmcCr, BALB/cCrgl, BALB/cHeA, BALB/cAnNCr, BALB/cPt, BALB/cWehiUnm, BALB/cOrnl and BALB/cArg whereas BALB/cJ and BALB/cSki BoyPt were resistant to EAO. Aspermatogenesis and autoimmune vasitis, two additional lesions characteristic of murine EAO, were found to correlate with susceptibility to autoimmune orchitis. Susceptibility and/or disease resistance did not segregate within any of the evolutionary branches of the BALB/c genealogic tree nor did it correlate with any of the previously described allelic differences distinguishing BALB/c substrains. Therefore, differential disease susceptibility may represent the manifestation of mutational and/or retroviral induced genotypic differences in the regulatory genes controlling testicular autoimmunity.

Experimental allergic orchitis in mice. I. Genetic control of susceptibility and resistance to induction of autoimmune orchitis.

Inbred strains of mice were studied for their susceptibility to the induction of experimental allergic orchitis after sensitization with mouse testicular homogenate in complete Freund's adjuvant accompanied by injections of extract from Bordetella pertussis. Susceptibility to autoimmune orchitis was found to be linked to the major histocompatibility complex in BALB/c and C57BL/10 mice and mapped to genes encoded within the H-2Dd region. In five of six groups of bidirectional (susceptible X resistant)F1 hybrids, H-2Dd-linked susceptibility was inherited as a dominant autosomal trait. However, in (BALB/cByJ X DBA/2J)F1 and (DBA/2J X BALB/cByJ)F1 hybrids, dominant autosomal resistance to the induction of autoimmune orchitis was observed. Backcross analysis between the resistant F1 hybrid and the susceptible BALB/cByJ parent suggests that a single independently segregating DBA/2J locus is capable of negating H-2Dd-linked susceptibility, and controls resistance to the induction of autoimmune orchitis.

In vivo effects of cyclosporin A: abrogation of the induction of experimental allergic orchitis and sparing of the generation of suppressor cells.

Cyclosporin A (CyA; 10 mg/kg/day) administration for 14 days, starting on the day of immunization with testicular antigen (TA) in complete Freund's adjuvant (CFA), almost completely abrogated the induction of experimental allergic orchitis (EAO), delayed skin reactivities to both TA and purified protein derivative of tuberculin (PPD), and antisperm antibody response in strain 13 guinea pigs when examined 2 weeks after immunization. The unresponsive state induced was of a transitory nature. After cessation of CyA treatment, EAO-eliciting capability and cellular immune responsiveness recovered in relatively short time, while restoration of humoral immune responsiveness was delayed. Transfer of lymph node cells taken from CyA-treated, EAO-suppressed animals at 2 weeks postimmunization into normal syngeneic recipients inhibited the induction of EAO and delayed skin response. The suppressor cell activity appeared to be at least in part antigen-specific. It seems likely, therefore, that the profound suppression of EAO by CyA could be explained as due to the additive effect of the inhibition of helper/inducer T cell generation and the sparing or activation of suppressor cell populations.

Lymphocyte proliferative response in vitro and its cellular dependency in guinea-pigs with experimental allergic orchitis.

The development of cellular hypersensitivity was measured by the proliferative response of lymph node cells in vitro and a skin test to partly purified testicular antigen. There was a slight stimulation of lymph node cells and of the delayed cutaneous response at 1-2 weeks after sensitization with testicular antigen in Freund's complete adjuvant and then, after a decline in response, there was a pronounced peak at 6 weeks after sensitizaton. The early response coincided with the onset and active inflammatory stage of the effect on the testis, while the major peak was consistent with a state of aspermatogenesis. The proliferative response of unseparated lymph node cells could not be attributed to the function of T or B cells acting alone, although at 6 weeks after sensitization B-cell populations did become slightly responsive to antigen. The response of T lymphocytes was enhanced by the presence of B lymphocytes or peritoneal macrophages at 2 and 6 weeks after sensitization, but B cells did not appear to interact with macrophages. We conclude that T cells are essential to the proliferative response of lymph node cells during the induction of experimental allergic orchitis in guinea-pigs.

Immunological effects of thermal injury. I. Inhibition of spermatogenesis in guinea pigs.

Unilateral thermal injury to guinea pig testes has elicited the formation of organ- and species-specific antibodies against a testicular antigen. The antibodies were of an IgG1 nature, and reacted with autologous as well as homologous testicular extracts. A significant number of burned animals showed pathological changes in the contralateral testis, which were similar to those observed after the induction of experimental allergic orchitis by active immunization with testicular tissue. These results indicate that thermal injury may be associated with autoimmunization of the host by the injured organ.