Group A streptococcal antigen exposed rat model to investigate neurobehavioral and cardiac complications associated with post-streptococcal autoimmune sequelae

Background:The neuropsychiatric disorders due to post-streptococcal autoimmune complications such as Sydenham's chorea(SC)are associated with acute rheumatic fever and rheumatic heart disease(ARF/RHD).An animal model that exhibits char-acteristics of both cardiac and neurobehavioral defects in ARF/RHD would be an important adjunct for future studies.Since age,gender,strain differences,and geno-types impact on the development of autoimmunity,we investigated the behavior of male and female Wistar and Lewis rat strains in two age cohorts(6 weeks and 12 weeks)under normal husbandry conditions and following exposure to group A streptococcus(GAS).Methods:Standard behavioral assessments were performed to determine the impair-ments in fine motor control(food manipulation test),gait and balance(beam walk-ing test),and obsessive-compulsive behavior(grooming and marble burying tests).Furthermore,electrocardiography,histology,and behavioral assessments were per-formed on male and female Lewis rats injected with GAS antigens.Results:For control Lewis rats there were no significant age and gender dependent differences in marble burying,food manipulation,beam walking and grooming be-haviors.In contrast significant age-dependent differences were observed in Wistar rats in all the behavioral tests except for food manipulation.Therefore,Lewis rats were selected for further experiments to determine the effect of GAS.After ex-posure to GAS,Lewis rats demonstrated neurobehavioral abnormalities and cardiac pathology akin to SC and ARF/RHD,respectively.Conclusion:We have characterised a new model that provides longitudinal stability of age-dependent behavior,to simultaneously investigate both neurobehavioral and cardiac abnormalities associated with post-streptococcal complications.

Influence of Yanyankang Powder (眼炎康散) on Th1/Th2 in Rats with Experimental Autoimmune Uveitis

Objective： To study the influence of Yanyankang Powder （眼炎康散） on Th1/Th2 in rats with experimental autoimmune uveitis （EAU）. Methods： The EAU models were induced in Lewis rats by immunization with interphotoreceptor retinoid binding protein （IRBP） 1177-1191 in complete Freund＇s adjuvant. The rats were randomly divided into 3 groups： a model control group, a Yanyankang group, and a prednisone group, 9 rats in each group. The model control group was intervened with saline solution by gavage. The Yanyankang group was intervened with Yanyankang Powder 4 g/（kg·day） by gavage. The prednisone group were intervened with prednisone acetate tablets 5 mg/（kg·d） by gavage. All groups were intervened after immunization once every 2 days for 18 days and monitored by slit-lamp biomicroscopy daily until day 18. The levels of gamma interferon （INF-γ） and interleukin-10 （IL-10） in the supernatants of T cells were determined by enzyme-linked immunosorbent assay. Polymerase chain reaction （PCR） technology was used for measuring Thl and Th2 related cytokine mRNA expressions. Results： Slighter intraocular inflammation was found in the Yanyankang group and the prednisone group than the control group. The levels of the IFN-γ and IL-10 in the supernatants of the spleen lymph node cells were 382.33±6.30, 155.87±4.46 μg/L in the Yanyankang group and 270.93 ± 7.76, 265.32 ± 11.88 μg/L in the prednisone group. Both had significant differences compared with the control group （941.53± 8.59, 20.67± 4.65 μg/L; P=0.01）. The PCR results showed the same tendency. Conclusion： Yanyankang Powder showed favorable effects in the rats with EAU by influencing the function of Th1 and Th2 cells.