Non-lethal rodent malarial infection prevents collagen-induced arthritis in mice via anti-arthritic immunomodulation.

AIMS: Immunomodulatory effects of parasitic infections on the outcomes of allergic or autoimmune disorders have been addressed in many experimental studies. We examined the effects of Plasmodium yoelii 17X NL (Py) infection on collagen-induced arthritis (CIA). METHODS AND RESULTS: Male DBA/1J mice were immunized with bovine type II collagen (IIC). Py inoculation was induced at three different time points (1, 4 weeks after or 4 weeks before the immunization). Only the inoculation at 4 weeks after IIC immunization significantly inhibited arthritis development. Non-malarial anaemia induced by phenylhydrazine hydrochloride (PHZ) did not affect arthritis development. In the infected mice, anti-IIC IgG levels were transiently reduced. In addition, splenic production of pro-arthritic cytokines (IL-17 and TNF-α) and IFN-γ decreased, whereas IL-10 production increased. Flow cytometric analysis clarified that the main IL-10 producers in Py-infected mice had the CD4+ CD25- Foxp3- phenotype, presumably Tr1 cells. CONCLUSION: We demonstrated that experimental malarial infection alleviated autoimmune arthritis via immunomodulation, suggesting the importance of malaria in the hygiene hypothesis and the significance of searching for therapeutic immunomodulatory molecules from malarial parasites.

Cardiopulmonary pathology in primary murine toxocariasis.

The cellular infiltration in the 1st week was marked in group III & II compared to group I. Parts of larvae were encountered more in the group III than in group I & II. Eosinophilic alveolar exudate was detected more in group III in subgroups a, b and c, in group II only in subgroup (a) and not in group I. Lobar pneumonia was reported in subgroups a and b, in group III in subgroup a, in group II and not in group I. Cardiomegaly was reported in 7.1%, 10.7% and 64.2% in group I, II and III respectively. Mechanical traumatic effect of larval migration in group III was more than group II, I. The extensive haemorrhagic areas and diffuse cellular in filtrations and parts of larvae were predominant in subgroup (a) of group III in Granulomata & began to appear in subgroup (c). First, it was diffuse then became circumscribed in pleural and subpleural areas. Haemorrhagic areas in the endocardium was observed in 7.1%, 17.8% and 89.3% in groups I, II and III respectively. Foci of cellular infiltration, diffuse interstitial infiltration, granulomas, thickening of blood vessels, necrosis of cardiac muscle and focal fragmentation of muscle fibers were encountered.