Heat-Killed Malassezia Pachydermatis Suspension Modulates the Activity of Macrophages Challenged with Encephalitozoon Cuniculi

Abstract Background Encephalitozoon cuniculi, are obligate intracellular fungi that determine emerging diseases in humans and other animals, with economic relevance. Studies have shown that Malassezia are able to modulate the production of pro and anti-inflammatory cytokines by keratinocytes and human monocytes and has an immunomodulatory effect. In the present work, we evaluate the effects of heat-killed M. pachydermatis suspension on the modulation of the response of macrophages challenged with the microsporidia E. cuniculi. Methods Heat-killed M. pachydermatis suspension was used to treat macrophage for 1 hour, subsequently, macrophages were infected with spores of E. cuniculi (2:1) and evaluated at 15, 30, 60 minutes and 48 hours. To determine the phagocytic capacity (PC) and index (PI), cultures were stained with Calcofluor and the spores, internalized or not, were counted. Results Microbicidal and phagocytic activity was evaluated by transmission electron microscopy (TEM). The untreated macrophages and had PC, PI, and larger amounts of phagocytosed spores than those treated, but by TEM it was observed that in macrophages treated the microbicidal activity was faster, since in the phagocytic vacuoles there were few spores in different degrees of degeneration and few amounts of amorphous material. Macrophages treated with heat-killed M. pachydermatis suspension showed lower PI and PC, with the incipient presence of E. cuniculi in phagosomes inside these macrophages. Additionally, these same treated macrophages had a mixed pattern of cytokine release with a Th1, Th2 and Th17 profile, with emphasis on IL-10, IL-4, IL-17, IL-6 and IFN-g secretion, particularly greater production of anti-inflammatory cytokines. Conclusions Our results showed that the treatment with heat-killed M. pachydermatis suspension determined an increase in the release of cytokines and reduced the phagocytic activity of macrophages challenged with E. cuniculi