Localization of eosinophil granule major basic protein in paracoccidioidomycosis lesions.

Abstract

Abstract. Paracoccidioidomycosis is a chronic granulomatous disease caused by the fungus Paracoccidioides brasiliensis. Although eosinophils have long been associated with the immune defense against helminths, the role of eosinophils in the immune response to fungal diseases is not as well studied. The eosinophil granule major basic protein is toxic to helminths and mammalian cells in vitro, and its release has been used as a marker of eosinophil localization and degranulation. To determine whether eosinophil infiltration and degranulation, as evidenced by the deposition of major basic protein, occur in lesions of P. brasiliensis, we used an immunofluorescence technique to localize the P. brasiliensis organisms and eosinophils and major basic protein. Initially, all tissues were stained with polyclonal antibody to major basic protein; subsequently, colocalization of major basic protein and P. brasiliensis by double staining with mouse and rabbit antibodies, respectively, was performed. Nine biopsy tissues from seven patients were analyzed. All nine biopsies showed infiltration of intact eosinophils using both the monoclonal and the polyclonal anti-major basic protein antibodies, along with the presence of P. brasiliensis. Furthermore, using the polyclonal antimajor basic protein antibody, nine of nine tissues showed extracellular major basic protein deposition (granular or diffuse fluorescence staining outside of intact eosinophils). The double staining procedure using the anti-major basic protein monoclonal antibody showed extracellular deposition in five of eight biopsies; in these five biopsies, approximately 60% of the areas containing P. brasiliensis had extracellular major basic protein deposited on the organisms. These observations support the hypothesis that the eosinophil, through toxic granule proteins such as major basic protein, participates in the pathophysiology of paracoccidioidomycosis.

Depletion of Neutrophils Exacerbates the Early Inflammatory Immune Response in Lungs of Mice Infected withParacoccidioides brasiliensis

“…Similar findings have been described for coccidioidomycosis in which peripheral eosinophilia and eosinophilic microabscesses are correlated with progressive infection, indicative of a poor prognosis [59–61]. Additional studies support the hypothesis that the eosinophil participates in the pathophysiology of PCM through its toxic granule proteins [62–64]. In 2013, Muniz et al [65] stated that the cytoplasmic granules of eosinophils are able to function as “cluster bombs” amplifying the differential secretory properties of these cells, releasing cationic proteins, cytokines, chemokines, and growth factors which could contribute to the persistence of infection, exacerbation of the inflammatory response, and subsequent death of P. brasiliensis -infected neutrophil-depleted mice observed in the present study.…”

Rat eosinophils stimulate the expansion of Cryptococcus neoformans-specific CD4+ and CD8+ T cells with a T-helper 1 profile

“…16 Although the role of eosinophils in the immune response to fungal infections has not been extensively studied, there are some results suggesting that Coccidioidomycosis, caused by the fungus Coccidioides immitis, may be accompanied by an increase in peripheral blood eosinophils of the order of 3-10%. 17 Moreover, during Paracoccidioidomycosis in humans, Wagner et al 18 have shown a clear association among the presence of Paracoccidioides brasiliensis, infiltration of the lesion by eosinophils and deposition of myelin basic protein (MBP) on the fungus. In this regard, Feldmesser et al 19 have demonstrated in vitro that rat eosinophils phagocytose opsonized C. neoformans yeasts, and they also observed a direct interaction between eosinophils and C. neoformans in vivo during an experimental murine intratracheal infection.…”

Pulmonary immune responses induced in BALB/c mice by Paracoccidioides brasiliensis conidia

“…However, Wagner et al [47] described in human samples that eosinophils were observed in direct association to or nearby P. brasiliensis. Nonetheless, in the majority of the corresponding publications, these cells were ignored, something that could be attributed to the fact that the haematoxylin and eosin stain often fails to show the presence of these cells [47]. In our model, we used special stainings such as Sirius Red to determine the presence of eosinophils (Fig.…”