Caracterização da microbiota cutânea e análise da resposta imunológica em pacientes com
dermatite seborreica e seus familiares

Funding agency: Sao Paulo Research Foundation

Researchers: Luciana Paulino (PI), Humberto Cavallin (collaborator)

Human skin is home to different microorganisms, including bacteria and fungi. A large part of the fungi that inhabit healthy human skin belong to the Malassezia genus, which are also associated with skin diseases, among them seborrheic dermatitis (SD). SD is a disease of high prevalence worldwide, characterized by the occurrence of itching and flaking, especially in the scalp. The role that fungi of the genus Malassezia play in SD is still not completely elucidated, and probably the host’s immune response also plays an important role in the pathogenic process. The bacterial microbiota of healthy skin is quite diverse, but the genera Propionibacterium, Corynebacterium and Staphylococcus are among the most frequently found. The processes of acquisition, transmission and interactions between fungal and bacterial microbiotes are still poorly understood. This work aims to characterize the fungal and bacterial microbiotas of healthy skin and SD patients, to investigate the transmission of microorganisms between members of the same family and the environment where they reside, and to analyze the local and systemic immune response. For this purpose, skin samples from three areas of the body will be obtained from healthy individuals and patients with SD, as well as their family members (five families from each group), samples from their homes and pets. Microbial communities will be evaluated by large-scale sequencing using universal primers for fungi and bacteria that respectively amplify the ITS1 region and the 16S gene of the ribosomal RNA operon. The relative expression in the skin of genes that code for IFN-³, IL-1 ±, IL-2 and IL-8 will be studied by means of real-time quantitative PCR, and the systemic response will be analyzed through the quantification of serum levels of same cytokines using ELISA. The study of the skin microbiota together with the local and systemic immune response will bring a new perspective for understanding the pathogenic process of skin disease whose etiology has not yet been elucidated. (AU)