Biography
Daniela Ramos Rodrigues has completed her PhD in 2013 from the Universidade Estadual Paulista. She is currently a Postdoctoral fellow from the same university and immunology paracoccidioidomycosis is her main area of research.
Abstract
Paracoccidioidomycosis is a systemic mycosis, endemic to most Latin American countries, especially in Brazil, whose etiologic agent is the thermo dimorphic fungus of genus Paracoccidioides, comprising cryptic species of Paracoccidioides brasiliensis (Pb), S1, PS2, PS3 and Paracoccidioides lutzii. Studies aiming to characterize the immune response of the infected host have focused on the role of different subsets of CD4+ cells with special interest for the mechanisms involved in the preferential induction of either of them, which are largely dependent on the initial interaction of the fungus with cells of the innate immune response. Neutrophils were recently shown to influence the activation of different leukocyte types including NK cells, B cells and DCs. Therefore, neutrophils by regulating DCs recruitment and activation may have an important role in the development of adaptive immune response. Here, we aimed to evaluate whether human PMNs sensitized with the fungus are able to modulate DCs capacity to induce naïve CD4+ T cells proliferation. Peripheral blood PMNs obtained from 9 healthy donors were sensitized with Pb18 and/or Pb265 for 48 hours, co-cultured with autologous DCs by 48 hours followed by co-culture with autologous CD4+ cells by 120 hours. Phytohemaglutinin (PHA) was used as positive control to CD4+ cells proliferation. We found that neutrophils sensitized with Pb18 or Pb265 activate DCs to induce an intense CD4+ cells proliferation. We concluded that a crosstalk between neutrophils and DCs may be very important for induction of the host adaptive immune response against P. brasiliensis.
Biography
Reginaldo Keller Fernandes has completed his Master’s degree from Universidade Estadual Paulista and currently pursuing his Doctoral studies at the same university. He is studying Immunology of Paracoccidioidomycosis. He has also published 5 papers in reputed journals.
Abstract
Paracoccidioidomycosis is a systemic mycosis, endemic to most Latin American countries, especially in Brazil, whose etiologic agent is the thermo dimorphic fungus of the genus Paracoccidioides, comprising cryptic species of Paracoccidioides brasiliensis (Pb), S1, PS2, PS3 and Paracoccidioides lutzii. The consequences of the fungus interaction with cells of the innate immune response, such as dendritic cells (DCs), highlighting the ability of these cells to instruct the adaptive immune response are not fully understood. In a previous study we found that human monocytes derived DCs fail to adequately mature in response to Pb. Thus, we aimed to evaluate whether these cells are able to induce CD4 proliferation and what is the predominant profile of the proliferated cells. Human DCs obtained from in vitro differentiation of monocytes were challenged with more (Pb18) and less virulent (Pb265) fungus strains during 48 hours, followed by co culture with CD4+ cells by 48 hours to 120 hours. Phytohemaglutinin (PHA) was used as positive control to CD4+ cells proliferation. Our results showed which dendritic cells challenged with Paracoccidioides brasiliensis induce Treg response. These findings may provide novel information for the understanding of the complex interplay between the host and this fungus.