Dados do Trabalho

Título

Neutrophils of paucibacillary leprosy patients have decreased phagocytic capacity and low production of IL-8

Introdução

Leprosy is an infectious disease caused by Mycobacterium leprae. One of the most intriguing aspects of leprosy is the development of different clinical forms that directly depend on the immune response developed by the host. Paucibacillary (PB) patients present a strong cell-mediated response against the bacillus, and involvement of Th1 cytokines. On the other hand, multibacillary (MB) patients present progressive reduction of cellular response, increase humoral response and predominance of Th2 cytokines. Although much has been discussed about the development of the immune response in leprosy, the role of neutrophils are unclear. Neutrophils are cells of the innate immune system that can show high plasticity and phenotypic, morphological and functional heterogeneity important for the resolution of infections.

Objetivo (s)

Our objective was to evaluate the heterogeneity of the neutrophilic response of leprosy patients and healthy donors (HD) regarding nuclear morphology, phagocytic capacity, ROS production and IL-8 release.

Material e Métodos

This project is approved by CEP IOC/Fiocruz (CAAE 56113716.5.0000.5248). Neutrophils of PB, MB and HD were isolated from peripheral blood by Ficoll-Paque density gradient technique followed by lysis of red blood cells by ACK. Neutrophils were submitted to cytocentrifugation for the quantification of nuclear segments. Functional assays was performed to evaluate ROS generation, phagocytic capacity and cytokine production by flow cytometry and ELISA.

Resultados e Conclusão

The segmentation analysis revealed no difference in the morphological profile of the cells. The phagocytic capacity was not altered between PB x MB patients. However, it was higher in HD neutrophils after 1h-3h of stimulation with S.aureus BioParticles conjugate, when compared to PB patients. Analysis of ROS production revealed no difference in comparison between groups. Finally, we observed that PB neutrophil released low concentrations of IL-8 compared to HD and MB neutrophils. CONCLUSION: We conclude that neutrophils of PB patients are less responsive to S.aureus, LPS or M.leprae stimulation. These data are preliminary and other aspects related to the neutrophil response need to be investigated.

Palavras-chave

Neutrophils, leprosy

Agradecimentos

A equipe do laboratório de Hanseníase, a equipe e aos pacientes do Ambulatório Souza Araújo, ao programa de pós-graduação em biologia celular e molecular do IOC, a Fiocruz RJ, a Capes e ao CNPq