Increased frequency of NK and gamma delta 1 T cells in a cohort of patients with sepsis

Abstract

ABSTRACT: Introduction: The mechanisms involved in the immunopathogenesis of sepsis are not well established. The clinical and therapeutic relevance of several soluble mediators has been described and the contribution of cellular components with immunoregulatory roles has begun to be elucidated. Objective: To describe changes in the frequency and production of IFN-γ and IL-10 occurring in NK cells and γδ T lymphocytes in a cohort of patients with different manifestations of septic syndrome. Materials and methods: This was a prospective cohort study. Patients with sepsis (n=26), and severe sepsis (n=83) from adult emergency rooms and intensive care units, as well as healthy volunteers (n=8), were included. For all participants, the frequency and phenotype of NK cells and γδ T lymphocytes and the percentage of IFN-γ and IL-10 positive NK and γδ T cells were evaluated by flow cytometry. The NK cells were phenotyped based on the expression of CD56 and CD16 and the γδ T cells on the expression of δ1 and δ2 chains. Results: Patients with sepsis and severe sepsis exhibited an increase in the frequency of NK cells with changes in the proportion of the CD56bright/CD16¯, CD56bright/CD16dim and CD56dimCD16¯ subpopulations; these cells showed a proinflammatory cytokine profile. A decrease in the Vδ2 subset of γδ T lymphocytes was also observed. Conclusions: Our results indicate a role for NK and γδT cells during sepsis, however, their exact contribution in the pathogenesis of sepsis syndrome requires further studies.