Evaluation of Interleukin17and Interleukin 23 expression in patients with active and latent tuberculosis infection

Abstract

<strong><em>Objective(s)</em></strong>: Tuberculosis is one of the most important infectious diseases with high mortality rates worldwide, especially in developing countries. Interleukin17 (IL-17) is an important acquired immunity cytokine, which is mainly produced by CD4⁺TH17 cells. It can recruit neutrophils and macrophages to the infected site in the lungs. IL-23 is one of the most important inducers of IL-17. In the present study, the expressions of IL-23 and IL-17 were examined in the pathogenesis of tuberculosis. <br/><strong><em>Materials and Methods: </em></strong>Peripheral blood mononuclear cells (PBMCs) were isolated from subjects with latent tuberculosis infection (LTB) and newly diagnosed active tuberculosis patients (ATB). <br/>PBMCs were activated with purified protein derivative (PPD) for 72 hr. Activated cells were harvested, RNA was extracted, and cDNA was synthesized. IL-17 and IL-23 mRNA expressions were evaluated by real-time PCR. The frequency of Th17 cells was examined by flowcytometry. <br/><strong><em>Results: </em></strong>The expressions of IL-17 and IL-23 mRNA were lower in patients than subjects with LTB (<em>P</em><0.05). The frequency of IL-17 producing CD4+ T cells in patients with active TB was lower than LTB subjects (<em>P</em><0.05). <br/><strong><em>Conclusion:</em></strong> The results of the present study might suggest that IL-17 and IL-23 play critical roles in the immune response against TB.