Review Article Complexity and Controversies over the Cytokine Profiles of T Helper Cell Subpopulations in Tuberculosis

Copyright © 2015 Marcos Vinicius da Silva et al.This is an open access article distributed under theCreative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the originalwork is properly cited. Tuberculosis (TB) is a contagious infectious disease caused by the TB-causing bacillusMycobacterium tuberculosis and is considered a public health problem with enormous social impact. Disease progression is determined mainly by the balance between the microorganism and the host defense systems. Although the immune system controls the infection, this control does not necessarily lead to sterilization. Over recent decades, the patterns of CD4+ T cell responses have been studied with a goal of complete understanding of the immunological mechanisms involved in the maintenance of latent or active tuberculosis infection and of the clinical cure after treatment. Conflicting results have been suggested over the years, particularly in studies comparing experimental models and human disease. In recent years, in addition toTh1,Th2, andTh17 profiles, new standards of cellular immune responses, such as Th9, Th22, and IFN