title: Subpopulations of helper T lymphocytes in tuberculous pleurisy.
abstract: Although it is curable, tuberculosis continues to be is a major global public health problem, especially in developing countries. Tuberculous pleural effusion (TPE) is one of the most common forms of extrapulmonary tuberculosis. It has been well documented that CD4(+) T lymphocytes are dominant leukocytes present in TPE. Traditionally, CD4(+) T cells have been classified into two functionally distinct subsets, helper T-cell type 1 (Th1) and Th2 cells, based on their cytokine production profiles. Recently, regulatory T cells, Th17 cells, Th9 cells, and Th22 cells have been added to the 'portfolio' of Th cells. In this review, we summarize recent findings regarding the phenotypic characteristics of the above Th cells, the mechanisms of differentiation and recruitment of Th cells into pleural space, and the immune regulation of Th cells in TPE environment. We also describe the interplay between different Th cells, as well as between Th cells and other type of cells, such as pleural mesothelial cells in TPE. Further studies should be directed at identifying the mediators and mechanisms involved in the immunoregulatory properties of pleural Th cells in tuberculosis infection.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Beijing Chaoyang Hospital, Capital Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing 100020, China.
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Tong
authors.forename: Huan-Zhong
authors.initials: HZ
authors.lastname: Shi
mesh_terms: D006801:Humans; D016906:Interleukin-9 / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology; D014396:Tuberculosis, Pleural / Q000276:immunology*; D000097043:Interleukin-22
chemical_list: D016906:Interleukin-9; D007378:Interleukins; D000097043:Interleukin-22; C508607:IL9 protein, human