title: IL-17 and IFN-γ production in peripheral blood following BCG vaccination and Mycobacterium tuberculosis infection in human.
abstract: BACKGROUND
  During Mycobacterium tuberculosis (Mtb) infection, cells of the immune system rely on cytokines to regulate the activity of other immune and structural cells such as IFN-gamma and IL-4. Recent studies suggest that Th17 cells secreting IL-17 may play a potential role in tuberculosis (TB) development.
  
  
  OBJECTIVE
  To assess the effect of IL-17 on TB development, we provide a systematic review on the production of IL-17, IFN-gamma and IL-4 in infants or children vaccinated with BCG and in TB patients.
  
  
  METHODS
  The literature relevant with IL-17 and IFN-gamma production with or without IL-4 on human TB was retrieved from PubMed, EMBASE, Cochrane Library, BIOSIS Previews and the China Biomedicine Literature Databases (CBM) using the search terms "Interleukin-17 or Th17 cells" and "Tuberculosis". The information of included studies, the production of IL-17 and IFN-gamma responding to antigens in the peripheral blood in vitro, was independently extracted by the first two researchers and subsequently qualitatively analyzed.
  
  
  RESULTS
  Nine studies from a total of 226 retrieved publications met the criteria. These included studies showed that BCG vaccination induced dramatically high level of IL-17 similar to IFN-gamma; The level of IL-17 and IFN-gamma were low while IL-4 was high in patients with active TB; IL-17 and IFN-gamma had a similar trend of increase during the conversion from active to latent TB while IL-4 inclined to decrease in this process.
  
  
  CONCLUSIONS
  IL-17 acts as an effector molecule similar to IFN-gamma after BCG vaccination and Mtb infection to protect human against TB. The current findings do not support IL-17 as an inducer of tissue damage in TB.
authors.affiliation: College of Veterinary Medicine, Gansu Agriculture University, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: Tian
authors.forename: B
authors.initials: B
authors.lastname: Zhu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Ling
authors.forename: Y
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000097:blood*; D059425:Interferon-gamma Release Tests; D020381:Interleukin-17 / Q000097:blood*; D015847:Interleukin-4 / Q000097:blood; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology* / Q000382:microbiology; D014376:Tuberculosis / Q000097:blood / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*
chemical_list: D001500:BCG Vaccine; C508598:IL4 protein, human; D020381:Interleukin-17; D015847:Interleukin-4; D007371:Interferon-gamma