Vitamin D rescues impaired Mycobacterium tuberculosis-mediated tumor necrosis factor release in macrophages of HIV-seropositive individuals through an enhanced Toll-like receptor signaling pathway in vitro

Infect Immun. 2013 Jan;81(1):2-10. doi: 10.1128/IAI.00666-12. Epub 2012 Oct 15.

Abstract

Mycobacterium tuberculosis disease represents an enormous global health problem, with exceptionally high morbidity and mortality in HIV-seropositive (HIV(+)) persons. Alveolar macrophages from HIV(+) persons demonstrate specific and targeted impairment of critical host cell responses, including impaired M. tuberculosis-mediated tumor necrosis factor (TNF) release and macrophage apoptosis. Vitamin D may promote anti-M. tuberculosis responses through upregulation of macrophage NO, NADPH oxidase, cathelicidin, and autophagy mechanisms, but whether vitamin D promotes anti-M. tuberculosis mechanisms in HIV(+) macrophages is not known. In the current study, human macrophages exposed to M. tuberculosis demonstrated robust release of TNF, IκB degradation, and NF-κB nuclear translocation, and these responses were independent of vitamin D pretreatment. In marked contrast, HIV(+) U1 human macrophages exposed to M. tuberculosis demonstrated very low TNF release and no significant IκB degradation or NF-κB nuclear translocation, whereas vitamin D pretreatment restored these critical responses. The vitamin D-mediated restored responses were dependent in part on macrophage CD14 expression. Importantly, similar response patterns were observed with clinically relevant human alveolar macrophages from healthy individuals and asymptomatic HIV(+) persons at high clinical risk of M. tuberculosis infection. Taken together with the observation that local bronchoalveolar lavage fluid (BALF) levels of vitamin D are severely deficient in HIV(+) persons, the data from this study demonstrate that exogenous vitamin D can selectively rescue impaired critical innate immune responses in vitro in alveolar macrophages from HIV(+) persons at risk for M. tuberculosis disease, supporting a potential role for exogenous vitamin D as a therapeutic adjuvant in M. tuberculosis infection in HIV(+) persons.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bronchoalveolar Lavage Fluid / immunology
  • Cell Line
  • HIV Seropositivity / immunology
  • HIV Seropositivity / metabolism
  • HIV Seropositivity / microbiology*
  • Humans
  • Lipopolysaccharide Receptors / genetics
  • Lipopolysaccharide Receptors / immunology
  • Lipopolysaccharide Receptors / metabolism
  • Macrophages, Alveolar / drug effects
  • Macrophages, Alveolar / immunology*
  • Macrophages, Alveolar / metabolism
  • Macrophages, Alveolar / virology
  • Mycobacterium tuberculosis / immunology*
  • Mycobacterium tuberculosis / metabolism
  • NF-kappa B / immunology
  • NF-kappa B / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / immunology
  • RNA, Messenger / metabolism
  • Signal Transduction / immunology
  • Toll-Like Receptors / immunology*
  • Toll-Like Receptors / metabolism
  • Tuberculosis / metabolism
  • Tuberculosis / virology
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / immunology*
  • Tumor Necrosis Factor-alpha / metabolism
  • U937 Cells
  • Up-Regulation / immunology
  • Vitamin D / immunology
  • Vitamin D / metabolism
  • Vitamin D / pharmacology*

Substances

  • Lipopolysaccharide Receptors
  • NF-kappa B
  • RNA, Messenger
  • Toll-Like Receptors
  • Tumor Necrosis Factor-alpha
  • Vitamin D