Up-regulation of TLR2 and TLR4 in dendritic cells in response to HIV type 1 and coinfection with opportunistic pathogens

AIDS Res Hum Retroviruses. 2011 Oct;27(10):1099-109. doi: 10.1089/aid.2010.0302. Epub 2011 Apr 20.

Abstract

The ability to trigger an innate immune response against opportunistic pathogens associated with HIV-1 infection is an important aspect of AIDS pathogenesis. Toll-like receptors (TLRs) play a critical role in innate immunity against pathogens, but in HIV-1 patients coinfected with opportunistic infections, the regulation of TLR expression has not been studied. In this context, we have evaluated the expression of TLR2 and TLR4 in monocytes, plasmacytoid dendritic cells, and myeloid dendritic cells of HIV-1 patients with or without opportunistic infections. Forty-nine HIV-1-infected individuals were classified according to viral load, highly active antiretroviral therapy (HAART), and the presence or absence of opportunistic infections, and 21 healthy subjects served as controls. Increased expression of TLR2 and TLR4 was observed in myeloid dendritic cells of HIV-1 patients coinfected with opportunistic infections (without HAART), while TLR4 increased in plasmacytoid dendritic cells, compared to both HIV-1 without opportunistic infections and healthy subjects. Moreover, TLR2 expression was higher in patients with opportunistic infections without HAART and up-regulation of TLR expression in HIV-1 patients coinfected with opportunistic infections was more pronounced in dendritic cells derived from individuals coinfected with Mycobacterium tuberculosis. The results indicate that TLR expression in innate immune cells is up-regulated in patients with a high HIV-1 load and coinfected with opportunistic pathogens. We suggest that modulation of TLRs expression represents a mechanism that promotes HIV-1 replication and AIDS pathogenesis in patients coinfected with opportunistic pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS-Related Opportunistic Infections / immunology*
  • AIDS-Related Opportunistic Infections / microbiology
  • AIDS-Related Opportunistic Infections / virology
  • Adult
  • Antiretroviral Therapy, Highly Active
  • Bacterial Infections / complications
  • Bacterial Infections / immunology
  • Bacterial Infections / microbiology
  • CD4 Lymphocyte Count
  • Candida / immunology
  • Candida / pathogenicity
  • Candidiasis / complications
  • Candidiasis / immunology
  • Candidiasis / microbiology
  • Case-Control Studies
  • Coinfection*
  • Dendritic Cells / immunology*
  • Female
  • Flow Cytometry
  • Gene Expression Regulation
  • HIV Infections / complications
  • HIV Infections / immunology*
  • HIV Infections / microbiology
  • HIV Infections / virology
  • HIV-1 / immunology
  • HIV-1 / pathogenicity
  • Humans
  • Male
  • Middle Aged
  • Monocytes / immunology
  • Mycobacterium tuberculosis / immunology
  • Mycobacterium tuberculosis / pathogenicity
  • RNA, Messenger / analysis
  • RNA, Viral / blood
  • RNA, Viral / genetics
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / immunology*
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / immunology*
  • Up-Regulation
  • Viral Load
  • Young Adult

Substances

  • RNA, Messenger
  • RNA, Viral
  • TLR2 protein, human
  • TLR4 protein, human
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4