Attenuation of toll-like receptor expression and function in latent tuberculosis by coexistent filarial infection with restoration following antifilarial chemotherapy.

• Main Authors: Subash Babu, Sajid Q Bhat, N Pavan Kumar, R Anuradha, Paul Kumaran, P G Gopi, C Kolappan, V Kumaraswami, Thomas B Nutman
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2009-07-01
• Series: PLoS Neglected Tropical Diseases
• Online Access: http://europepmc.org/articles/PMC2710006?pdf=render

Mycobacterium tuberculosis (Mtb) and filarial coinfection is highly prevalent, and the presence of filarial infections may regulate the Toll-like receptor (TLR)-dependent immune response needed to control Mtb infection. By analyzing the baseline and mycobacterial antigen-stimulated expression of TLR1, 2, 4, and 9 (in individuals with latent tuberculosis [TB] with or without filarial infection), we were able to demonstrate that filarial infection, coincident with Mtb, significantly diminishes both baseline and Mtb antigen-specific TLR2 and TLR9 expression. In addition, pro-inflammatory cytokine responses to TLR2 and 9 ligands are significantly diminished in filaria/TB-coinfected individuals. Definitive treatment of lymphatic filariasis significantly restores the pro-inflammatory cytokine responses in individuals with latent TB. Coincident filarial infection exerted a profound inhibitory effect on protective mycobacteria-specific TLR-mediated immune responses in latent tuberculosis and suggests a novel mechanism by which concomitant filarial infections predispose to the development of active tuberculosis in humans.