A Novel Ligand of Toll-like Receptor 4 From the Sheath of Wuchereria bancrofti Microfilaria Induces Proinflammatory Response in Macrophages. (7th February 2017)

• Record Type: Journal Article
• Authors: Mukherjee, Suprabhat; Mukherjee, Sandip; Maiti, Tushar K.; Bhattacharya, Samir; Sinha Babu, Santi P.
• Is Part Of: Journal of infectious diseases. Volume 215:Number 6(2017:Mar. 15)
• Page Start: 954
• Page End: 965
• Publication Date: 2017-02-07
• Subjects: Wuchereria bancrofti -- MfP -- Macrophage -- TLR4 -- cytokines -- inflammatory response.; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jix067
• Languages: English
• ISSNs: 0022-1899

Abstract

Summary: A novel microfilarial sheath protein of Wuchereria bancrofti acts as a ligand of Toll-like receptor 4 to induce inflammation, chemotaxis, and polarization of host macrophages to promote immunopathology in lymphatic filariasis. Abstract: Background: Lymphatic filariasis, frequently caused from Wuchereria bancrofti infection, is endemic in several parts of the globe and responsible for human health problems and socioeconomic loss to a large extent. Inflammatory consequences originating from host–parasite interaction play a major role in the disease pathology and allied complications. The identity of the key mediator of this process is yet unknown in filarial research. Methods: Microfilarial protein (MfP) was isolated from the sheath of W. bancrofti microfilariae through ultrafiltration, followed by chromatographic separation. Expression of signaling molecules was studied by enzyme-linked immunosorbent assay and immunoblotting. Binding of MfP to Toll-like receptor 4 (TLR4) was determined by co-immunoprecipitation, fluorescein isothiocyanate-probing, and surface plasmon resonance analysis. Results: We found that MfP (approximately 70 kDa) binds to macrophage-TLR4 and triggers nuclear factor kappa beta activation that upregulates secretion of proinflammatory cytokines. Microfilarial protein failed to induce inflammation in either TLR KO macrophage or macrophage treated with TLR4 inhibitor, indicating that MfP acts through TLR4. We have also detected phenotypic transformation of macrophages from anti-inflammatory (M2) to proinflammatory (M1) subtype after incubation with MfP. Conclusions: Microfilarial protein appears to be a new ligand of TLR4 from W. bancrofti . Determination of its functional attributions in the host–parasite relationship, especially immunopathogenesis of filarial infection, may improve our understanding.