Expression of cathelicidin LL-37 during Mycobacterium tuberculosis infection in human alveolar macrophages, monocytes, neutrophils, and epithelial cells.
The innate immune response in human tuberculosis is not completely understood. To improve our knowledge regarding the role of cathelicidin hCAP-18/LL37 in the innate immune response to tuberculosis infection, we used immunohistochemistry, immunoelectron microscopy, and gene expression to study the induction and production of the antimicrobial peptide in A549 epithelial cells, alveolar macrophages (AM), neutrophils, and monocyte-derived macrophages (MDM) after infection with Mycobacterium tuberculosis. We demonstrated that mycobacterial infection induced the expression and production of LL-37 in all cells studied, with AM being the most efficient. We did not detect peptide expression in tuberculous granulomas, suggesting that LL-37 participates only during early infection. Through the study of Toll-like receptors (TLR) in MDM, we showed that LL-37 can be induced by stimulation through TLR-2, TLR-4, and TLR-9. This last TLR was strongly stimulated by M. tuberculosis DNA. We concluded that LL-37 may have an important role in the innate immune response against M. tuberculosis.
Rivas-Santiago
Bruno
B
Unidad de Investigación Médica-Zacatecas, IMSS, Zacatecas, México.
Hernandez-Pando
Rogelio
R
Carranza
Claudia
C
Juarez
Esmeralda
E
Contreras
Juan Leon
JL
Aguilar-Leon
Diana
D
Torres
Martha
M
Sada
Eduardo
E
D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis*; D018893:Bronchoalveolar Lavage; D002460:Cell Line; D002478:Cells, Cultured; D003593:Cytoplasm / Q000737:chemistry; D004847:Epithelial Cells / Q000737:chemistry / Q000276:immunology* / Q000382:microbiology; D020869:Gene Expression Profiling; D006099:Granuloma / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000276:immunology* / Q000382:microbiology; D016253:Microscopy, Immunoelectron; D009000:Monocytes / Q000737:chemistry / Q000276:immunology* / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D009504:Neutrophils / Q000737:chemistry / Q000276:immunology* / Q000382:microbiology; D051193:Toll-Like Receptors / Q000276:immunology; D054804:Cathelicidins
D023181:Antimicrobial Cationic Peptides; D051193:Toll-Like Receptors; D054804:Cathelicidins