Expression of beta defensin 2 in experimental pulmonary tuberculosis: tentative approach for vaccine development.

BACKGROUND AND AIMS: Defensins are low molecular weight antimicrobial and immunomodulatory peptides. Their participation against Mycobacterium tuberculosis (MTb) infection has been scarcely studied. METHODS: We describe the kinetics of murine ß-defensin 2 (mBD-2) expression by quantitative real-time PCR and cellular location by immunohistochemistry in murine models of progressive pulmonary tuberculosis and latent infection. RESULTS: During progressive disease, mBD2 gene expression raised its peak at 14 days postinfection, whereas in latent infection it was at 90 days. In both models, mBD-2 immunostaining was essentially located in cells with dendritic morphology located near mediastinal lymph nodes, which correlated with the previous reported highest expression of cell-mediated protected immunity in both models. CONCLUSIONS: These results suggest that mBD-2 may play a role in the control of bacilli growth by contributing to establish a Th1 response, being a link between innate and adaptative immunity. These data may be used for the development of new vaccine approaches.