Mexican Institute for Social Security IMSS

Zacatecas, Mexico

Mexican Institute for Social Security IMSS

Zacatecas, Mexico
SEARCH FILTERS
Time filter
Source Type

Montoya-Rosales A.,Autonomous University of San Luis Potosi | Montoya-Rosales A.,Mexican Institute for Social Security IMSS | Provvedi R.,University of Padua | Torres-Juarez F.,Mexican Institute for Social Security IMSS | And 4 more authors.
Tuberculosis | Year: 2017

Antimicrobial peptides (AMPs) are mainly produced by epithelial cells and macrophages to eliminate infecting mycobacteria through direct antimicrobial activity and immunomodulation. Indeed, it has been described that this line of defense is essential to control infection. However, Mycobacterium tuberculosis (Mtb) has developed mechanisms to avoid AMPs activity, for instance lysX adds lysine residues to surface phospholipids changing their net charge, leading to the repelling of the AMPs. In the present study, we determined that lysX gene is differentially expressed among Mtb strains. To achieve this aim we used several well-characterized Mtb clinical isolates, lysX mutated strains and reference strains. Our results showed that in the presence of AMPs, lysX expression increased significantly. Strains with higher lysX expression showed increased levels of intracellular survival in vivo and in vitro and induced more severe lesion related with pneumonia. Results showed that ability of Mtb to replicate intracellularly was directly correlated to the level of lysX expression showing that the amount of lysX produced by the bacterial cell is an important variable for the modulation of Mtb virulence. © 2017 Elsevier Ltd


Torres-Juarez F.,Mexican Institute for Social Security IMSS | Cardenas-Vargas A.,Mexican Institute for Social Security IMSS | Montoya-Rosales A.,Mexican Institute for Social Security IMSS | Gonzalez-Curiel I.,Mexican Institute for Social Security IMSS | And 4 more authors.
Infection and Immunity | Year: 2015

Tuberculosis is one of the most important infectious diseases worldwide. The susceptibility to this disease depends to a great extent on the innate immune response against mycobacteria. Host defense peptides (HDP) are one of the first barriers to counteract infection. Cathelicidin (LL-37) is an HDP that has many immunomodulatory effects besides its weak antimicrobial activity. Despite advances in the study of the innate immune response in tuberculosis, the immunological role of LL-37 during M. tuberculosis infection has not been clarified. Monocyte-derived macrophages were infected with M. tuberculosis strain H37Rv and then treated with 1, 5, or 15 μg/ml of exogenous LL-37 for 4, 8, and 24 h. Exogenous LL-37 decreased tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17) while inducing anti-inflammatory IL-10 and transforming growth factor β (TGF-β) production. Interestingly, the decreased production of anti-inflammatory cytokines did not reduce antimycobacterial activity. These results are consistent with the concept that LL-37 can modulate the expression of cytokines during mycobacterial infection and this activity was independent of the P2X7 receptor. Thus, LL-37 modulates the response of macrophages during infection, controlling the expression of proinflammatory and anti-inflammatory cytokines. © 2015, American Society for Microbiology.


PubMed | University of British Columbia and Mexican Institute for Social Security IMSS
Type: Journal Article | Journal: Infection and immunity | Year: 2015

Tuberculosis is one of the most important infectious diseases worldwide. The susceptibility to this disease depends to a great extent on the innate immune response against mycobacteria. Host defense peptides (HDP) are one of the first barriers to counteract infection. Cathelicidin (LL-37) is an HDP that has many immunomodulatory effects besides its weak antimicrobial activity. Despite advances in the study of the innate immune response in tuberculosis, the immunological role of LL-37 during M. tuberculosis infection has not been clarified. Monocyte-derived macrophages were infected with M. tuberculosis strain H37Rv and then treated with 1, 5, or 15 g/ml of exogenous LL-37 for 4, 8, and 24 h. Exogenous LL-37 decreased tumor necrosis factor alpha (TNF-) and interleukin-17 (IL-17) while inducing anti-inflammatory IL-10 and transforming growth factor (TGF-) production. Interestingly, the decreased production of anti-inflammatory cytokines did not reduce antimycobacterial activity. These results are consistent with the concept that LL-37 can modulate the expression of cytokines during mycobacterial infection and this activity was independent of the P2X7 receptor. Thus, LL-37 modulates the response of macrophages during infection, controlling the expression of proinflammatory and anti-inflammatory cytokines.

Loading Mexican Institute for Social Security IMSS collaborators
Loading Mexican Institute for Social Security IMSS collaborators