Values of p<0.05 were considered significant. We acknowledge the financial support of the Canadian Institutes for Health Research (MOP 67211 and MOP 84037 to C.A.P). The authors thank Marie-Hélène Lacombe from the RI-MUHC Immunophenotyping Platform PLX-4720 research buy for FACS Sorting and Genny Fortin for the help with RT-PCR. C.A.P. holds the Canada Research Chair. Conflict of interest: The authors declare no financial and commercial conflict of interest. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. “
caused by Nocardia brasiliensis is a common disease in tropical regions. This ailment is characterized by a localized chronic inflammation that mainly affects the lower limbs. Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns, inducing the production of proinflammatory
mediators. The role of TLRs in the immune response against N. brasiliensis is unknown. The selleckchem aim of this work was to locate and quantify in a murine model the expression of TLR2 and TLR4 in the infection site using reverse transcription-PCR and immunohistochemistry. The results showed that TLR2 expression increased in the infected tissue, whereas TLR4 expression decreased. The presence of TLR2 and TLR4 was demonstrated in different cell populations throughout the chronic infectious process. In the early stages of this process, TLR2 was expressed in neutrophils and macrophages in direct contact with the inoculum, whereas TLR4 was observed in mast cells. In the advanced stages of the infection, TLR2 was expressed in foam cells and fibroblasts and was likely associated
with bacterial containment, while TLR4 was downregulated, probably resulting in an imbalance between the host immune response and the bacterial load that favoured chronic disease. Mycetoma is a chronic Vitamin B12 subcutaneous granulomatous infection caused in humans by traumatic inoculation with either fungi (eumycetoma) or Gram-positive filamentous bacteria (actinomycetoma). It occurs worldwide and is endemic in tropical and subtropical regions. In Mexico, 98% of mycetoma cases are actinomycetomas, of which 84% are produced by Nocardia brasiliensis (López-Martínez et al., 1992, 2006). The disease progresses slowly from inoculation to the presentation of symptoms, which include chronic swelling and deformation of the infected area and the formation of sinuses discharging purulent material containing tissue debris, inflammatory cells, and granules (microcolonies) of the aetiological agent. The infection generally remains localized, but it can spread to the underlying bone and muscle and to adjacent organs such as lung and brain, which can lead to fatal outcomes (McNeil & Brown, 1994). Inflammation involves cells and molecules that limit or eliminate dangerous agents (Rubin et al., 2006; Kumar et al., 2010).