title: The antituberculosis drug pyrazinamide affects the course of cutaneous leishmaniasis in vivo and increases activation of macrophages and dendritic cells.
abstract: Antileishmanial therapy is suboptimal due to toxicity, high cost, and development of resistance to available drugs. Pyrazinamide (PZA) is a constituent of short-course tuberculosis chemotherapy. We investigated the effect of PZA on Leishmania major promastigote and amastigote survival. Promastigotes were more sensitive to the drug than amastigotes, with concentrations at which 50% of parasites were inhibited (MIC(50)) of 16.1 and 8.2 microM, respectively (48 h posttreatment). Moreover, 90% of amastigotes were eliminated at 120 h posttreatment, indicating that longer treatments will result in parasite elimination. Most strikingly, PZA treatment of infected C57BL/6 mice resulted in protection against disease and in a 100-fold reduction in the parasite burden. PZA treatment of J774 cells and bone marrow-derived dendritic cells and macrophages increased interleukin 12, tumor necrosis factor alpha, and activation marker expression, as well as nitric oxide production, suggesting that PZA enhances effective immune responses against the parasite. PZA treatment also activates dendritic cells deficient in Toll-like receptor 2 and 4 expression to initiate a proinflammatory response, confirming that the immunostimulatory effect of PZA is directly caused by the drug and is independent of Toll-like receptor stimulation. These results not only are strongly indicative of the promise of PZA as an alternative antileishmanial chemotherapy but also suggest that PZA causes collateral immunostimulation, a phenomenon that has never been reported for this drug.
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. sm457@cornell.edu
authors.forename: Susana
authors.initials: S
authors.lastname: Mendez
authors.forename: Ryan
authors.initials: R
authors.lastname: Traslavina
authors.forename: Meleana
authors.initials: M
authors.lastname: Hinchman
authors.forename: Lu
authors.initials: L
authors.lastname: Huang
authors.forename: Patricia
authors.initials: P
authors.lastname: Green
authors.forename: Michael H
authors.initials: MH
authors.lastname: Cynamon
authors.forename: John T
authors.initials: JT
authors.lastname: Welch
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000627:therapeutic use*; D000995:Antitubercular Agents / Q000627:therapeutic use*; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003713:Dendritic Cells / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D016773:Leishmaniasis, Cutaneous / Q000188:drug therapy*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000378:metabolism; D011718:Pyrazinamide / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000981:Antiprotozoal Agents; D000995:Antitubercular Agents; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D011718:Pyrazinamide; D009569:Nitric Oxide