Involvement of nitric oxide and its up/down stream molecules in the immunity against parasitic infections

Abstract

Nitric oxide (NO) is a potent mediator with diverse roles in regulating cellular functions and signaling pathways. The NO synthase (NOS) enzyme family consists of three major isoforms, which convey variety of messages between cells, including signals for vasorelaxation, neurotransmission and cytotoxicity. This family of enzymes are generally classified as neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Increased levels of NO are induced from iNOS during infection; while eNOS and nNOS may be produced at the baseline in normal conditions. An association of some key cytokines appears to be essential for NOS gene regulation in the immunity of infections. Accumulating evidence indicates that parasitic diseases are commonly associated with elevated production of NO. NO plays a role in the immunoregulation and it is implicated in the host non-specific defence in a variety of infections. Nevertheless, the functional role of NO and NOS isoforms in the immune responses of host against the majority of parasites is still highly controversial. In the present review, the role of parasitic infections will be discussed in the controversy related to the NO production and iNOS gene expression in different parasites and a variety of experimental models.

Immunomodulatory effects of recombinant BCG expressing MSP-1C ofPlasmodium falciparumon LPS- or LPS+IFN-γ-stimulated J774A.1 cells

“…57 Activated macrophages produce large amount of NO, a reactive mediator produced via the NADPH-and l-argininedependent enzyme nitric oxide synthase as a defense strategy against infections. 58,59 The role of NO in the host's response to malaria infection has been increasingly investigated. Previous reports have suggested that NO is essential in preventing or moderating the severe manifestations of malaria infection.…”

“…Moreover, NO has also been reported to have direct anti-parasitic activity that can kill P. falciparum in vitro. 17,18,[59][60][61][62] Therefore, enhanced induced NO production in macrophages infected with rBCG vaccine indicating the ability of the rBCG strain to protect against malaria infection.…”

Untitled

“…Nitric oxide formation has been encountered in many parasitic infections including Giardia [30,31]. It is considered as only part of an immunopathological series against infection [32]. The low NO level may be credited to the release of arginine deiminase and flavohemoglobins by Giardia trophozoites which consumes all the local arginine (precursor of nitric acid formation) [33].…”

Partial Immunotherapy of Leishmaniasis by in vivo Trial of L-Arginine in Balb/c Mice Infected with Leishmania major via Nitric Oxide Pathway

“…We have previously published the detailed applications of NO modulators, time course infected Balb/c mice. Significance of differences (*p<0.05, ***p<0.001) was determined by student's t-test and one-way anova test using Graph Pad Prism software (n = 10 mice/group) and the associated changes in spleen, as well as plasma, brain and liver concentrations of NO in intracellular parasites including plasmodium and Leishmania (Nahrevanian et al, 2007(Nahrevanian et al, , 2009a(Nahrevanian et al, , 2009b(Nahrevanian et al, , 2012Nahrevanian and Dascombe, 2001;Nahrevanian, 2009;Nemati et al, 2013). This is the first application of oral, local and injection forms of L-Arg against Iranian strain L. major MRHO/IR/75/ER.…”