Immune system recognition of Trypanosoma cruzi

The effects of nitric oxide on the immune system during Trypanosoma cruzi infection

“…TLRs can sense the presence of T. cruzi (Campos & Gazzinelli 2004), however, because it is an intracellular protozoan, T. cruzi has an extremely complex antigenic repertoire (Buscaglia et al 2006). This makes it difficult to determine the exact mechanism by which the large diversity of cell-surface molecules on T. cruzi are recognised by the innate immune system (Tarleton 2007). Although other molecules may be involved, it is known that innate recognition of glycophosphatidylinositol-anchored mucin-like glycoproteins from T. cruzi are potent inducers of NO biosynthesis by IFN-γ-activated macrophages (Camargo et al 1997).…”

Swimming against the current: genetic vaccination against Trypanosoma cruzi infection in mice

“…During the early stages of the acute phase, hosts survive because of strong innate immunity, mediated mostly by Toll-like receptors through the activation of the adaptor molecule MyD88 (Campos et al 2004, Bafica et al 2006, Bartholomeu et al 2008. However, to avoid elimination, the parasite manages to significantly delay the onset of the CD8 + T cell-mediated immunity (CMI) response (Martin et al 2006, Tzelepis et al 2006, 2007. This manoeuvre is critical for the parasite to establish the infection.…”

“…These genetically deficient mouse strains are highly susceptible to acute infection because they are unable to control parasitemia , Tarleton 2007. While MHC I-and CD8-deficient mice lack only CD8 + T CMI responses, MHC class II or CD4 deficiency leads to a more general failure, with reductions in both the antibody and the CD8 immune responses (Rottenberg et al 1993, Tarleton 2007, Tzelepis et al 2007.…”

“…Therefore, CD4 + T cells may play an extremely important role in generating different mechanisms of protection. However, their function as an effector mechanism during naturally acquired immunity is less clear, as CD8-deficient mice are highly susceptible to infection with most parasite strains (Tarleton 2007, Tzelepis et al 2007.…”

The effects of nitric oxide on the immune response during giardiasis

“…These cytokines are produced in response to pathogen associated molecular patterns (PAMPs), which can be sensed mainly by the action of pattern recognition receptors (PRR), such as Toll-like receptors (TLRs). 24,25 Signaling through these innate immune recognition receptors leads to activation of transcription factors NF-κB and AP-1, which regulate the expression of iNOS. 26 …”