To determine the influence of
different clinical symptoms, on TLR expression, the expression of TLR2, TLR4 and TLR9 in unstimulated neutrophils from healthy, asymptomatic and nonhealing CL subjects was measured. As shown in Figure 4, neutrophils of all three groups expressed transcripts of TLR2, TLR4 and TLR9 as well. Altogether, the expression of TLR2, TLR4 and TLR9 was significantly increased in nonhealing subjects compared with two other groups (P < 0·05), but no difference was seen between healthy and asymptomatic subjects (P > 0·05). Neutrophils have been shown to play an important role as host cell in the early phase of L. major infection. Therefore, more evaluation and better understanding of its immune response contribution against parasite are required to understand different aspects PLX3397 mw of interaction between host AZD2281 and pathogen, which, in this case, is followed by macrophage involvement. In the present work, the immune modulatory effect of CpG-ODN class A and B on the production of TNF-α, TGF-β and IL-8, as factors during interaction
between neutrophils and L. major, has been investigated (3,4,6). Extensive studies involving human Peripheral blood mononuclear cell (PBMC) identified two distinct classes of immunostimulatory CpG-ODN. B type DNA has phosphorothioate backbone, encodes multiple TCGTT and/or TCGTA, triggers the maturation of plasmocytoid dendritic cells and stimulates the production of IgM and IL-6. A ODN has mixed phosphodiester/phosphorothioate backbones and contains a single hexameric Purine/Pyrimidine/CG/Purine/Pyrimidine motif flanked by self-complementary bases CYTH4 that form a stem-loop structure capped at the 3′ end by a poly G tail. A ODN triggers the maturation of APC and induces the secretion of IFN-γ and IFN-α (29). Previous studies of nonhuman primates showed that administration of CpG-ODN type A at the site of infection 3 days before and after a challenge with L. major enhanced host resistance and reduced the lesion severity. In another study, it has been found that systemic
administration of class A ODN limits the size of lesions following an intradermal infection with L. major, suggesting a potential role for CpG-ODN in L. major treatment (30). Besides these data, there are limited and conflicting information in the literatures on the production of cytokines by neutrophils stimulated with CpG-ODN. The results obtained here showed that IL-8 was constitutively produced in the samples. This observation could be explained on the basis of activation of neutrophils by phagocytosis of ficoll during cell separation procedure (31–33). CpG-ODN class A, but not class B, was found to induce high level of IL-8 in neutrophils. This result is, however, not consistent with the data obtained by Hayashi et al. (23) which indicated that human neutrophils synthesized IL-8 in response to CpG-ODN class A only if pretreated with GM-CSF.