Host immune response against Mycobacterium tuberculosis is mediated by cellular immunity, in which cytokines and Th1 cells play a critical role. In the process of control of the infection by mycobacteria, TNF-alpha seems to have a primordial function. This cytokine acts in synergy with IFN-gamma, stimulating the production of reactive nitrogen intermediates (RNIs), thus mediating the tuberculostatic function of macrophages, and also stimulating the migration of immune cells to the infection site, contributing to granuloma formation, which controls the disease progression. IFN-gamma is the main cytokine involved in the immune response against mycobacteria, and its major function is the activation of macrophages, allowing them to exert its microbicidal role functions. Different from TNF-alpha and IFN-gamma, IL-10 is considered primarily an inhibitory cytokine, important to an adequate balance between inflammatory and immunopathologic responses. The increase in IL-10 levels seems to support the survival of mycobacteria in the host. Although there is not yet conclusive studies concerning a clear dichotomy between Th1 and Th2 responses, involving protective immunity and susceptibility to the disease, respectively, we can suggest that the knowledge about this responses based on the prevailing cytokine profile can help to elucidate the immune response related to the protection against M. tuberculosis.

Leishmaniases are caused by obligate intracellular protozoan parasites of the genus Leishmania. They cause a spectrum of diseases, most notably visceral (VL), cutaneous (CL), and mucosal (ML) leishmaniasis, which affect millions of people around the world, each year. Despite scientific advances, leishmaniases cases are expanding, constituting an important public health problem. Immunological and molecular diagnostic tools have been increasingly applied for the early detection of these parasitic infections, since the existence of limitations in clinical and parasitological examinations may provide false results, thus interfering in epidemiological research and diseases control. Although there is a great diversity of available immunological assays, important common deficiencies persist, which explains the current exploration of the molecular biology in research fields, especially the Polymerase Chain Reaction (PCR) and its variants, such as real-time quantitative PCR. However, in the last years, significant results have also been reached inside of immunological context (especially by Flow Cytometry), for humans and dogs, demonstrated by research works of the New and Old worlds. In spite of their potential to clarify and minimize the present global situation of the diseases, the implementation of molecular or immunological innovative reference assays for VL and CL at health services is still a challenge due to several reasons, including lack of standardization among laboratories and structural concerns. In this article we bring classical and current information about technological advances for the immunological and molecular leishmaniases diagnosis, their features, and applications.

The present work reports on the synthesis, anti-Trypanosoma cruzi activities and docking studies of a novel series of 2-(pyridin-2-yl)-1,3-thiazoles derived from 2-pyridine thiosemicarbazone. The majority of these compounds are potent cruzain inhibitors and showed excellent inhibition on the trypomastigote form of the parasite, and the resulting structure-activity relationships are discussed. Together, these data present a novel series of thiazolyl hydrazones with potential effects against Chagas disease and they could be important leads in continuing development against Chagas disease.

The reactivities of sera from chronic chagasic patients against the trypomastigote excreted-secreted antigens (TESA) of Trypanosoma cruzi strains with different biodemes were analyzed by TESA-blot and TESA–enzyme-linked immunosorbent assay (ELISA). Although both tests presented high sensitivity and specificity, TESA-ELISA is more appropriate for screening a larger number of samples

Cramoll 1,4 is a lectin extracted from Cratylia mollis Mart. seeds that has shown antitumor and lymphocyte mitogenic activities in other studies. The aim of this work was to investigate, in vitro, the immunomodulatory activity of Cramoll 1,4 on experimental cultures of mice lymphocytes through cytotoxic assays, nitric oxide (NO) concentrations and IL-10 and IFN-γ production. Cramoll 1,4 did not show cytotoxic activity at 1-25 μg/mL concentrations, similar results were observed with concanavalin A (Con A) and phytohemagglutinin (PHA) lectins. The minimum production of IL-10 was observed in splenocytes cultivated with Con A, PHA and Cramoll 1,4 lectins. However, splenocytes treated with Cramoll 1,4 showed higher IFN-γ production in comparison with PHA and Con A (p < 0.05 for both). Production of NO was effectively suppressed in murine cells stimulated with the lectins and was only detected after 72 h for PHA in relation to non-stimulated lymphocytes (p < 0.05). Cramoll 1,4 was not toxic to murine lymphocytes, induced Th1 response through IFN-γ production and showed antiinflammatory activity through NO suppression. Therefore, Cramoll 1,4 can be considered a lectin with immunomodulatory activity.