NOTCH1 and DLL4 are involved in the human tuberculosis progression and immune response activation.

Tuberculosis (TB) is the leading cause of mortality among infectious diseases worldwide. The study of molecular targets for therapy and diagnosis suggested that Notch signaling is an important pathway for the maintenance of the immune response during Mycobacterium tuberculosis (Mtb) infection. We evaluated the participation of the Notch pathway in the modulation of immune response during Mtb infection, and observed that patients with active TB had increased DLL4 expression in intermediate and non-classic monocytes.

Bothrops moojeni venom and BmooLAAO-I downmodulate CXCL8/IL-8 and CCL2/MCP-1 production and oxidative burst response, and upregulate CD11b expression in human neutrophils.

Bothrops snake venoms contain biologically active components, including L-amino acid oxidases (LAAO) that induce significant leukocyte accumulation at inflammatory sites characterized by early neutrophil infiltration. As it remains unclear how snake venoms modulate neutrophil activation and chemokine production, here we examined whether Bothrops moojeni crude venom (BmV) and its LAAO (BmooLAAO-I) affect expression of the surface activation markers CD11b and CD66b, production of the chemokines CCL2/MCP-1, CCL5/RANTES, CXCL8/IL-8, CXCL9/MIG, and CXCL-10/IP-10, and activation of oxidative burst in human neutrophils. Cell viability, expression of activation markers, and chemokine production were assessed by flow cytometry, while the oxidative burst response was measured by chemiluminescence.

The Driving of Immune Response by Th1 Adjuvants in Immunization of Mice with Trypanosoma cruzi marinkellei Elicits a Controversial Infection Control.

In previous studies, we have demonstrated that inoculation with a Trypanosoma cruzi marinkellei (avirulent RM1 strain) was able to reduce parasitemia in mice challenged with T. cruzi, although it was not able to prevent histopathological lesions. Th1 response stimulation by immunization is necessary for T.

Immunomodulatory activity of Tityus serrulatus scorpion venom on human T lymphocytes.

Background: Tityus serrulatus scorpion venom (TsV) contains toxins that act on K(+) and Na(+) channels and account for the venom's toxic effects. TsV can activate murine peritoneal macrophages, but its effects on human lymphocytes have been poorly investigated. Considering that lymphocytes may play an important role in envenomation, we assessed whether TsV affects the expression of phenotypic (CD3, CD4, and CD8) and activation (CD69, CD25, and HLA-DR) markers, cell proliferation, and cytokine production in peripheral blood mononuclear cells.

Immunoregulatory actions of melatonin and zinc during chronic Trypanosoma cruzi infection.

After one century of the discovery of Chagas' disease and the development of an efficient drug with amplitude of actions both in the acute and chronic phase is still a challenge. Alternative immune modulators have been exhaustively used. For that purpose, melatonin and zinc were administered during chronic Trypanosoma cruzi-infected Wistar rats and several endpoints were assessed.

Immunomodulatory properties and anti-apoptotic effects of zinc and melatonin in an experimental model of chronic Chagas disease.

The immunomodulatory effects of melatonin and zinc during chronic experimental Chagas' disease were studied. Early and late apoptosis by Annexin V-propidium iodide staining were evaluated. The expression of CD28, CD80, CD86, CD45RA and CD4(+)T and CD8(+)T cells were also evaluated by flow cytometry analysis.

The acute phase of Trypanosoma cruzi infection is attenuated in 5-lipoxygenase-deficient mice.

In the present work we examine the contribution of 5-lipoxygenase- (5-LO-) derived lipid mediators to immune responses during the acute phase of Trypanosoma cruzi infection in 5-LO gene knockout (5-LO(-/-)) mice and wild-type (WT) mice. Compared with WT mice, the 5-LO(-/-) mice developed less parasitemia/tissue parasitism, less inflammatory cell infiltrates, and a lower mortality. This resistance of 5-LO(-/-) mice correlated with several differences in the immune response to infection, including reduced PGE2 synthesis; sustained capacity of splenocytes to produce high levels of interleukin (IL)-12 early in the infection; enhanced splenocyte production of IL-1β, IL-6, and IFN-γ; rapid T-cell polarization to secrete high quantities of IFN-γ and low quantities of IL-10; and greater numbers of CD8(+)CD44(high)CD62L(low) memory effector T cells at the end of the acute phase of infection.

L-amino acid oxidase isolated from Bothrops pirajai induces apoptosis in BCR-ABL-positive cells and potentiates imatinib mesylate effect.

Chronic myeloid leukaemia (CML) is a myeloproliferative disorder characterized by the presence of Philadelphia chromosome and by BCR-ABL1, which encodes the BCR-ABL oncoprotein. Although imatinib mesylate (IM) is effective for CML treatment, patients in accelerated and blastic phases of the disease are often refractory to this therapy, and there are also cases of IM resistance in patients in the chronic phase. Therefore, potential new drugs are being investigated to improve the efficiency of the therapy of CML such as snake venoms and their compounds.

A DNA vaccine candidate encoding the structural prM/E proteins elicits a strong immune response and protects mice against dengue-4 virus infection.

A DNA vaccine expressing dengue-4 virus premembrane (prM) and envelope (E) genes was produced by inserting these genes into a mammalian expression plasmid (pCI). Following a thorough screening, including confirmation of protein expression in vitro, a recombinant clone expressing these genes was selected and used to immunize BALB/c mice. After 3 immunizations all the animals produced detectable levels of neutralizing antibodies against dengue-4 virus.

Immunological effects of interferon-alpha on chronic myelogenous leukemia.

Treatment with interferon-alpha is effective for chronic myelogenous leukemia in the chronic phase (CML-CP), but the immunological mechanisms of the antileukemic effect of this substance are still unclear. The objective of this study was to investigate the immunological effects of interferon-alpha in CML patients. Markers of cellular activation and apoptosis, natural killer (NK) cell cytotoxicity and production of intracellular cytokines (IFN-gamma, IL-2 and IL-4) were determined by flow cytometry in the peripheral blood mononuclear cells (PBMC) of 26 CML-CP patients before and 3, 6 and 9 months after IFN-alpha treatment.