An Assessment of the In Vitro Antioxidant Activity of Cobalt Nanoparticles Synthesized From Millettia pinnata, Butea monosperma, and Madhuca indica Extracts: A Comparative Study.

Objective This study aimed to synthesize cobalt nanoparticles (CoNPs) via the green synthesis method using , leaf (MPL), flower (BMF), and flower (MIF) as eco-friendly reducing agents. It further aimed to compare the effectiveness of these plant extracts in CoNPs production and evaluate the antioxidant activities of the synthesized nanoparticles (NPs), establishing a link between the phytochemical constituents of the extracts and the antioxidant capacity of CoNPs for potential applications in drug development and environmental sustainability. Materials and methods CoNPs were synthesized using aqueous extracts of MPL, BMF, and MIF.

Immunization against full-length protein and peptides from the Lutzomyia longipalpis sand fly salivary component maxadilan protects against Leishmania major infection in a murine model.

Leishmaniasis is an arthropod vectored disease causing considerable human morbidity and mortality. Vaccination remains the most realistic and practical means to interrupt the growing number and diversity of sand fly vectors and reservoirs of Leishmania. Since transmission of Leishmania is achieved exclusively by sand fly vectors via immune-modulating salivary substances, conventional vaccination requiring an unmodified host immune response for success are potentially destined to fail unless immunomodulatory factors are somehow neutralized.

2,3,7,8-tetrachlorodibenzo-p-dioxin slows the progression of experimental cutaneous Leishmaniasis in susceptible BALB/c and SCID mice.

In a model of experimental cutaneous leishmaniasis, pre-exposure of Leishmania major-resistant mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an aryl hydrocarbon receptor agonist, causes suppression of the protective anti-parasite T helper 1 response while paradoxically also reducing parasite burdens in those animals. In this study, we examined if TCDD exposure could also reduce parasite burdens in L. major-susceptible BALB/c mice.

BluePort: a platform to study the eosinophilic response of mice to the bite of a vector of Leishmania parasites, Lutzomyia longipalpis sand flies.

Background: Visceral Leishmaniasis is a serious human disease transmitted, in the New World, by Lutzomyia longipalpis sand flies. Natural resistance to Leishmania transmission in residents of endemic areas has been attributed to the acquisition of immunity to sand fly salivary proteins. One theoretical way to accelerate the acquisition of this immunity is to increase the density of antigen-presenting cells at the sand fly bite site.

Cysteine-free proteins in the immunobiology of arthropod-borne diseases.

One approach to identify epitopes that could be used in the design of vaccines to control several arthropod-borne diseases simultaneously is to look for common structural features in the secretome of the pathogens that cause them. Using a novel bioinformatics technique, cysteine-abundance and distribution analysis, we found that many different proteins secreted by several arthropod-borne pathogens, including Plasmodium falciparum, Borrelia burgdorferi, and eight species of Proteobacteria, are devoid of cysteine residues. The identification of three cysteine-abundance and distribution patterns in several families of proteins secreted by pathogenic and nonpathogenic Proteobacteria, and not found when the amino acid analyzed was tryptophan, provides evidence of forces restricting the content of cysteine residues in microbial proteins during evolution.

Local suppression of T cell responses by arginase-induced L-arginine depletion in nonhealing leishmaniasis.

The balance between T helper (Th) 1 and Th2 cell responses is a major determinant of the outcome of experimental leishmaniasis, but polarized Th1 or Th2 responses are not sufficient to account for healing or nonhealing. Here we show that high arginase activity, a hallmark of nonhealing disease, is primarily expressed locally at the site of pathology. The high arginase activity causes local depletion of L-arginine, which impairs the capacity of T cells in the lesion to proliferate and to produce interferon-gamma, while T cells in the local draining lymph nodes respond normally.

Lutzomyia longipalpis salivary peptide maxadilan alters murine dendritic cell expression of CD80/86, CCR7, and cytokine secretion and reprograms dendritic cell-mediated cytokine release from cultures containing allogeneic T cells.

Leishmania protozoan parasites, the etiologic agent of leishmaniasis, are transmitted exclusively by phlebotomine sand flies of the genera Phlebotomus and Lutzomyia. In addition to parasites, the infectious bite inoculum contains arthropod salivary components. One well-characterized salivary component from Lutzomyia longipalpis is maxadilan (MAX), a vasodilator acting via the type I receptor for the pituitary cyclic AMP activating peptide.

Protection of susceptible BALB/c mice from challenge with Leishmania major by nucleoside hydrolase, a soluble exo-antigen of Leishmania.

Leishmania major culture-derived, soluble, exogenous antigens have been shown to be a source of vaccine targets for the parasite. We have previously reported that L. major culture-derived, soluble, exogenous antigens can immunize BALB/c mice against challenge with L.

Objective evaluation of skin prick test reactions using digital photography.

Background: The skin prick test has been used worldwide to determine IgE-mediated hypersensitivity. However, the most current method to record this reaction has problems with accuracy and precision.

Objective: To demonstrate a new approach to measure the skin prick reaction and its kinetics with precision.

Cross-protection against Leishmania donovani but not L. Braziliensis caused by vaccination with L. Major soluble promastigote exogenous antigens in BALB/c mice.

Vaccinating with soluble Leishmania major promastigote exogenous antigens (LmSEAgs) protects mice against challenge with L. major. To explore the potential of LmSEAgs to cross-protect against infection with other species of Leishmania, BALB/c mice were immunized with LmSEAgs prior to challenge with either L.

Immunomodulatory effects of the Lutzomyia longipalpis salivary gland protein maxadilan on mouse macrophages.

Infection with Leishmania major is enhanced when the sand fly Lutzomyia longipalpis salivary peptide maxadilan (MAX) is injected along with the parasite. Here we determined the effect that MAX has on the secretion of cytokines and nitric oxide (NO) and on parasite survival in macrophages (MPhis). The cytokines produced by MPhis can enhance a type 1 response, which will increase NO and the killing of intracellular pathogens such as L.

Effect of Lutzomyia longipalpis salivary gland extracts on leukocyte migration induced by Leishmania major.

The mechanism by which the salivary gland lysate (SGL) of Lutzomyia longipalpis enables Leishmania infection remains under investigation. One possibility is that saliva promotes cellular recruitment leading to development of skin lesions. In this study, we investigated leukocyte recruitment induced by L.

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) reduces Leishmania major burdens in C57BL/6 mice.

Acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can suppress adaptive immunity. In this study, pre-exposure of Leishmania major-infected mice to TCDD caused a dose-dependent and unexpected decrease in parasite burdens on day 20 after infection. In contrast, TCDD-mediated lymphoid atrophy, suppressed antibody levels, and enhanced interleukin-2 production were observed as expected.

Salivary gland extracts of Culicoides sonorensis inhibit murine lymphocyte proliferation and no production by macrophages.

Culicoides biting midges serve as vectors of pathogens affecting humans and domestic animals. Culicoides sonorensis is a vector of several arboviruses in North American that cause substantial economic losses to the US livestock industry. Previous studies showed that C.

Is it possible to develop pan-arthropod vaccines?

Hematophagous arthropods that transmit the etiological agents of arthropod-borne diseases have become the focus of anti-vector vaccines, targeted mainly at components of their saliva and midgut. These efforts have been directed mostly towards developing species-specific vaccines. An alternative is to target cross-reactive epitopes that have been preserved during evolution of the arthropods.

Nanodisk-associated amphotericin B clears Leishmania major cutaneous infection in susceptible BALB/c mice.

Nanometer-scale, apolipoprotein-stabilized phospholipid bilayer disk complexes (nanodisks [ND]) harboring the toxic and poorly soluble antileishmanial agent amphotericin B (AMB) were examined for efficacy in treatment of Leishmania major-infected BALB/c mice (Mus musculus). L. major-infected mice were intraperitoneally (i.

Novel compounds active against Leishmania major.

Leishmania major is an important trypanosomatid pathogen that causes leishmaniasis, which is a serious disease in much of the Old World. Current treatments include a small number of antimony compounds that, while somewhat effective, are limited by serious side effects. We have screened a small portion of a unique chemical library and have found at least three novel compounds that are effective against L.

Characterization of the early cellular immune response to Leishmania major using peripheral blood mononuclear cells from Leishmania-naive humans.

While the response to Leishmania major is well characterized in mice, there is much less known about the human immune response, particularly early after exposure to the parasite. Therefore, we developed a primary in vitro (PIV) system that allowed us to address these questions. We co-cultured peripheral blood mononuclear cells from Leishmania-naive donors with L.

The surface-mosaic model in host-parasite relationships.

The dynamics of protein adsorption to a microbial surface could be of significance in host-parasite relationships because non-defense proteins might interfere with the binding of defense proteins. A surface mosaic of defense and non-defense proteins formed on the microbial surface could activate one of the tissue reactivity programs via a binary code (help or silence) generated by the adsorbed proteins. Understanding the mechanisms of the mosaic formation and its evolution might help to identify evasion mechanisms used by virulent microorganisms.

Immunization with Leishmania major exogenous antigens protects susceptible BALB/c mice against challenge infection with L. major.

The potential of Leishmania major culture-derived soluble exogenous antigens (SEAgs) to induce a protective response in susceptible BALB/c mice challenged with L. major promastigotes was investigated. Groups of BALB/c mice were immunized with L.

Characterization of an I-E-restricted, gp63-specific, CD4-T-cell clone from Leishmania major-resistant C3H mice that secretes type 2 cytokines and exacerbates infection with L. major.

A T-cell clone (designated KLmB-3) was derived from resistant C3H mice 2 weeks after infection with Leishmania major. KLmB-3 was a CD4-T-cell clone that utilized the V beta 8.1 T-cell receptor.

The human cytokine response to Leishmania major early after exposure to the parasite in vitro.

Leishmaniasis is caused by the protozoan parasite Leishmania spp. In murine leishmaniasis, a T helper cell type-I (Th1) response, characterized by the secretion of interferon (IFN)-gamma is necessary for clearing the infection. whereas a Th2 response, accompanied by the production of interleukin (IL)-5, can exacerbate the disease.

Lutzomyia longipalpis salivary gland homogenate impairs cytokine production and costimulatory molecule expression on human monocytes and dendritic cells.

In this report, we describe an investigation of the effects of Lutzomyia longipalpis sand fly salivary gland homogenates (SGH) on cytokine production and expression of costimulatory molecules on human monocytes, macrophages (Mphis), and dendritic cells (DCs). SGH of L. longipalpis induced an increase in interleukin-6 (IL-6), IL-8 and IL-12p40 production but a decrease in tumor necrosis factor alpha and IL-10 production by lipopolysaccharida (LPS)-stimulated monocytes.

Short report: requirement of b cells for delayed type hypersensitivity-like pathology after secondary infection with Leishmania major in resistant C57BL/6 mice.

B cell-deficient C57B1/6 (microMT) mice were resistant to Leishmania major after both primary and secondary parasite challenge. However, unlike in wild-type mice, secondary infection in microMT mice was not accompanied by a marked delayed type hypersensitivity-like response, and interferon-gamma (IFN-gamma) levels were approximately half of those in wild-type mice. These results suggest that B cells are involved in IFN-gamma production and the pathology of secondary infection.

Immunomodulatory effects of Maxadilan and Phlebotomus papatasi sand fly salivary gland lysates on human primary in vitro immune responses.

Leishmaniasis is a parasitic disease transmitted by the bite of Leishmania-infected sand flies. Here we show for the first time the ability of Maxadilan (Max), a vasodilatory peptide isolated from the sand fly Lutzomyia longipalpis, and salivary gland lysate (SGL) from Phlebotomus papatasi to decrease the secretion of Type 1 cytokines and to enhance the production of the Type 2 cytokine interleukin (IL)-6 by human peripheral blood mononuclear cells (PBMC) and monocytes. We found Max decreased the secretion of interferon (IFN)-gamma and IL-12p40 by PBMC and TNF-alpha by monocytes.