Evaluation of the lymphoproliferation of mononuclear cells in cutaneous leishmaniasis patients treated with Libidibia ferrea

American integumentary leishmaniasis (ATL) is a neglected disease that mostly affects vulnerable populations. Its broad spectrum of clinical manifestations is related to the type of immune response produced by the host and the species of Leishmania involved. In recent years, the use of medicinal plants has become a therapeutic alternative in the treatment of infectious parasitic diseases. This research aimed to evaluate the lymphoproliferative responses of peripheral blood mononuclear cells (PBMCs) of patients with cutaneous leishmaniasis (CL) before and after treatment, and healthy individuals. The lymphoproliferative response was evaluated in cell culture using stimuli of the dichloromethane fraction (DCM) obtained from Libidibia ferrea, Glucantime® and phytohemagglutinin - PHA using a BrdU Cell Proliferation after 72 h of incubation. In cultures treated with the DCM fraction, intense induction of lymphoproliferation was observed (p<0.0001), as was also observed in response to the PHA mitogen, and there was a significant difference when compared with the conventional treatment (p<0.0135). In the post-treatment and healthy groups, although the compound induced lymphoproliferation, there was no statistical difference. These results suggest that the organic compound played an important inducing role in lymphoproliferation, which highlights the importance of continuity involving new studies in order to evaluate its immunomodulatory activity.

Effect of Prophylactic Vaccination with the Membrane-Bound Acid Phosphatase Gene of Leishmania mexicana in the Murine Model of Localized Cutaneous Leishmaniasis

Leishmaniasis is a disease caused by an intracellular protozoan parasite of the genus Leishmania. Current treatments for leishmaniasis are long, toxic, and expensive and are not available in some endemic regions. Attempts to develop an effective vaccine are feasible, but no vaccine is in active clinical use. In this study, the LmxMBA gene of Leishmania mexicana was selected as a possible vaccine candidate using the reverse vaccinology approach, and the prophylactic effect generated by DNA vaccination with this gene in a murine model of cutaneous leishmaniasis was evaluated. The results showed that prophylactic vaccination with pVAX1::LmxMBA significantly reduced the size of the lesion and the parasitic load on the footpad, compared to the control groups. At a histological level, a smaller number of parasites were evident in the dermis, as well as the absence of connective tissue damage. Mice immunized with plasmid pVAX1::LmxMBA induced immunity characterized by an increase in the IgG 2 a / IgG 1 > 1 ratio and a higher rate of lymphocyte proliferation. In this study, immunization with the plasmid promoted an improvement in the macroscopic and microscopic clinical manifestations of the experimental infection by L. mexicana, with a T helper 1 response characterized by an IgG 2 a / IgG 1 > 1 ratio and high lymphoproliferative response. These findings support immunization with the plasmid pVAX1::LmxMBA as a preventive strategy against cutaneous infection of L. mexicana.

Blocking IL-10 signaling with soluble IL-10 receptor restores in vitro specific lymphoproliferative response in dogs with leishmaniasis caused by Leishmania infantum

rIL-10 plays a major role in restricting exaggerated inflammatory and immune responses, thus preventing tissue damage. However, the restriction of inflammatory and immune responses by IL-10 can also favor the development and/or persistence of chronic infections or neoplasms. Dogs that succumb to canine leishmaniasis (CanL) caused by L. infantum develop exhaustion of T lymphocytes and are unable to mount appropriate cellular immune responses to control the infection. These animals fail to mount specific lymphoproliferative responses and produce interferon gamma and TNF-alpha that would activate macrophages and promote destruction of intracellular parasites. Blocking IL-10 signaling may contribute to the treatment of CanL. In order to obtain a tool for this blockage, the present work endeavored to identify the canine casIL-10R1 amino acid sequence, generate a recombinant baculovirus chromosome encoding this molecule, which was expressed in insect cells and subsequently purified to obtain rcasIL-10R1. In addition, rcasIL-10R1 was able to bind to homologous IL-10 and block IL-10 signaling pathway, as well as to promote lymphoproliferation in dogs with leishmaniasis caused by L. infantum.

Intranasal Immunization of Mice with Multiepitope Chimeric Vaccine Candidate Based on Conserved Autotransporters SigA, Pic and Sap, Confers Protection against Shigella flexneri

Shigellosis is a diarrheal disease and the World Health Organization prompts the development of a vaccine against Shigella flexneri. The autotransporters SigA, Pic and Sap are conserved among Shigella spp. We previously designed an in silico vaccine with immunodominat epitopes from those autotransporters, and the GroEL protein of S. typhi as an adjuvant. Here, we evaluated the immunogenicity and protective efficacy of the chimeric multiepitope protein, named rMESF, in mice against lethal infection with S. flexneri. rMESF was administered to mice alone through the intranasal (i.n.) route or accompanied with Complete Freund’s adjuvant (CFA) intradermically (i.d.), subcutaneously (s.c.), and intramuscular (i.m.), as well as with Imject alum (i.m.). All immunized mice increased IgG, IgG1, IgG2a, IgA and fecal IgA titers compared to PBS+CFA and PBS+alum control groups. Furthermore, i.n. immunization of mice with rMESF alone presented the highest titers of serum and fecal IgA. Cytokine levels (IFN-γ, TNF-α, IL-4, and IL-17) and lymphocyte proliferation increased in all experimental groups, with the highest lymphoproliferative response in i.n. mice immunized with rMESF alone, which presented 100% protection against S. flexneri. In summary, this vaccine vests protective immunity and highlights the importance of mucosal immunity activation for the elimination of S. flexneri.

Blocking IL-10 signaling with soluble IL-10 receptor restores specific lymphoproliferative response in dogs with leishmaniasis caused by Leishmania infantum

AbstractrIL-10 plays a major role in restricting exaggerated inflammatory and immune responses, thus preventing tissue damage. However, the restriction of inflammatory and immune responses by IL-10 can also favor the development and/or persistence of chronic infections or neoplasms. Dogs that succumb to leishmaniasis caused by L. infantum (CanL) develop exhaustion of T lymphocytes and are unable to mount appropriate cellular immune responses to control the infection. These animals fail to mount specific lymphoproliferative responses and produce interferon gamma and TNF-alpha that would activate macrophages and promote destruction of intracellular parasites. Blocking IL-10 signaling may contribute to the treatment of CanL. In order to obtain a tool for this blockage, the present work endeavored to identify the canine casIL-10R1 amino acid sequence, generate a recombinant baculovirus chromosome encoding this molecule, which was expressed in insect cells and subsequently purified to obtain rcasIL-10R1. In addition, rcasIL-10R1 was able to bind to homologous IL-10 and block IL-10 signaling pathway, as well as to promote lymphoproliferation in dogs with leishmaniasis caused by L. infantum.

Lymphoproliferation Impairment and Oxidative Stress in Blood Cells from Early Parkinson’s Disease Patients

In Parkinson’s Disease (PD), the peripheral changes in the functional capacity and redox state of immune cells has been scarcely investigated, especially in the early PD stages. Aging is a risk factor for PD, and the age-related impairment of the immune system, based on a chronic-oxidative stress situation, is involved in the rate of aging. We analyzed several functions in isolated peripheral blood neutrophils and mononuclear cells from PD stage 2 patients, and compared the results to those in healthy elderly and adult controls. Several oxidative stress and damage parameters were studied in whole blood cells. The results showed an impairment of the lymphoproliferative response in stimulated conditions in the PD patients compared with age-matched controls, who also showed typical immunosenescence in comparison with adult individuals. Higher oxidative stress and damage were observed in whole blood cells from PD patients (lower glutathione peroxidase activity, and higher oxidized glutathione and malondialdehyde contents). Our results suggest an accelerated immunosenescence in PD stage 2, and that several of the parameters studied could be appropriate peripheral biomarkers in the early stages of PD.

Mitigation potential of distillery sludge against ochratoxin A induced immunological alterations in broiler chicks

Ochratoxin A (OTA) is a potent mycotoxin injurious to poultry health and an alarming factor for poultry industry while distillery sludge (DS) is a waste product of molasses based industries rich in proteins and certain essential vitamins and other nutrients. The present study was done to estimate the immunological alterations induced by OTA in broiler chicks and amelioration of these alterations by dietary supplementation of DS. For this purpose, 480 one-day old broiler chicks procured from a local hatchery, were divided into sixteen equal groups and were given different combinations of OTA (150, 300 and 1000 µg/kg feed) and DS (5, 10 and 20 g/kg feed). Parameters studied were antibodies response to sheep red blood cells (SRBCs), lymphoproliferative response to PHA-P and phagocytic index as studied by carbon clearance assay. The results of this study showed that feeding DS with 150 and 300 µg/kg OTA ameliorated OTA induced alterations, but this amelioration was partial when 1000 µg/kg OTA was used along with DS. From this study it could be concluded that DS has beneficial effects in birds suffering from ochratoxicosis. However, the proper level of DS to produce such mitigation against specific level of OTA is yet to be determined.