CD4+ and CD8+ T-cell multi-epitope chimeric protein associated with an MPLA adjuvant induce protective efficacy and long-term immunological memory for the immunoprophylaxis of American Tegumentary Leishmaniasis.

American Tegumentary Leishmaniasis (ATL) is a disease of high severity and incidence in Brazil, in addition to being a worldwide concern in public health. Leishmania amazonensis is one of the etiological agents of ATL, and the inefficiency of control measures, associated with the high toxicity of the treatment and the lack of effective immunoprophylactic strategies, makes the development of vaccines indispensable and imminent. In this light, the present study proposes to elaborate a chimeric protein (rChiP), based on the fusion of multiple epitopes of CD4+/CD8+ T cells, identified in the immunoproteome of the parasites L. amazonensis and L. braziliensis. The designed chimeric protein was tested in the L. amazonensis murine model of infection using the following formulations: 25 µg of the rChiP in saline (rChiP group) and 25 µg of the rChiP plus 25 µg of MPLA-PHAD® (rChiP+MPLA group). After completing immunization, CD4+ and CD8+ T cells, stimulated with SLa-Antigen or rChiP, showed an increased production of nitric oxide and intracytoplasmic pro-inflammatory cytokines, in addition to the generation of central and effector memory T cells. rChiP and rChiP+MPLA formulations were able to promote an effective protection against L. amazonensis infection determined by a reduction in the development of skin lesions and lower parasitic burden. Reduction in the development of skin lesions and lower parasitic burden in the vaccinated groups were associated with an increase of nitrite, CD4+/CD8+IFN-γ+TNF-α+ and CD4+/CD8+CD44highCD62Lhigh/low T cells, IgGTotal, IgG2a, and lower rates of IgG1 and CD4+/CD8+IL-10+. This data suggests that proposed formulations could be considered potential tools to prevent ATL.

Mapping linear B-cell epitopes of the Tryparedoxin Peroxidase and its implications in the serological diagnosis of tegumentary leishmaniasis.

Diagnosis of tegumentary leishmaniasis (TL) is essential to avoid permanent damage and severe functional sequelae and there is an urgent need to discover new antigens. The present study aimed to comprehensively evaluate the potential use of the Tryparedoxin Peroxidase (TryP) as an antigen for serological tests. The proposal integrates data from immunoproteomics with immunoinformatics, in addition to a precise analysis of protein levels in the evolutionary stages of the parasite by flow cytometry. To evaluate the performance in the diagnosis of TL, Enzyme-Linked Immunosorbent Assay (ELISA) assays were performed using the recombinant protein and the respective B-cell epitope, followed by an analysis of the contribution of this peptide in the recognition of the protein by patients, evaluated by serum depletion assays. We showed that the TryP has a linear B-cell epitope with high divergence compared to orthologs from Trypanosoma cruzi and Homo sapiens. The results also show high expression and positive cells for TryP (TryP+) in the infective metacyclic promastigotes (MET) and intracellular (24 and 48 hours) stages. From the depletion assays, it was possible to confirm the contribution of the peptide in the specific recognition of the TryP protein by patients with TL (13.7-15.9%). ELISA using the peptide showed high performance in the diagnosis compared to the recombinant TryP (rTryP), Soluble Leishmania braziliensis Antigen (sLba) and Immunofluorescence Assay (IFA) with accuracy of 94.29, 89.29, 65.00 and 37.14%, respectively). We can conclude that the MNEPAPP peptide is a potential antigen for the diagnosis of TL.

The Sigma-2 receptor / transmembrane protein 97 (σ2R/TMEM97) modulator JVW-1034 reduces heavy alcohol drinking and associated pain states in male mice.

Alcohol Use Disorder (AUD) is a chronic relapsing disorder characterized by compulsive alcohol intake, loss of control over alcohol intake, and a negative emotional state when access to alcohol is prevented. AUD is also closely tied to pain, as repeated alcohol drinking leads to increased pain sensitivity during withdrawal. The sigma-2 receptor, recently identified as transmembrane protein 97 (σ2R/TMEM97), is an integral membrane protein involved in cholesterol homeostasis and lipid metabolism. Selective σ2R/Tmem97 modulators have been recently shown to relieve mechanical hypersensitivity in animal models of neuropathic pain as well as to attenuate alcohol withdrawal signs in C. elegans and to reduce alcohol drinking in rats, suggesting a potential key role for this protein in alcohol-related behaviors. In this study, we tested the effects of a potent and selective σ2R/TMEM97 ligand, JVW-1034, on heavy alcohol drinking and alcohol-induced heightened pain states in mice using an intermittent access model. Administration of JVW-1034 decreased both ethanol intake and preference for ethanol, without affecting water intake, total fluid intake, or food intake. Notably, this effect was specific for alcohol, as JVW-1034 had no effect on sucrose intake. Furthermore, JVW-1034 reduced both thermal hyperalgesia and mechanical hypersensitivity in ethanol withdrawn mice. Our data provide important evidence that modulation of σ2R/TMEM97 with small molecules can mediate heavy alcohol drinking as well as chronic alcohol-induced heightened pain sensitivity, thereby identifying a promising novel pharmacological target for AUD and associated pain states.