Cytotoxic activity in cutaneous leishmaniasis

Determination of key hub genes in Leishmaniasis as potential factors in diagnosis and treatment based on a bioinformatics study

Leishmaniasis is an infectious disease caused by protozoan parasites from different species of leishmania. The disease is transmitted by female sandflies that carry these parasites. In this study, datasets on leishmaniasis published in the GEO database were analyzed and summarized. The analysis in all three datasets (GSE43880, GSE55664, and GSE63931) used in this study has been performed on the skin wounds of patients infected with a clinical form of leishmania (Leishmania braziliensis), and biopsies have been taken from them. To identify differentially expressed genes (DEGs) between leishmaniasis patients and controls, the robust rank aggregation (RRA) procedure was applied. We performed gene functional annotation and protein-protein interaction (PPI) network analysis to demonstrate the putative functionalities of the DEGs. The study utilized Molecular Complex Detection (MCODE), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) to detect molecular complexes within the protein-protein interaction (PPI) network and conduct analyses on the identified functional modules. The CytoHubba plugin's results were paired with RRA analysis to determine the hub genes. Finally, the interaction between miRNAs and hub genes was predicted. Based on the RRA integrated analysis, 407 DEGs were identified (263 up-regulated genes and 144 down-regulated genes). The top three modules were listed after creating the PPI network via the MCODE plug. Seven hub genes were found using the CytoHubba app and RRA: CXCL10, GBP1, GNLY, GZMA, GZMB, NKG7, and UBD. According to our enrichment analysis, these functional modules were primarily associated with immune pathways, cytokine activity/signaling pathways, and inflammation pathways. However, a UBD hub gene is interestingly involved in the ubiquitination pathways of pathogenesis. The mirNet database predicted the hub gene's interaction with miRNAs, and results revealed that several miRNAs, including mir-146a-5p, crucial in fighting pathogenesis. The key hub genes discovered in this work may be considered as potential biomarkers in diagnosis, development of agonists/antagonist, novel vaccine design, and will greatly contribute to clinical studies in the future.

Effectiveness of low-level laser therapy in reducing pain score and healing time of recurrent aphthous stomatitis: a systematic review and meta-analysis

BACKGROUND

Recurrent aphthous stomatitis (RAS) is a common chronic inflammatory oral disease that negatively impacts the quality of life. Current therapies aim to reduce pain and healing process yet challenges such as rapid loss due to salivary flushing in topical drugs and adverse effects due to prolonged use of systemic medications require further notice. Low-level laser therapy is reported with immediate pain relief and faster healing thus preserving the potential for optimal treatment modalities. This review critically analyses and summarizes the effectiveness of LLLT in reducing pain scores and healing time of RAS.

METHODS

A systematic search was conducted in ScienceDirect, PubMed, and Scopus using keywords of low-level laser therapy, photo-biomodulation therapy, and recurrent aphthous stomatitis. RCTs between 1967 to June 2022, presenting characteristics of the laser and reporting pain score and/or healing time of RAS after irradiation were included. Animal studies and recurrent aphthous ulcers with a history of systemic conditions were excluded. Studies were critically appraised using the RoB 2 tool. A meta-analysis was performed using inverse variance random effects.

RESULTS

Fourteen trials with a total of 664 patients were included. Reduced pain was reported in 13 studies, while shortened healing time was presented in 4. The pooling of two studies after CO2 irradiation demonstrated faster healing time compared to placebo (MD - 3.72; 95% CI - 4.18, - 3.25).

CONCLUSION

Pain score and healing time of RAS were reduced after irradiation with LLLT. RoB resulted in "some concerns" urging well-designed RCTs with larger samples to further assess each laser application for comparison.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022355737.

Chlorella vulgaris extract and Imiquimod as new therapeutic targets for leishmaniasis: An immunological approach

The therapeutic regimen for the treatment of American Tegumentary Leishmaniasis (ATL) is targeted at the death of the parasite; therefore, it is essential to develop a treatment that can act on the parasite, combined with the modulation of the inflammatory profile. Thus, the aim of this study was to make an in vitro evaluation of the therapeutic potential of Chlorella vulgaris extract (CV) and Imiquimod for ATL. Selectivity indices (SI) were determined by inhibitory concentration assays (IC50) in L. braziliensis cells and cytotoxic concentrations (CC50) were measured in human cells using the MTT method, based on the CV microalgae extract (IC50 concentrations of 15.63 to 500 µg/mL; CC50 concentrations of 62.5-1000 µg/mL) in comparison with the reference drugs and Imiquimod. The immune response was evaluated in healthy human cells by gene expression (RT-qPCR) and cytokine production (Flow Cytometry). The CV extract (SI = 6.89) indicated promising results by showing higher SI than meglumine antimoniate (SI = 3.44) (reference drug). In all analyses, CV presented a protective profile by stimulating the production of Th1 profile cytokines to a larger extent than the reference drugs. Imiquimod showed a high expression for Tbx21, GATA3, RORc and Foxp3 genes, with increased production only of the TNF cytokine. Therefore, the data highlight the natural extract and Imiquimod as strong therapeutic or adjuvant candidates against ATL, owing to modulation of immune response profiles, low toxicity in human cells and toxic action on the parasite.

Transcriptome Analysis Identifies the Crosstalk between Dendritic and Natural Killer Cells in Human Cutaneous Leishmaniasis

Skin ulcers of cutaneous leishmaniasis (CL) are characterized by a localized inflammatory response mediated by innate and adaptive immune cells, including dendritic cells (DC) and natural killer (NK) cells. Bidirectional interactions between DCs and NK cells contribute to tailor leishmaniasis outcome. Despite advances in the Leishmania biology field in recent decades, the mechanisms involved in DC/NK-mediated control of Leishmania sp. pathogenesis as well as the cellular and molecular players involved in such interaction remain unclear. The present study sought to investigate canonical pathways associated with CL arising from Leishmania braziliensis infection. Initially, two publicly available microarray datasets of skin biopsies from active CL lesions were analyzed, and five pathways were identified using differentially expressed genes. The "Crosstalk between DCs and NK cells" pathway was notable due to a high number of modulated genes. The molecules significantly involved in this pathway were identified, and our findings were validated in newly obtained CL biopsies. We found increased expression of TLR4, TNFRSF1B, IL-15, IL-6, CD40, CCR7, TNF and IFNG, confirming the analysis of publicly available datasets. These findings reveal the "crosstalk between DCs and NK cells" as a potential pathway to be further explored in the pathogenesis of CL, especially the expression of CCR7, which is correlated with lesion development.

Autophagy induced macrophages by α-alumina(α-AL2O3) conjugated cysteine peptidase, enhances the cytotoxic activity of CD8+ T lymphocytes against Leishmania major

Introduction

Induction of a protective immune response against Leishmania major requires the activation of both TH1 and CD8+ T lymphocytes. Because L. major is an intra-phagosomal parasite, its antigens do not have access to MHC-I. The present study aimed to evaluate the effect of cysteine peptidase A (CPA)/cysteine peptidase B (CPB) conjugated to α-AL2O3 on autophagy induction in L. major infected macrophages and subsequent activation of cytotoxic CD8+ T lymphocytes.

Methods

Recombinant CPA and CPB of L. major were produced in expression vectors and purified. Aldehyde functionalized α-AL2O3 were conjugated to hydrazine-modified CPA/CPB by a chemical bond was confirmed by Fourier-transform infrared spectroscopy (FTIR). The High efficient internalization of α-AL2O3 conjugated CPA/CPB to macrophages was confirmed using a fluorescence microscope and flowcytometry. Induction of the acidic autophagosome and LC3 conversion in macrophages was determined by acridine orange (AO) staining and western blot. Autophagy-activated macrophages were used for CD8+ T cell priming. Cytotoxic activity of the primed CD8+ T cell against L. major infected macrophages was measured using apoptosis assay.

Results

α-AL2O3 conjugated CPA/CPB enhances macrophages antigen uptake and increases acidic vacuole formation and LC-3I to LC-3II conversion. Co-culture of autophagy-activated macrophages with CD8+ T cells augmented CD8+ T cells priming and proliferation more than in other study groups. These primed CD8+ T cells induce significant apoptotic death of L. major infected macrophages compared with non-primed CD8+ T cells.

Conclusion

α-AL2O3 nanoparticles enhance the cross-presentation of L. major antigens to CD8+ T cells by inducing autophagy. This finding supports the positive role of autophagy and encourages the use of α-AL2O3 in vaccine design.

Toll-Like Receptor 3 (TLR3) Is Engaged in the Intracellular Survival of the Protozoan Parasite Leishmania (Leishmania) amazonensis

The protozoan parasite Leishmania (L.) amazonensis infects and replicates inside host macrophages due to subversion of the innate host cell response. In the present study, we demonstrate that TLR3 is required for the intracellular growth of L. (L.) amazonensis. We observed restricted intracellular infection of TLR3^-/- mouse macrophages, reduced levels of IFN1β and IL-10, and increased levels of IL-12 upon L. (L.) amazonensis infection, compared with their wild-type counterparts. Accordingly, in vivo infection of TLR3^-/- mice with L. (L.) amazonensis displayed a significant reduction in lesion size. Leishmania (L.) amazonensis infection induced TLR3 proteolytic cleavage, which is a process required for TLR3 signaling. The chemical inhibition of TLR3 cleavage or infection by CPB-deficient mutant L. (L.) mexicana resulted in reduced parasite load and restricted the expression of IFN1β and IL-10. Furthermore, we show that the dsRNA sensor molecule PKR (dsRNA-activated protein kinase) cooperates with TLR3 signaling to potentiate the expression of IL-10 and IFN1β and parasite survival. Altogether, our results show that TLR3 signaling is engaged during L. (L.) amazonensis infection and this component of innate immunity modulates the host cell response.

Development of an immunogen containing CD4+/CD8+ T-cell epitopes for the prophylaxis of tegumentary leishmaniasis

Abstract

Tegumentary leishmaniasis (TL) is a disease of high severity and incidence in Brazil, and Leishmania braziliensis is its main etiological agent. The inefficiency of control measures, such as high toxicity and costs of current treatments and the lack of effective immunoprophylactic strategies, makes the development of vaccines indispensable and imminent. In this light, the present work developed a gene encoding multiple T-cell (CD4⁺/CD8⁺) epitope, derived from conserved proteins found in Leishmania species and associated with TL, to generate a chimeric protein (rMEP/TL) and compose a vaccine formulation. For this, six T-cell epitopes were selected by immunoinformatics approaches from proteins present in the amastigote stage and associated with host-parasite interactions. The following formulations were then tested in an L. braziliensis murine infection model: rMEP/TL in saline or associated with MPLA-PHAD^®. Our data revealed that, after immunization (three doses; 14-day intervals) and subsequent challenging, rMEP/TL and rMEP/TL + MPLA-vaccinated mice showed an increased production of key immunological biomarkers of protection, such as IgG_2a, IgG_2a/IgG₁, NO, CD4⁺, and CD8⁺ T-cells with IFN-γ and TNF-α production, associated with a reduction in CD4⁺IL-10⁺ and CD8⁺IL-10⁺ T-cells. Vaccines also induced the development of central (CD44^highCD62L^high) and effector (CD44^highCD62L^low) memory of CD4⁺ and CD8⁺ T-cells. These findings, associated with the observation of lower rates of parasite burdens in the vaccinated groups, when compared to the control groups, suggest that immunization with rMEP/TL and, preferably, associated with an adjuvant, may be considered an effective tool to prevent TL.

Key points

• Rational design approaches for vaccine development.

• Central and effector memory of CD4+ and CD8+ T-cells.

• Vaccine comprised of rMEP/TL plus MPLA as an effective tool to prevent TL.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-12033-7.

Protection and Pathology in Leishmania braziliensis Infection

Leishmania killing is mediated by IFN-γ-activated macrophages, but IFN-γ production and macrophage activation are insufficient to control L. braziliensis infection. In American tegumentary leishmaniasis (ATL), pathology results from an exaggerated inflammatory response. This report presents an overview of our contributions regarding ATL pathogenesis, highlighting future directions to improve the management of L. braziliensis infection. Monocytes and lymphocytes from individuals exposed to L. braziliensis but who do not develop CL, i.e., subclinical infection (SC), exhibit lower respiratory burst and IFN-γ production, yet more efficiently kill L. braziliensis. As vaccines aimed at inducing IL-12 and IFN-γ do not sufficiently prevent CL, the elucidation of how subjects with SC infection kill Leishmania may lead to new approaches to controlling ATL. While inflammation arising from the recruitment of inflammatory cells via chemokines induced by IFN-γ and TNF or IL-17 is observed and contributes to pathology, cytotoxic CD8⁺ T cells and NK cells play a key role in the pathogenesis of L. braziliensis infection. The increased transcription of genes related to inflammation and cytotoxicity, e.g., granzyme A, granzyme B, NLRP3 and IL-1β, has been documented in CL tissue samples. The release of products by killed cells leads to NLRP3 inflammasome activation, IL-1β production and additional damage to skin and mucosal tissues. The use of drugs that downmodulate the inflammatory response in combination with chemotherapy improves the ATL cure rate and decreases healing time.

Parasites causing cutaneous wounds: Theory and practice from a dermatological point of view

A wide range of parasites can infest open wounds, or cause wounds due to the effects of the infestation. Parasitic infestations can involve the skin and subcutaneous tissues, with various clinical manifestations. In case of cutaneous wounds related to infestations, protozoa, helminths and arthropods are the main groups of parasites involved and emerging new aspects have been recently reported. Treating the wound correctly is fundamental in these patients in order to reduce the development of pathological scars and prevent complications. In particular, a gentle debridement for devitalized/infested tissue removal, the appropriate use of topical antiseptics and dressings such as hydrogel, hydrocolloids and antimicrobial dressings can be useful to control superinfections, moisture balance, inflammation and to promote edge proliferation.

The Leishmania antigen-specific pro-inflammatory response in cutaneous leishmaniasis is linked to disease progression but not to the therapeutic failure of pentavalent antimonials

High levels of pro-inflammatory cytokines in cutaneous leishmaniasis patients are associated with tissue damage and ulcer development. We found higher levels of TNF and IL-1β in peripheral blood mononuclear cell supernatants in response to soluble Leishmania antigen in individuals with a longer duration of disease. In addition, L. braziliensis-infected patients with a longer disease progression before treatment presented a shorter time to cure after treatment onset. No associations were found between the levels of the pro-inflammatory cytokines IL-6, TNF and IL-1-β and patients' response to pentavalent antimony treatment. Our data suggest that while the Leishmania antigen-specific pro-inflammatory cytokines investigated may lead to ulcer development, they do not influence therapeutic failure in cutaneous leishmaniasis patients.

Inhibition of gamma-secretase activity without interfering in Notch signalling decreases inflammatory response in patients with cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) patients present an exacerbated inflammatory response associated with tissue damage and ulcer development. Increasing numbers of patients have exhibited treatment failure, which remains not well understood. We hypothesized that adjuvant anti-inflammatory therapy would benefit CL patients. The aim of the present study was to investigate the contribution of Notch signalling and gamma-secretase activity to the inflammatory response observed in CL patients. Notch signalling is a molecular signalling pathway conserved among animal species. Gamma-secretase forms a complex of proteins that, among other pathways, modulates Notch signalling and immune response. We found that Notch 1 cell receptor signalling protects against the pathologic inflammatory response, and JLK6, a gamma-secretase inhibitor that does not interfere with Notch signalling, was shown to decrease the in-vitro inflammatory response in CL. Our data suggest that JLK6 may serve as an adjuvant treatment for CL patients.

Immunological role of keratinocytes in leishmaniasis

Following inoculation of Leishmania, a protozoan parasite, into the skin of a mammal, the epidermal keratinocytes recognize the parasite and influence the local immune response that can give rise to different outcomes of leishmaniasis. The early keratinocyte-derived cytokines and keratinocytes-T cells interactions shape the anti-leishmanial immune responses that contribute to the resistance or susceptibility to leishmaniasis. The keratinocyte-derived cytokines can directly potentiate the leishmanicidal activity of monocytes and macrophages. As keratinocytes express MHC-II and enhance the expression of costimulatory molecules, these cells act as antigen-presenting cells (APCs) in cutaneous leishmaniasis (CL). Depending on the epidermal microenvironment, the keratinocytes induce various types of effector CD4⁺ T cells. Keratinocyte apoptosis and necrosis have been also implicated in ulceration in CL. Further, keratinocytes contribute to the healing of Leishmania-related cutaneous wounds. However, keratinocyte-derived IL-10 may play a key role in the development of post-kala-azar dermal leishmaniasis (PKDL). In this review, a comprehensive discussion regarding the multiple roles played by keratinocytes during leishmaniasis was provided, while highlighting novel insights concerning the immunological and pathological roles of these cells.

Innate immune response: ally or enemy in cutaneous leishmaniasis?

Cutaneous leishmaniasis (CL) is an infectious and neglected disease caused by parasites of the genus Leishmania, which produces a wide spectrum of cutaneous manifestations. CL research has shown that the innate immune activity of cells such as neutrophils, natural killers, macrophages, dendritic cells and the complement system are capable of controlling this infection. However, Leishmania can also modulate the immune activity of these cells to promote its own survival and proliferation at the intracellular level. This review discusses the role of the innate immune response in the control and spread of this infection.

Mastomys natalensis Has a Cellular Immune Response Profile Distinct from Laboratory Mice

The multimammate mouse (Mastomys natalensis; M. natalensis) has been identified as a major reservoir for multiple human pathogens including Lassa virus (LASV), Leishmania spp., Yersinia spp., and Borrelia spp. Although M. natalensis are related to well-characterized mouse and rat species commonly used in laboratory models, there is an absence of established assays and reagents to study the host immune responses of M. natalensis. As a result, there are major limitations to our understanding of immunopathology and mechanisms of immunological pathogen control in this increasingly important rodent species. In the current study, a large panel of commercially available rodent reagents were screened to identify their cross-reactivity with M. natalensis. Using these reagents, ex vivo assays were established and optimized to evaluate lymphocyte proliferation and cytokine production by M. natalensis lymphocytes. In contrast to C57BL/6J mice, lymphocytes from M. natalensis were relatively non-responsive to common stimuli such as phytohaemagglutinin P and lipopolysaccharide. However, they readily responded to concanavalin A stimulation as indicated by proliferation and cytokine production. In summary, we describe lymphoproliferative and cytokine assays demonstrating that the cellular immune responses in M. natalensis to commonly used mitogens differ from a laboratory-bred mouse strain.

Understanding the immune responses involved in mediating protection or immunopathology during leishmaniasis

Leishmaniasis is a vector-borne Neglected Tropical Disease (NTD) transmitted by the sand fly and is a major public health problem worldwide. Infections caused by Leishmania clinically manifest as a wide range of diseases, such as cutaneous (CL), diffuse cutaneous (DCL), mucosal (MCL) and visceral leishmaniasis (VL). The host innate and adaptative immune responses play critical roles in the defense against leishmaniasis. However, Leishmania parasites also manipulate the host immune response for their survival and replication. In addition, other factors such as sand fly salivary proteins and microbiota also promote disease susceptibility and parasite spread by modulating local immune response. Thus, a complex interplay between parasite, sand fly and the host immunity governs disease severity and outcome. In this review, we discuss the host immune response during Leishmania infection and highlight the factors associated with resistance or susceptibility.

Human CD8+ T Cells Release Extracellular Traps Co-Localized With Cytotoxic Vesicles That Are Associated With Lesion Progression and Severity in Human Leishmaniasis

Cell death plays a fundamental role in mounting protective and pathogenic immunity. Etosis is a cell death mechanism defined by the release of extracellular traps (ETs), which can foster inflammation and exert microbicidal activity. While etosis is often associated with innate cells, recent studies showed that B cells and CD4+ T cells can release ETs. Here we investigate whether CD8+ T cells can also release ETs, which might be related to cytotoxicity and tissue pathology. To these ends, we first employed an in vitro system stimulating human CD8+ T cells isolated from healthy volunteers with anti-CD3/anti-CD28. Using time-frame video, confocal and electron microscopy, we demonstrate that human CD8+ T cells release ETs upon stimulation (herein LETs – lymphocyte extracellular traps), which display unique morphology and functional characteristics. CD8+ T cell-derived LETs form long strands that co-localize with CD107a, a marker of vesicles containing cytotoxic granules. In addition, these structures connect the LET-releasing cell to other neighboring cells, often resulting in cell death. After demonstrating the release of LETs by human CD8+ T cells in vitro, we went on to study the occurrence of CD8-derived LETs in a human disease setting. Thus, we evaluated the occurrence of CD8-derived LETs in lesions from patients with human tegumentary leishmaniasis, where CD8+ T cells play a key role in mediating pathology. In addition, we evaluated the association of these structures with the intensity of the inflammatory infiltrate in early and late cutaneous, as well as in mucosal leishmaniasis lesions. We demonstrated that progression and severity of debilitating and mutilating forms of human tegumentary leishmaniasis are associated with the frequency of CD8+ T cells in etosis, as well as the occurrence of CD8-derived LETs carrying CD107a+ vesicles in the lesions. We propose that CD8+ T cell derived LETs may serve as a tool for delivering cytotoxic vesicles to distant target cells, providing insights into mechanisms of CD8+ T cell mediated pathology.

Tissue Damage in Human Cutaneous Leishmaniasis: Correlations Between Inflammatory Cells and Molecule Expression

Cutaneous leishmaniasis (CL) is caused by the bite of the infected sand fly, which inoculates parasites of Leishmania spp and triggers an immune response. An exacerbated cutaneous inflammatory response is crucial for controlling parasite burden but can also promote tissue damage. This study aimed to characterize the populations of natural killer (NK), CD57⁺, CD4⁺, and CD8⁺ T cells, CD20⁺ B cells, as well as CD68⁺ macrophages, in biopsies of ulcerated CL lesions, and quantify the production of perforin⁺, grazyme B⁺, interleukin 1 beta (IL-1β⁺) and Tumor Necrosis Factor (TNF-α⁺ cells). We then correlated these parameters with necrosis, inflammation and the number of amastigotes. CD4⁺ T cells were positively correlated to the extent of inflammation, B cells and IL-1β⁺ were associated with the extent of necrosis, CD68⁺ macrophages and perforin were correlated with the number of amastigotes, and CD57⁺ NK cells was correlated to CD68⁺ macrophages and amastigotes. In sum, the finding suggests that the production of cytotoxic granules and cytokines by inflammatory cells contributes to tissue damage in CL lesions.

IL-1 family and Cutaneous Leishmaniasis: A poorly understood relationship

The cytokines of the interleukin (IL) -1 family act in the initiation of an effective immune response in Leishmania infection, represented mainly by the T helper 1 (Th1) profile, in addition to being associated with disease exacerbation and controversial contributions in the Th2 responses. The family also includes members who self-regulate inflammation, such as antagonists and anti-inflammatory cytokines, most of which have not yet been studied in Cutaneous Leishmaniasis (CL) in humans. Here we summarize findings about what is known so far about the role of these cytokines in mice, the main study model, and in humans. We reinforce the importance of studies of these cytokines as new targets in the context of CL.

Activated cytotoxic T cells within zoonotic cutaneous leishmaniasis lesions

Introduction

Zoonotic cutaneous leishmaniasis (ZCL), due to infection by Leishmania (L). major, is characterized by polymorphic clinical manifestations which could be attributed to the host's immune response. In this study we investigated the involvement of cytotoxic cells on the outcome of the disease.

Methods

Expression of granzyme B (GrB), granulysine (Grly), and interferon (IFN)‐γ was evaluated within ZCL lesion specimens using the technique of real‐time quantitative polymerase chain reaction (RT‐qPCR). Immunohistochemical staining was performed using anti‐CD3, CD4, CD8, CD56, GrB, and IFN‐γ antibodies to identify the phenotype of GrB and IFN‐γ‐producing cells.

Results

GrB and Grly mRNA was detected within 75% and 80% of ZCL lesions, respectively. Statistical analysis demonstrated a significant correlation between levels of GrB and Grly. Interestingly, expression of these molecules correlates negatively with the lesion's age. The highest levels were measured in early lesions (E‐ZCL) (lesion age ≤1 month) comparing to late lesions (L‐ZCL) (lesion age >1 month). Otherwise, IFN‐γ mRNA was detected only within 56% and a positive correlation was found between levels of this cytokine and those of GrB. Immunohistochemical analysis showed that GrB is produced essentially by CD8⁺T cells whereas IFN‐γ is produced by both CD4⁺ and CD8⁺T cells.

Conclusion

Together our results demonstrate the presence of cytotoxic cells producing GrB and Grly within leishmaniasis cutaneous lesions.

The miRNA 361-3p, a Regulator of GZMB and TNF Is Associated With Therapeutic Failure and Longer Time Healing of Cutaneous Leishmaniasis Caused by L. (viannia) braziliensis

L. (viannia) braziliensis infection causes American Tegumentary Leishmaniasis (ATL), with prolonged time to healing lesions. The potent inflammatory response developed by the host is important to control the parasite burden and infection however an unbalanced immunity may cooperate to the tissue damage observed. The range of mechanisms underlying the pathological responses associated with ATL still needs to be better understood. That includes epigenetic regulation by non-coding MicroRNAs (miRNAs), non-coding sequences around 22 nucleotides that act as post-transcriptional regulators of RNAs encoding proteins. The miRNAs have been associated with diverse parasitic diseases, including leishmaniasis. Here we evaluated miRNAs that targeted genes expressed in cutaneous leishmaniasis lesions (CL) by comparing its expression in both CL and normal skin obtained from the same individual. In addition, we evaluated if the miRNAs expression would be correlated with clinical parameters such as therapeutic failure, healing time as well as lesion size. The miR-361-3p and miR-140-3p were significantly more expressed in CL lesions compared to normal skin samples (p = 0.0001 and p < 0.0001, respectively). In addition, the miR-361-3p was correlated with both, therapeutic failure and healing time of disease (r = 0.6, p = 0.003 and r = 0.5, p = 0.007, respectively). In addition, complementary analysis shown that miR-361-3p is able to identify with good sensitivity (81.2%) and specificity (100%) patients who tend to fail initial treatment with pentavalent antimonial (Sbv). Finally, the survival analysis considering “cure” as the endpoint showed that the higher the expression of miR-361-3p, the longer the healing time of CL. Overall, our data suggest the potential of miR-361-3p as a prognostic biomarker in CL caused by L. braziliensis.