Screening of TNFα, IL-10 and TLR4 single nucleotide polymorphisms in individuals with asymptomatic and chronic cutaneous leishmaniasis in Colombia: a pilot study

Lupeol stimulates iNOS, TNF-α, and IL-10 expression in the U937 cell line infected with old-world Leishmania donovani

OBJECTIVE

Visceral leishmaniasis is a neglected tropical disease that can be lethal if not treated. The available medicines have severe side effects, such as toxicity and drug resistance. Various investigations are looking into new anti-leishmanial compounds from natural products that have little impact on host cells. Lupeol, a triterpenoid present in the flora of many edible plants, has been shown to have antimicrobial properties. The present study investigated the immunomodulatory effects of lupeol on U937 macrophages infected with Leishmania donovani, focusing on the expression of key cytokines and enzymes involved in the immune response.

METHODS

U937 macrophages were infected with Leishmania donovani amastigotes and treated with varying concentrations of lupeol throughout three days. The expression levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), and interleukin-10 (IL-10) were measured using real-time polymerase chain reaction (RT-PCR). A positive simulation of gene expression was estimated using ΔΔCT to assess relative expression.

RESULTS

The results demonstrated that lupeol significantly upregulated iNOS and TNF-α expression, especially at higher concentrations, indicating enhanced pro-inflammatory and anti-leishmanial activity. Interestingly, IL-10 expression also increased, suggesting a complex immunomodulatory role of lupeol that involves both pro-inflammatory and anti-inflammatory pathways. Pearson correlation analysis revealed a strong association between iNOS and TNF-α (0.97692), as well as a moderate correlation between iNOS and IL-10 (0.51603).

CONCLUSION

These findings suggest that lupeol may promote a balanced immune response, enhancing the body's ability to combat L. donovani while potentially mitigating excessive inflammation. Lupeol can potentially serve as a novel therapeutic agent against visceral leishmaniasis.

Low levels of TNFA gene expression seem to favor the development of pulmonary tuberculosis in a population from the Brazilian Amazon

TNF-α is a Th1 cytokine profile active in the control of Mycobacterium tuberculosis infection, IL-10 is associated with persistence of bacterial infection. The aim of the study was to investigate the association of TNFA -308G/A and IL10 -819C/T polymorphisms and TNFA and IL10 gene expression levels with pulmonary and extrapulmonary tuberculosis (n = 200) and control (n = 200). The individuals were submitted to genotyping and quantification of gene expression performed by real-time quantitative polymerase chain reaction (qPCR). No association was observed between the frequencies of polymorphisms evaluated and pulmonary tuberculosis. The frequency of polymorphic genotypes for TNFA -308G/A were associated with the extrapulmonary tuberculosis (p = 0.0445). The levels of TNFA expression were lower in the pulmonary tuberculosis group than in the control (p = 0.0009). There was a positive correlation between the levels of TNFA and IL10 in patients with pulmonary tuberculosis (r = 0.560; p = 0.0103). Reduced levels of TNFA expression may promote the formation of an anti-inflammatory microenvironment, favoring the persistence of the bacillus in the host, contributing to the establishment of pulmonary tuberculosis.

Single nucleotide polymorphisms in genes involved in immune responses and outcome of tegumentary leishmaniasis

Leishmaniases are neglected tropical diseases with a broad clinical spectrum. Tegumentary leishmaniasis (TL) is a disease caused by different Leishmania species, transmitted by phlebotomine sand flies and distributed worldwide. TL can present a cutaneous (CL) or mucocutaneous (MCL) clinical form depending on factors inherent to the parasite, the host and the vector. Polymorphisms in the immune response genes are host genetic factors that influence the pathogenesis or control of leishmaniasis. Single nucleotide polymorphisms (SNPs) in immune genes have been evaluated in several countries where leishmaniasis is endemic. In this review, we report studies on SNPs in several immune genes that might be associated with susceptibility or resistance to TL. We summarize studies from around the world and in Brazil, highlight the difficulties of these studies and future analyses needed to enhance our knowledge regarding host genetic factors in TL. Understanding the genetic characteristics of the host that facilitate resistance or susceptibility to leishmaniasis can contribute to the development of immunotherapy schedules for this disease. The current treatment methods are toxic, and no human vaccine is available.

Association between interleukin 10 (IL-10) polymorphisms and leishmaniasis progression: a systematic review and meta-analysis

Interleukin 10 (IL-10) is associated with the progression of leishmaniasis because it inhibits the leishmanicidal action of macrophages and the production of mediators such as IFN-γ and nitric oxide. Studies have shown that specific polymorphisms are associated with the regulatory role of IL-10 and the development of more relevant clinical forms of leishamaniasis. We performed a systematic review and meta-analysis to determine whether single nucleotide polymorphisms (SNPs) of IL-10 influence the progression of leishmaniasis. The selected articles were read in full and only those consistent with the eligibility criteria were included in our study. Seven studies were eligible according to the inclusion criteria and were included in the present systematic review, but only five were subjected to statistical analysis. The pooled odds ratios showed no significant association between the rs1800871 SNP and the progression of leishmaniasis in all genotype models, including the dominant, recessive, homozygote, heterozygote, and allelic models. Regarding the association between rs1800896 SNP and the progression of leishmaniasis, the pooled odds ratios showed no association under all genotype models. Hence, IL-10 SNPs did not show significant association and were not considered a risk factor for the progression of leishmaniasis.

Crowdsourcing to develop open-access learning resources on antimicrobial resistance

Objectives

Antimicrobial resistance (AMR) is a significant threat to global public health. Many medical curricula have limited clinical cases and materials focused on AMR, yet enhanced AMR education and training are needed to support antimicrobial stewardship programmes. We used crowdsourcing methods to develop open-access, learner-centred AMR resources. Crowdsourcing is the process of having a large group, including experts and non-experts, solve a problem and then share solutions with the public.

Methods

We organised a global crowdsourcing contest soliciting AMR-related multiple-choice questions, infographics, and images. First, we convened a diverse steering committee group to finalise a call for entries. Second, we launched the contest and disseminated the call for entries using social media, blog posts, email, and an in-person event. Partner institutions included two digital healthcare platforms: Figure 1^® and Ding Xiang Yuan. Both organizations serve as online communities for healthcare specialists and professionals to report and comment on clinical information. At the end of the call, solicited entries were screened for eligibility and judged on merit and relevance to AMR learning and education. Exceptional entries were recognised, awarded prizes, and further reviewed for sharing with the public via open-access platforms.

Results

We received 59 entries from nine countries. These included 54 multiple-choice questions, four infographics, and one image. Eligible entries (n = 56) were reviewed and assigned a score on a 1–10 scale. Eight entries received mean scores greater than 6.0 and were selected as finalists. The eight finalist entries consisted of three infographics and five multiple-choice questions. They were disseminated through open-access publications and online medical communities. Although we launched a global call, we relied heavily on medical student groups and the entries received were not entirely globally representative.

Conclusions

We demonstrate that crowdsourcing challenge contests can be used to identify infectious disease teaching materials. Medical educators and curriculum developers can adapt this method to solicit additional teaching content for medical students.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06628-0.

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.

Genetic variations in the human immune system influence susceptibility to tegumentary leishmaniasis: a systematic review and meta-analysis

OBJECTIVES

The outcomes of tegumentary leishmaniasis (TL) rely on a complex interaction between the host immune system and the parasite. This study assessed the influence of polymorphisms in immune-related genes on TL.

METHODS

Web of Science, Scopus, PubMed, and Embase databases were searched systemically. The meta-analysis used a retrospective model in examining alleles, heterozygotes, and homozygotes. A quality assessment and an analysis of cumulative evidence were performed.

RESULTS

A total of 29 genes (encoding for cytokines, chemokines, and other immune receptors) and 84 polymorphisms were analyzed. The IL-1β_rs16944 (OR = 1.341, p = 0.003), TNF-α_rs1800629 (OR = 3.804, p = 0.004), MIF_rs755622 (OR = 3.357, p = 0.001), and INF- γ_rs243056 (OR = 1.670, p = 0.028) polymorphisms were speculated as risk factor for TL. They decrease the expression of the corresponding genes crucial for TL control. The quality assessment score was approximately 50%, suggesting the need for a clear method and polymorphism characterization for further comparison. The relevant risk of bias and other considerations resulted in low and moderate cumulative evidence confidence.

CONCLUSIONS

IL-1β_rs16944, TNF-α_rs1800629, MIF_rs755622, and INF-γ_rs2430561 polymorphisms were speculated as risk factor for TL, corroborating that IL-1β, TNF-α, INF-γ, and MIF are involved in the TL pathogenesis.

Meta-analysis of -308G > A polymorphism in TNFα gene and susceptibility to leishmaniasis

The clinical spectrum of leishmaniasis depends on several factors, including Leishmania species and immunogenetic factors. Tumor necrosis factor α (TNFα) plays a central role in immunity against intracellular infections. Many studies have reported that TNFα-308G > A polymorphism is associated with susceptibility to intracellular infections and influences TNFα production. Some studies on the implications of TNFα-308G > A polymorphism in the susceptibility to cutaneous leishmaniasis and visceral leishmaniasis showed controversial results. To draw an overall conclusion using accurate data analysis by increasing the number of cases studied, a meta-analysis was performed based on data from the studies included in the analysis. A total of 1264 patients and 2350 controls were enrolled in the meta-analysis. The results showed no significant association between allele G and allele A of -308G > A polymorphism and leishmaniasis by taking the two subgroups separately [OR_CL = 0.99 (0.84-1.18) and OR_VL = 1.19 (0.88-1.59)] or together [OR = 1.04 (0.90-1.20)]. This meta-analysis insinuates the absence of statistical evidence for an association between allele G and allele A of TNFα-308G > A polymorphism and Leishmania infection outcome. This suggests that TNFα, despite its crucial role in the immune response against Leishmania infection, is not the sole determinant factor. Other factors, such as gene-gene and gene-environment interactions, receptors, and signaling pathway efficiency, may influence TNFα function.

Prevalence and associated factors of asymptomatic leishmaniasis: a systematic review and meta-analysis

Asymptomatic leishmaniasis is believed to play important role in maintaining the transmission of Leishmania spp. within endemic communities. Therefore, the efforts to eliminate leishmaniasis are daunting if we cannot manage asymptomatic leishmaniasis well. To clarify the global prevalence and factors associated with the asymptomatic Leishmania infection, we assessed the prevalence of asymptomatic leishmaniasis by a systematic review followed by meta-analyses. In addition, factors associated with the asymptomatic leishmaniasis versus symptomatic were also analyzed. We included all of the original articles alluding to the human asymptomatic leishmaniasis that was confirmed by at least one laboratory diagnosis method regardless of age, sex, race, and ethnicity of the patients, study design, publication date or languages. In total, 111 original articles were chosen for the data extraction. Based on our meta-analyses of the original articles reporting asymptomatic leishmaniasis mostly in endemic areas, the prevalence of asymptomatic leishmaniasis was 11.2% [95% confidence interval (CI) 8.6%-14.4%] in general population, 36.7% [95% CI 27.6%-46.8%] in inhabitants living in the same or neighboring household to the symptomatic patients, and 11.8% [95% CI 7.1%-19%] in HIV infected patients. Among individuals with leishmaniasis, 64.9% [95% CI 54.7%-73.9%] were asymptomatic and males were more susceptible to develop symptoms, with OR=1.88, 95% CI 1.19-2.99, P=0.007. Meta-regression analysis showed no significant change in the prevalence of asymptomatic leishmaniasis during the last 40 years.

Genetic variability of molecules involved in the disease pathogenesis in Leishmania infection

Macrophages are the primary host cell for Leishmania parasites, by Toll like receptors (TLR-MyD88) that are central components of the innate and adaptive immunity against leishmania infection. The CD40/CD40L interaction has also been shown to be important in resistance to various protozoa. In this context, one of the most important properties of suppressors of cytokine signalling (SOCS) proteins, especially SOCS1 and SOCS3, is the regulation of macrophages cell for Leishmania parasites. In the present study we evaluated variants of molecules involved in activation and modulation of leishmanicidal signaling cascades and the possible associations between polymorphisms present in the TLR2, TLR4, MyD88, CD40, SOCS1, SOCS3 genes with susceptibility/resistent to Leishmania. The results suggest the absence of any association between TLR2 and TLR4 variants and susceptibility to Leishmaniasis. Analysis of the nucleotide sequence encoding the TIR recognition domain of the MyD88 molecule showed that it is highly conserved when compared to the reference sequences. In contrast, heterozygous rs 12953258, which reflects a decrease in the expression of SOCS3, suggesting that it may be involved in the leishmaniasis susceptibility. This study is a first advance in the analysis of polymorphisms of genes involved in the signaling pathway of the macrophage and their relationship with leishmaniases infection and disease progression.

A historical review of the role of cytokines involved in leishmaniasis

Leishmaniasis is an infectious disease caused by the Leishmania genus, affecting millions of persons in the world. Despite increased studies, no vaccine has been developed against leishmaniasis, and drug resistance is evolving in some Leishmania species (spp). Innate and acquired immune cells and their associated cytokines interplay together to determine the immune responses related outcomes in leishmaniasis. Interferon (IFN)-γ or macrophage activating factor (MAF) is the first effective lymphokine (LK), with a related function to leishmaniasis, discovered in 1979. This review article discussed the history of cytokines involved in Leishmania infection, and it is the first report demonstrating the involvement in the disease by focusing on cutaneous leishmaniasis. Up to now, the role of many cytokines has been determined and the literature review showed that IL-35 is the latest known cytokine involved in leishmaniasis. This review revealed that the cytokines have pleiotropic effects, depending upon the cytokine environment, generated during the infection and the host genetic background or infecting Leishmania spp. Overall, advances in our knowledge of immune cells and their secreted cytokines, contributing to the protection or pathological process of leishmaniasis may help to reach new approaches for immunotherapy.

Association of cytokine gene polymorphisms with susceptibility to cutaneous leishmaniasis in a Turkish population

AIMS

The objective of this study was to determine the association of TNF-α -308 G/A, IFN-γ +874 T/A, IL-12B + 1188 A/C, IL-10 -1082 G/A and IL-4 -590 C/T polymorphisms with susceptibility to CL.

METHODS AND RESULTS

A total of 55 CL patients and 110 controls from Sanlıurfa province of Turkey were included to this study. Polymorphisms were genotyped by 'polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)' and 'amplification refractory mutation system-PCR (ARMS-PCR)' methods. A statistically significant difference was noted in the allele (P < .001, P = .002) and genotype (P < .001, P = .001,) frequencies of TNF-α -308 G/A and IL-4 -590 C/T, respectively. TNF-α 308 GG versus GA genotype (OR = 19.556 [95% CI 8.310-46.019] P < .001), GG versus GA + AA genotype (OR = 20.444 [95% CI 8.707-48.004] P < .001) and G versus A allele (OR = 6.968 [95% CI 3.903-12.440] P < .001) revealed significant association with CL. IL-4 -590 CC versus TT + CT genotype (OR = 2.049 [95% CI 1.025-4.096], P = .041) and C versus T allele (OR = 2.441 [95% CI 1.355-4.396], P = .002) revealed significant association with CL.

CONCLUSION

Our study indicates that TNF-α 308 G/A and IL-4-590 C/T polymorphisms are significantly associated with susceptibility to CL. Individuals carrying A allele at TNF-α promoter -308 position and T allele at IL-4 promoter -590 position are at a higher risk for CL.

Antileishmanial Activity of Niosomal Combination Forms of Tioxolone along with Benzoxonium Chloride against Leishmania tropica

In this study, we carried out extensive in vitro studies on various concentrations of tioxolone along with benzoxonium chloride and their niosomal forms against Leishmania tropica. Niosomes were prepared by the hydration method and were evaluated for morphology, size, release study, and encapsulation efficiency. This study measured leishmanicidal activity against promastigote and amastigote, apoptosis and gene expression levels of free solution and niosomal-encapsulated tioxolone along with benzoxonium chloride. Span/Tween 60 niosome had good physical stability and high encapsulation efficiency (more than 97%). The release profile of the entrapped compound showed that a gradual release rate. The combination of niosomal forms on promastigote and amastigote were more effective than glucantime. Also, the niosomal form of this compound was significantly less toxic than glucantime (P≤0.05). The flowcytometric analysis on niosomal form of drugs showed that higher number of early apoptotic event as the principal mode of action (89.13% in 200 μg/ml). Also, the niosomal compound increased the expression level of IL-12 and metacaspase genes and decreased the expression level of the IL-10 gene, which further confirming the immunomodulatory role as the mechanism of action. We observed the synergistic effects of these 2 drugs that induced the apoptotic pathways and also up regulation of an immunomodulatory role against as the main mode of action. Also, niosomal form of this combination was safe and demonstrated strong anti-leishmaniasis effects highlights further therapeutic approaches against anthroponotic cutaneous leishmaniasis in future planning.

Lack of association between single-nucleotide polymorphisms of pro- and anti-inflammatory cytokines and HTLV-1-associated myelopathy / tropical spastic paraparesis development in patients from Rio de Janeiro, Brazil

Background

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive neurological and inflammatory disease, associated with HTLV-1 infection. HAM/TSP neurological disease is a consequence of an inflammatory reaction, and adaptive immune responses, through the secretion of anti-inflammatory and pro-inflammatory cytokines, play an important role in the outcome of infection and disease progression. Studies addressing the association between cytokines functional single nucleotide polymorphisms and HAM/TSP development are scarce.

Methods

The genetic polymorphisms of cytokine genes were evaluated in HAM/TSP patients (n = 68) and in asymptomatic HTLV-1 positive carriers (n = 83) from Rio de Janeiro, Brazil, in a case-control study. HTLV-1 infected patients were genotyped for SNPs in five cytokine genes: TNFA-308G/A, IL6-174G/C, IFNG + 874 T/A, TGFB at the codons + 10 T/C and + 25G/C, IL10-592C/A and -819C/T, and -1082A/G and proviral load (PVL) was quantified. Associations between genotypes, haplotypes, clinical outcome and pro viral load were evaluated.

Results

Lack of association between the cytokine polymorphisms and disease outcome was observed. The genotypes TNFA-308GG, IL6-174GG/GC, IL10-592AA and -819CC and TGFb1 high producers phenotypes were correlated with higher PVL in HAM/TSP patients versus asymptomatic carriers.

Conclusions

We did not observe association between cytokine polymorphisms and risk for HAM/TSP development in Brazilian HTLV-1 infected individuals, regardless of differences in PVL between HAM/TSP versus asymptomatic carriers in specific cytokine polymorphisms.

Role of interleukin-10 polymorphisms and haplotypes in polycystic ovary syndrome risk

Polycystic ovary syndrome (PCOS) is one of the most frequently encountered endocrine malfunctions. The etiology of PCOS is complex and unclear. We aimed to investigate the role of three common SNPs (rs1800896, rs1800871 and rs1800872) of IL-10 in the development of PCOS in a Chinese population. We recruited 360 patients with PCOS and 360 healthy controls in this study. SNP genotyping of IL-10 rs1800896, rs1800871 and rs1800872 was implemented in a 384-well plate format on the Sequenom MassARRAY^® System (Sequenom, San Diego, USA). Individuals carrying the GG genotype of rs1800872 were associated with an increased risk of PCOS when compared with the AA genotype (OR = 3.04, 95% CI = 1.62-5.69). No linkage disequilibrium was observed among IL-10 rs1800896, rs1800871 and rs1800872. The C-T-A (OR = 1.53, 95% CI = 1.05-2.35) haplotype indicated an increased risk of PCOS, while the A-C-G (OR = 0.72, 95% CI = 0.53-0.98) showed a reduced risk of PCOS. In summary, this study firstly estimates the association between IL-10 polymorphisms and haplotype and PCOS risk in the Chinese population.