Single nucleotide polymorphisms of the genes IL-2, IL-2RB, and JAK3 in patients with cutaneous leishmaniasis caused by Leishmania (V.) guyanensis in Manaus, Amazonas, Brazil

Caspase-1 Variants and Plasma IL-1β in Patients with Leishmania guyanensis Cutaneous Leishmaniasis in the Amazonas

Leishmaniasis, a disease caused by protozoan Leishmania spp., exhibits a broad range of clinical manifestations. Host resistance or susceptibility to infections is often influenced by the genetic make-up associated with natural immunity. Caspase-1, a key component of the NLRP3 inflammasome, is critical for processing pro-IL-1β into its active form, IL-1β, while CARD8 functions as an NLRP3 inflammasome inhibitor. We conducted a case-control study comparing L. guyanensis-cutaneous leishmaniasis (Lg-CL) patients with healthy individuals (HCs) by analyzing the CASP1 genetic variants rs530537A>G, rs531542C>T, rs531604A>T and rs560880G>T. Additionally, a combined analysis of CARD8rs2043211A>T with CASP1rs530537 was performed. The genotype distribution for the four variants showed no significant differences between Lg-CL patients and HCs. However, the haplotype analysis of the four CASP1 variants identified the GTTT haplotype as associated with a 19% decreased likelihood of Lg-CL development, suggesting a protective effect against disease progression. The combined analysis of CARD8 with CASP1 variants indicated that individuals homozygous for both variants (GG/TT) exhibited a 38% reduced risk of developing Lg-CL (OR = 0.62 [95%CI:0.46-0.83]) in comparison to individuals with other genotype combinations. No correlation was found between the CASP1 variant genotypes and plasma IL-1β levels. CASP1 may act as a genetic modifier in Lg-CL.

Cytokines signatures and susceptibility to cutaneous leishmaniasis in patients from Sistan and Baluchestan province of Iran

BACKGROUND

Cutaneous leishmaniasis (CL) is a complex, multifactorial disease that results from environmental factors such as parasite polymorphism, phlebotomine vectors, and host genetic factors. Some studies have identified specific genetic factors that may be associated with cutaneous leishmaniasis. The objective of this research was to resolve the association of 8 cytokine polymorphisms, including TNF-α -308 A/G (rs 1800629), TNF-α -238 A/G (rs 361525), TGF-β1 -509 T/C (rs 1800469), TGF-β1+ 915 G/C (rs 1800471), IFN-γ -874 T/A (rs 2430561), IFN-γ -179 G/A (rs 2069709), IL-10 -819 C/T (rs 1800871), and IL-10 -592 A/C (rs 1800872) with susceptibility to CL.

METHODS

A total of 152 patients with designated CL and 100 healthy controls were selected from those referred to Sistan and Baluchestan hospitals. CL was diagnosed by microscopic examination of Giemsa-stained samples and culture. Leishmania species were identified using ITS2 gene PCR amplification with universal primers. Genetic polymorphism was determined by the ARMS PCR method on extracted genomic DNA of individuals. Eight SNPs cytokines were genotyped.

RESULTS

Most of the Genotypic and allelic frequency comparisons between patients with CL and healthy subjects showed no difference, except 3. Individual SNP analysis showed highest association of TGF-β1 -509 (rs1800469) -CC genotype (P = 0.03, OR = 7.05, 95 % CI = 3.3-15) with 5.7-fold increase, IFN-γ -874 (rs 2430561) -AA genotype (P = 0.04, OR = 4.72, 95 % CI = 1.6-14) with 4.2-fold increase, and IL10 -819 (rs1800871) -CC genotype (P = 0.05, OR = 3.63, 95 % CI = 2.5-5.3) with 1.9-fold increase, with CL. Odds ratios (ORs) and 95 % confidence intervals (CIs) were evaluated to assess the association power.

CONCLUSION

Our results conclude that rs1800469 (TGF-β1), rs2430561 (INF-γ), and rs1800872 (IL10) polymorphisms are associated with CL in southeastern Iranian people.

A fine mapping of single nucleotide variants and haplotype analysis of IL13 gene in patients with Leishmania guyanensis-cutaneous leishmaniasis and plasma cytokines IL-4, IL-5, and IL-13

Introduction

Leishmaniasis continues to pose a substantial health burden in 97 countries worldwide. The progression and outcome of Leishmania infection are influenced by various factors, including the cytokine milieu, the skin microbiota at the infection site, the specific Leishmania species involved, the genetic background of the host, and the parasite load. In endemic regions to leishmaniasis, only a fraction of individuals infected actually develops the disease. Overexpression of IL-13 in naturally resistant C57BL/6 mice renders them susceptible to L. major infection. Haplotypes constructed from several single nucleotide variant (SNV) along a chromosome fragment may provide insight into any SNV near the fragment that may be genuinely associated with a phenotype in genetic association studies.

Methods

We investigated nine SNVs (SNV1rs1881457A>C, SNV2rs1295687C>G, SNV3rs2069744C>T, SNV4rs2069747C>T, SNV5rs20541A>G, SNV6rs1295685A>G, SNV7rs848A>C, SNV8rs2069750G >C, and SNV9rs847T>C) spanning the entire IL13 gene in patients with L. guyanensis cutaneous leishmaniasis (Lg-CL).

Results

Our analysis did not reveal any significant association between the SNVs and susceptibility/protection against Lg-CL development. However, haplotype analysis, excluding SNV4rs2069747 and SNV8rs2069750 due to low minor allele frequency, revealed that carriers of the haplotype CCCTAAC had a 93% reduced likelihood developing Lg-CL. Similarly, the haplotypes ACCCGCT (ORadj=0.02 [95% CI 0.00-0.07]; p-value, 6.0×10-19) and AGCTAAC (ORadj=0.00[95% CI 0.00-0.00]; p-value 2.7×10-12) appeared to provide protection against the development of Lg-CL. Conversely, carriers of haplotype ACCTGCC have 190% increased likelihood of developing Lg-CL (ORadj=2.9 [95%CI 1.68-5.2]; p-value, 2.5×10-6). Similarly, haplotype ACCCAAT (ORadj=2.7 [95%CI 1.5-4.7]; p-value, 3.2×10-5) and haplotype AGCCGCC are associated with susceptibility to the development of Lg-CL (ORadj=1.7[95%CI 1.04-2.8]; p-value, 0.01). In our investigation, we also found a correlation between the genotypes of rs2069744, rs20541, rs1295685, rs847, and rs848 and plasma IL-5 levels among Lg-Cl patients. Furthermore, rs20541 showed a correlation with plasma IL-13 levels among Lg-Cl patients, while rs2069744 and rs848 showed a correlation with plasma IL-4 levels among the same group.

Conclusions

Overall, our study identifies three haplotypes of IL13 associated with resistance to disease development and three haplotypes linked to susceptibility. These findings suggest the possibility of a variant outside the gene region that may contribute, in conjunction with other genes, to differences in susceptibility and partially to the pathology.

Variants of CARD8 in Leishmania guyanensis-cutaneous leishmaniasis and influence of the variants genotypes on circulating plasma cytokines IL-1β, TNFα and IL-8

Nucleotide-binding oligomerization domain, leucine-rich repeat-containing protein family (NLR) are intracellular pathogen recognition receptors mediating innate immunity, releasing proinflammatory cytokines IL-1β and IL-18, and promoting pyroptotic cell death, upon sensing pathogenic or endogenous danger signals. In animal models, NLRP3 inflammasome has a dual role, pathogenic or protective in Leishmania-infection, depending on the Leishmania species and mice strain. Caspase recruitment containing domain 8 (CARD8) is a negative regulator of NLRP3 inflammasome and also an inhibitor of transcription factor NFĸB, a major transcription factor of proinflammatory cytokines. We investigated whether single nucleotide variants in CARD8 may partially explain why only a proportion of individuals coming from the same area of endemicity of leishmaniasis develop cutaneous leishmaniasis caused by Leishmania guyanensis. We genotyped four single nucleotide variants of the CARD8 gene by direct nucleotide sequencing in 1741 individuals from an endemic area of leishmaniasis, constituting 850 patients with CL and 891 healthy controls. The frequencies of the genotypes of the variants rs2288877 T>C, rs73944113 C>T, and rs2043211 A>T are similar among the patients with CL and HC, while the variant rs2288876 A>G) reveals an excess of the genotype AA among the patients with CL (44%) compared to 37% in the HC group. Allele A of the variant rs2288876 A>G) is associated with susceptibility to CL (OR = 1.2 [95%CI 1.03-1.4]; P = 0.01). Haplotype analysis showed that individuals harboring the haplotype CCAA have 280% odds of developing CL caused by L. guyanensis (OR = 3.8 [95% CI 2.0-7.7]; p = 0.00004). The variants rs2288877 T>C and rs2288876 A>G correlate with the plasma level of IL-8. Spearman correlation showed a significant positive correlation between the rs2288876 A>G allele A and the level of IL-8 (ρ = 0.22; p = 0.0002). CARD8 may partially contribute to the development of CL caused by L. guyanensis.

Role of Treg, Breg and other cytokine sets in host protection and immunopathology during human leishmaniasis: Are they potential valuable markers in clinical settings and vaccine evaluation?

Leishmaniasis is a vector-borne disease caused by obligate intracellular protozoan parasites that can infect humans and other mammals. Pro- and anti-inflammatory cytokines are important regulators of innate and specific responses in Leishmania infection. Resistance to leishmaniasis is related to T helper 1 (Th1) response with the production of pro-inflammatory cytokines: IL-12, IL-1β, IFN-γ, TNF-α, IL-2 leading to activation of macrophages and parasite killing. Instead, a more intense Th2 (IL-4, IL-5, IL-13), Treg (IL-10 and TGF-β) and Breg response (IL-10 and IL-35) are related to parasite persistence through the inhibition of macrophage activation, which promotes the escape from host immune system. Interestingly, a cytokine involved in the parasite killing in one form of leishmaniasis may be "pathogen friendly" in another form of the disease. To date, few studies are focusing on the role of Treg and Breg cytokines in human models of leishmaniasis; therefore, further investigations are needed to clarify their potential role in the diagnosis and prognosis of such protozoan infections, as well as in the development of vaccines against leishmaniasis. This review summarizes the current knowledge about the role of cytokines produced by Th1, Th2, Treg, and Breg cells involved in Leishmania disease progression and host protection. Some cytokines might play a role as diagnostic and prognostic clinical markers, or they could represent a novel approach leading to new anti-leishmaniasis therapies. Overall, advances in knowledge of the complex network of cytokines secreted by immune cells could help to better understand signaling pathways and host immune responses during Leishmania infection. This approach would allow these mediators to be used as therapeutic strategies against leishmaniasis.

Screening of core genes prognostic for sepsis and construction of a ceRNA regulatory network

OBJECTIVE

To screen out core genes potentially prognostic for sepsis and construct a competing endogenous RNA (ceRNA) regulatory network.

METHODS

Subjects included in this project were 23 sepsis patients and 10 healthy people. RNA-seq for lncRNA, miRNA and mRNA was performed in the peripheral blood samples. Differentially expressed RNAs (DER) were screened out for further analysis. GO annotation and GSEA functional clustering were performed to view the functional enrichment of DEmRNAs. Core genes of prognostic significance were screened out with the weighted correlation network analysis (WGCNA). Meta-analysis and Survival analysis was devised in different microarray datasets. RT-qPCR was conducted to validate these core genes. A ceRNA network was accordingly constructed according to the correlation analysis and molecular interaction prediction.

RESULTS

RNA-seq and differential analysis screened out 1,044 DEmRNAs, 66 DEmiRNAs and 155 DElncRNAs. The GO and GSEA analysis revealed that DEmRNAs are mainly involved in inflammatory response, immune regulation, neutrophil activation. WGCNA revealed 4 potential core genes, including CD247, IL-2Rβ, TGF-βR3 and IL-1R2. In vitro cellular experiment showed up-regulated expression of IL-1R2 while down-regulated of CD247, IL-2Rβ, TGF-βR3 in sepsis patients. Correspondingly, a ceRNA regulatory network was build based on the core genes, and multiple lncRNAs and miRNAs were identified to have a potential regulatory role in sepsis.

CONCLUSION

This study identified four core genes, including CD247, IL-1R2, IL-2Rβ and TGF-βR3, with potential to be novel biomarkers for the prognosis of sepsis. In the meantime, a ceRNA network was constructed aiming to guide further study on prognostic mechanism in sepsis.

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.

Variants of MIRNA146A rs2910164 and MIRNA499 rs3746444 are associated with the development of cutaneous leishmaniasis caused by Leishmania guyanensis and with plasma chemokine IL-8

Leishmania are intracellular protozoan parasites that cause a wide spectrum of clinical manifestations in genetically susceptible individuals with an insufficient or balanced Th1 immune response to eliminate the parasite. MiRNAs play important regulatory role in numerous biological processes including essential cellular functions. miR146-a acts as an inhibitor of interleukin 1 receptor associated kinase 1 (IRAK1) and tumour necrosis factor (TNF) receptor associated factor 6 (TRAF6) present in the toll-like receptors pathway while miR499a modulates TGF-β and TNF signalling pathways. Here, we investigated whether MIRNA146A rs2910164 and MIRNA499 rs3746444 variants are associated with the development of L. guyanensis (Lg)-cutaneous leishmaniasis (CL). The variants MIR146A rs2910164 and MIR499A rs3746444 were assessed in 850 patients with Lg-CL and 891 healthy controls by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma cytokines were measured using the BioPlex assay. Carriers of rs2910164 CC genotype have 30% higher odds of developing CL (ORadj_age/sex = 1.3 [95%CI 0.9–1.8]; Padj_age/sex 0.14) compared to individuals with the genotype GG (ORadj_age/sex = 0.77 [95%CI 0.56–1.0]; Padj_age/sex 0.14) if exposed to Lg-infection. Heterozygous GC individuals also showed lower odds of developing CL (ORadj_age/sex = 0.77 [95%CI 0.5–1.1]; Padj_age/sex 0.09). Homozygosity for the allele C is suggestive of an association with the development of Lg-CL among exposed individuals to Lg-infection. However, the odds of developing CL associated with the CC genotype was evident only in male individuals (OR_adjage = 1.3 [95% CI = 0.9–2.0]; P_adjage = 0.06). Individuals homozygous for the G allele tend to have higher plasma IL-8 and CCL5. Similarly, for the MIR499A rs3746444, an association with the G allele was only observed among male individuals (OR = 1.4 [1.0–1.9]; P = 0.009). In a dominant model, individuals with the G allele (GG-GA) when compared to the AA genotype reveals that carriers of the G allele have 40% elevated odds of developing Lg-CL (ORadj_age = 1.4 [1.1–1.9]). Individuals with the GG genotype have higher odds of developing Lg-CL (ORadj_age/sex = 2.0 [95%CI 0.83–5.0]; P_adjage = 0.01. Individuals homozygous for the G allele have higher plasma IL-8. Genetic combinations of both variants revealed that male individuals exposed to Lg bearing three or four susceptible alleles have higher odds of developing Lg-CL (OR = 2.3 [95% CI 1.0–4.7]; p = 0.017). Both MIR146A rs2910164 and MIR499A rs3746444 are associated with the development of Lg-CL and this association is prevalent in male individuals.

Leishmaniasis is caused by infection with Leishmania parasites. In regions with the presence of Leishmania parasites, all people do not develop the disease despite similar exposure. Only a proportion of inhabitants progress to the development of disease. Clinical manifestations depend on the vector and Leishmania species, as well the host genetic background and genetically determined immune responses. miRNAs play important roles in regulating gene expression and many biological processes including immune pathways. miR-146a targets TRAF6 and IRAK1 genes, that encode key adaptor molecules downstream of toll-like receptors (TLRs). TLRs are critical in immune response to Leishmania-infection. miR499-a modulates inflammation-related signalling pathways such as TGFβ, TNFα and TLR pathways. In this study, we showed that MIR146A and MIR499A variants are risk factors to developing cutaneous leishmaniasis caused by L. guyanensis in Amazonas state of Brazil. Individuals with these variants are susceptible to the development of CL.

TREM1 rs2234237 (Thr25Ser) Polymorphism in Patients with Cutaneous Leishmaniasis Caused by Leishmania guyanensis: A Case-Control Study in the State of Amazonas, Brazil

Background: Leishmaniasis is an infectious disease caused by Leishmania parasites. A Th1 immune response is necessary in the acute phase to control the pathogen. The triggering receptor expressed on myeloid cells (TREM)-1 is a potent amplifier of inflammation. Our aim is to identify whether the TREM1 variant rs2234237 A/T (Thr25Ser) is associated with the disease development of cutaneous leishmaniasis (CL) in Leishmania guyanensis-infected individuals. The effects of the rs2234237 genotypes on plasma cytokines IL-1β, IL-6, IL-8, IL-10, MCP-1 and TNF-α are also investigated. Methods: 838 patients with CL and 818 healthy controls (HCs) living in the same endemic areas were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism. Plasma cytokines were assayed in 400 patients with CL and 400 HCs using the BioPlex assay. Results: The genotypes’ and alleles’ frequencies were similar in both patients with CL (AA = 618, 74%; AT = 202, 24%; TT = 18, 2%) and in HCs (AA = 580, 71%; AT = 220, 27%; TT = 18, 2%). Rs2234237 showed a modest effect on plasma IL-10 that disappeared when correction of the p-value was applied. Plasma IL-10 by rs2234237 genotypes were (mean ± SEM; AA = 2.91 pg/mL ± 0.14; AT = 2.35 pg/mL ± 0.12; TT = 3.14 pg/mL ± 0.56; p = 0.05). Conclusion: The TREM1 rs2234237 (Thr25Ser) seems to have no influence on the susceptibility or resistance to L. guyanensis infections.

Polymorphism in the IL-1β promoter is associated with IgG antibody response to circumsporozoite protein repeats of Plasmodium vivax

BACKGROUND

It is well established that infection by Plasmodium vivax is a result of host-parasite interactions. In the present study, association with the IL1/IL2 cytokine profiles, anticircumsporozoite protein antibody levels and parasitic loads was evaluated in individuals naturally infected with P. vivax in an endemic area of the Brazilian Amazon.

METHODS

Molecular diagnosis of P. vivax and variants was performed using the PCR-RFLP method and IL1B -511C>T, IL2 -330T>G and IL2+114T>G polymorphisms were identified using PCR-RFLP and allele-specific PCR. IL-1β and IL-2 cytokine levels were detected by flow cytometry and circumsporozoite protein (CSP) antibodies were measured by ELISA.

RESULTS

Three variants of P. vivax CSP were identified and VK247 was found to be the most frequent. However, the prevalence and magnitude of IgG antibodies were higher for the VK210 variant. Furthermore, the antibody response to the CSP variants was not associated with the presence of the variant in the infection. Significant differences were observed between the single nucleotide polymorphism (SNP) -511T>C in the IL1B gene and levels of antibodies to the VK247 and P. vivax-like variants, but there were no associations between SNPs in IL1 and IL2 genes and their plasma products.

CONCLUSIONS

Individuals with the rs16944 CC genotype in the IL1β gene have higher antibody levels to the CSP of P. vivax of VK247 and P. vivax-like variants.

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.