Polymorphisms in B Cell Co-Stimulatory Genes Are Associated with IgG Antibody Responses against Blood-Stage Proteins of Plasmodium vivax

Multi-omics immune regulatory mechanisms in lung adenocarcinoma metastasis and survival time

Lung adenocarcinoma (LUAD) is the most common type of lung cancer. Despite previous research on immune mechanisms and related molecules in LUAD, the specific regulatory mechanisms of these molecules in the immune microenvironment remain unclear. Furthermore, the impact of regulatory genes or RNA on LUAD metastasis and survival time is yet to be understood. To address these gaps, we collected a substantial amount of data, including 17,226 gene expression profiles from 1,018 samples, 370,640 methylation sites from 461 samples, and 248 miRNAs from 513 samples. Our aim was to explore the genes, miRNAs, and methylation sites associated with LUAD progression. Leveraging the regulatory functions of miRNAs and methylation sites, we identified target and regulated genes. Through the utilization of LASSO and survival analysis, we pinpointed 22 key genes that play pivotal roles in the immune regulatory mechanism of LUAD. Notably, the expression levels of these 22 genes demonstrated significant discriminatory power in predicting LUAD patient survival time. Additionally, our deep learning model accurately predicted distant metastasis in LUAD patients using the expression levels of these genes. Further pathway enrichment analysis revealed that these 22 genes are significantly enriched in pathways closely linked to LUAD progression. Through Immune Infiltration Assay, we observed that T cell CD4 memory resting, monocytes, and macrophages.M2 were the three most abundant cell types in the immune microenvironment of LUAD. These cells are known to play crucial roles in tumor growth, invasion, and metastasis. Single-cell data analysis further validated the functional significance of these genes, indicating their involvement not only in immune cells but also in epithelial cells, showcasing significant differential expression. Overall, this study sheds light on the regulatory mechanisms underlying the immune microenvironment of LUAD by identifying key genes associated with LUAD progression. The findings provide insights into potential prognostic markers and therapeutic targets.

B-Cell Epitope Mapping of the Plasmodium falciparum Malaria Vaccine Candidate GMZ2.6c in a Naturally Exposed Population of the Brazilian Amazon

The GMZ2.6c malaria vaccine candidate is a multi-stage P. falciparum chimeric protein that contains a fragment of the sexual-stage Pfs48/45-6C protein genetically fused to GMZ2, an asexual-stage vaccine construction consisting of the N-terminal region of the glutamate-rich protein (GLURP) and the C-terminal region of the merozoite surface protein-3 (MSP-3). Previous studies showed that GMZ2.6c is widely recognized by antibodies from Brazilian exposed individuals and that its components are immunogenic in natural infection by P. falciparum. In addition, anti-GMZ2.6c antibodies increase with exposure to infection and may contribute to parasite immunity. Therefore, identifying epitopes of proteins recognized by antibodies may be an important tool for understanding protective immunity. Herein, we identify and validate the B-cell epitopes of GMZ2.6c as immunogenic and immunodominant in individuals exposed to malaria living in endemic areas of the Brazilian Amazon. Specific IgG antibodies and subclasses against MSP-3, GLURP, and Pfs48/45 epitopes were detected by ELISA using synthetic peptides corresponding to B-cell epitopes previously described for MSP-3 and GLURP or identified by BepiPred for Pfs48/45. The results showed that the immunodominant epitopes were P11 from GLURP and MSP-3c and DG210 from MSP-3. The IgG1 and IgG3 subclasses were preferentially induced against these epitopes, supporting previous studies that these proteins are targets for cytophilic antibodies, important for the acquisition of protective immunity. Most individuals presented detectable IgG antibodies against Pfs48/45a and/or Pfs48/45b, validating the prediction of linear B-cell epitopes. The higher frequency and antibody levels against different epitopes from GLURP, MSP-3, and Pfs48/45 provide additional information that may suggest the relevance of GMZ2.6c as a multi-stage malaria vaccine candidate.

The rs1883832 Polymorphism (CD40-1C>T) Affects the Intensity of IgA Responses after BNT162b2 Vaccination

The effectiveness of coronavirus disease 2019 (COVID-19) vaccination strategies is affected by several factors, including the genetic background of the host. In our study, we evaluated the contribution of the functional polymorphism rs1883832 affecting the Kozak sequence of the TNFSF5 gene (c.-1C>T), encoding CD40, to humoral immune responses after vaccination with the spike protein of SARS-CoV-2. The rs1883832 polymorphism was analyzed by PCR-RFLP in 476 individuals (male/female: 216/260, median age: 55.0 years, range: 20−105) of whom 342 received the BNT162b2 mRNA vaccine and 134 received the adenovirus-based vector vaccines (67 on ChAdOx1-nCoV-19 vaccine, 67 on Ad.26.COV2.S vaccine). The IgG and IgA responses were evaluated with chemiluminescent microparticle and ELISA assays on days 21, 42, and 90 after the first dose. The T allele of the rs1883832 polymorphism (allele frequency: 32.8%) was significantly associated with lower IgA levels and represented, as revealed by multivariable analysis, an independent risk factor for reduced anti-spike protein IgA levels on days 42 and 90 following BNT162b2 mRNA vaccination. Similar to serum anti-spike IgA levels, a trend of lower anti-spike IgA concentrations in saliva was found in individuals with the T allele of rs1883832. Finally, the intensity of IgA and IgG responses on day 42 significantly affected the prevalence of COVID-19 after vaccination. The rs1883832 polymorphism may be used as a molecular predictor of the intensity of anti-spike IgA responses after BNT162b2 mRNA vaccination.

CD209 and Not CD28 or STAT6 Polymorphism Mediates Clinical Malaria and Parasitemia among Children from Nigeria

Malaria remains a significant disease, causing epic health problems and challenges all over the world, especially in sub-Saharan Africa. CD209 and CD28 genes act as co-stimulators and regulators of the immune system, while the STAT6 gene has been reported to mediate cytokine-induced responses. Single nucleotide polymorphisms of these genes might lead to differential disease susceptibility among populations at risk for malaria, due to alterations in the immune response. We aim to identify key drivers of the immune response to malaria infection among the three SNPs: CD209 (rs4804803), CD28 (rs35593994) and STAT6 (rs3024974). After approval and informed consent, we genotyped blood samples from a total of 531 children recruited from Nigeria using the Taqman SNP genotyping assay and performed comparative analysis of clinical covariates among malaria-infected children. Our results reveal the CD209 (rs4804803) polymorphism as a susceptibility factor for malaria infection, significantly increasing the risk of disease among children, but not CD28 (rs35593994) or STAT6 (rs3024974) polymorphisms. Specifically, individuals with the homozygous mutant allele (rs4804803G/G) for the CD209 gene have a significantly greater susceptibility to malaria, and presented with higher mean parasitemia. This observation may be due to a defective antigen presentation and priming, leading to an ineffective downstream adaptive immune response needed to combat infection, as well as the resultant higher parasitemia and disease manifestation. We conclude that the CD209 gene is a critical driver of the immune response during malaria infection, and can serve as a predictor of disease susceptibility or a biomarker for disease diagnosis.

Antibody responses within two leading Plasmodium vivax vaccine candidate antigens in three geographically diverse malaria-endemic regions of India

Background

Identifying highly immunogenic blood stage antigens which can work as target for naturally acquired antibodies in different eco-epidemiological settings is an important step for designing malaria vaccine. Blood stage proteins of Plasmodium vivax, apical membrane antigen-1 (PvAMA-1) and 19 kDa fragment of merozoite surface protein (PvMSP-1₁₉) are such promising vaccine candidate antigens. This study determined the naturally-acquired antibody response to PvAMA-1 and PvMSP-1₁₉ antigens in individuals living in three geographically diverse malaria endemic regions of India.

Methods

A total of 234 blood samples were collected from individuals living in three different eco-epidemiological settings, Chennai, Nadiad, and Rourkela of India. Indirect ELISA was performed to measure human IgG antibodies against recombinant PvAMA-1 and PvMSP-1₁₉ antigens. The difference in seroprevalence and factors associated with antibody responses at each site was statistically analysed.

Results

The overall seroprevalence was 40.6% for PvAMA-1 and 62.4% for PvMSP-1₁₉. Seroprevalence to PvAMA-1 was higher in Chennai (47%) followed by Nadiad (46.7%) and Rourkela (27.6%). For PvMSP-1₁₉, seroprevalence was higher in Chennai (80.3%) as compared to Nadiad (53.3%) and Rourkela (57.9%). Seroprevalence for both the antigens were found to be higher in Chennai where P. vivax is the dominant malaria species. In addition, heterogeneous antibody response was observed for PvAMA-1 and PvMSP-1₁₉ antigens at each of the study sites. Two factors, age and malaria positivity were significantly associated with seropositivity for both the antigens PvAMA-1 and PvMSP-1₁₉.

Conclusion

These data suggest that natural acquired antibody response is higher for PvMSP-1₁₉ antigen as compared to PvAMA-1 antigen in individuals living in three geographically diverse malaria endemic regions in India. PvMSP-1₁₉ appears to be highly immunogenic in Indian population and has great potential as a malaria vaccine candidate. The differences in immune response against vaccine candidate antigens in different endemic settings should be taken into account for development of asexual stage based P. vivax malaria vaccine, which in turn can enhance malaria control efforts.

The immunology of Plasmodium vivax malaria

Plasmodium vivax infection, the predominant cause of malaria in Asia and Latin America, affects ~14 million individuals annually, with considerable adverse effects on wellbeing and socioeconomic development. A clinical hallmark of Plasmodium infection, the paroxysm, is driven by pyrogenic cytokines produced during the immune response. Here, we review studies on the role of specific immune cell types, cognate innate immune receptors, and inflammatory cytokines on parasite control and disease symptoms. This review also summarizes studies on recurrent infections in individuals living in endemic regions as well as asymptomatic infections, a serious barrier to eliminating this disease. We propose potential mechanisms behind these repeated and subclinical infections, such as poor induction of immunological memory cells and inefficient T effector cells. We address the role of antibody-mediated resistance to P. vivax infection and discuss current progress in vaccine development. Finally, we review immunoregulatory mechanisms, such as inhibitory receptors, T regulatory cells, and the anti-inflammatory cytokine, IL-10, that antagonizes both innate and acquired immune responses, interfering with the development of protective immunity and parasite clearance. These studies provide new insights for the clinical management of symptomatic as well as asymptomatic individuals and the development of an efficacious vaccine for vivax malaria.

Enteroparasite and vivax malaria co-infection on the Brazil-French Guiana border: Epidemiological, haematological and immunological aspects

Malaria-enteroparasitic co-infections are known for their endemicity. Although they are prevalent, little is known about their epidemiology and effect on the immune response. This study evaluated the effect of enteroparasite co-infections with malaria caused by Plasmodium vivax in a border area between Brazil and French Guiana. The cross sectional study took place in Oiapoque, a municipality of Amapá, on the Amazon border. Malaria was diagnosed using thick blood smears, haemoglobin dosage by an automated method and coproparasitology by the Hoffman and Faust methods. The anti-PvMSP-1₁₉ IgG antibodies in the plasma were evaluated using ELISA and Th1 (IFN-γ, TNF-α and IL-2), and Th2 (IL-4, IL-5 and IL-10) cytokine counts were performed by flow cytometry. The participants were grouped into those that were monoinfected with vivax malaria (M), vivax malaria-enteroparasite co-infected (CI), monoinfected with enteroparasite (E) and endemic controls (EC), who were negative for both diseases. 441 individuals were included and grouped according to their infection status: [M 6.9% (30/441)], [Cl 26.5% (117/441)], [E 32.4% (143/441)] and [EC 34.2% (151/441)]. Males prevailed among the (M) 77% (23/30) and (CI) 60% (70/117) groups. There was a difference in haemoglobin levels among the different groups under study for [EC-E], [EC-Cl], [E-M] and [Cl-M], with (p < 0.01). Anaemia was expressed as a percentage between individuals [CI-EC (p < 0.05)]. In terms of parasitaemia, there were differences for the groups [CI-M (p < 0.05)]. Anti-PvMSP-1₁₉ antibodies were detected in 51.2% (226/441) of the population. The level of cytokines evaluation revealed a large variation in TNF-α and IL-10 concentrations in the co-infected group. In this study we did not observe any influence of coinfection on the acquisition of IgG antibodies against PvMSP119, as well as on the profile of the cytokines that characterize the Th1 and Th2 patterns. However, co-infection increased TNF-α and IL-10 levels.

Severe vivax malaria: a prospective exploration at a tertiary healthcare centre in Southwestern India

Plasmodium vivax is recognized to cause severe malaria and mortality. We aimed to determine the proportion of disease severity, the spectrum of complications, underlying non-infectious comorbidities and predictors of severity in monoinfection P. vivax malaria among adults at a tertiary healthcare centre in Southwestern India. A prospective cohort study was conducted among microscopically confirmed monoinfection P. vivax acute malaria patients aged, ≥18 years. Cases with pregnancy and concomitant febrile illnesses including mixed malaria were excluded. Cases were distinguished as either 'severe' or 'non-severe' P. vivax malaria as per the definitions laid by the World Health Organization. Of total 511 acute P. vivax cases studied, 23.9% (122/511) had severe malaria. The proportion of severity did not vary between microscopy alone and additional nPCR proved monoinfection P. vivax subgroups. There was no significant difference (p = 0.296) in the occurrence of non-infectious comorbidities among non-severe (9.0%, 35/389) and severe (12.3%, 15/122) vivax groups. Multiple complications despite early parasite clearance resulted in delayed casualty in two cases, indicating overall case fatality rate of 3/1000 cases. Age >40 years, rising respiratory rate, total bilirubin, serum creatinine and falling hemoglobin were the independent predictors of disease severity in this vivax malaria cohort. Total and direct bilirubin and serum urea had good discriminatory performance for severe vivax malaria. Total bilirubin should be considered as an important prognostic marker while managing P. vivax malaria. Patients with multiple complications must be treated cautiously as there may be delayed deterioration leading to mortality despite parasite clearance.

Cytokine gene polymorphisms are not associated with anti-PvDBP, anti-PvAMA-1 or anti-PvMSP-119 IgG antibody levels in a malaria-endemic area of the Brazilian Amazon

Background

The immune response against Plasmodium vivax immunogenic epitopes is regulated by pro- and anti-inflammatory cytokines that determine antibody levels and class switching. Cytokine gene polymorphisms may be responsible for changes in the humoral immune response against malaria. The aim of this study was to evaluate whether polymorphisms in the TNFA, IFNG and IL10 genes would alter the levels of anti-PvAMA1, PvDBP and -PvMSP-1₁₉ IgG antibodies in patients with vivax malaria.

Methods

Samples from 90 vivax malaria-infected and 51 uninfected subjects from an endemic area of the Brazilian Amazon were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) to identify polymorphisms of the genes TNFA (−1031T > C, −308G > A, −238G > A), IFNG (+874T > A) and IL10 (−819C > T, −592C > A). The levels of total IgG against PvAMA1, PvDBP and PvMSP-1₁₉ were determined using an enzyme-linked immunosorbent assay (ELISA). Associations between the polymorphisms and the antibody response were assessed by means of logistic regression models.

Results

No significant differences were found in the levels of IgG antibodies against the PvAMA-1, PvDBP or PvMSP-1₁₉ proteins in relation to the studied polymorphisms.

Conclusions

Although no associations were found among the evaluated genotypes and alleles and anti-merozoite IgG class P. vivax antibody levels, this study helps elucidate the immunogenic profile involved in the humoral immune response in malaria.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1414-3) contains supplementary material, which is available to authorized users.

Immunogenetic markers associated with a naturally acquired humoral immune response against an N-terminal antigen of Plasmodium vivax merozoite surface protein 1 (PvMSP-1)

Background

Humoral immune responses against proteins of asexual blood-stage malaria parasites have been associated with clinical immunity. However, variations in the antibody-driven responses may be associated with a genetic component of the human host. The objective of the present study was to evaluate the influence of co-stimulatory molecule gene polymorphisms of the immune system on the magnitude of the humoral immune response against a Plasmodium vivax vaccine candidate antigen.

Methods

Polymorphisms in the CD28, CTLA4, ICOS, CD40, CD86 and BLYS genes of 178 subjects infected with P. vivax in an endemic area of the Brazilian Amazon were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The levels of IgM, total IgG and IgG subclasses specific for ICB2-5, i.e., the N-terminal portion of P. vivax merozoite surface protein 1 (PvMSP-1), were determined by enzyme-linked immuno assay. The associations between the polymorphisms and the antibody response were assessed by means of logistic regression models.

Results

After correcting for multiple testing, the IgG1 levels were significantly higher in individuals recessive for the single nucleotide polymorphism rs3116496 in CD28 (p = 0.00004). Furthermore, the interaction between CD28 rs35593994 and BLYS rs9514828 had an influence on the IgM levels (p = 0.0009).

Conclusions

The results of the present study support the hypothesis that polymorphisms in the genes of co-stimulatory components of the immune system can contribute to a natural antibody-driven response against P. vivax antigens.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1350-2) contains supplementary material, which is available to authorized users.