Phenotypic profiling of CD8+ T cells during Plasmodium vivax blood-stage infection

Submitted by Repositório Arca ([email protected]) on 2019-04-24T17:38:50Z No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Janaína Nascimento ([email protected]) on 2019-08-13T14:21:37Z (GMT) No. of bitstreams: 2 ve_ Hojo-Souza_Natália_etal_INI_2015.pdf: 1172050 bytes, checksum: b1948378bfee8669ad90694b3aa2cb60 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-08-13T14:21:37Z (GMT). No. of bitstreams: 2 ve_ Hojo-Souza_Natália_etal_INI_2015.pdf: 1172050 bytes, checksum: b1948378bfee8669ad90694b3aa2cb60 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Centro de Pesquisa em Medicina Tropical. Porto Velho, RO, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Centro de Pesquisa em Medicina Tropical. Porto Velho, RO, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro. RJ, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brasil.Background: For a long time, the role of CD8+ T cells in blood-stage malaria was not considered important because erythrocytes do not express major histocompatibility complex (MHC) class I proteins. While recent evidences suggest that CD8+ T cells may play an important role during the erythrocytic phase of infection by eliminating parasites, CD8+ T cells might also contribute to modulate the host response through production of regulatory cytokines. Thus, the role of CD8+ T cells during blood-stage malaria is unclear. Here, we report the phenotypic profiling of CD8+ T cells subsets from patients with uncomplicated symptomatic P. vivax malaria. Methods: Blood samples were collected from 20 Plasmodium vivax-infected individuals and 12 healthy individuals. Immunophenotyping was conducted by flow cytometry. Plasma levels of IFN-γ, TNF-α and IL-10 were determined by ELISA/CBA. Unpaired t-test or Mann–Whitney test was used depending on the data distribution. Results: P. vivax-infected subjects had lower percentages and absolute numbers of CD8+ CD45RA+ and CD8+ CD45RO+ T cells when compared to uninfected individuals (p ≤ 0.0002). A significantly lower absolute number of circulating CD8+ CD45+ CCR7+ cells (p = 0.002) was observed in P. vivax-infected individuals indicating that infection reduces the number of central memory T cells. Cytokine expression was significantly reduced in the naïve T cells from infected individuals compared with negative controls, as shown by lower numbers of IFN-γ + (p = 0.001), TNF-α+ (p < 0.0001) and IL-10+ (p < 0.0001) CD8+ T cells. Despite the reduction in the number of CD8+ memory T cells producing IFN-γ (p < 0.0001), P. vivax-infected individuals demonstrated a significant increase in memory CD8+ TNF-α+ (p = 0.016) and CD8+ IL-10+ (p = 0.004) cells. Positive correlations were observed between absolute numbers of CD8+ IL-10+ and numbers of CD8+ IFN-γ + (p < 0.001) and CD8+ TNF-α+ T cells (p ≤ 0.0001). Finally, an increase in the plasma levels of TNF-α (p = 0.017) and IL-10 (p = 0.006) and a decrease in the IFN-γ plasma level (p <0.0001) were observed in the P. vivax-infected individuals. Conclusions: P. vivax infection reduces the numbers of different subsets of CD8+ T cells, particularly the memory cells, during blood-stage of infection and enhances the number of CD8+ memory T cells expressing IL-10, which positively correlates with the number of cells expressing TNF-α and IFN-γ

Estudo da ocorrência de polimorfismos de nucleotídeo único em genes codificadores de membros da família das citocinas IL-1 e IL-17 e suas associações com a cardiomiopatia chagásica humana

Exportado OPUSMade available in DSpace on 2019-08-13T01:17:09Z (GMT). No. of bitstreams: 1 disserta__o_final___nat_lia_satchiko.pdf: 1409455 bytes, checksum: 6aadb6e6e26a416ea41d3ac74cfc54ce (MD5) Previous issue date: 28A doença de Chagas é causada pelo protozoário Trypanosoma cruzi e caracteriza-se por uma fase aguda, seguida de uma fase crônica. Na fase crônica, a maioria dos pacientes não apresenta sinais clínicos da doença, sendo classificados como indeterminados. Entretanto, cerca de 20-30% desenvolvem a forma sintomática da doença (cardíaca e/ou digestiva), sendo a cardiomiopatia chagásica crônica (CCC) a forma mais grave da doença de Chagas. A ampla variação no quadro clínico de pacientes chagásicos permite hipotetizar que fatores genéticos relacionados ao hospedeiro, em especial os polimorfismos genéticos, possam ser responsáveis, em parte, pelas diferenças interindividuais de resposta à infecção pelo patógeno. Nesse sentido, o presente trabalho teve como objetivo principal avaliar possíveis associações entre polimorfismos de nucleotídeo único (SNPs) de genes codificadores das interleucinas IL-1, IL-1, IL-1ra, IL-17A e IL-17F e a suscetibilidade ao desenvolvimento de CCC em pacientes brasileiros provenientes do estado de Minas Gerais. As genotipagens dos polimorfismos IL1A (-889C/T), IL1B (+3954C/T), IL1RN (+2018T/C), IL17A (-197A/G) e IL17F (+7488T/C) foram realizadas em uma amostra de 109 pacientes com CCC e 59 indeterminados, usando a técnica de PCR em tempo real Os níveis plasmáticos da citocina IL-1 foram obtidos de 20 pacientes por meio de reações de ELISA. Pacientes portadores da variante alélica T para IL-1 e IL-1 possuem duas vezes mais chance de desenvolver a forma cardíaca quando comparados com a forma indeterminada (IL-1: OR=2,01; IC=1,06-3,82; p=0,032; IL-1: OR=2,53; IC=1,18-5,42; p=0,015). O mesmo foi observado quando se comparou a frequência da variante alélica T (IL-1:OR=1,67; IC=1,01-2,77; p=0,043; IL-1:OR=2,16; IC=1,11-4,19; p=0,020). Por outro lado, a ocorrência do genótipo heterozigoto (TC) da IL-1ra (antagonista de receptor da IL-1) apresentou associação com a forma clínica indeterminada (OR=2,27; IC=1,02-5,04; p=0,042). As análises multivariadas no cluster da IL-1 demonstraram que pacientes com perfil mais pró-inflamatório (portadores das variantes T para IL-1 e IL-1) possuem ainda maior chance de desenvolver a CCC (OR=3,14; IC=1,35-7,32; p=0,008). Entretanto, não houve diferenças estatisticamente significativas nos níveis plasmáticos da IL-1 entre os grupos de pacientes indeterminado e cardíaco dilatado.Em relação aos polimorfismos nos genes que codificam para IL-17, o estudo da IL-17A revelou que os portadores do genótipo A- (GG) possuem duas vezes mais chance de desenvolver a forma cardíaca quando comparados com a indeterminada (OR=2,08; IC=1,08-4,00; p=0,027). Resultado similar foi observado em relação à frequência alélica (OR=1,71; IC=1,00-2,91; p=0,048). Em relação ao polimorfismo da IL-17F, não foi encontrada nenhuma associação com as diferentes formas da doença de Chagas na população estudada. Os resultados indicam que polimorfismos em genes da família IL-1 e da IL-17A estão associados com diferentes cursos clínicos da doença de Chagas.Chagas disease, caused by the protozoan Trypanosoma cruzi, is characterized by an acute phase followed by a chronic phase. Most patients in the chronic phase do not present any clinical signs being clinically classified as indeterminate. On the other hand, about 30% of the patients develop the symptomatic clinical forms (cardiac and/or digestive), and the chronic chagasic cardiomyopathy (CCC) is the most severe form of Chagas disease. The wide variation in clinical presentation of chagasic patients allow us to hypothesize that genetic factors related to the host, particularly genetic polymorphisms, may be responsible, at least in part, by the interindividual differences in the response to the infection. Thus, the present study aimed to assess possible associations between single nucleotide polymorphisms of genes encoding the IL-1, IL-1, IL-1ra, IL-17A and IL-17F and the susceptibility to the development of CCC in Brazilian patients from Minas Gerais. The genotyping of IL1A (-889C/T), IL1B (+3954C/T), IL1RN (+2018T/C), IL17A (-197A/G) e IL17F (+7488T/C) polymorphisms was performed in a sample of 109 patients with CCC and 59 with the indeterminate form, using Real Time PCR. The plasmatic levels of IL-1 were obtained from 20 patients using ELISA reaction. Patients carrying the T variant for IL-1 e IL-1 have two times more chance of developing the cardiac form as compared to the indeterminate form (IL-1:OR=2,01; CI=1,06-3,82; p=0,032; IL-1:OR=2,53; CI=1,18-5,42; p=0,015). The same was observed when we analyzed the allelic frequency (IL-1:OR=1,67; CI=1,01-2,77; p=0,043; IL-1:OR=2,16; CI=1,11-4,19; p=0,020). On the other hand, the heterozygote genotype (TC) of IL-1ra (antagonist receptor of IL-1) was associated with the indeterminate form (OR=2,27; CI=1,02-5,04; p=0,042). Multivariate analysis combining SNPs of IL-1 cluster demonstrated that patients with a more pro-inflammatory profile (carriers of the T variant for both IL-1 and IL-1) have greater chance of developing CCC (OR=3,14; CI=1,35-7,32; p=0,008). No difference was observed in the plasmatic levels of IL-1 between indeterminate and dilated cardiac patients. The study of IL-17A showed that carriers of the A- genotype (GG) have two times more chance of developing the cardiac form as compared with the indeterminate form (OR=2,08; CI=1,08-4,00; p=0.027). A similar result was observed for the allelic frequency (OR=1,71; CI=1,00-2,91; p=0.048). For the IL-17F polymorphism, no association with different forms of Chagas disease was found in the population under study. In summary, our results showed that polymorphisms in IL-1 family and IL-17A genes are associated with different clinical outcomes of Chagas diseas

Clinical symptom profile of hospitalized COVID-19 Brazilian patients according to SARS-CoV-2 variants

OBJECTIVES The aim of this study was to investigate the prevalence of the main symptoms in Brazilian coronavirus disease 2019 (COVID-19) patients hospitalized during 4 distinct waves, based on their infection with different severe acute respiratory disease coronavirus 2 (SARS-CoV-2) variants. METHODS This study included hospitalized patients who tested positive for SARS-CoV-2 during 15 weeks around the peak of each of 4 waves: W1, ancestral strain/B.1 lineage (May 31 to September 12, 2020); W2, Gamma/P.1 variant (January 31 to May 15, 2021); W3, Omicron variant (December 5, 2021 to March 19, 2022); and W4, BA.4/BA.5 subvariants (May 22 to September 3, 2022). Symptom data were extracted from the Brazilian Severe Acute Respiratory Syndrome Database. Relative risks were calculated, and an analysis of symptom networks was performed. RESULTS Patients who were hospitalized during the prevalence of the Gamma/P.1 variant demonstrated a higher risk, primarily for symptoms such as fatigue, abdominal pain, low oxygen saturation, and sore throat, than patients hospitalized during the first wave. Conversely, patients who were hospitalized during the predominance of the Omicron variant exhibited a lower relative risk, particularly for symptoms such as loss of smell, loss of taste, diarrhea, fever, respiratory distress, and dyspnea. Similar results were observed in COVID-19 patients who were hospitalized during the wave of the Omicron subvariants BA.4/BA.5. A symptom network analysis, conducted to explore co-occurrence patterns among different variants, revealed significant differential profiles across the 4 waves, with the most notable difference observed between the W2 and W4 networks. CONCLUSIONS Overall, the relative risks and patterns of symptom co-occurrence associated with different SARS-CoV-2 variants may reflect disease severity

On the analysis of mortality risk factors for hospitalized COVID-19 patients: A data-driven study using the major Brazilian database.

BackgroundBrazil became the epicenter of the COVID-19 epidemic in a brief period of a few months after the first officially registered case. The knowledge of the epidemiological/clinical profile and the risk factors of Brazilian COVID-19 patients can assist in the decision making of physicians in the implementation of early and most appropriate measures for poor prognosis patients. However, these reports are missing. Here we present a comprehensive study that addresses this demand.MethodsThis data-driven study was based on the Brazilian Ministry of Health Database (SIVEP-Gripe) regarding notified cases of hospitalized COVID-19 patients during the period from February 26th to August 10th, 2020. Demographic data, clinical symptoms, comorbidities and other additional information of patients were analyzed.ResultsThe hospitalization rate was higher for male gender (56.56%) and for older age patients of both sexes. Overall, the lethality rate was quite high (41.28%) among hospitalized patients, especially those over 60 years of age. Most prevalent symptoms were cough, dyspnoea, fever, low oxygen saturation and respiratory distress. Cardiac disease, diabetes, obesity, kidney disease, neurological disease, and pneumopathy were the most prevalent comorbidities. A high prevalence of hospitalized COVID-19 patients with cardiac disease (65.7%) and diabetes (53.55%) and with a high lethality rate of around 50% was observed. The intensive care unit (ICU) admission rate was 39.37% and of these 62.4% died. 24.4% of patients required invasive mechanical ventilation (IMV), with high mortality among them (82.98%). The main mortality risk predictors were older age and IMV requirement. In addition, socioeconomic conditions have been shown to significantly influence the disease outcome, regardless of age and comorbidities.ConclusionOur study provides a comprehensive overview of the hospitalized Brazilian COVID-19 patients profile and the mortality risk factors. The analysis also evidenced that the disease outcome is influenced by multiple factors, as unequally affects different segments of population

Contributions of IFN-γ and granulysin to the clearance of Plasmodium yoelii blood stage.

P. vivax-infected Retics (iRetics) express human leukocyte antigen class I (HLA-I), are recognized by CD8+ T cells and killed by granulysin (GNLY) and granzymes. However, how Plasmodium infection induces MHC-I expression on Retics is unknown. In addition, whether GNLY helps control Plasmodium infection in vivo has not been studied. Here, we examine these questions using rodent infection with the P. yoelii 17XNL strain, which has tropism for Retics. Infection with P. yoelii caused extramedullary erythropoiesis, reticulocytosis and expansion of CD8+CD44+CD62L- IFN-γ-producing T cells that form immune synapses with iRetics. We now provide evidence that MHC-I expression by iRetic is dependent on IFN-γ-induced transcription of IRF-1, MHC-I and β2-microglobulin (β2-m) in erythroblasts. Consistently, CTLs from infected wild type (WT) mice formed immune synapses with iRetics in an IFN-γ- and MHC-I-dependent manner. When challenged with P. yoelii 17XNL, WT mice cleared parasitemia and survived, while IFN-γ KO mice remained parasitemic and all died. β2-m KO mice that do not express MHC-I and have virtually no CD8+ T cells had prolonged parasitemia, and 80% survived. Because mice do not express GNLY, GNLY-transgenic mice can be used to assess the in vivo importance of GNLY. Parasite clearance was accelerated in GNLY-transgenic mice and depletion of CD8+ T cells ablated the GNLY-mediated resistance to P. yoelii. Altogether, our results indicate that in addition to previously described mechanisms, IFN-γ promotes host resistance to the Retic-tropic P. yoelii 17XNL strain by promoting MHC-I expression on iRetics that become targets for CD8+ cytotoxic T lymphocytes and GNLY

Protective Immunity against Gamma and Zeta Variants after Inactivated SARS-CoV-2 Virus Immunization

The persistent circulation of SARS-CoV-2 represents an ongoing global threat due to the emergence of new viral variants that can sometimes evade the immune system of previously exposed or vaccinated individuals. We conducted a follow-up study of adult individuals that had received an inactivated SARS-CoV-2 vaccine, evaluating antibody production and neutralizing activity over a period of 6 months. In addition, we performed mice immunization with inactivated SARS-CoV-2, and evaluated the immune response and pathological outcomes against Gamma and Zeta variant infection. Vaccinated individuals produced high levels of antibodies with robust neutralizing activity, which was significantly reduced against Gamma and Zeta variants. Production of IgG anti-S antibodies and neutralizing activity robustly reduced after 6 months of vaccination. Immunized mice demonstrated cellular response against Gamma and Zeta variants, and after viral infection, reduced viral loads, IL-6 expression, and histopathological outcome in the lungs. TNF levels were unchanged in immunized or not immunized mice after infection with the Gamma variant. Furthermore, serum neutralization activity rapidly increases after infection with the Gamma and Zeta variants. Our data suggest that immunization with inactivated WT SARS-CoV-2 induces a promptly responsive cross-reactive immunity response against the Gamma and Zeta variants, reducing COVID-19 pathological outcomes