Differential regulatory T cell signature after recovery from mild COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by a range of symptoms in which host immune response have been associated with disease progression. However, the putative role of regulatory T cells (Tregs) in determining COVID-19 outcomes has not been thoroughly investigated. Here, we compared peripheral Tregs between volunteers not previously infected with SARS-CoV-2 (healthy control [HC]) and volunteers who recovered from mild (Mild Recovered) and severe (Severe Recovered) COVID-19. Peripheral blood mononuclear cells (PBMC) were stimulated with SARS-CoV-2 synthetic peptides (Pool Spike CoV-2 and Pool CoV-2) or staphylococcal enterotoxin B (SEB). Results of a multicolor flow cytometric assay showed higher Treg frequency and expression of IL-10, IL-17, perforin, granzyme B, PD-1, and CD39/CD73 co-expression in Treg among the PBMC from the Mild Recovered group than in the Severe Recovered or HC groups for certain SARS-CoV-2 related stimulus. Moreover, Mild Recovered unstimulated samples presented a higher Tregs frequency and expression of IL-10 and granzyme B than did that of HC. Compared with Pool CoV-2 stimuli, Pool Spike CoV-2 reduced IL-10 expression and improved PD-1 expression in Tregs from volunteers in the Mild Recovered group. Interestingly, Pool Spike CoV-2 elicited a decrease in Treg IL-17+ frequency in the Severe Recovered group. In HC, the expression of latency-associated peptide (LAP) and cytotoxic granule co-expression by Tregs was higher in Pool CoV-2 stimulated samples. While Pool Spike CoV-2 stimulation reduced the frequency of IL-10+ and CTLA-4+ Tregs in PBMC from volunteers in the Mild Recovered group who had not experienced certain symptoms, higher levels of perforin and perforin+granzyme B+ co-expression by Tregs were found in the Mild Recovered group in volunteers who had experienced dyspnea. Finally, we found differential expression of CD39 and CD73 among volunteers in the Mild Recovered group between those who had and had not experienced musculoskeletal pain. Collectively, our study suggests that changes in the immunosuppressive repertoire of Tregs can influence the development of a distinct COVID-19 clinical profile, revealing that a possible modulation of Tregs exists among volunteers of the Mild Recovered group between those who did and did not develop certain symptoms, leading to mild disease.

Is IFN expression by NK cells a hallmark of severe COVID-19?

Natural Killer cells (NK) are crucial in host defense against viruses. There are many unanswered questions about the immune system in COVID-19, especially the mechanisms that contribute to the development of mild or severe forms of the disease. Although NK cells may have an essential role in the pathogenesis of COVID-19, the mechanisms involved in this process are not yet fully elucidated. Here, we demonstrate that CD3-CD56+ NK cells frequency in the volunteers who recovered from mild COVID-19 (Mild CoV) presented a significant increase compared to the healthy control (HC) and individuals recovering from severe COVID-19 (Severe CoV) groups. Furthermore, distinct IFN profiles in recovered COVID-19 patients with mild or severe clinical forms of the disease were observed in the total NK cells (CD3-CD56+). In the first group, NK cells express increased levels of IFN-α compared to the severe CoV, while higher production of IFN-γ in severe CoV was found. Moreover, NK cells in mild CoV express more cytolytic granules depicted by granzyme B and perforin. Compared to HC, PBMCs from mild CoV presented higher Ki-67 and TIM-3 production after Pool CoV-2 and Pool Spike CoV-2 peptides stimulus. In addition, non-stimulated PBMCs in the mild CoV group had higher NK TIM-3+ frequency than severe CoV. In the mild CoV group, Pool Spike CoV-2 and Pool CoV-2 peptides stimuli elicited higher granzyme B and perforin coexpression and IFN-α production by PBMCs. However, in severe CoV, Pool Spike CoV-2 reduced the coexpression of granzyme B, perforin, and CD107a suggesting a decrease in the cytotoxic activity of NK cells. Therefore, our study shows that NK cells may have a crucial role in COVID-19 with the involvement of IFN-α and cytotoxic properties that aid in developing qualified immune responses. Furthermore, the data suggest that higher amounts of IFN-γ may be linked to the severity of this disease.

Análise microbiológica da água consumida nas escolas públicas municipais urbanas de ensino fundamental de um município de pequeno porte no estado da Paraíba / Microbiological analysis of water consumed in the urban municipal public schools of fundamental education of a small municipality in the state of Paraíba

O objetivo desse estudo foi analisar a qualidade microbiológica da água consumida nas escolas públicas municipais urbanas de ensino fundamental da cidade Cuité, Paraíba. Foi conduzido um estudo transversal do tipo pesquisa de campo experimental e descritivo, onde foram coletadas amostras individuais dos filtros e bebedouros das seis escolas, assim como realizadas perguntas aos responsáveis técnicos sobre origem, transporte e acondicionamento da água. Das amostras de água analisadas apenas uma apresentou todos os ensaios dentro dos parâmetros legais de potabilidade. Nenhuma das escolas referiu controle quanto à qualidade da água e higienização dos reservatórios. Por fim, a água utilizada para consumo humano, na quase totalidade das escolas encontra-se fora do padrão de potabilidade definido pela legislação vigente.

Human CD8 T-cell activation in acute and chronic chikungunya infection.

There is a need for more detailed elucidation of T-cell immunity in chikungunya infection. CD8 T cells are one of main actors against viruses. Here, we analysed CD8+ T lymphocytes from patients in the acute and chronic phases of chikungunya disease (CHIKD). Our results demonstrate that CD8+ T cells expressed higher ex vivo granzyme B, perforin and CD107A expression in patients in the acute phase of CHIKD compared with healthy individuals and higher ex vivo expression of CD69, interleukin-17A, interleukin-10 and CD95 ligand, and co-expression of CD95/CD95 ligand. These results elucidate the importance of these lymphocytes, demonstrating immune mechanisms mediated in human chikungunya infection.

Effect of the yellow passion fruit peel flour (Passiflora edulis f. flavicarpa deg.) in insulin sensitivity in type 2 diabetes mellitus patients.

BACKGROUND: A study with the yellow passion fruit peel flour showed positive action in blood glucose control as therapies' adjuvant in patients with type 2 diabetes mellitus. Therefore, we evaluated its effect on insulin sensitivity since there is a quest for studies that focus at better understanding of insulin resistance aspects in diabetic patients. Furthermore its relationship with chronic complications can also give good prospects for alternative treatments. METHODS: A total of 43 type 2 diabetes volunteers (28 females and 15 males) ingested 30 g/day of the yellow passion fruit peel flour for two months. The levels of blood glucose and fasting insulin, HOMA index and glycated hemoglobin were measured for each patient before and after dietary supplementation. RESULTS: There was a significant difference in the fasting blood glucose values (P = 0.000) and glycated hemoglobin (P = 0.032) after supplementation. It was also seen a reduction in HOMA IR (P = 0.005) in the supplemented group, however it was not observed changes in insulin values for females. HOMA beta (P = 0.000) showed significant increase in its values for the studied group. CONCLUSIONS: The supplementation used decreased insulin resistance in type 2 diabetic patients, suggesting a positive action in blood glucose control as adjuvant therapy in conventional treatments.

Efeito da farinha da casca do maracujá-amarelo (Passiflora edulis f. flavicarpa Deg.) nos níveis glicêmicos e lipídicos de pacientes diabéticos tipo 2 / Effect of the flour of the yellow passion fruit peel (Passiflora edulis f. flavicarpa Deg.) in the glycemic and lipid levels of type 2 diabetes patients

A suplementação da dieta com fibras solúveis pode ser considerada uma importante medida terapêutica no tratamento de pacientes diabéticos e obesos. Para avaliar o efeito da farinha da casca de maracujá amarelo rica em pectina, foi realizado um ensaio clínico fase II com 43 pacientes portadores de Diabetes Mellitus tipo 2. Estes receberam diariamente 30 g do produto testado durante 60 dias. Observou-se diferença estatística significante na glicemia de jejum (p = 0,000) acompanhada pela redução nos valores médios da hemoglobina glicada (p = 0,032). Em relação ao perfil lipídico, não foi verificado redução dos níveis de colesterol total e colesterol LDL nos pacientes ao longo deste estudo; entretanto, houve redução nos níveis de Triglicerídeos e aumento do colesterol HDL nos mesmos. Os níveis glicêmicos apresentados pelos pacientes antes e após o uso da farinha da casca do maracujá são compatíveis com uma ação positiva no controle da glicemia como adjuvante das terapias convencionais.

The supplementation of diet with soluble dietary fiber can be considered an important therapy measure in the treatment of diabetic and obese patients. In order to evaluate the effect of the flour of the yellow passion fruit peel which is rich in pectin, a phase II clinical trial with 43 patients with type 2 Diabetes Mellitus was performed. They received daily 30 g of the tested product for 60 days. Statistically significant difference was observed in fasting plasma glucose (p = 0.000) accompanied by a reduction in the average values of glycated hemoglobin (p = 0.032). In relation to the lipid profile, there were no reduced levels of total cholesterol and LDL-cholesterol in patients during this study; however, there were reduction in the levels of Triglycerides and increase in HDL cholesterol in them. The glycemic levels presented by the patients before and after the use of the passion fruit peel flour are compatible to a positive action to control blood glucose as an adjunct of conventional therapies.