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We report 4 highly pathogenic avian influenza A(H5N1) clade 2.3.4.4.b viruses in samples collected during June 2023 from Royal terns and Cabot's terns in Brazil. Phylodynamic analysis revealed viral movement from Peru to Brazil, indicating a concerning spread of this clade along the Atlantic Americas migratory bird flyway.
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Charadriiformes , Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Influenza Humana , Animais , Humanos , Influenza Aviária/epidemiologia , Animais Selvagens , Brasil/epidemiologia , Aves , FilogeniaRESUMO
Clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 virus was detected in the South American sea lions found dead in Santa Catarina, Brazil, in October 2023. Whole genome sequencing and comparative phylogenetic analysis were conducted to investigate the origin, genetic diversity, and zoonotic potentials of the H5N1 viruses. The H5N1 viruses belonged to the genotype B3.2 of clade 2.3.4.4b H5N1 virus, which was identified in North America and disseminated to South America. They have acquired new amino acid substitutions related to mammalian host affinity. Our study provides insights into the genetic landscape of HPAI H5N1 viruses in Brazil, highlighting the continuous evolutionary processes contributing to their possible adaptation to mammalian hosts.
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Virus da Influenza A Subtipo H5N1 , Filogenia , Leões-Marinhos , Sequenciamento Completo do Genoma , Animais , Leões-Marinhos/virologia , Brasil , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/classificação , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Genoma Viral , Genótipo , Variação GenéticaRESUMO
We detected arenavirus RNA in 1.6% of 1,047 bats in Brazil that were sampled during 2007-2011. We identified Tacaribe virus in 2 Artibeus sp. bats and a new arenavirus species in Carollia perspicillata bats that we named Tietê mammarenavirus. Our results suggest that bats are an underrecognized arenavirus reservoir.
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Arenavirus , Quirópteros , Animais , Arenavirus/genética , Brasil/epidemiologiaRESUMO
BACKGROUND: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. METHODS: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28â days after enrolment. RESULTS: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48-68)â years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8-12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference -3.7%, 95% CI -18.8-11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. CONCLUSIONS: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone.
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COVID-19 , Idoso , COVID-19/terapia , Humanos , Imunização Passiva , Masculino , Pessoa de Meia-Idade , Plasma , SARS-CoV-2 , Resultado do Tratamento , Soroterapia para COVID-19RESUMO
Yellow fever virus RNA is usually detected in blood of infected humans. We detected virus RNA in urine and semen samples from a convalescent patient. A complete virus genome was sequenced for an isolate from a urine sample. This virus had a South American I genotype and unique synapomorphic changes.
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Sêmen/virologia , Febre Amarela/epidemiologia , Vírus da Febre Amarela , Idoso , Brasil/epidemiologia , Humanos , Masculino , RNA Viral/análise , RNA Viral/urina , Sêmen/química , Análise de Sequência de DNA , Febre Amarela/urina , Vírus da Febre Amarela/genéticaAssuntos
Microcefalia/virologia , Eliminação de Partículas Virais , Infecção por Zika virus/congênito , Zika virus/fisiologia , Feminino , Humanos , Recém-Nascido , Masculino , Microcefalia/diagnóstico por imagem , Gravidez , Zika virus/genética , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologiaRESUMO
The whole genome sequence of a low pathogenicity avian influenza virus (H6N2) was sequenced from a Brazilian teal (Amazonetta brasiliensis) in Brazil, 2023. Phylogenetic analysis of the whole genome revealed a distinct genome pertaining to South American LPAIV from 2014 to 2016, indicating extensive circulation among South American wild birds.
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Influenza A viruses of the H2 subtype represent a zoonotic and pandemic threat to humans due to a lack of widespread specific immunity. Although A(H2) viruses that circulate in wild bird reservoirs are distinct from the 1957 pandemic A(H2N2) viruses, there is concern that they could impact animal and public health. There is limited information on AIVs in Latin America, and next to nothing about H2 subtypes in Brazil. In the present study, we report the occurrence and genomic sequences of two influenza A viruses isolated from wild-caught white-rumped sandpipers (Calidris fuscicollis). One virus, identified as A(H2N1), was isolated from a bird captured in Restinga de Jurubatiba National Park (PNRJ, Rio de Janeiro), while the other, identified as A(H2N2), was isolated from a bird captured in Lagoa do Peixe National Park (PNLP, Rio Grande do Sul). DNA sequencing and phylogenetic analysis of the obtained sequences revealed that each virus belonged to distinct subtypes. Furthermore, the phylogenetic analysis indicated that the genomic sequence of the A(H2N1) virus isolated from PNRJ was most closely related to other A(H2N1) viruses isolated from North American birds. On the other hand, the A(H2N2) virus genome recovered from the PNLP-captured bird exhibited a more diverse origin, with some sequences closely related to viruses from Iceland and North America, and others showing similarity to virus sequences recovered from birds in South America. Viral genes of diverse origins were identified in one of the viruses, indicating local reassortment. This suggests that the extreme South of Brazil may serve as an environment conducive to reassortment between avian influenza virus lineages from North and South America, potentially contributing to an increase in overall viral diversity.
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Charadriiformes , Vírus da Influenza A , Influenza Aviária , Filogenia , Vírus Reordenados , Animais , Brasil , Influenza Aviária/virologia , Influenza Aviária/epidemiologia , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Charadriiformes/virologia , Genoma Viral , Aves/virologiaRESUMO
Since the molecular mechanisms determining COVID-19 severity are not yet well understood, there is a demand for biomarkers derived from comparative transcriptome analyses of mild and severe cases, combined with patients' clinico-demographic and laboratory data. Here the transcriptomic response of human leukocytes to SARS-CoV-2 infection was investigated by focusing on the differences between mild and severe cases and between age subgroups (younger and older adults). Three transcriptional modules correlated with these traits were functionally characterized, as well as 23 differentially expressed genes (DEGs) associated to disease severity. One module, correlated with severe cases and older patients, had an overrepresentation of genes involved in innate immune response and in neutrophil activation, whereas two other modules, correlated with disease severity and younger patients, harbored genes involved in the innate immune response to viral infections, and in the regulation of this response. This transcriptomic mechanism could be related to the better outcome observed in younger COVID-19 patients. The DEGs, all hyper-expressed in the group of severe cases, were mostly involved in neutrophil activation and in the p53 pathway, therefore related to inflammation and lymphopenia. These biomarkers may be useful for getting a better stratification of risk factors in COVID-19.
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Fatores Etários , COVID-19 , Gravidade do Paciente , Humanos , Biomarcadores/metabolismo , COVID-19/genética , Leucócitos/metabolismo , SARS-CoV-2/metabolismo , TranscriptomaRESUMO
Introduction: Bats are critical to maintaining healthy ecosystems and many species are threatened primarily due to global habitat loss. Bats are also important hosts of a range of viruses, several of which have had significant impacts on global public health. The emergence of these viruses has been associated with land-use change and decreased host species richness. Yet, few studies have assessed how bat communities and the viruses they host alter with land-use change, particularly in highly biodiverse sites. Methods: In this study, we investigate the effects of deforestation on bat host species richness and diversity, and viral prevalence and richness across five forested sites and three nearby deforested sites in the interior Atlantic Forest of southern Brazil. Nested-PCR and qPCR were used to amplify and detect viral genetic sequence from six viral families (corona-, adeno-, herpes-, hanta-, paramyxo-, and astro-viridae) in 944 blood, saliva and rectal samples collected from 335 bats. Results: We found that deforested sites had a less diverse bat community than forested sites, but higher viral prevalence and richness after controlling for confounding factors. Viral detection was more likely in juvenile males located in deforested sites. Interestingly, we also found a significant effect of host bat species on viral prevalence indicating that viral taxa were detected more frequently in some species than others. In particular, viruses from the Coronaviridae family were detected more frequently in generalist species compared to specialist species. Discussion: Our findings suggest that deforestation may drive changes in the ecosystem which reduce bat host diversity while increasing the abundance of generalist species which host a wider range of viruses.
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Quirópteros , Vírus , Humanos , Animais , Masculino , Ecossistema , Brasil/epidemiologia , Prevalência , Florestas , Vírus/genéticaRESUMO
Background: Administration of convalescent plasma may serve as an adjunct to supportive treatment to prevent COVID-19 progression and death. We aimed to evaluate the efficacy and safety of 2 volumes of intravenous convalescent plasma (CP) with high antibody titers for the treatment of severe cases of COVID-19. Methods: We conducted a Bayesian, randomized, open-label, multicenter, controlled clinical trial in 7 Brazilian hospitals. Adults admitted to hospital with positive RT-PCR for SARS-CoV2, within 10 days of the symptom onset, were eligible. Patients were randomly assigned (1:1:1) to receive standard of care (SoC) alone, or in combination with 200 mL (150-300 mL) of CP (Low-volume), or 400 mL (300-600 mL) of CP (High-volume); infusion had to be performed within 24 h of randomization. Randomization was centralized, stratified by center. The primary outcome was the time until clinical improvement up to day 28, measured by the WHO ten-point scale, assessed in the intention-to-treat population. Interim and terminal analyses were performed in a Bayesian framework. Trial registered at ClinicalTrials.gov: NCT04415086. Findings: Between June 2, 2020, and November 18, 2020, 129 patients were enrolled and randomly assigned to SoC (n = 42), Low-volume (n = 43) or High-volume (n = 44) CP. Donors presented a median titer of neutralizing antibodies of 1:320 (interquartile range, 1:160 to 1:1088). No evidence of any benefit of convalescent plasma was observed, with Bayesian estimate of 28-day clinical improvement of 72.7% (95%CI, 58.8 to 84.7) in the SoC versus 64.1% (95%ci, 53.8 to 73.7) in the pooled experimental groups (mean difference of -8.7%, 95%CI, -24.6 to 8.2). There was one case of cutaneous mild allergic reaction related to plasma transfusion and one case of suspected transfusion-related acute lung injury but deemed not to be related to convalescent plasma infusion. Interpretation: In this prospective, randomized trial of adult hospitalized patients with severe COVID-19, convalescent plasma was not associated with clinical benefits. Funding: Brazilian Ministry of Science, Technology and Innovation, Fundação de Amparo à Pesquisa do Estado de São Paulo.
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CoronaVac is an inactivated SARS-CoV-2 vaccine that has been rolled out in several low and middle-income countries including Brazil, where it was the mainstay of the first wave of immunization of healthcare workers and the elderly population. We aimed to assess the T cell and antibody responses of vaccinated individuals as compared to convalescent patients. We detected IgG against SARS-CoV-2 antigens, neutralizing antibodies against the reference Wuhan SARS-CoV-2 strain and used SARS-CoV-2 peptides to detect IFN-g and IL-2 specific T cell responses in a group of CoronaVac vaccinated individuals (N = 101) and convalescent (N = 72) individuals. The frequency among vaccinated individuals, of whom 96% displayed T cell and/or antibody responses to SARS-CoV-2, is comparable to 98.5% responses of convalescent individuals. We observed that among vaccinated individuals, men and individuals 55 years or older developed significantly lower anti-RBD, anti-NP and neutralization titers against the Wuhan strain and antigen-induced IL-2 production by T cells. Neutralizing antibody responses for Gamma variant were even lower than for the Wuhan strain. Even though some studies indicated CoronaVac helped reduce mortality among elderly people, considering the appearance of novel variants of concern, CoronaVac vaccinated individuals above 55 years old are likely to benefit from a heterologous third dose/booster vaccine to increase immune response and likely protection.
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Vacinas contra COVID-19 , COVID-19 , Idoso , Anticorpos Neutralizantes , Anticorpos Antivirais , Formação de Anticorpos , COVID-19/prevenção & controle , Humanos , Imunização Secundária , Interleucina-2 , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Linfócitos TRESUMO
The SARS-CoV-2 pandemic have been affecting millions of people worldwide, since the beginning of 2020. COVID-19 can cause a wide range of clinical symptoms, which varies from asymptomatic presentation to severe respiratory insufficiency, exacerbation of immune response, disseminated microthrombosis and multiple organ failure, which may lead to dead. Due to the rapid spread of SARS-CoV-2, the development of vaccines to minimize COVID-19 severity in the world population is imperious. One of the employed techniques to produce vaccines against emerging viruses is the synthesis of recombinant proteins, which can be used as immunizing agents. Based on the exposed, the aim of the present study was to verify the systemic and immunological effects of IM administration of recombinant Nucleocapsid protein (NP), derived from SARS-CoV-2 and produced by this research group, in 2 different strains of rats (Rattus norvegicus); Wistar and Lewis. For this purpose, experimental animals received 4 injections of NP, once a week, and were submitted to biochemical and histological analysis. Our results showed that NP inoculations were safe for the animals, which presented no clinical symptoms of worrying side effects, nor laboratorial alterations in the main biochemical and histological parameters, suggesting the absence of toxicity induced by NP. Moreover, NP injections successfully triggered the production of specific anti-SARS-CoV-2 IgG antibodies by both Wistar and Lewis rats, showing the sensitization to have been well sufficient for the immunization of these strains of rats. Additionally, we observed the local lung activation of the Bronchus-Associated Lymphoid Tissue (BALT) of rats in the NP groups, suggesting that NP elicits specific lung immune response. Although pre-clinical and clinical studies are still required, our data support the recombinant NP produced by this research group as a potential immunizing agent for massive vaccination, and may represent advantages upon other recombinant proteins, since it seems to induce specific pulmonary protection.
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COVID-19 , SARS-CoV-2 , Animais , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunidade , Imunização , Pulmão , Proteínas do Nucleocapsídeo , Ratos , Ratos Endogâmicos Lew , Ratos Wistar , Proteínas Recombinantes , Glicoproteína da Espícula de Coronavírus , VacinaçãoRESUMO
BACKGROUND: The SARS-CoV-2 infections are still imposing a great public health challenge despite the recent developments in vaccines and therapy. Searching for diagnostic and prognostic methods that are fast, low-cost and accurate are essential for disease control and patient recovery. The MALDI-TOF mass spectrometry technique is rapid, low cost and accurate when compared to other MS methods, thus its use is already reported in the literature for various applications, including microorganism identification, diagnosis and prognosis of diseases. METHODS: Here we developed a prognostic method for COVID-19 using the proteomic profile of saliva samples submitted to MALDI-TOF and machine learning algorithms to train models for COVID-19 severity assessment. RESULTS: We achieved an accuracy of 88.5%, specificity of 85% and sensitivity of 91.5% for classification between mild/moderate and severe conditions. When we tested the model performance in an independent dataset, we achieved an accuracy, sensitivity and specificity of 67.18, 52.17 and 75.60% respectively. CONCLUSION: Saliva is already reported to have high inter-sample variation; however, our results demonstrates that this approach has the potential to be a prognostic method for COVID-19. Additionally, the technology used is already available in several clinics, facilitating the implementation of the method. Further investigation using a larger dataset is necessary to consolidate the technique.
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Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a "flip-flop" phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites.
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Substituição de Aminoácidos , Evolução Molecular , Proteínas de Ligação ao GTP/genética , Vírus Sinciciais Respiratórios/genética , Proteínas Virais/genética , Epitopos , Variação Genética , Genótipo , Humanos , Filogenia , Infecções RespiratóriasRESUMO
The structural spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) plays an essential role in infection and is an important target for neutralizing antibody recognition. Mutations in the S gene can generate variants of concern (VOCs), which improve "viral fitness" through selective or survival advantages, such as increased ACE-2 receptor affinity, infectivity, viral replication, higher transmissibility, resistance to neutralizing antibodies and immune escape, increasing disease severity and reinfection risk. Five VOCs have been recognized and include B.1.1.7 (U.K.), B.1.351 (South Africa), P.1 (Brazil), B.1.617.2 (India), and B.1.1.529 (multiple countries). In this review, we addressed the following critical points concerning VOCs: a) characteristics of the SARS-CoV-2 VOCs with mutations in the S gene; b) possible evasion of variants from neutralizing antibodies generated through vaccination, previous infection, or immune therapies; c) potential risk of new pandemic waves induced by the variants worldwide; and d) perspectives for further studies and actions aimed at preventing or reducing the impact of new variants during the current COVID-19 pandemic.
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COVID-19 , SARS-CoV-2 , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , Evasão da Resposta Imune , Mutação , PandemiasRESUMO
An unprecedented global health crisis has been caused by a new virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We performed experiments to test if a hypertonic saline solution was capable of inhibiting virus replication. Our data show that 1.2% NaCl inhibited virus replication by 90%, achieving 100% of inhibition at 1.5% in the nonhuman primate kidney cell line Vero, and 1.1% of NaCl was sufficient to inhibit the virus replication by 88% in human epithelial lung cell line Calu-3. Furthermore, our results indicate that the inhibition is due to an intracellular mechanism and not to the dissociation of the spike SARS-CoV-2 protein and its human receptor. NaCl depolarizes the plasma membrane causing a low energy state (high ADP/ATP concentration ratio) without impairing mitochondrial function, supposedly associated with the inhibition of the SARS-CoV-2 life cycle. Membrane depolarization and intracellular energy deprivation are possible mechanisms by which the hypertonic saline solution efficiently prevents virus replication in vitro assays.
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Newcastle disease virus (NDV) can infect over 250 bird species with variable pathogenicity; it can also infect humans in rare cases. The present study investigated an outbreak in feral pigeons in São Paulo city, Brazil, in 2019. Affected birds displayed neurological signs, and hemorrhages were observed in different tissues. Histopathology changes with infiltration of mononuclear inflammatory cells were also found in the brain, kidney, proventriculus, heart, and spleen. NDV staining was detected by immunohistochemistry. Twenty-seven out of thirty-four tested samples (swabs and tissues) were positive for Newcastle disease virus by RT-qPCR test, targeting the M gene. One isolate, obtained from a pool of positive swab samples, was characterized by the intracerebral pathogenicity index (ICPI) and the hemagglutination inhibition (HI) tests. This isolate had an ICPI of 0.99, confirming a virulent NDV strain. The monoclonal antibody 617/161, which recognizes a distinct epitope in pigeon NDV strains, inhibited the isolate with an HI titer of 512. A complete genome of NDV was obtained using next-generation sequencing. Phylogenetic analysis based on the complete CDS F gene grouped the detected isolate with other viruses from subgenotype VI.2.1.2, class II, including one previously reported in Southern Brazil in 2014. This study reports a comprehensive characterization of the subgenotype VI.2.1.2, which seems to have been circulating in Brazilian urban areas since 2014. Due to the zoonotic risk of NDV, virus surveillance in feral pigeons should also be systematically performed in urban areas.
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Columbidae , Surtos de Doenças/veterinária , Doença de Newcastle/epidemiologia , Vírus da Doença de Newcastle/genética , Animais , Brasil/epidemiologia , Genoma Viral , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Doença de Newcastle/patologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/classificação , Vírus da Doença de Newcastle/isolamento & purificação , Vírus da Doença de Newcastle/patogenicidade , Filogenia , Virulência , Sequenciamento Completo do GenomaRESUMO
Chronic cytomegalovirus (CMV) infection is a trigger factor for the development of immunosenescence and negatively impacts the immune response to influenza virus vaccination (IVV) in older adults. However, the role of physical exercise training in this context is unknown. Thus, the aim of this study was to investigate whether the regular practice of combined exercise training can improve the specific antibody response to IVV in CMV-seropositive older adults. Eighty older adults were distributed into two groups-non-practitioners (NP, n = 31, age = 74.06 ± 6.4 years) and practitioners of combined exercise training (CET, n = 49, age = 71.7 ± 5.8 years)-for at least 12 months. Both volunteer groups were submitted to IVV and blood samples were collected before (pre) and 30 days after (post) the vaccination. Concerning the specific antibody response to IVV, higher serum levels of specific immunoglobulin A (IgA) were found in the CET group post- than pre-vaccination (p < 0.01), whereas higher levels of specific immunoglobulin M (IgM) were observed both in the NP (p < 0.05) and CET (p < 0.001) groups post-vaccination as compared to the pre-vaccination values. Serum levels of specific immunoglobulin G (IgG) for IVV and CMV, as well as interleukin 6 (IL-6) and IL-10, were similar between the time points evaluated. However, the IL-10/IL-6 ratio post-vaccination was higher (p < 0.05) in the CET group than that before vaccination. Negative correlations were observed between the specific IgG levels for IVV and CMV only in the CET group, both pre- and post-vaccination. In addition, negative correlations were found between IL-10 and specific IgG for CMV in all volunteer groups pre- and post-vaccination, whereas a positive correlation between IL-10 and specific-IgG for IVV pre- and post-vaccination was observed in the CET group. In addition, with the hemagglutination inhibition (HAI) assay, it was found that 32.2% of the NP group and 32.6% of the CET group were responders to IVV and displayed reductions in the CMV serostatus (p < 0.05 and p < 0.001, respectively) and increases in naive and effector CD8+ T cells post-vaccination (p < 0.01). However, only the responders from the CET group showed significant reductions in the ratio of effector to naive CD8+ T cells (p < 0.05) and increased IL-10 levels post-vaccination (p < 0.001). In summary, this study demonstrates that the improvement in the response to IVV in CMV-seropositive older adults was related to an anti-inflammatory status and enhancement of naive CD8+ T cells, particularly associated with regular practice of CET.
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Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Memória Imunológica , Vacinas contra Influenza/imunologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/virologia , Exercício Físico , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Masculino , VacinaçãoRESUMO
BACKGROUND: Although glutamine is able to improve the immune response, its action in the upper airway immunity against the influenza virus vaccine remains unclear. Therefore, we aimed to evaluate the L-glutamine supplementation effect on the mucosal immune/inflammatory response of elderly subjects vaccinated against the influenza virus. METHODS: Saliva sampling from 83 physically active elderly volunteers were collected pre- and 30 days after influenza virus vaccination and supplementation with L-glutamine (Gln, n = 42) or placebo (PL, n = 41). RESULTS: Gln group showed higher salivary levels of interleukin (IL)-17, total secretory immunoglobulin A (SIgA), and specific-SIgA post-vaccination than values found pre-vaccination and in the PL group post-vaccination. Whereas higher salivary levels of IL-6 and IL-10 were observed post-vaccination in the Gln group, IL-37 levels were lower post-vaccination in both groups than the values pre-vaccination. Tumor necrosis factor (TNF)-α levels were unchanged. Positive correlations between IL-6 and IL-10 were found in all volunteer groups pre- and post-vaccination and also between IL-17 and IL-6 or IL-10 in the Gln group post-vaccination. A negative correlation between IL-37 and IL-10 was found pre- and post-vaccination in the PL group. CONCLUSION: Gln supplementation was able to modulate salivary cytokine profile and increase SIgA levels, both total and specific to the influenza virus vaccine, in physically active elderly subjects.