MARCELO ALVES FERREIRA
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina
LIM/59 - Laboratório de Biologia Celular, Hospital das Clínicas, Faculdade de Medicina
LIM/59 - Laboratório de Biologia Celular, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
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conferenceObject Immune Responses Of CVID Patients To COVID-19 Vaccines(2023) MEDEIROS, Giuliana Xavier de; FERREIRA, Loisi de Carvalho Pereira; MAGAWA, Jhosiene Yukari; KURAMOTO, Andreia; SASAHARA, Greyce Luri; FERREIRA, Marcelo; BARROS, Myrthes Maragna Toledo; KALIL, Jorge; MARINHO, Ana Karolina Barreto Berselli; CUNHA-NETO, Edecio; SANTOS, Keity Souza; KOKRON, Cristina- Immunodominant antibody responses directed to SARS-CoV-2 hotspot mutation sites and risk of immune escape(2023) OLIVEIRA, Jamille Ramos; RUIZ, Cesar Manuel Remuzgo; MACHADO, Rafael Rahal Guaragna; MAGAWA, Jhosiene Yukari; DAHER, Isabela Pazotti; URBANSKI, Alysson Henrique; SCHMITZ, Gabriela Justamante Haendel; ARCURI, Helen Andrade; FERREIRA, Marcelo Alves; SASAHARA, Greyce Luri; MEDEIROS, Giuliana Xavier de; JR, Roberto Carlos Vieira Silva; DURIGON, Edison Luiz; BOSCARDIN, Silvia Beatriz; ROSA, Daniela Santoro; SCHECHTMAN, Deborah; NAKAYA, Helder. I. I.; CUNHA-NETO, Edecio; GADERMAIER, Gabriele; KALIL, Jorge; COELHO, Veronica; SANTOS, Keity SouzaIntroductionConsidering the likely need for the development of novel effective vaccines adapted to emerging relevant CoV-2 variants, the increasing knowledge of epitope recognition profile among convalescents and afterwards vaccinated with identification of immunodominant regions may provide important information. MethodsWe used an RBD peptide microarray to identify IgG and IgA binding regions in serum of 71 COVID-19 convalescents and 18 vaccinated individuals. ResultsWe found a set of immunodominant RBD antibody epitopes, each recognized by more than 30% of the tested cohort, that differ among the two different groups and are within conserved regions among betacoronavirus. Of those, only one peptide, P44 (S415-429), recognized by 68% of convalescents, presented IgG and IgA antibody reactivity that positively correlated with nAb titers, suggesting that this is a relevant RBD region and a potential target of IgG/IgA neutralizing activity. DiscussionThis peptide is localized within the area of contact with ACE-2 and harbors the mutation hotspot site K417 present in gamma (K417T), beta (K417N), and omicron (K417N) variants of concern. The epitope profile of vaccinated individuals differed from convalescents, with a more diverse repertoire of immunodominant peptides, recognized by more than 30% of the cohort. Noteworthy, immunodominant regions of recognition by vaccinated coincide with mutation sites at Omicron BA.1, an important variant emerging after massive vaccination. Together, our data show that immune pressure induced by dominant antibody responses may favor hotspot mutation sites and the selection of variants capable of evading humoral response.
- Development, validation and application of a questionnaire to qualify the indoor environmental exposure of patients with respiratory allergy(2023) SOUZA, Barbara de; FERREIRA, Marcelo Alves; KALIL, Jorge; GIAVINA-BIANCHI, Pedro; AGONDI, Rosana CamaraObjective Environmental control includes measures to prevent exposure to common aeroallergens in an individual's home. Questionnaires are part of the clinical practice of health assessment, and are also widely used in research. Our aim was to develop and validate a questionnaire to identify possible sources of aeroallergens present in the indoor environment. Methods This study describes the development, validation and application of a questionnaire. For content validation the Content Validation Index and Ordinal Cronbach's Alpha Index have been used; Polychoric Correlations for the agreement between judges; and an Exploratory Factor Analysis for the structure of the questionnaire, while for reliability assessment, Intraclass Correlation Coefficient has been applied. Results Twenty-one doctors participated as judges to validate the questionnaire, which 204 patients answered. The Content Validity Index for all the questions on the ""Clarity"" aspect was 0.846 +/- 0.152 and on the ""Relevance"" aspect, 0.954 +/- 0.080. Cronbach's alpha coefficient for the ""Clarity"" aspect was 0.88 with a 95% confidence intervals (CI) and the ""Relevance"" aspect, 0.94 with a 95% CI. The average Intraclass Correlation Coefficient was 0.94 and all the F tests were highly significant. Conclusions The questionnaire developed by our group was considered valid and reliable, and is capable of portraying the home environment without the need for a personal visit to the patient's home. This questionnaire would be a good tool to use in research or during patient consultations to assess the patient's home environment, as this latter assessment is essential for the management of patients with respiratory allergies.
- Reduced T Cell and Antibody Responses to Inactivated Coronavirus Vaccine Among Individuals Above 55 Years Old(2022) MEDEIROS, Giuliana X.; SASAHARA, Greyce Luri; MAGAWA, Jhosiene Y.; NUNES, Joao Paulo S.; BRUNO, Fernanda R.; KURAMOTO, Andreia C.; ALMEIDA, Rafael R.; FERREIRA, Marcelo A.; SCAGION, Guilherme P.; CANDIDO, Erika D.; LEAL, Fabyano B.; OLIVEIRA, Danielle B. L.; DURIGON, Edison L.; SILVA JR., Roberto Carlos V.; ROSA, Daniela S.; BOSCARDIN, Silvia B.; COELHO, Veronica; KALIL, Jorge; SANTOS, Keity S.; CUNHA-NETO, EdecioCoronaVac 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.