ISABELA PAZOTTI DAHER
Projetos de Pesquisa
Unidades Organizacionais
LIM/60 - Laboratório de Imunologia Clínica e Alergia, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- 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.
- ZnO-Based Electrochemical Immunosensor to Assess Vaccine-Induced Antibody-Mediated Immunity against Wild-Type and Gamma SARS-CoV-2 Strains(2023) NUNEZ, Freddy A.; CASTRO, Ana C. H.; DAHER, Isabela P.; CUNHA-NETO, Edecio; KALIL, Jorge; BOSCARDIN, Silvia B.; LANFREDI, Alexandre J. C.; OLIVEIRA, Vivian L. de; ALVES, Wendel A.The evaluation of serological responses to COVID-19 is crucial for population-level surveillance, developing new vaccines, and evaluating the efficacy of different immunization programs. Research and development of point-of-care test technologies remain essential to improving immunity assessment, especially for SARS-CoV-2 variants that partially evade vaccine-induced immune responses. In this work, an impedimetric biosensor based on the immobilization of the recombinant trimeric wild-type spike protein (S protein) on zinc oxide nanorods (ZnONRs) was employed for serological evaluation. We successfully assessed its applicability using serum samples from spike-based COVID-19 vaccines: ChAdOx1-S (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech). Overall, the ZnONRs/ spike-modified electrode displayed accurate results for both vaccines, showing excellent potential as a tool for assessing and monitoring seroprevalence in the population. A refined outcome of this technology was achieved when the ZnO immunosensor was functionalized with the S protein from the P.1 linage (Gamma variant). Serological responses against samples from vaccinated individuals were acquired with excellent performance. Following studies based on traditional serological tests, the ZnONRs/spike immunosensor data reveal that ChAdOx1-S vaccinated individuals present significantly less antibody-mediated immunity against the Gamma variant than the BNT162b2 vaccine, highlighting the great potential of this point-of-care technology for evaluating vaccine-induced humoral immunity against different SARS-CoV-2 strains.