Immune characterization of a Colombian family cluster with SARS-CoV-2 infection

• Published in: Biomédica
• Main Authors: Wbeimar Aguilar-Jiménez, Lizdany Flórez-Álvarez, Daniel S. Rincón, Damariz Marín-Palma, Alexandra Sánchez-Martínez, Jahnnyer Martínez, María Isabel Zapata, John D. Loaiza, Constanza Cárdenas, Fanny Guzmán, Paula A. Velilla, Natalia A. Taborda, Wildeman Zapata, Juan C. Hernández, Francisco J. Díaz, María T. Rugeles
• Format: Article in Journal/Newspaper
• Language: English; Spanish
• Published: Instituto Nacional de Salud 2021
• Subjects: coronavirus infections; inflammation; killer cells; natural; t-lymphocytes; antibodies; neutralizing; Medicine; R; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.7705/biomedica.5976; https://doaj.org/article/1091ede54c9245c7a794ff3ae63ff6fe

Introduction: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. Objective: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. Materials and methods: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. Results: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. Conclusion: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.