OMIP-91: A 27-color flow cytometry panel to evaluate the phenotype and function of human conventional and unconventional T-cells.

This 27-color panel was developed to simultaneously measure different T-cell populations (CD4, CD8, γδ T-cells, and MAIT cells) and their subsets (Memory, Th1, Th2, Th17, Tfh, and Treg) along with functional markers associated with their activation status, cytokine production and cytotoxicity. This panel will be useful for both in vivo and in vitro studies evaluating T-cells in the context of human health and disease. This panel is valuable in settings where samples are limited as a large amount of data will be generated using small volumes of blood.

A case report describing the immune response of an infant with congenital heart disease and severe COVID-19.

Background: Children with SARS-CoV-2 infection generally present with milder symptoms or are asymptomatic in comparison with adults, however severe disease occurs in a subset of children. To date, the immune correlates of severe COVID-19 in young children have been poorly characterised. Methods: We report the kinetics of immune responses in relation to clinical and virological features in an infant with acute severe COVID-19 using high-dimensional flow cytometry and multiplex cytokine analysis. Results: Systemic cellular and cytokine profiling show an initial increase in neutrophils and monocytes with depletion of lymphoid cell populations (particularly CD8 + T and NK cells) and elevated inflammatory cytokines. Expansion of memory CD4 + T (but not CD8 + T) cells occurred over time, with a predominant Th2 bias. Marked activation of T cell populations observed during the acute infection gradually resolved as the child recovered. Substantial in vitro activation of T-cell populations and robust cytokine production, in response to inactivated SARS-CoV-2 stimulation, was observed 3 months after infection indicating durable, long-lived cellular immune memory. Conclusions: These findings provide important insights into the immune response of a young infant with severe COVID-19 and will help to inform future research into therapeutic targets for high-risk groups.