Biology subjects

Di Santo, J.

Publications and source records attributed to Di Santo, J..

3 recordsLinked to original sources

bioRxiv2023

High-dimensional spectral cytometry panels for whole blood immune phenotyping

The need to understand the mechanisms and pathways of immune responses in pathogenic conditions such as cancer and autoimmunity requires awareness of natural immune variability in healthy subjects. To this end, various systems immunology studies have been established. Among them, the Milieu Interieur (MI) study was established to define the boundaries of a healthy immune response and identify determinants of immune response variation. MI used immunophenotyping of a 1000 healthy donor cohort by flow cytometry as a principal outcome for immune variance at steady state. For the 10-year longitudinal MI study, we have developed two high-dimensional spectral flow cytometry panels that allow deep characterization of innate and adaptive whole blood immune cells (35 and 34 fluorescent markers, respectively) and standardized the protocol for sample handling, staining, acquisition, and data analysis. This permits the reproducible quantification of over 182 immune cell phenotypes through robust immunophenotyping at a single site. This highly standardized protocol was applied to samples from patients with autoimmune/inflammatory diseases. It is currently used for characterization of the impact of age and environmental factors on peripheral blood immune phenotypes of >400 donors from the initial MI cohort.

immunology↗

bioRxiv2021

A measles-vectored COVID-19 vaccine induces long-term immunity and protection from SARS-CoV-2 challenge in mice

In light of the expanding SARS-CoV-2 pandemic, developing efficient vaccines that can provide sufficient coverage for the world population is a global health priority. The measles virus (MV)-vectored vaccine is an attractive candidate given the measles vaccines extensive safety history, well-established manufacturing process, and induction of strong, long-lasting immunity. We developed an MV-based SARS-CoV-2 vaccine using either the full-length spike (S) or S2 subunit as the antigen. While the S2 antigen failed to induce neutralizing antibodies, the prefusion-stabilized, full-length S (MV-ATU2-SF-2P-dER) construct proved to be an attractive vaccine candidate, eliciting strong Th1-dominant T-cell and neutralizing antibody responses against the S antigen while minimizing reactivity to the vector itself. Neutralizing antibody titers remained high three months after homologous prime-boost immunization, and infectious virus was undetectable in all animals after challenge with a mouse-adapted SARS-CoV-2 virus.

immunology↗

bioRxiv2020

Human T-bet governs innate and innate-like adaptive IFN-γ immunity against mycobacteria

Inborn errors of human IFN-{gamma} immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to an inherited deficiency of the transcription factor T-bet. This deficiency abolishes the expression of T-bet target genes, including IFNG, by altering chromatin accessibility and DNA methylation in CD4+ T cells. The patient has profoundly diminished counts of mycobacterial-reactive circulating NK, invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and V{delta}2+ {gamma}{delta} T lymphocytes, and of non-mycobacterial-reactive classic TH1 lymphocytes, the remainders of which also produce abnormally low amounts of IFN-{gamma}. Other IFN-{gamma}-producing lymphocyte subsets however develop normally, but with low levels of IFN-{gamma} production, with exception of V{delta}2- {gamma}{delta} T lymphocytes, which produce normal amounts of IFN-{gamma} in response to non-mycobacterial stimulation, and non-classic TH1 (TH1*) lymphocytes, which produce IFN-{gamma} normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of, and IFN-{gamma} production by, innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and V{delta}2+ {gamma}{delta} T cells), with mycobacterial-specific, IFN-{gamma}-producing, purely adaptive {beta} TH1* cells unable to compensate for this deficit.

immunology↗