A study led by Moriya Tsuji, professor at the Texas A&M University School of Engineering Medicine, has identified specific T-cell profiles that distinguish between mild and severe cases of COVID-19. The research, published in the journal iScience, suggests these findings can guide the creation of vaccines resistant to viral mutations.
The study focused on CD8+ T cells, which are white blood cells responsible for mounting an immune response against infections. While previous research often compared patients with different human leukocyte antigen (HLA) types, Tsuji sought to make direct comparisons by isolating variables. He described the previous methodology as comparing "oranges and apples," stating his goal was to compare a green apple to a red apple.
To achieve this, Tsuji collaborated with researchers from Columbia University Vagelos College of Physicians and Surgeons and the Federal University of Minas Gerais in Brazil. The team analyzed blood samples collected in 2020 from 42 patients who were all HLA-A2-positive, prior to the availability of COVID-19 vaccines. They examined 8,402 SARS-CoV-2-reactive T-cells produced by these patients.
The analysis revealed that patients with mild disease possessed more CD8+ T cells capable of mounting a strong, multi-pronged response that lasted up to four months. In contrast, patients with severe disease exhibited dysfunctional T-cell types.
The researchers noted that many viral parts recognized by these T-cells remain unchanged across variants because they are located inside the virus rather than on its surface, reducing the pressure for mutation.
