Decline in neutralising antibody responses, but sustained T-cell immunity, in COVID-19 patients at 7 months post-infection.

Objectives: This study aimed to explore the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific humoral responses and T-cell responses in patients who have recovered from coronavirus disease 2019 (COVID-19) to understand the natural protective immune responses and to facilitate the development of vaccines.

Methods: We conducted a combined assessment of the changes in neutralising antibody levels and SARS-CoV-2-specific T-cell responses over time in 27 patients up to 7 months after infection.

Results: The neutralising antibody remained detectable in 96.

Characteristics of T-cell responses in COVID-19 patients with prolonged SARS-CoV-2 positivity - a cohort study.

Objective: SARS-CoV-2 has caused a worldwide pandemic of COVID-19. The existence of prolonged SARS-CoV-2 positivity (PP) has further increased the burden on the health system. Since T cells are vital for viral control, we aimed to evaluate the characteristics of T-cell responses associated with PP.

High levels of soluble CD25 in COVID-19 severity suggest a divergence between anti-viral and pro-inflammatory T-cell responses.

Objectives: We aimed to gain an understanding of the paradox of the immunity in COVID-19 patients with T cells showing both functional defects and hyperactivation and enhanced proliferation.

Methods: A total of 280 hospitalised patients with COVID-19 were evaluated for cytokine profiles and clinical features including viral shedding. A mouse model of acute infection by lymphocytic choriomeningitis virus (LCMV) was applied to dissect the relationship between immunological, virological and pathological features.

Ablation of NTPDase2+ cells inhibits the formation of filiform papillae in tongue tip.

Background: Lingual epithelia in the tongue tip are among the most rapidly regenerating tissues, but the mechanism of cell genesis in this tissue is still unknown. Previous study has suggested the existence of multiple stem cell pools in lingual epithelia and papillae. Like K14+ and Sox2+ cells, NTPDase2+ cells have characteristics of stem cells.