Memory T cells effectively recognize the SARS-CoV-2 hypermutated BA.2.86 variant.

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infections are controlled by T cells.
• The cross-recognition capacity of memory T cells against highly mutated SARS-CoV-2 variants, like BA.2.86, remains unclear.

Purpose of the Study:

• To investigate whether memory T cells induced by prior SARS-CoV-2 infection or vaccination can cross-recognize the emergent BA.2.86 variant.
• To assess the magnitude and function of SARS-CoV-2 spike-specific T cells against BA.2.86.

Main Methods:

• Analysis of two cohorts: healthy controls and individuals with chronic lymphocytic leukemia.
• Assessment of SARS-CoV-2 spike-specific CD4+ and CD8+ T cell responses against BA.2.86 mutated epitopes.
• Evaluation of T cell magnitude, cytokine expression, and proliferative capacity.

Main Results:

• SARS-CoV-2 spike-specific CD4+ and CD8+ T cells demonstrated resilient immune recognition of the BA.2.86 variant in both cohorts.
• Largely preserved T cell magnitudes were observed against mutated spike epitopes of BA.2.86.
• Sustained cytokine expression and proliferative capacity of T cells were confirmed.

Conclusions:

• Memory CD4+ and CD8+ T cells maintain effective immune recognition of highly mutated SARS-CoV-2 variants, including BA.2.86.
• These findings suggest that T cell-mediated immunity provides a robust defense against emerging SARS-CoV-2 variants.