Implications of Accumulation of Clonally Expanded and Senescent CD4 ⁺GNLY⁺ T Cells in Immunological Non-responders of HIV-1 infection

Increased CD4 ⁺GNLY⁺ T cells have been confirmed to be inversely associated with CD4⁺ T cell count in immunological non-responders (INRs), however, the underlying mechanisms are unknown. This study aimed to elucidate the characteristics of CD4 ⁺GNLY⁺ T cells and their relationship with immune restoration. Single-cell RNA sequencing, single-cell TCR sequencing, and flow cytometry were used to analyze the frequency, phenotypes, and function of CD4 ⁺GNLY⁺ T cells. Moreover, Enzyme linked immunosorbent assay was performed to detect plasma cytokines production in patients. CD4 ⁺GNLY⁺ T cells were found to be highly clonally expanded, characterized by higher levels of cytotoxicity, senescence, P24, and HIV-1 DNA than CD4 ⁺GNLY^- T cells. Additionally, the frequency of CD4 ⁺GNLY⁺ T cells increased after ART, and further increased in INRs, and were positively associated with the antiretroviral therapy duration in INR. Furthermore, increased IL-15 levels in INRs positively correlated with the frequency and senescence of CD4 ⁺GNLY⁺ T cells, suggesting that CD4 ⁺GNLY⁺ T cells may provide new insights for understanding the poor immune reconstitution of INRs. In conclusion, increased, highly clonally expanded, and senescent CD4 ⁺GNLY⁺ T cells may contribute to poor immune reconstitution in HIV-1 infection.