Expression profiles of GPR56 and CD99 in T cells of AIDS patients and assessment of diagnostic value.

OBJECTIVES

GPR56, an adhesion G protein-coupled receptor, and CD99, a cell-surface glycoprotein, have emerged as important immunomodulators in HIV infection. GPR56 plays a crucial role in T cell migration, activation, and the interaction between the virus and the host cell. Concurrently, CD99 is implicated in regulating key processes such as T cell adhesion, migration, and apoptotic signaling. This study aimed to investigate their dynamic expression in T-cell subsets as potential biomarkers for AIDS progression and diagnosis.

METHODS

Differentially expressed genes in T cells were screened using single-cell RNA sequencing. Experimental validation was performed by flow cytometry on peripheral blood samples from 36 PLWH (male:31, female:5, age: 41.58±12.42) and 35 healthy controls (male:25, female:10, age: 32.17±12.09). Systematically evaluated the protein expression profiles of GPR56 and CD99 on the surface of T cells. The Pearson method assessed correlation, and receiver operating characteristic (ROC) analysis evaluated diagnostic performance.

RESULTS

GPR56 expression on CD8⁺ T cells increased significantly with disease progression (P < 0.05), while CD99 expression remained stable across stages. The CD8⁺GPR56⁺CD99⁺ T-cell subset demonstrated high diagnostic accuracy for HIV infection (AUC = 0.90), with frequencies that increased progressively with disease severity. Moderate co-expression of GPR56 and CD99 was observed in CD8⁺ T cells in both cohorts. In contrast, CD4⁺GPR56⁺ T cells showed no discriminative capacity between early-stage patients and controls.

CONCLUSIONS

GPR56 and CD99 exhibit distinct expression patterns during HIV infection. The CD8⁺GPR56⁺ and CD8⁺GPR56⁺CD99⁺ T-cell subsets serve as potent stage-specific biomarkers, with combined GPR56/CD99 analysis enhancing diagnostic precision for advanced AIDS.