Detection of CD8 T-cell expansions with restricted T-cell receptor V gene usage in infants vertically infected by HIV-1

Objective: To investigate the T-cell receptor (TCR) repertoire usage in infants born to mothers infected with HIV-1 in order to discern possible perturbations in TCR usage as a consequence of HIV-1 infection. Design: Blood samples from five HIV-1-infected and six non-infected children born to HIV-1-seropositive mothers were collected at two to three timepoints during the first and second year of life and the TCR variable gene usage was determined. Methods: Triple staining flow cytometry analysis using a panel of monoclonal antibodies (MAb) to TCR Vα and Vβ gene products and antibodies to CD4 and CD8 was performed. Results: Frequent large expansions of CD8+ lymphocyte subpopulations bearing distinct Vα and Vβ gene products was seen in HIV-1-infected children (four out of five) but was rarely detected in uninfected children. Conclusion: The study demonstrated the frequent occurrence of persistent and clonal expansions of CD8+T cells bearing distinct Vα/Vβ gene products in some HIV-1 vertically infected infants similar to those observed during primary infection in adults.