CD4 and HIV-1 infection: Using this model, we predicted the dynamics of naive CD4+ and CD8+ T-cell numbers and their TRECs in HIV-1 infection by i) increasing the naive T-cell loss rates d in accordance with the turnover estimates of our deuterium labeling studies among chronic HIV-1 infected individuals [17], and ii) deducing the peripheral T-cell division rates of naive CD4+ and CD8+ T cells from the combination of d and the observed net loss of these cells in HIV infection (see Supplemental Methods in S1 File).