CD4 and coinfection: However, the most direct evidence for a CD4+ T cell-independent role for the control of Mtb infection in its latent form derived from experiments that demonstrated that macaques with Mtb infection/LTBI also presented chronic immune activation after SIV co-infection, while macaque with Mtb infection/LTBI, which experienced comparable levels of CD4+ T cell reduction after administration of a depleting antibody, did not.