CD4 and hereditary spastic paraplegia: Current in vitro HIV latency-reactivation models are mainly based on TCR-stimulated resting memory/effector CD4+ T cells (Sahu et al., 2006; Marini et al., 2008; Tyagi et al., 2010), and the reactivation of latent HIV-1 in resting naïve CD4+ T cells undergoing HSP has not been further investigated.