CD4 and HIV infectious disease: The biological significance of IL-7 has been consolidated in translational and clinical studies to improve host immunity to infectious diseases by activation of CD4+ T-cell populations and re-programming of the antigen-specific T-cell repertoire in the context of TB, human immunodeficiency virus (HIV) infection and sepsis in preclinical (Maeurer et al., 2000; Vassena et al., 2012; Rao et al., 2013; Kulkarni et al., 2018) as well as clinical settings (Sportes et al., 2008; Levy et al., 2009; Francois et al., 2018).