CCL2 and HIV infectious disease: In response to HIV infection, the rapid activation of microglia may also release neurotoxic factors, including proinflammatory cytokines such as TNFα, IL-1β, IL-6 (Milligan et al., 2001a; Schoeniger-Skinner et al., 2007; Liu et al., 2016), chemokines such as monocyte chemoattractant protein-1 (MCP-1), fractalkine (FKN) (Zhao et al., 2017; Ru et al., 2019), excitatory amino acids (Porcheray et al., 2006; Tian et al., 2012), nerve growth factors such as brain-derived neurotropic factor (BDNF) (Wang et al., 2017), and reactive oxygen species (Patrizio and Levi, 1994; Holguin et al., 2004).