Table 2. Immunomodulation as a key role in early life stress-induced depression.

Inflammatory cytokine	Stress exposure	Depression-like behavior	Main findings	References
IL-1β	MS	Promoting	IL-1β in the vHIP, PFC and serum increase under ELS-induced depression	Wang et al., 2017
IL-6	MS	Promoting	IL-6 increases under ELS-induced depression.	Miller and Cole, 2012
Il-10	MS	Promoting	IL-10 in the amygdala and hypothalamus decrease under ELS-induced depression.	DellaGioia et al., 2010
TNF-α	MS	Promoting	Pro-inflammatory markers TNF-α is up regulated under ELS-induced depression.	Wang et al., 2017
CRP	ELS	Promoting	CRP increases under ELS-induced depression.	Danese et al., 2008
TLR 4	ELS	Promoting	The expression of gene encoding TLR 4 is up-regulated under ELS-induced depression.	Carroll et al., 2011

Abbreviations: IL-1β: interleukin-1β; MS: maternal separation; vHIP: ventral hippocampus; PFC: prefrontal cortex; IL-6: interleukin-6; IL-10: interleukin-10; TNF-α: tumor necrosis factor-α; CRP: C-reactive protein; ELS: early life stress; TLR 4: Toll-like receptor.