Table 2.

Characteristics of peripheral immune cell infiltration and nanomedicine interventions in the CNS

Entity	Recruitment signals / targets	Timing & localization	Pathological role / mechanism of action	References
Neutrophils	CXCL1, IL-8	Early recruitment	Induce oxidative stress; release cytotoxic NETs	Nowaczewska-Kuchta et al.( 2025), Liu et al. (2025b)
T-cells	Not specified	Subsequent migration into the parenchyma	Secrete granzyme B; reinforce microglial M1 polarization	(Yang et al. (2025b), Van Hove et al. (2025)
Monocytes	CCL2/CX3CL1 gradients	Simultaneous attraction (with T-cells)	Differentiate into cytokine-amplifying macrophage-like cells	Tian et al. (2025a), Nie et al. (2025), Dong et al. (2025)

BBB Blood–brain barrier, CCL2 C–C motif chemokine ligand 2, CCR2 C–C chemokine receptor type 2, CNS Central nervous system, CTLA-4 Cytotoxic T-lymphocyte-associated protein 4, IL-8 Interleukin-8, NETs Neutrophil extracellular traps, PD-1 Programmed cell death protein 1