Day/night variations of myeloid and lymphoid cell subsets in the murine inguinal lymph node

WAGNER, PAULA M.; PRUCCA, CÉSAR G.; BOFFELLI, LUCIA; PIQUERAS, VIRGINIA A.; CORREA, SILVIA G.; MACCIONI, MARIANA; GUIDO, MARIO E.

FEBS Open Bio

Wiley

Año: 2025

2211-5463

Circadian rhythms orchestrate physiological processes, including immunefunction, across a 24-h cycle. This study investigates the temporal distribu-tion of immune cell populations in healthy mice entrained to a 12:12-hlight–dark cycle. Inguinal lymph node (iLN) samples were collected at zeit-geber times (ZT) 0 (lights on) and ZT12 (lights off) to assess immune cellcomposition. A significantly higher proportion of natural killer T (NKT)cells and neutrophils was observed at ZT0 compared to ZT12, while den-dritic cells, macrophages, and natural killer (NK) cells showed no signifi-cant temporal variation. Additionally, adaptive immune cells, particularlyProgrammed cell Death protein 1+ (PD1+) Cluster of differentiation 4+(CD4+) and PD1+ Cluster of differentiation 8+ (CD8+) T cells, were moreabundant during the light phase. These findings suggest a diurnal patternin immune readiness, with implications for optimizing immunotherapeuticinterventions based on circadian timing.