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Negatu, S.

Publications and source records attributed to Negatu, S..

2 recordsLinked to original sources

Acute Paternal Immune Activation Shapes Embryonic Development and Protects Offspring from Viral Infection

The evolutionary arms race between host and pathogen is traditionally framed as a multigenerational paradigm, where beneficial host immune adaptations accrue in a population over time through DNA sequence variation. If pathogens exposure alters epigenetic information inherited by offspring through paternal gametes, advantageous immune traits could emerge within a single generation. We show that acute paternal immune activation (PIA) induces immune signaling in the male reproductive tract and remodels the sperm small RNA profile. Using IVF, we show that altered sperm small RNAs from immune-activated males reprograms gene expression in preimplantation embryos, eliciting sex-specific transcriptional responses. This transcriptional program is reflected in a striking inherited phenotype, as male offspring sired by PIA males exhibit enhanced survival following lethal viral challenge. These findings identify sperm small RNAs as a molecular mechanism that links PIA to embryonic development and offspring immunity, providing a comprehensive framework for how PIA shapes inherited pathogen protection.

immunology↗

CXCL10+ peripheral activation niches couple preferred sites of Th1 entry with optimal APC encounter

Correct positioning of T cells within infected tissues is critical for T cell activation and pathogen control. Upon tissue entry, effector T cells must efficiently locate antigen presenting cells (APC) for peripheral activation. We reveal that tissue entry and initial peripheral activation of Th1 effector T cells are tightly linked to perivascular positioning of chemokine-expressing APCs. Dermal inflammation induced tissue-wide de novo generation of discrete perivascular CXCL10+ cell clusters, enriched for CD11c+MHC-II+ monocyte-derived dendritic cells. These chemokine clusters were hot spots for both Th1 extravasation and activation in the inflamed skin. CXCR3-dependent Th1 localization to the cluster micro-environment prolonged T-APC interactions and boosted function. Both the frequency and range of these clusters were enhanced via a Th1-intrinsic, IFN{gamma}-dependent positive feedback loop. Thus, the perivascular CXCL10+ clusters act as initial peripheral activation niches, optimizing controlled activation broadly throughout the tissue by coupling Th1 tissue entry with enhanced opportunities for Th1-APC encounter.

immunology↗