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Miller-Ensminger, T.

Publications and source records attributed to Miller-Ensminger, T..

4 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↗

Physiologic variation in sperm miRNAs tune embryonic gene regulatory programs and developmental outcomes

Small RNAs delivered by sperm can transmit environmentally regulated, epigenetically inherited phenotypes to offspring, yet the mechanisms by which modest changes in sperm microRNA abundance overcome dilution within the much larger egg to influence embryonic development remain unresolved. Here, we show that physiologically relevant variation in individual sperm miRNAs is sufficient to quantitatively program embryonic gene expression and developmental outcomes. Using parthenogenetic and fertilized embryos, we show that as few as 200 molecules of miR-200c-3p or miR-465c-3p induces reproducible, dose-dependent gene expression responses across defined developmental windows. Parthenogenetic embryos faithfully recapitulate early miRNA-driven gene expression changes observed in fertilized embryos, validating their use for isolating early regulatory mechanisms. We further developed AGO2-REMORA, an RNA adenosine base editor fused to Argonaute2 to map miRNA-mRNA interactions in embryos, revealing that early mRNA repression reflects direct miRNA targeting, while transcriptional changes at later stages arise as secondary consequences of these initial interactions. Furthermore, we show that modest elevation of miR-200c-3p during early development is sufficient to induce transcriptional alterations through early development and produce craniofacial phenotypes in late-stage embryos, recapitulating features of fetal alcohol syndrome associated with paternal alcohol consumption. Together, these findings establish a generalizable framework by which small perturbations in sperm miRNA content quantitatively modulate early gene regulatory programs, triggering cascades that persist throughout development and influence offspring phenotype.

developmental biology↗

Interleukin-27 is antiviral at the maternal-fetal interface.

Congenital viral infections can have severe consequences for pregnancy and fetal outcomes. Remarkably, the fetal-derived placenta serves as a robust barrier to infection through meticulous regulation by immune effectors and a diverse repertoire of cytokines. Yet, the regulatory roles of many cytokines remain undefined at the maternal-fetal interface. Interleukin 27 (IL-27) is a highly expressed cytokine in the placenta whose functional consequence during congenital infection is unknown. Here, we utilized trophoblast organoids (TO) derived from primary human placentas and a mouse model of congenital viral infection to uncover the functional role of IL-27 signaling during pregnancy. We show that TOs constitutively express IL-27 and its receptor, IL27RA, and demonstrate that IL-27 signaling restricts Zika virus (ZIKV) infection of TOs. Through bulk RNA-sequencing of TOs in the absence and presence of IL-27 signaling, we demonstrate IL-27-mediated upregulation of antiviral genes. Finally, we show that IL-27 signaling is critical within the context of congenital murine ZIKV infection, as IL-27 restricts placental ZIKV burdens and protects against pathologic fetal outcomes early in gestation. These findings collectively demonstrate a novel role for IL-27 in the placenta and establish IL-27 as an innate antiviral defense at the maternal-fetal interface during congenital viral infection.

microbiology↗

Human erythroid progenitors express antigen presentation machinery

Early-life immune exposures can profoundly impact lifelong health. However, functional mechanisms underlying fetal immune development remain incomplete. Erythrocytes are not typically considered active immune mediators, primarily because erythroid precursors discard their organelles as they mature, thus losing the ability to alter gene expression in response to stimuli. Erythroid progenitors and precursors circulate in human fetuses and neonates. Although there is limited evidence that erythroid precursors are immunomodulatory, our understanding of the underlying mechanisms remains inadequate. To define the immunobiological role of fetal and perinatal erythroid progenitors and precursors, we analyzed single cell RNA-sequencing data and found that transcriptomics support erythroid progenitors as putative immune mediators. Unexpectedly, we discovered that human erythroid progenitors constitutively express Major Histocompatibility Complex (MHC) class II antigen processing and presentation machinery, which are hallmarks of specialized antigen presenting immune cells. Furthermore, we demonstrate that erythroid progenitors internalize and cleave foreign proteins into peptide antigens. Unlike conventional antigen presenting cells, erythroid progenitors express atypical costimulatory molecules and immunoregulatory cytokines that direct the development of regulatory T cells, which are critical for establishing maternal-fetal tolerance. Expression of MHC II in definitive erythroid progenitors begins during the second trimester, coinciding with the appearance of mature T cells in the fetus, and is absent in primitive progenitors. Lastly, we demonstrate physical and molecular interaction potential of erythroid progenitors and T cells in the fetal liver. Our findings shed light on a unique orchestrator of fetal immunity and provide insight into the mechanisms by which erythroid cells contribute to host defense.

immunology↗