Uterine natural killer (uNK) cells are a tissue-resident lymphocyte population critical for pregnancy success. Although mouse models have demonstrated that uNK cell deficiency results in abnormal placentation and poor pregnancy outcomes, the generalizability of this knowledge to humans remains unclear. Here, we compared tissue samples collected from a cohort of human recipients of uterus transplant (UTx) at high risk for pregnancy complications with healthy controls using flow cytometry, immunofluorescence microscopy, and single-cell RNA sequencing (scRNA-seq). Subsets of tissue-resident uNK cells were reduced in endometrial and decidual samples from recipients of UTx compared with healthy control samples. Loss of tissue-resident uNK cells was associated with histopathologic evidence of maternal vascular malperfusion in placentas from recipients of UTx and related pregnancy complications including preeclampsia. scRNA-seq of UTx endometrial biopsies and deciduae further revealed that the NK cell reduction in recipients of UTx correlated with impaired transcriptional programming of NK tissue residency arising from the inhibition of signaling by nuclear factor of activated T cells (NFAT). In vitro culture of uNK cells from healthy controls with the NFAT inhibitor tacrolimus resulted in down-regulation of adhesion molecules. Together, these experiments suggested that NFAT-dependent genes modulate multiple molecular tissue residency programs in uNK cells, including early residency programs involving activator protein-1 (AP-1) family transcription factors and later residency programs characterized by up-regulation of surface integrins by transforming growth factor-β (TGF-β). Collectively, these data identify a previously undescribed role for NFAT in uNK tissue residency and provide mechanistic insights into the biologic basis of pregnancy complications due to alteration of tissue-resident NK cell subsets in humans.

Uterine tissue-resident natural killer (trNK) cells are essential for pregnancy, supporting spiral artery remodeling and fetal growth. Although mouse studies suggest trNK cells arise from both resident and recruited populations, the molecular programming governing human trNK residency remains poorly understood. This study aimed to elucidate the molecular programming of trNK cells as they enter the uterus. Using multiomic analyses, we compared NK cells from human endometrium and peripheral blood, identifying a conserved early residency program (ERP) originally characterized in CD8 T resident memory cells. The ERP comprises 80 genes, including transcription factors FOS, JUNB, NR4A2, and EGR1, previously shown to be critical for tissue residency. ERP enrichment was observed in ITGA1lo endometrial NK cells, termed founder NK (fNK) cells, due to their transcriptional similarity to peripheral blood NCAM1hi cells despite their endometrial origin. From fNK cells to mature ITGA1+ trNK populations, ERP expression progressively increased. Transcriptomic and proteomic analyses revealed differential ERP utilization among trNK subsets. A foundational ERP, including NR4A2, EGR1, and FOS, associated with trNK1 cells, while a divergent ERP, comprising JUNB and JUND, was enriched in trNK3 cells. These findings demonstrate that early transcriptional regulation drives residency establishment and shapes mature functional specialization, advancing our understanding of residency molecular drivers. Supported by NIH/NICHD 1F31HD114429 Mucosal and Regional Immunology (MUC)

Uterine tissue resident natural killer cells (trNKs) are hypothesized to ensure healthy pregnancy by secreting factors that regulate extravillous trophoblast invasion and spiral arterial remodeling in humans. Studies have associated absent or altered trNKs with pregnancy complications. In utero investigation of trNK development and function in pregnancy is limited in human studies. We can utilize mouse models to perform mechanistic and functional studies of trNKs. While mouse pregnancy models have been routinely used to study trNKs, whether mouse trNKs align with human trNKs has yet to be fully defined. We hypothesize that mouse trNK phenotypes overlap with humans. To test this hypothesis, we studied uterine trNKs in pregnant C57BL/6 mice. Mice were sacrificed at gd6.5 when uterine trNKs are most abundant, and uteri were harvested for flow cytometry. We found CD39+ and CD39- trNK subsets that may align phenotypically with human trNKs. CD39+ and CD39- trNKs were 14.0% and 4.5% of total live, CD45+ cells respectively. While CD103+ mouse trNKs were present like in humans, they represented only 0.1% of live, CD45+ cells. These data suggest that mouse uterine trNK subsets have phenotypes that map to human uterine trNKs. Further work is needed to analyze mouse uterine trNK subsets across pregnancy and to elucidate their transcriptomes for comparison to human uterine trNK subsets. Research is supported by NIH/NIAID R01AI177369 and NIGMS T32GM135028-04. Mucosal and Regional Immunology (MUC)

Human uterine natural killer cells (uNKs) are a tissue-resident, innate lymphocyte population that have critical roles in supporting pregnancy health. uNKs derive from circulatory cells in the peripheral blood which immigrate into the endometrium and become resident as they reconstitute the uterine lining after menses. How tissue-resident uterine NK cells arise from blood-based precursor cells is unknown. Here, we identify early tissue immigrants, developmental intermediates, and mature effector states in human endometrium. We also uncover a transcriptional program of TGF-β responsive genes that is upregulated in recent tissue immigrants prior to expression of effector molecules. Differences in TGF-β responsiveness of uNK precursors promote differential expression of divergent effector uNK subsets, resulting in either repression or preservation of cytotoxic effector potential. Collectively, these data suggest a molecular mechanism of tissue-resident uNK maturation that links tissue residency with the acquisition of divergent effector functions in human endometrium.

Pig-to-human xenotransplantation is rapidly approaching the clinical arena; however, it is unclear which immunomodulatory regimens will effectively control human immune responses to pig xenografts. We transplanted a gene-edited pig kidney into a brain-dead human recipient on pharmacologic immunosuppression and studied the human immune response to the xenograft using spatial transcriptomics and single-cell RNA sequencing. Human immune cells were uncommon in the porcine kidney cortex early after xenotransplantation and consisted of primarily myeloid cells. Both the porcine resident macrophages and human infiltrating macrophages expressed genes consistent with an alternatively activated, anti-inflammatory phenotype. No significant infiltration of human B or T cells into the porcine kidney xenograft was detected. Altogether, these findings provide proof of concept that conventional pharmacologic immunosuppression is sufficient to restrict infiltration of human immune cells into the xenograft early after compatible pig-to-human kidney xenotransplantation.

Summary Uterine natural killer cells are critical for pregnancy success, but the origin and development of these cells in humans remain unclear. Here we use various single cell approaches to identify the transcriptional programs governing uterine NK cell development in humans. These analyses suggest a developmental continuum which begins with seeding of the endometrium with blood immature CD56 bright precursors, evolves through CD56 bright endometrial founder NK cells, and ends with tissue resident decidual NK cells during pregnancy which possess non-cytotoxic functions. Our work identifies a role for sequential programs of tissue residency in the differentiation of these cells, as differentiating endometrial tissue resident NK (trNK) cells acquire early and late transcriptional programs of residency which coincide with acquisition of unique non-cytotoxic effector programs. Notably, we identified early residency programs in human endometrial trNKs by expression of NR4A2 , AP-1 transcription factors, and other immediate early response genes that were shared with CD8 tissue resident memory T cells in mice, suggesting conservation of transcriptional programs of early tissue residency programs across species and cell types. Late residency programs were guided by TGFβ, which promoted expression of various integrins and trNK subset diversification within the non-pregnant endometrium. Altogether, these data identify the molecular foundations for endometrial trNK heterogeneity and suggest that the uterine NK diversity observed during pregnancy is established before embryo implantation and intimately tied to residency programming.

Uterine natural killer cells (uNKs) are a tissue resident lymphocyte population that are critical for pregnancy success. Although mouse models have demonstrated that NK deficiency results in abnormal placentation and poor pregnancy outcomes, the generalizability of this knowledge to humans remains unclear. Here we identify uterus transplant (UTx) recipients as a human population with reduced uNK cells and altered pregnancy phenotypes. We show that the NK reduction in UTx correlates with impaired transcriptional programming of NK tissue residency arising from the inhibition of NFAT-mediated signaling. Our observations suggest that NFAT-dependent genes modulate multiple molecular tissue residency programs in uNKs. These include early residency programs involving AP-1-family transcription factors and TGF-β-mediated upregulation of surface integrins. Collectively, our data identify a previously undescribed role for NFAT in uterine NK tissue residency and provide novel mechanistic insights into the biologic basis of pregnancy complications due to alteration of tissue resident NK subsets in humans. One Sentence Summary:Role of NFAT in uterine NK cell tissue residency.

Demand for kidney grafts outpaces supply, limiting kidney transplantation as a treatment for kidney failure. Xenotransplantation has the potential to make kidney transplantation available to many more patients with kidney failure, but the ability of xenografts to support human physiologic homeostasis has not been established. A brain-dead adult decedent underwent bilateral native nephrectomies followed by 10 gene-edited (four gene knockouts, six human transgenes) pig-to-human xenotransplantation. Physiologic parameters and laboratory values were measured for seven days in a critical care setting. Data collection aimed to assess homeostasis by measuring components of the renin-angiotensin-aldosterone system, parathyroid hormone signaling, glomerular filtration rate, and markers of salt and water balance. Mean arterial blood pressure was maintained above 60 mmHg throughout. Pig kidneys secreted renin (post-operative day three to seven mean and standard deviation: 47.3 ± 9 pg/mL). Aldosterone and angiotensin II levels were present (post-operative day three to seven, 57.0 ± 8 pg/mL and 5.4 ± 4.3 pg/mL, respectively) despite plasma renin activity under 0.6 ng/mL/hr. Parathyroid hormone levels followed ionized calcium. Urine output down trended from 37 L to 6 L per day with 4.5 L of electrolyte free water loss on post-operative day six. Aquaporin 2 channels were detected in the apical surface of principal cells, supporting pig kidney response to human vasopressin. Serum creatinine down trended to 0.9 mg/dL by day seven. Glomerular filtration rate ranged 90-240 mL/min by creatinine clearance and single-dose inulin clearance. Thus, in a human decedent model, xenotransplantation of 10 gene-edited pig kidneys provided physiologic balance for seven days. Hence, our in-human study paves the way for future clinical study of pig-to-human kidney xenotransplantation in living persons.

Abstract Tissue-resident uterine NK cells are essential for successful pregnancy, yet the molecular mechanisms guiding their tissue residency programming early after infiltration of blood-based precursors remain unknown. We examined the transition of CD56+ peripheral blood NK cells to a uterine resident state by performing scRNA-seq on enriched CD56+ cells from a matched peripheral blood (pb) and endometrial (e) biopsy taken during the secretory phase. Our integrated analysis comparing eNK vs pbNK cells identified a tissue adaptation signature. Key components of this signature included NR4A2 (94% vs 0%, p=9.46e-22), FOS (90% vs 9%, p=9.05e-14), and JUNB (77% vs 16%, p=3.15e-07) respectively. This signature also mirrored genes previously identified in activated murine intestinal CD8+ TRM cells early after LCMV infection. This signature was found in all endometrial CD56+ cells, including CD56bright CD16- eNKs, NKTs, and conventional eNKs (CD56dimCD16+). Pathway analysis implicated IL-17 and IL-18 cytokines, along with NFAT and VEGF signals in tissue residency programming. In conclusion, these data expand our understanding of early transcriptional programs in lymphocyte tissue adaptation, revealing the involvement of cytokines beyond TGF-β. Our data further indicate that signals associated with early tissue adaptation are conserved across species and cell types independent of an antigen receptor.

Millions of traumatic brain injuries (TBIs) occur annually. TBIs commonly result from falls, traffic accidents, and sports-related injuries, all of which involve rotational acceleration/deceleration of the brain. During these injuries, the brain endures a multitude of primary insults including compression of brain tissue, damaged vasculature, and diffuse axonal injury. All of these deleterious effects can contribute to secondary brain ischemia, cellular death, and neuroinflammation that progress for weeks, months, and lifetime after injury. While the linear effects of head trauma have been extensively modeled, less is known about how rotational injuries mediate neuronal damage following injury. Here, we developed a new model of repetitive rotational head trauma in rodents and demonstrated acute and prolonged pathological, behavioral, and electrophysiological effects of rotational TBI (rTBI). We identify aberrant Cyclin-dependent kinase 5 (Cdk5) activity as a principal mediator of rTBI. We utilized Cdk5-enriched phosphoproteomics to uncover potential downstream mediators of rTBI and show pharmacological inhibition of Cdk5 reduces the cognitive and pathological consequences of injury. These studies contribute meaningfully to our understanding of the mechanisms of rTBI and how they may be effectively treated.

ABSTRACT Millions of traumatic brain injuries (TBIs) occur annually. TBIs commonly result from falls, traffic accidents, and sports-related injuries, all of which involve rotational acceleration/deceleration of the brain. During these injuries, the brain endures a multitude of primary insults including compression of brain tissue, damaged vasculature, and diffuse axonal injury. All of these deleterious effects can contribute to secondary brain ischemia, cellular death, and neuroinflammation that progress for weeks to months after injury and impede neurological recovery. While the linear effects of head trauma have been extensively modeled, less is known about how rotational injuries mediate neuronal damage following injury. Here, we developed a new model of rotational head trauma in rodents and extensively characterized the pathological, behavioral, and electrophysiological effects of rotational TBI (rTBI). We identify aberrant cyclin dependent kinase 5 (Cdk5) activity as a principal mediator of rTBI and show pharmacological inhibition of Cdk5 reduces the cognitive and pathological consequences of injury. Finally, we utilize Cdk5-enriched phosphoproteomics to uncover potential downstream mediators of rTBI. These studies contribute meaningfully to our understanding of the mechanisms of rTBI and how they may be effectively treated.