Biology subjects

Manley, N. R.

Publications and source records attributed to Manley, N. R..

7 recordsLinked to original sources

bioRxiv2025

Adult mice with neonatal-like T cell subsets exhibit increased susceptibility to Bordetella pertussis and influenza infection

Infants are significantly more susceptible to respiratory infection, often resulting in increased morbidity and hospitalization, and occasionally death. This susceptibility is partially explained by the developing nature of the thymus in human infants at, and for several months after, birth. However, the contribution of T cells produced in this thymic microenvironment to infant immune responses has received minimal investigation. Here, we utilized a previously described mouse model (Foxn1{Delta}/{Delta}) which exhibits a persistently immature thymus. Through further characterization, we have determined that adult Foxn1{Delta}/{Delta} mice retain some unique T cells observed in neonatal mice including CD8{beta}+ {gamma}{delta} T cells and CD8 T cells displaying a memory-like phenotype. For this reason, we assessed the potential of these neonatal-like T responses to two pathogens which disproportionately affect neonates, Bordetella pertussis (Bp) and influenza. Utilizing these infections, we demonstrate that T cells generated in an incompletely developed thymus fail to control or mount an effective response against Bp. We also observe that Foxn1{Delta}/{Delta} mice control acute influenza infection, a response which does not require IL-17. However, the Foxn1{Delta}/{Delta} mice fail to generate an influenza nucleoprotein (NP) specific CD8+ T cell response which is likely associated with their inability to fully clear the infection. Together, these data suggest that Foxn1{Delta}/{Delta} mice can be utilized to study the generation, function, and persistence of some unique T cells made in a neonatal-like thymus.

immunology↗

bioRxiv2025

Coordinated changes in thymic stromal and hematopoietic cells that define the perinatal to juvenile transition

T cells in the perinatal thymus have distinct phenotypes and functions that may be instructed by age-specific features of the microenvironment. We evaluated molecular and cellular profiles of thymic stromal cells, including thymic epithelial cells (TECs), mesenchyme, endothelium, and hematopoietic antigen presenting cells (hAPCs), from birth through one-month of age in mice. Single-cell transcriptional profiling, flow cytometry, and immunohistochemistry revealed coordinated stromal changes accompanied by altered thymocyte differentiation at defined transitional ages during the shift from perinatal growth to juvenile homeostasis, which was mirrored in humans. These analyses link diminished IGF2 expression by mesenchymal cells with activation of the RB pathway in TECs at the transition. Moreover, a coordinated increase in type I interferon signaling in stroma across the transition is associated with altered antigen processing and presentation signatures in TECs and hAPCs. Collectively, these datasets provide a resource to interrogate thymic stroma across the perinatal to juvenile transition.

immunology↗

bioRxiv2024

Premature thymic involution in young Foxn1lacz mutant mice causes peripheral T cell phenotypes similar to aging-induced immunosenescence

The thymus is a primary lymphoid organ generating self-restricted and self-tolerant naive T-cells. Early in life the thymus starts to involute, resulting in decreased naive T-cell output which may be more self-reactive, leading to an increased prevalence of autoimmunity. A decrease in the transcription factor FOXN1 is an early event in thymic involution. Using the Foxn1lacz model, we studied how premature thymic involution affects the thymic microenvironment, thymocytes, and peripheral T cell immunity. We found that early thymic involution led to aged-like thymic epithelial cells that resulted in aged-like thymocyte phenotypes, with a significant decrease in CD4+ single-positive T-cells. We also observed severe lymphopenia in Foxn1lacz mice caused by the premature decrease in T-cell production, resulting in a peripheral T-cell phenotype similar to de novo aged peripheral T-cells. Moreover, following T cell receptor stimulation, Foxn1lacz peripheral T cells had reduced IL-2 secretion and strong initial IFN-g responses, resembling aged wild-type peripheral T-cell responses. Lastly, influenza response in Foxn1lacz had a reduction in some aspects of T cell responses to influenza infection, similar to thymectomized mice. Our study shows an independent and direct impact of premature thymic involution on both thymopoiesis and peripheral immune niches likely contributing to immunosenescence and inflammaging as observed in the elderly population.

immunology↗

bioRxiv2023

Maintaining intact parathyroid glands throughout life requires Dicer and microRNA-mediated mTORC1 signaling

Secondary hyperparathyroidism (SHP) frequently accompanies chronic kidney disease (CKD), contributing to morbidity and mortality in patients. Our previous findings demonstrated that PT-Dicer-/- mice, with parathyroid specific deletion of Dicer and consequently microRNA, maintained normal serum PTH levels but failed to increase serum PTH in response to the major inducers of PTH secretion, hypocalcemia and CKD. Additionally, we elucidated a critical role of mTORC1 in CKD-induced SHP. We now explored the roles of Dicer and mTORC1 in parathyroid development and function. Despite sustaining normal serum PTH levels, PT-Dicer-/- mice displayed apoptotic loss of intact parathyroid glands postnatally, which were replaced by scattered cell clusters, and reduced mTORC1 activity. PT-mTORC1-/- mice exhibited the absence of intact parathyroid glands, while retaining normal serum PTH levels, mirroring the characteristics of PT-Dicer-/- mice. Conversely, PT-Tsc1-/-mice with hyperactivated mTORC1 exhibited enlarged glands and elevated serum PTH and calcium levels. Significantly, PT-Dicer-/-;Tsc1-/- double knockout mice demonstrated a reversal of the aparathyroidism of PT-Dicer-/- mice, preserving intact parathyroid glands and reinstating CKD-induced SHP. Lastly, data collected from a network of 106 healthcare organizations demonstrated that drug-induced mTOR inhibition is associated with reduced elevation of serum PTH levels in kidney transplant recipients. The latter findings offer physiological validation for our observations in genetically modified mouse models, highlighting the central role of mTORC1 signaling in CKD-SHP. Altogether, our results indicate that mTOR operates downstream of Dicer and miRNA. Consequently, Dicer, miRNA and mTORC1 collectively play a crucial role in maintaining the postnatal integrity and function of the parathyroid glands.

developmental biology↗

bioRxiv2022

Mechanisms underlying the reprogramming of mouse embryonic fibroblasts to thymic epithelial cells

Thymic epithelial cells (TECs) are a critical functional component of the thymuss ability to generate T cells for the adaptive immune system in vertebrates. However, no in vitro system for studying TEC function exists. Overexpression of the transcription factor FOXN1 initiates reprogramming of fibroblasts into TEC-like cells (iTECs) that support T cell differentiation in culture or after transplant. In this study, we characterized iTEC reprogramming at the cellular and molecular level to determine how reprogramming proceeds and identify mechanisms that can be targeted for improving this process. These data show that iTEC reprogramming consists of discrete gene expression changes that differ in early and late reprogramming, and that iTECs upregulate markers of both cortical and medullary TEC (cTEC and mTEC) lineages, although mTEC differentiation is blocked at a progenitor stage. We demonstrate that promoting proliferation enhances iTEC generation, and that Notch inhibition allows induction of mTEC differentiation. Finally, we show that a major difference between iTEC and fetal TEC is the expression of MHCII. This study supports future efforts to improve iTEC reprogramming for both research and translational uses.

developmental biology↗

bioRxiv2021

Dynamic structural cell responses in the thymus to acute injury, regeneration, and age

The thymus is essential for establishing adaptive immunity yet undergoes age-related atrophy leading to compromised immune responsiveness. The thymus is also extremely sensitive to acute insult and although capable of regeneration, this capacity declines with age. Focusing on non-hematopoietic stromal cells, and using single-cell and spatial transcriptomics, lineage-tracing, and advanced imaging, we discovered two atypical thymic epithelial cell (TEC) states that emerged with age. Age-associated (aa)TECs formed atypical high-density epithelial clusters that were devoid of thymocytes, an accretion of non-functional thymic tissue that worsened with age and exhibited features of partial epithelial-to-mesenchymal transition (EMT). In silico interaction analysis revealed that aaTEC emergence drew tonic signals from other TEC populations at baseline, acting as a sink for TEC growth factors. Following damage, aaTEC expanded substantially, further perturbing trophic pathways, and correlating with defective regeneration of the involuted thymus. These findings define a unique feature of thymic involution linked to immune aging.

immunology↗

bioRxiv2021

Ovarian cysts and granulosa cell tumors develop after sublethal total body irradiation in mice

BackgroundLocalized and total body irradiation are used to treat certain cancers and also used prior to transplantation of stem cells or organs. However, the use of radiation also induces collateral damage to the cells of healthy tissue. Although the acute damage of radiation to oocytes is well known, the long-term effects induced by radiation to stromal cells and their relationship with age are still unclear. MethodsA total of 206 two-month-old female mice were whole-body exposed to gamma rays at doses of 0, 0.5, 1, 2, or 4 Gy, respectively. The mice were sacrificed at 3.5, 9, 12, or 18 months of age and pathological changes including cysts and tumors were assessed in the ovary and other organs. ResultsThe overall incidence of visible pathological changes of mice receiving irradiation was 33.7% in the ovary, but much lower in the liver, spleen, lung, thymus, and skin. Among these, the ovarian cyst formation rate was 24.7%, and tumor lesions were 10.2%, respectively, compared to 5% cyst formation and no tumor lesions among control, unirradiated mice. Statistical analysis showed that cyst formation was age, but not dose-dependent, whereas the formation of tumor lesions was dependent on both age and radiation dose. Pathology analysis indicated that most ovarian cysts originated from follicles and both tumor lesions analyzed originated from granulosa cells. ConclusionOvaries are highly susceptible to the effects of radiation. Long-term damage is increased after total body irradiation in mice, manifested by higher incidences of cyst formation and tumor lesions. The ovarian stromal-derived granulosa cells might play an essential role in these changes.

cancer biology↗