Publications by authors named "David A Hildeman"

Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker.

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Plexiform neurofibromas (PNFs) are benign nerve tumors driven by loss of the tumor suppressor in Schwann cells. PNFs are rich in immune cells, but whether immune cells are necessary for tumorigenesis is unknown. We show that inhibition of stimulator of interferon gene (STING) reduces plasma CXCL10, tumor T cell and dendritic cell (DC) recruitment, and tumor formation.

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Article Synopsis
  • The connectivity enhanced structure activity relationship (ceSAR) is a new in silico method for drug discovery that combines cheminformatics with transcriptional signature analysis from the LINCS library.* -
  • ceSAR ranks drug candidates based on their similarity to known compounds and the impact on specific gene knockdowns, and then refines these ranks using molecular docking techniques and machine learning.* -
  • Benchmark tests show that ceSAR significantly reduces false positives and speeds up the drug discovery process, with successful application in finding inhibitors for the BCL2A1 target linked to melanoma and inflammation.*
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Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker.

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Fibrosis is a common outcome of numerous pathologies, including chronic kidney disease (CKD), a progressive renal function deterioration. Current approaches to target activated fibroblasts, key effector contributors to fibrotic tissue remodeling, lack specificity. Here, we report Gucy1α1 as a specific kidney fibroblast marker.

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Acute cellular rejection (ACR) affects >80% of pediatric liver transplant recipients within 5 years, and late ACR is associated with graft failure. Traditional anti-rejection therapy for late ACR is ineffective and has remained unchanged for six decades. Although CD8+ T cells promote late ACR, little has been done to define their specificity and gene expression.

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Introduction: Significant evidence suggests a connection between transplant rejection and the presence of high levels of pre-existing memory T cells. Viral infection can elicit viral-specific memory T cells that cross-react with allo-MHC capable of driving allograft rejection in mice. Despite these advances, and despite their critical role in transplant rejection, a systematic study of allo-reactive memory T cells, their specificities, and the role of cross-reactivity with viral antigens has not been performed.

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  • Maternal decidual CD8+ T cells play a critical role in balancing immune responses to infections while ensuring tolerance to fetal and placental antigens.
  • Research reveals that these T cells display characteristics of both activation and dysfunction and contain distinct memory populations, with some shared with peripheral blood.
  • The study found that both fetus- and virus-specific decidual CD8+ T cells exhibit similar functionality, indicating that not all immune responses to fetal antigens are suppressed, which is important for understanding placental health and congenital infections.
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The 'immune risk profile' has been shown to predict mortality in the elderly, highlighting the need to better understand age-related immune dysfunction. While aging leads to many defects affecting all arms of the immune system, this review is focused on the accrual of immuno-suppressive CD4 + T cell populations, including FoxP3 + regulatory T cells, and subsets of IL-10-producing T follicular helper cells. New data suggest that such accumulations constitute feedback mechanisms to temper the ongoing progressive low-grade inflammation that develops with age, the so-called "inflammaging", and by doing so, how they have the potential to promote healthier aging.

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Bulk analysis of renal allograft biopsies (rBx) identified RNA transcripts associated with acute cellular rejection (ACR); however, these lacked cellular context critical to mechanistic understanding of how rejection occurs despite immunosuppression (IS). We performed combined single-cell RNA transcriptomic and TCR-α/β sequencing on rBx from patients with ACR under differing IS drugs: tacrolimus, iscalimab, and belatacept. We found distinct CD8+ T cell phenotypes (e.

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Apoptosis is a form of regulated cell death (RCD) that involves proteases of the caspase family. Pharmacological and genetic strategies that experimentally inhibit or delay apoptosis in mammalian systems have elucidated the key contribution of this process not only to (post-)embryonic development and adult tissue homeostasis, but also to the etiology of multiple human disorders. Consistent with this notion, while defects in the molecular machinery for apoptotic cell death impair organismal development and promote oncogenesis, the unwarranted activation of apoptosis promotes cell loss and tissue damage in the context of various neurological, cardiovascular, renal, hepatic, infectious, neoplastic and inflammatory conditions.

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Article Synopsis
  • - Recent research indicates that an abnormal population of T follicular helper cells (Tfh10) that produces IL-10 accumulates with age, contributing to reduced effectiveness of vaccines in older adults.
  • - Analysis revealed that aged Tfh and Tfh10 cells show increased CD153 expression, linked to higher IL-6 levels and the molecule c-Maf, which are associated with "inflammaging."
  • - Blocking CD153 in older mice led to decreased vaccine-driven antibody responses, highlighting that while Tfh cell function declines with age, increased CD153 may still enhance some of their activity in response to vaccines.
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Aging profoundly affects immune-system function, promoting susceptibility to pathogens, cancers and chronic inflammation. We previously identified a population of IL-10-producing, T follicular helper-like cells (" "), linked to suppressed vaccine responses in aged mice. Here, we integrate single-cell ( )RNA-seq, scATAC-seq and genome-scale modeling to characterize Tfh10 - and the full CD4 memory T cell ( ) compartment - in young and old mice.

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Following their proliferative expansion and differentiation into effector cells like Th1, Tfh, and T central memory precursors (Tcmp), most effector CD4+ T cells die, while some survive and become memory cells. Here, we explored how Bcl-2 family members controlled the survival of CD4+ T cells during distinct phases of mouse acute LCMV infection. During expansion, we found that Th1 cells dominated the response, downregulated expression of Bcl-2, and did not require Bcl-2 for survival.

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To date, plasma cell (PC)-targeted therapies have been limited by suboptimal PC depletion and antibody rebound. We hypothesized this is partly because of PC residence in protective bone marrow (BM) microenvironments. The purpose of this proof-of-concept study was to examine the effects of the CXCR4 antagonist, plerixafor, on PC BM residence; its safety profile (alone and in combination with a proteasome inhibitor, bortezomib); and the transcriptional effect on BMPCs in HLA-sensitized kidney transplant candidates.

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Bulk analysis of renal allograft biopsies (rBx) identified RNA transcripts associated with acute cellular rejection (ACR); however, these lacked cellular context critical to mechanistic understanding. We performed combined single cell RNA transcriptomic and TCRα/β sequencing on rBx from patients with ACR under differing immunosuppression (IS): tacrolimus, iscalimab, and belatacept. TCR analysis revealed a highly restricted CD8 T cell clonal expansion (CD8 ), independent of HLA mismatch or IS type.

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Age-associated microglial dysfunction contributes to the accumulation of amyloid-β (Aβ) plaques in Alzheimer's disease. Although several studies have shown age-related declines in the phagocytic capacity of myeloid cells, relatively few have examined phagocytosis of normally aged microglia. Furthermore, much of the existing data on aging microglial function have been generated in accelerated genetic models of Alzheimer's disease.

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Article Synopsis
  • Aging and obesity both involve chronic, low-grade inflammation and dysfunctional immune responses, with emerging research revealing their interconnected mechanisms.
  • Chronic inflammation in these conditions alters the immune system's baseline state, where aging leads to regulatory immune populations that worsen dysfunction, while obesity affects immune cell function due to expanding fat tissue.
  • The review aims to compare these altered immune states in aging and obesity and explore how they contribute to a common issue: reduced effectiveness of vaccines.
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The precursors of TCRαβCD8αα intraepithelial lymphocytes (IEL) arise in the thymus through a complex process of agonist selection. We and others have shown that the proapoptotic protein, Bim, is critical to limit the number of thymic IEL precursors (IELp), as loss of Bim at the CD4CD8 double-positive stage of development drastically increases IELp. The factors determining this cell death versus survival decision remain largely unknown.

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The world is currently in a pandemic of COVID-19 (Coronavirus disease-2019) caused by a novel positive-sense, single-stranded RNA β-coronavirus referred to as SARS-CoV-2. Here we investigated rates of SARS-CoV-2 infection in the greater Cincinnati, Ohio, USA metropolitan area from August 13 to December 8, 2020, just prior to initiation of the national vaccination program. Examination of 9,550 adult blood donor volunteers for serum IgG antibody positivity against the SARS-CoV-2 Spike protein showed an overall prevalence of 8.

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  • Researchers explored how gender and aging affect obesity and metabolism in female mice, addressing challenges in modeling severe obesity.
  • The study involved feeding mice different diets (chow or high fat) at varying temperatures and measured weight gain, glucose levels, liver health, and inflammation.
  • Results showed that aging impacts obesity severity differently based on diet and gender, with older mice exhibiting a unique immune response that reduces metabolic dysfunction linked to obesity.
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Kidney transplant recipients administered belatacept-based maintenance immunosuppression present with a more favorable metabolic profile, reduced incidence of de novo donor-specific antibodies (DSAs), and improved renal function and long-term patient/graft survival relative to individuals receiving calcineurin inhibitor (CNI)-based immunosuppression. However, the rates and severity of acute rejection (AR) are greater with the approved belatacept-based regimen than with CNI-based immunosuppression. Although these early co-stimulation blockade-resistant rejections are typically steroid sensitive, the higher rate of cellular AR has led many transplant centers to adopt immunosuppressive regimens that differ from the approved label.

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Aging results in profound immune dysfunction, resulting in the decline of vaccine responsiveness previously attributed to irreversible defects in the immune system. In addition to increased interleukin-6 (IL-6), we found aged mice exhibit increased systemic IL-10 that requires forkhead box P3-negative (FoxP3), but not FoxP3, CD4T cells. Most IL-10-producing cells manifested a T follicular helper (Tfh) phenotype and required the Tfh cytokines IL-6 and IL-21 for their accrual, so we refer to them as Tfh10 cells.

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Increasing evidence points to a key role for NK cells in controlling adaptive immune responses. In studies examining the role of CD1d on CD4+ T cell responses, we found that a line of CD1d-deficient mice on the C57BL/6J background had a homozygous 129 locus on chromosome 6 containing the entire NK cell gene cluster. Mice possessing this locus (C57BL/6.

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Purpose Of Review: The goal of this review is to discuss new approaches to avoid CNI/CCS toxicities with a focus on new biologics and new methods to understand transplant rejection at the single-cell level.

Recent Findings: Recently developed biologics hold significant promise as the next wave of therapeutics designed to promote CNI/CCS-free long-term allograft acceptance. Indeed, belatacept, soluble CTLA4-Ig, is largely devoid of CNI-like toxicities, although it is accompanied by an increased frequency of acute rejection.

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