Biology subjects

Feldman, H. A.

Publications and source records attributed to Feldman, H. A..

6 recordsLinked to original sources

bioRxiv2026

A Large-Scale Deep Normative Modeling of Primary Sulcal Patterns Reveals Deviations in a Spectrum of Disorders

Primary sulcal patterns, the spatial arrangement of the earliest cortical folds, emerge prenatally and remain essentially stable after birth. Alterations are associated with cognitive outcomes and hold promise as clinical biomarkers. However, detecting abnormalities is challenging due to the high topological variability and complexity of normal individual sulcal patterns. Here, we introduce an unsupervised generative model that quantifies individual sulcal pattern deviations against a normative baseline learned from 10,349 typically developing subjects spanning early childhood through adulthood. We combine a generative reconstruction error with a discriminator trained on diffusion-generated pseudo-atypical graphs to leverage their complementary strengths in sensitivity and robustness. The discriminator captures subtle anomalies and is robust to demographic and data quality variations, whereas the generative model enables severity stratification and demonstrates cross-site generalizability. Across two clinical cohorts spanning subtle to overt sulcal abnormalities (congenital heart disease and polymicrogyria), our model captured global and localized condition-related deviations and linked them to neurodevelopmental outcomes. By enabling population-scale, individualized quantification of sulcal deviations, this framework provides a foundation for future clinical risk stratification.

neuroscience↗

bioRxiv2025

Refined cell transfer model reveals roles for Ascl2 and Cxcr3 in splenic localization of mouse NK cells during virus infection

Cell transfer experiments complement the rigorous investigation of antiviral and antitumor functions of natural killer (NK) cells. Success in these endeavors is enhanced by expansion of small numbers of input NK cells driven by viral antigens or homeostatic proliferation in immunodeficient hosts. In contrast, analysis of other NK-cell functions, including immunoregulation, are non-proliferative and require an intact immune system in recipient mice. We reveal poor persistence of conventional congenic (CD45.1) BoyJ NK cells following adoptive transfer in comparison to CRISPR-generated CD45.1+ (JAXBoy) NK cells. Reciprocal transfers between C57BL/6 and JAXBoy mice substantially improve seeding and maintenance of donor NK cells. Using this system, we confirm that CXCR3 re-positions NK cells in the white pulp of the spleen after infection, which is vital for immunoregulation. Moreover, we discovered that the transcription factor ASCL2 is required for recruitment of NK cells into the spleen and white pulp. These results provide improved tools and novel insights into NK cell biology. Key pointsO_LIJAXBoy are superior to conventional BoyJ mice for NK cell persistence after transfer. C_LIO_LICXCR3 repositions donor NK cells in T/B-zones of the spleen after infection. C_LIO_LIThe transcription factor ASCL2 is required for NK-cell recruitment to spleen white pulp. C_LI

immunology↗

bioRxiv2024

Prothrombin prevents fatal T cell-dependent anemia during chronic virus infection of mice

Thrombin promotes the proliferation and function of CD8+ T cells. To test if thrombin prevents exhaustion and sustains antiviral T cell activity during chronic viral infection, we depleted the thrombin-precursor prothrombin to 10% of normal levels in mice prior to infection with the clone 13 strain of lymphocytic choriomeningitis virus. Unexpectedly, prothrombin insufficiency resulted in 100% mortality after infection that was prevented by depletion of CD8+ T cells, suggesting that reduced availability of prothrombin enhances virus-induced immunopathology. Yet, the number, function, and apparent exhaustion of virus-specific T cells were measurably unaffected by prothrombin depletion. Histological analysis of the lung, heart, liver, kidney, spleen, intestine, and brain did not reveal any evidence of hemorrhage or increased tissue damage in low prothrombin mice that could explain mortality. Viral loads were also similar in infected mice regardless of prothrombin levels. Instead, infection of prothrombin-depleted mice resulted in a severe, T cell-dependent anemia associated with increased hemolysis. Thus, thrombin plays an unexpected protective role in preventing hemolytic anemia during virus infection, with potential implications for patients who are using direct thrombin inhibitors as an anticoagulant therapy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=194 SRC="FIGDIR/small/623028v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@d01b49org.highwire.dtl.DTLVardef@af76ddorg.highwire.dtl.DTLVardef@1a4b6e8org.highwire.dtl.DTLVardef@e44264_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2021

Transcription factor induction of vascular blood stem cell niches in vivo

The hematopoietic niche is a supportive microenvironment comprised of distinct cell types, including specialized vascular endothelial cells that directly interact with hematopoietic stem and progenitor cells (HSPCs). The molecular factors that specify niche endothelial cells and orchestrate HSPC homeostasis remain largely unknown. Using multi-dimensional gene expression and chromatin accessibility analyses, we define a conserved gene expression signature and cis-regulatory landscape unique to sinusoidal endothelial cells in the HSPC niche. Using enhancer mutagenesis and transcription factor overexpression, we elucidate a transcriptional code involving members of the Ets, Sox and Nuclear Hormone Receptor families that is sufficient to induce ectopic niche endothelial cells that associate with mesenchymal stromal cells and support the recruitment, maintenance and division of HSPCs in vivo. These studies set forth an approach for generating synthetic HSPC niches, in vitro or in vivo, and for effective therapies to modulate the endogenous niche.

developmental biology↗

bioRxiv2021

Natural killer cell immunosuppressive function requires CXCR3-dependent redistribution within lymphoid tissues

Natural killer (NK) cell suppression of T cells is a key determinant of viral pathogenesis and vaccine efficacy. This process involves perforin-dependent elimination of activated CD4 T cells during the first three days of infection. Although this mechanism requires cell-cell contact, NK cells and T cells typically reside in different compartments of lymphoid tissues at steady state. Here, we show that NK-cell suppression of T cells is associated with a transient accumulation of NK cells within T cell-rich sites of the spleen during lymphocytic choriomeningitis virus infection. The chemokine receptor CXCR3 is required for relocation to T-cell zones and suppression of antiviral T cells. Accordingly, this NK-cell migration is mediated by type I interferon (IFN)-dependent promotion of CXCR3 ligand expression. In contrast, adenoviral vectors that weakly induce type I IFN and do not stimulate NK-cell inhibition of T cells also do not promote measurable redistribution of NK cells to T-cell zones. Provision of supplemental IFN could rescue NK-cell migration during adenoviral vector immunization. Thus, type I IFN and CXCR3 are critical for properly positioning NK cells to constrain antiviral T-cell responses. Development of strategies to curtail migration of NK cells between lymphoid compartments may enhance vaccine-elicited immune responses.

immunology↗

bioRxiv2017

Polygenic hazard score: an enrichment marker for Alzheimer’s associated amyloid and tau deposition

BackgroundThere is an urgent need for the early identification of nondemented individuals at the highest risk of progressing to Alzheimers disease (AD) dementia for early therapeutic interventions. Our goal was to evaluate whether a recently validated polygenic hazard score (PHS) can be integrated with known in vivo CSF or PET biomarkers of amyloid or tau pathology to prospectively predict cognitive decline and clinical progression to AD dementia in nondemented older individuals.\n\nMethodsWe evaluated 347 cognitive normal (CN) and 599 mild cognitively impaired (MCI) individuals. We first investigated whether PHS can predict CSF or PET amyloid and tau deposition. We evaluated differences in positive and negative predictive values of biomarker status, as a function of PHS risk. Next, we used linear mixed-effects (LME) to examine if PHS and biomarker status in conjunction, best predict longitudinal cognitive and clinical progression. Lastly, we used survival analysis to investigate whether a combination of PHS and biomarker positivity predicts progression to AD dementia better than using PHS or biomarker positivity alone.\n\nFindingsIn CN and MCI individuals, we found that amyloid and total tau positivity systematically varies as a function of PHS. For individuals in greater than the 50th percentile PHS, the positive predictive value for amyloid approached 100%. Similarly, for individuals in less than the 25th percentile PHS, the negative predictive value for total tau approached 85%. Beyond APOE, high PHS individuals with amyloid and tau pathology showed the fastest rate of longitudinal cognitive decline and time to AD dementia progression. Among the CN subgroup, we similarly found that PHS was strongly associated with amyloid positivity and the combination of PHS and biomarker status significantly predicted longitudinal clinical progression.\n\nInterpretationAmong asymptomatic and mildly symptomatic older individuals, PHS considerably improves the predictive value of CSF or PET amyloid and tau biomarkers. Beyond APOE, PHS may be useful for risk stratification and cohort enrichment for MCI and preclinical AD therapeutic trials.

genetics↗