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Biology subjects

Kain, B.

Publications and source records attributed to Kain, B..

3 recordsLinked to original sources

Genotype-immunophenotype relationships in NPM1-mutant AML clonal evolution uncovered by single cell multiomic analysis

Acute myeloid leukemia (AML) is a multi-clonal disease, existing as a milieu of clones with unique but related genotypes as initiating clones acquire subsequent mutations. However, bulk sequencing cannot fully capture AML clonal architecture or the clonal evolution that occurs as patients undergo therapy. To interrogate clonal evolution, we performed simultaneous single cell molecular profiling and immunophenotyping on 43 samples from 32 NPM1-mutant AML patients at different stages of disease. Here we show that diagnosis and relapsed AML samples display similar clonal architecture patterns, but signaling mutations can drive increased clonal diversity specifically at relapse. We uncovered unique genotype-immunophenotype relationships regardless of disease state, suggesting leukemic lineage trajectories can be hard-wired by the mutations present. Analysis of longitudinal samples from patients on therapy identified dynamic clonal, transcriptomic, and immunophenotypic changes. Our studies provide resolved understanding of leukemic clonal evolution and the relationships between genotype and cell state in leukemia biology.

cancer biology↗

Hematopoietic stem cells are a long-term reservoir for trained immunity in a mouse model of chronic autoimmune disease

Trained immunity (TI) has been speculated to serve as a contributor to autoimmune disease (AD) pathogenesis via generation of hyper-inflammatory myeloid cells. Using a mouse model of systemic lupus erythematosus (SLE), we show that hematopoietic stem cells (HSC) constitute a transplantable, long-term reservoir for macrophages that exhibit features of TI, including increased Mycobacterium avium killing, inflammatory cytokine production, and augmented capacity to co-stimulate naive T cells. Strikingly, hematopoietic progenitor cells derived from these HSC exhibit unique molecular features characterized by reduced chromatin accessibility and transcription of metabolic genes, accompanied by reduced glycolysis and central carbon metabolism. Altogether, our data identify HSC as a functional unit of TI in chronic AD, establish increased T-cell costimulatory activity as a potentially pathogenic feature of TI in this setting, and show that macrophages inherit reduced metabolic activity from AD-exposed HSC, suggesting metabolic activation and TI can be decoupled. Our findings thus implicate HSC as a long-term reservoir for TI that could contribute to AD.

immunology↗

Hematopoietic stem and progenitor cells improve survival from sepsis by boosting immunomodulatory cells

New therapeutic strategies to reduce sepsis-related mortality are urgently needed, as sepsis accounts for 1 in 5 deaths worldwide. Since hematopoietic stem and progenitor cells (HSPCs) are responsible for producing blood and immune cells, including in response to immunological stress, we explored their potential for treating sepsis. In a mouse model of Group A Streptococcus (GAS)-induced sepsis, severe immunological stress was associated with significant depletion of bone marrow HSPCs and mortality within approximately 5-7 days. We hypothesized that the inflammatory environment of GAS infection drives rapid HSPC differentiation and depletion that can be rescued by infusion of donor HSPCs. Indeed, infusion of 10,000 naive HSPCs into GAS-infected mice resulted in rapid myelopoiesis and a 50-60% increase in overall survival. Surprisingly, mice receiving donor HSPCs displayed a similar pathogen load compared to untreated mice. Flow cytometric analysis revealed a significantly increased number of myeloid-derived suppressor cells in HSPC-infused mice, which correlated with reduced inflammatory cytokine levels and restored HSPC levels. These findings suggest that HSPCs play an essential immunomodulatory role that may translate into new therapeutic strategies for sepsis.

immunology↗