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Biology subjects

Enriquez, A. B.

Publications and source records attributed to Enriquez, A. B..

3 recordsLinked to original sources

Title: Multimodal profiling reveals Mycobacterium tuberculosis restricts lung mitochondrial immunometabolism to promote pathogenesis

Early events in the lung that shape protective immune responses to M. tuberculosis (Mtb) infection are not well understood but are critical for developing better vaccines and immunomodulatory therapies for tuberculosis. Here, we used high-dimensional flow cytometry, single-cell transcriptomics, and untargeted metabolomics to define the early lung immune environment that precedes the development of protective versus pathogenic outcomes following aerosolized Mtb infection of mice. We show that Mtb induced sustained glycolysis in the lung while restricting oxidative phosphorylation (OXPHOS) and impairing mitochondria, in part through the Mtb serine protease Hip1, leading to low energy output and suboptimal macrophage-T cell interactions that promoted pathogenic immunity. However, robust induction of mitochondrial OXPHOS, amino acid metabolism, and fatty acid oxidation in the early lung resulted in high ATP output and enhanced innate-T cell signaling networks that stimulated protective immune responses. Moreover, we identified a novel mitochondrial immunometabolic lung signature associated with protective outcomes to Mtb infection in animal models and humans. Our studies identify induction of mitochondrial dysfunction as a mechanism employed by Mtb to manipulate lung immunometabolism to its benefit and reveal that maintenance of intact mitochondrial metabolism in the early lung is pivotal for generating protective outcomes to Mtb infection.

immunology↗

Endogenous EWSR1-FLI1 degron alleles enable control of fusion oncoprotein expression in tumor cell lines and xenografts

Pediatric malignancies frequently harbor chromosomal translocations that induce expression of fusion oncoproteins. The EWSR1-FLI1 fusion oncoprotein acts as a neomorphic transcription factor and is the dominant genetic driver of Ewings sarcoma. Interrogation of the mechanisms by which EWSR1-FLI1 drives tumorigenesis has been limited by a lack of model systems to precisely and selectively control its expression in patient-derived cell lines and xenografts. Here, we report the generation of a panel of patient-derived EWS cell lines in which inducible protein degrons were engineered into the endogenous EWSR1-FLI1 locus. These alleles enabled rapid and efficient depletion of EWSR1-FLI1. Complete suppression of EWSR1-FLI1 induced a reversible cell cycle arrest at the G1-S checkpoint, and we identified a core set of transcripts downstream of EWSR1-FLI1 across multiple cell lines and degron systems. Additionally, depletion of EWSR1-FLI1 potently suppressed tumor growth in xenograft models validating efforts to directly target EWSR1-FLI1 in Ewings sarcoma.

cancer biology↗

Neutralization activity in chronic HIV infection is characterized by a distinct programming of follicular helper CD4 T cells

A subset of people living with HIV (PLWH) can produce broadly neutralizing antibodies (bNAbs) against HIV, but the lymph node (LN) dynamics that promote the generation of these antibodies are poorly understood. Here, we explored LN-associated histological, immunological, and virological mechanisms of bNAb generation in a cohort of anti-retroviral therapy (ART)-naive PLWH. We found that participants who produce bNAbs, termed neutralizers, have a superior LN-associated B cell follicle architecture compared with PLWH who do not. The latter was associated with a significantly higher in situ prevalence of Bcl-6hi follicular helper CD4 T cells (TFH), expressing a molecular program that favors their differentiation and stemness, and significantly reduced IL-10 follicular suppressor CD4 T cells. Furthermore, our data reveal possible molecular targets mediating TFH-B cell interactions in neutralizers. Together, we identify cellular and molecular mechanisms that contribute to the development of bNAbs in PLWH.

immunology↗