Biology subjects

Esaulova, E.

Publications and source records attributed to Esaulova, E..

4 recordsLinked to original sources

bioRxiv2023

ATG5 suppresses type I IFN-dependent neutrophil swarming and NETosis

Inflammation is critical for controlling infections, but when left unchecked can cause tissue damage and disease. For tuberculosis, the leading cause of death due to infection1, host inflammation is responsible for the clinical symptoms2, morbidity2, and mortality3,4. Specifically, neutrophil-dominated inflammation is associated with tuberculosis disease progression3,5,6. Therefore, understanding how neutrophil functions are regulated during infection is important for developing ways to prevent disease. Atg5 was the first gene shown to specifically function within neutrophils to promote control of Mycobacterium tuberculosis7, the causative agent of tuberculosis. ATG5 is best studied for its role in autophagy8-11, however, the protective activity of ATG5 in neutrophils was unexpectedly independent of other autophagy proteins and remained elusive7. We report here that ATG5, but not other autophagy proteins, is required in neutrophils to suppress neutrophil NETosis and swarming that occur due to elevated type I interferon levels during M. tuberculosis infection. The elevated level of NETosis that results from loss of ATG5 expression contributes to the early susceptibility of Atg5fl/fl-LysM-Cre mice during M. tuberculosis infection. NETosis is associated with poor disease outcomes in tuberculosis12,13 and COVID-19 patients14,15, as well as during other inflammatory diseases in humans16,17. Our studies identify an essential regulator of NETosis and elucidate previously unappreciated roles for ATG5 during infection, which may inform the design of host-directed therapeutics modulating these pathways.

immunology↗

bioRxiv2021

Myeloid cell interferon responses correlate with clearance of SARS-CoV-2

The emergence of mutant SARS-CoV-2 strains associated with an increased risk of COVID-19-related death necessitates better understanding of the early viral dynamics, host responses and immunopathology. While studies have reported immune profiling using single cell RNA sequencing in terminal human COVID-19 patients, performing longitudinal immune cell dynamics in humans is challenging. Macaques are a suitable model of SARS-CoV-2 infection. We performed longitudinal single-cell RNA sequencing of bronchoalveolar lavage (BAL) cell suspensions from adult rhesus macaques infected with SARS-CoV-2 (n=6) to delineate the early dynamics of immune cells changes. The bronchoalveolar compartment exhibited dynamic changes in transcriptional landscape 3 days post-SARS-CoV-2-infection (3dpi) (peak viremia), relative to 14-17dpi (recovery phase) and pre-infection (baseline). We observed the accumulation of distinct populations of both macrophages and T-lymphocytes expressing strong interferon-driven inflammatory gene signature at 3dpi. Type I IFN response was highly induced in the plasmacytoid dendritic cells. The presence of a distinct HLADR+CD68+CD163+SIGLEC1+ macrophage population exhibiting higher angiotensin converting enzyme 2 (ACE2) expression was also observed. These macrophages were significantly recruited to the lungs of macaques at 3dpi and harbored SARS-CoV-2, while expressing a strong interferon-driven innate anti-viral gene signature. The accumulation of these responses correlated with decline in viremia and recovery. The recruitment of a myeloid cell-mediated Type I IFN response is associated with the rapid clearance of SARS-CoV-2 infection in macaques.

immunology↗

bioRxiv2021

Lung epithelial signaling mediates early vaccine-induced CD4+ T cell activation and Mtb control

Tuberculosis (TB) is one of the leading causes of death due to a single infectious agent. The development of a TB vaccine that induces durable and effective immunity to Mycobacterium tuberculosis (Mtb) infection is urgently needed. Early and superior Mtb control can be induced in M. bovis Bacillus Calmette-Guerin (BCG) vaccinated hosts when the innate immune response is targeted to generate effective vaccine-induced immunity. In the present study, we show that innate activation of DCs is critical for mucosal localization of clonally activated vaccine-induced CD4+ T cells in the lung, and superior early Mtb control. In addition, our study reveals that Th1/Th17 cytokine axis play an important role in superior vaccine induced immunity. Our studies also show that activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF{kappa}{beta}) pathway in lung epithelial cells is critical for the mucosal localization of activated vaccine-induced CD4+ T cells for rapid Mtb control. Thus, our study provides novel insights into the immune mechanisms that can overcome TB vaccine bottlenecks and provide early rapid Mtb control. ImportanceTuberculosis is a leading cause of death due to single infectious agent accounting 1.4 million deaths each year. The only licensed vaccine BCG is not effective due to variable efficacy. In our study, we determined the early immune events necessary for achieving complete protection in BCG vaccinated host. Our study reveals that innate activation of DCs can mediate superior and early Mtb control in BCG vaccinated host through lung epithelial cell signaling and localization of clonal activated, Mtb antigen specific, cytokine producing CD4+ T cells within the lung parenchyma and airways. Thus, our study provides novel insights into the immune mechanisms that can overcome TB vaccine bottlenecks and provide early rapid Mtb control.

immunology↗

bioRxiv2021

A non-canonical role for glutamate decarboxylase 1 in cancer cell amino acid homeostasis, independent of the GABA shunt.

Glutamate decarboxylase 1 (GAD1) is best known for its role in producing the neurotransmitter {gamma}-amino butyric acid (GABA) as part of the "GABA shunt" metabolic pathway, an alternative mechanism of glutamine anaplerosis for TCA cycle metabolism (Yogeeswari et al., 2005). However, understanding of the metabolic function of GAD1 in non-neuronal tissues has remained limited. Here, we show that GAD1 supports cancer cell proliferation independent of the GABA shunt. Despite its elevated expression in lung cancer tissue, GAD1 is not engaged in the GABA shunt in proliferating non-small cell lung cancer (NSCLC) cells, but rather is required for regulating amino acid homeostasis. Silencing GAD1 promotes a broad deficiency in amino acid uptake, leading to reduced glutamine-dependent TCA cycle metabolism and defects in serum- and amino acid-stimulated mTORC1 activation. Mechanistically, GAD1 regulates amino acid uptake through ATF4-dependent amino acid transporter expression including SLC7A5 (LAT1), an amino acid transporter required for branched chain amino acid (BCAA) uptake. Overexpression of LAT1 rescues the proliferative and mTORC1 signalling defects of GAD1-deficient tumor cells. Our results, therefore, define a non-canonical role for GAD1, independent of its characterised role in GABA metabolism, whereby GAD1 regulates amino acid homeostasis to maintain tumor cell proliferation.

cancer biology↗