Biology subjects

Teijaro, J. R.

Publications and source records attributed to Teijaro, J. R..

5 recordsLinked to original sources

bioRxiv2020

Identification of an N-acetylneuraminic acid-presenting bacteria isolated from a healthy human microbiome

N-acetylneuraminic acid is the most abundant sialic acid in humans and is generally expressed as the terminal sugar on intestinal mucus glycans. Several pathogenic bacterial species harvest sialic acid from the mucus, diet, as well as other intestinal sources and display this sugar on their own surface to evade sialic acid-binding immunoglobulin-type lectin (Siglec)-mediated host immune surveillance. While previous studies have identified bacterial enzymes associated with sialic acid catabolism, no reported methods permit the selective labeling, tracking, and quantitation of sialic acid-presenting microbes within complex multi-microbial systems. Here, we apply an interdisciplinary approach combining metabolic labeling, click chemistry, metagenomic, and whole-genome sequencing to selectively track and identify sialic acid-presenting microbes from a cultured healthy human fecal microbiome. We isolated and identified a new strain of Escherichia coli that incorporates sialic acid onto its own surface. Analysis of the sequence data reveals that this E. coli strain encodes for the NanT, NeuA, and NeuS genes necessary for harvesting environmental sialic acid and generating the capsular polysialic acid. We envision that this method is applicable to the detection and quantitation of sialic acid-presenting bacteria from human, animal, and environmental microbiomes, as well as investigating the importance of other carbohydrates to commensal and pathogenic bacteria.

microbiology↗

bioRxiv2020

TLR9-activated B cells improve their regulatory function by endogenously produced catecholamines

The sympathetic nervous system (SNS) contributes to immune balance by promoting anti-inflammatory B cells. However, whether B cells possess a self-regulating mechanism by which they modulate regulatory B cell (Breg) function is not well understood. In this study, we investigated the ability of B cells to synthesize catecholamines upon stimulation with different B cell activators. We found, that expression of the enzymes required to generate catecholamines, is upregulated by TLR9. TLR-9-specific expression of tyrosine hydroxylase (TH) correlated with upregulation of adrenergic receptors, enhanced IL-10 production, and with an overexpression of the co-inhibitory ligands PD-L1 and FasL. Moreover, concomitant stimulation of {beta}1-3-adrenergic receptors together with a BCR/TLR9 stimulus enhances the anti-inflammatory potential of Bregs to suppress CD4 T cells, a crucial population in the pathogenesis of autoimmune diseases, like rheumatoid arthritis. In conclusion, our data show that B cells possess autonomous mechanisms to modulate their regulatory function. These findings help to better understand the function of Bregs in autoimmune diseases and the interplay of sympathetic nervous system and B cell function.

immunology↗

bioRxiv2020

Rapid isolation of potent SARS-CoV-2 neutralizing antibodies and protection in a small animal model

The development of countermeasures to prevent and treat COVID-19 is a global health priority. In under 7 weeks, we enrolled a cohort of SARS-CoV-2-recovered participants, developed neutralization assays to interrogate serum and monoclonal antibody responses, adapted our high throughput antibody isolation, production and characterization pipeline to rapidly screen over 1000 antigen-specific antibodies, and established an animal model to test protection. We report multiple highly potent neutralizing antibodies (nAbs) and show that passive transfer of a nAb provides protection against high-dose SARS-CoV-2 challenge in Syrian hamsters. The study suggests a role for nAbs in prophylaxis, and potentially therapy, of COVID-19. The nAbs define protective epitopes to guide vaccine design.

immunology↗

bioRxiv2020

ISG15 drives immune pathology and respiratory failure during viral infection

Cytokine storm during respiratory viral infection is an indicator of disease severity and poor prognosis. Type 1 interferon (IFN-I) production and signaling has been reported to be causal in cytokine storm-associated pathology in several respiratory viral infections, however, the mechanisms by which IFN-I promotes disease pathogenesis remain poorly understood. Here, using Usp18-deficient, USP18 enzymatic-inactive and Isg15-deficient mouse models, we report that lack of deISGylation during persistent viral infection leads to severe immune pathology characterized by hematological disruptions, cytokine amplification, lung vascular leakage and death. This pathology requires T cells but not T cell-intrinsic deletion of Usp18. However, lack of Usp18 in myeloid cells mimicked the pathological manifestations observed in Usp18-/- or Usp18C61A mice which were dependent on Isg15. We further mechanistically demonstrate that interrupting the ISGylation/deISGylation circuit increases extracellular levels of ISG15 which is accompanied by inflammatory neutrophil accumulation to the lung. Importantly, neutrophil depletion reversed morbidity and mortality in Usp18C61A mice. In summary, we reveal that the enzymatic function of Usp18 is crucial for regulating extracellular release of ISG15. This is accompanied by altered neutrophil differentiation, cytokine amplification and mortality following persistent viral infection. Moreover, our results suggest that extracellular ISG15 may drive the inflammatory pathology observed and could be both a prospective predictor of disease outcome and a therapeutic target during severe respiratory viral infections.

immunology↗

bioRxiv2020

Detecting Tumor Specific Antigen-Reactive T cells from Tumor Infiltrating Lymphocytes via Interaction Dependent Fucosyl-biotinylation

Re-activation and clonal expansion of tumor specific antigen (TSA)-reactive T cells are critical to the success of checkpoint blockade and adoptive transfer of tumor-infiltrating lymphocyte (TIL) based therapies. There are no reliable markers to specifically identify the repertoire of TSA-reactive T cells due to their heterogeneous composition. Here we introduce FucoID as a general platform to detect endogenous antigen-specific T cells and study their biology. Through this interaction dependent labeling approach, TSA-reactive T cells can be detected and separated from bystander T cells in primary tumor digests based on their cell-surface enzymatic fucosyl-biotinylation. Compared to bystander TILs, TSA-reactive TILs possess a distinct TCR repertoire and unique gene features. Though exhibiting a dysfunctional phenotype, this subset of TILs possesses substantial capabilities of proliferation and tumor specific killing. FucoID features genetic manipulation-free procedures and a quick turnover cycle, and therefore should have the potential of accelerating the pace of personalized cancer treatment. HighlightsInteraction dependent fucosylation enables the detection and isolation of bona fide intratumoral tumor specific antigen-reactive T cells Tumor specific antigen-reactive CD8+ T cells possess capabilities to be expanded and adoptively transferred for tumor control Tumor specific antigen-reactive CD8+ T cells feature oligoclonal expansion and upregulate genes for the steroid biosynthesis and metabolic process Intratumoral bystander CD8+ T cells can be separated into two groups based on PD-1 expression that feature distinct gene modules

immunology↗