bioRxiv Science⌕ Search

Biology subjects

Shaukat, S.

Publications and source records attributed to Shaukat, S..

2 recordsLinked to original sources

Cirrhosis-associated immune dysfunction presents with preserved circulating lymphocyte function and altered intestinal intraepithelial lymphocyte profile

Bacterial infections are major drivers of decompensation and mortality in cirrhosis, yet the mechanisms underlying cirrhosis-associated immune dysfunction remain incompletely understood. Although current models frequently invoke adaptive immune exhaustion, intestinal intraepithelial lymphocytes (IELs), a central barrier immune compartment responsible for epithelial surveillance and microbial containment, have remained largely unexplored in cirrhosis. Here, we performed integrated immune profiling of paired duodenal biopsies and peripheral blood from healthy volunteers and patients with compensated or decompensated cirrhosis using spectral flow cytometry, plasma proteomics, immunofluorescence, and single-cell RNA sequencing. The healthy duodenal epithelium was dominated by CD8{beta} IELs, whereas cirrhosis was associated with marked depletion of these cells together with expansion of innate cytotoxic populations. Residual IELs exhibited attenuation of antimicrobial transcriptional programs alongside enrichment of innate-like cytotoxic pathways. Loss of CD8{beta} IELs was associated with coordinated reduction of CCR9 surface expression across circulating and mucosal CD8 T-cell compartments together with persistent systemic elevation of CCL25. In contrast, circulating lymphocytes retained functional competence and lacked enrichment of canonical exhaustion markers despite progressive inflammatory remodeling. Collectively, these findings identify defective intestinal IEL compartmentalization as a central feature of cirrhosis-associated immune dysfunction and implicate dysregulation of the CCL25-CCR9 axis in impaired mucosal immune surveillance. HighlightsO_LICirrhosis-associated immune dysfunction reflects defective mucosal immune compartmentalization rather than global adaptive immune paralysis C_LIO_LICirculating lymphocytes retain effector function and do not exhibit canonical exhaustion phenotypes C_LIO_LICD8{beta} intraepithelial lymphocytes are selectively depleted from the duodenal epithelium in cirrhosis C_LIO_LIPersistent systemic CCL25 elevation is associated with coordinated CCR9 loss across mucosal and circulating CD8 T-cell compartments C_LI

immunology↗

Rapid and sensitive direct detection and identification of poliovirus from stool and environmental surveillance samples using nanopore sequencing

Global poliovirus surveillance involves virus isolation from stool and environmental samples, intratypic differential (ITD) by PCR and sequencing of the VP1 region to distinguish vaccine (Sabin), vaccine-derived and wild-type polioviruses and ensure an appropriate response. This cell-culture algorithm takes 2-3 weeks on average between sample receipt and sequencing. Direct detection of viral RNA using PCR allows faster detection but has traditionally faced challenges related to poor sensitivity and difficulties in sequencing common samples containing poliovirus and enterovirus mixtures. We present a nested PCR and nanopore sequencing protocol that allows rapid (<3 days) and sensitive direct detection and sequencing of polioviruses in stool and environmental samples. We developed barcoded primers and a real-time analysis platform that generate accurate VP1 consensus sequences from multiplexed samples. The sensitivity and specificity compared with cell-culture were 90.9% (95% Confidence Interval: 75.7-98.1%) and 99.2% (95.5-100.0%) for wild-type 1 poliovirus, 92.5% (79.6-98.4%) and 98.7% (95.4-99.8%) for vaccine and vaccine-derived serotype 2 poliovirus, and 88.3% (81.2-93.5%) and 93.2% (88.6-96.3%) for Sabin 1 and 3 poliovirus alone or in mixtures when tested on 155 stool samples in Pakistan. Variant analysis of sequencing reads also allowed identification of polioviruses and enteroviruses in artificial mixtures and was able to distinguish complex mixtures of polioviruses in environmental samples. The median identity of consensus nanopore sequences with Sanger or Illumina sequences from the same samples was >99.9%. This novel method shows promise as a faster and safer alternative to cell-culture for the detection and real-time sequencing of polioviruses in stool and environmental samples.

microbiology↗