Biology subjects

Wong, M. C.

Publications and source records attributed to Wong, M. C..

3 recordsLinked to original sources

bioRxiv2025

Regulatory T cell stability determines the efficiency of bile duct regeneration during cholangitis.

Background and AimsCholangiopathies such as Primary Sclerosing Cholangitis (PSC) cause damage to the bile ducts and fibrosis with no effective cure. A reduction and impairment in the function of regulatory T cells (Tregs) occurs in PSC. Yet, it is currently unknown what consequence this has on bile duct regeneration. We investigate whether Tregs regulate bile duct regeneration and the dynamics of Tregs turnover during bile duct injury. Approach and ResultsWe used the transgenic Foxp3GFPDTR model to mimic reduced Tregs infiltration to the liver during bile duct injury and showed that reduced intrahepatic Tregs limits bile duct regeneration. Fate mapping of Tregs (Foxp3CreERTAi14) showed that Tregs acquire a pro-inflammatory phenotype within the inflammatory microenvironment, even after IL2 mediated Tregs expansion. Ox40L expression correlates with fibrosis in PSC patients. In the 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine (DDC)-diet mouse model of experimental cholangiopathy, combining IL2-complex administration and blocking Ox40L decreases periportal fibrosis level, increases Treg number and reduces the pro-inflammatory phenotype of Tregs. ConclusionsThese results indicate that Tregs mediate cholangiocyte response to biliary injury, and Tregs downregulate Foxp3 and acquire an inflammatory phenotype in an inflammatory microenvironment. Enhancing Treg numbers through IL2 complex administration and blocking Ox40 signalling simultaneously suppress the inflammatory phenotype of Tregs and reduces bile duct damage and fibrosis.

immunology↗

bioRxiv2020

Evidence of recombination in coronaviruses implicating pangolin origins of nCoV-2019

A novel coronavirus (nCoV-2019) was the cause of an outbreak of respiratory illness detected in Wuhan, Hubei Province, China in December of 2019. Genomic analyses of nCoV-2019 determined a 96% resemblance with a coronavirus isolated from a bat in 2013 (RaTG13); however, the receptor binding motif (RBM) of these two genomes share low sequence similarity. This divergence suggests a possible alternative source for the RBM coding sequence in nCoV-2019. We identified high sequence similarity in the RBM between nCoV-2019 and a coronavirus genome reconstructed from a viral metagenomic dataset from pangolins possibly indicating a more complex origin for nCoV-2019.

microbiology↗

bioRxiv2017

Limitation Of Dogwhelk Consumption Of Mussels By Crab Cues Depends On Dogwhelk Density And Cue Type

Predator nonconsumptive effects (NCEs) on prey activity are common in nature. Upon sensing predator cues, a common prey response is to reduce feeding to avoid being detected by predators. Using an aquatic system, this study investigated how prey density and predator cue type affect predator NCEs on prey feeding. Prey density was investigated because, as it increases, the individual risk of being preyed upon decreases, which may reduce NCEs if prey can detect conspecifics. Predator cue type was investigated because waterborne cues would trigger weaker NCEs than waterborne and tactile cues combined, as predation risk may be perceived by prey to be stronger in the second case. Specifically, a factorial experiment tested the hypotheses that (i) increasing dogwhelk (prey) density reduces the limitation that crab (predator) chemical cues can have on dogwhelk consumption of mussels and that (ii) chemical and tactile crab cues combined limit dogwhelk feeding more strongly than chemical crab cues alone. The results broadly supported these hypotheses. On the one hand, crab chemical cues limited the per-capita consumption of mussels by dogwhelks at a low dogwhelk density, but such NCEs disappeared at intermediate and high dogwhelk densities. On the other hand, the combination of chemical and tactile cues from crabs caused stronger NCEs, as dogwhelk consumption of mussels was negatively affected at all three dogwhelk densities. The structurally complex mussel beds may provide not only food for dogwhelks but a refuge from crab predation that allows dogwhelk density to limit crab NCEs when mediated by waterborne cues. Overall, this study suggests that prey evaluate conspecific density when assessing predation risk and that the type of cues prey are exposed to can affect their interpretation of risk.

animal behavior and cognition↗