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Biology subjects

Perera, M. L.

Publications and source records attributed to Perera, M. L..

2 recordsLinked to original sources

Microbial dysbiosis is evident in oral squamous cell carcinoma (OSCC) tissues of a group of Sri Lankan male patients with oral risk habits: Revisiting for confirming

BackgroundMetagenomic investigations into components of the oral microbiome in a single study remain scarce. ObjectiveTo ascertain the microbiome profile of oral squamous cell carcinoma (OSCC) tissues in a group of Sri Lankan male patients. MethodsFrom the main sample of an unmatched case-control study, a sub-sample consisting of 29 OSCC cases and 25 Fibroepithelial polyp (FEP) controls were selected. OSCC incisional and FEP excisional biopsies were collected and stored at -800C. DNA was extracted from frozen specimens using Gentra Puregene Tissue kit (Qiagen, Germany), solid tissue protocol. The DNA extracts were stored at -800C. Extracted DNA samples were sequenced by Illuminas 2x300 bp chemistry. High quality non-chimeric merged reads were classified to the species level by prioritized BLASTN-algorithm for bacteriome and BLASTN-algorithm with UNITEs named species sequences as reference for mycobiome. ResultsOur study identifies several potential periodontal pathogens, including Campylobacter concisus, Prevotella salivae, Prevotella loeschii, and Fusobacterium oral taxon 204. Additionally, Candida albicans is frequently associated with oral potentially malignant disorders (OPMDs) and oral cancers. Notably, we found a significant association between Candida etchellii and oral cancer for the first time. Furthermore, Capnocytophaga, Atopobium, and Candida were the most abundant microbial genera present in oral squamous cell carcinoma (OSCC) tissues. ConclusionsA dysbiotic microbiome was discovered in the tumor microenvironment of a group of OSCC male patients with oral risk habits. Validation of these biomarkers indifferent cohorts to supplement inadequacy in the diagnosis of epithelial dysplasia histologically is much warranted in the golden era of microbiome-first-medicine

microbiology↗

A Germinal Center Checkpoint of AIRE in B Cells LimitsAntibody Diversification

In response to antigens, B cells undergo antibody diversification, including affinity maturation and class switching, mediated by activation-induced cytidine deaminase (AID) in secondary lymphoid organs, but uncontrolled AID activity can precipitate autoimmunity and cancer. The regulation of antibody diversification is of fundamental importance, though the mechanisms underlying these pathways are not well understood. We found that autoimmune regulator (AIRE), the molecule essential for T cell tolerance, is expressed in germinal center (GC) B cells in a CD40-dependent manner, interacts with AID and negatively regulates antibody affinity maturation and class switching by inhibiting AID function. AIRE deficiency in B cells caused altered antibody repertoire, increased somatic hypermutations, elevated autoantibodies to T helper 17 effector cytokines and defective control of skin Candida albicans. These results define a GC B cell checkpoint of humoral immunity and illuminate new approaches of generating high-affinity neutralizing antibodies for immunotherapy.

immunology↗