B cell receptor signatures associated with strong and poor SARS-CoV-2 vaccine responses.

Breakthrough infection of SARS-CoV-2 is a serious challenge, as increased infections were documented in fully-vaccinated individuals. Recipients with poor antibody response are highly vulnerable to reinfection, whereas those with strong antibody responses achieve sterilizing immunity. Thus far, biomarkers associated with levels of vaccine-elicited antibody response are still lacking. Here, we studied the antibody response of age- and gender-controlled healthy cohort, who received inactivated SARS-CoV-2 vaccines and profiled the B cell receptor repertoires in longitudinally consecutive samples. Upon vaccination, all vaccinated individuals displayed a convergent antibody response with shared common antibody clones and public neutralizing antibodies. Strikingly, poor vaccine-responders are distinguishable from strong vaccine-responders by a biased V-usage before vaccination and IgG to IgM mRNA ratio. These findings reveal molecular signatures associated with the different levels of vaccine-induced antibody response, which could be further developed into biomarkers for the design of vaccination strategies.

The XRCC1 Arg280His gene polymorphism and hepatocellular carcinoma risk: a meta-analysis.

Many studies have suggested that the XRCC1 Arg280His gene polymorphism might be involved in the development of hepatocellular carcinoma (HCC). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to assess the association between XRCC1 Arg280His and HCC susceptibility. Published literature from PubMed, EMBASE and CNKI Data was searched. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed- or random- effects models when appropriate. Begg's test was used to measure publication bias. A total of 7 case-control studies covering 1,448 HCC cases and 1,544 controls were included. No significant variation in HCC risk was detected in any of the genetic models overall. In the stratified analysis, four studies with sample sizes over 300 produced similar results. The corresponding pooled ORs were not substantially altered after the exclusion of three studies deviating from Hardy-Weinberg equilibrium in the control group, which indicated reliability for our meta-analysis results.

Characterization of antimicrobial peptides isolated from the skin of the Chinese frog, Rana dybowskii.

The skins of amphibians secrete small antimicrobial peptides that fight infection and are being explored as potential alternatives to conventional antibiotics. In this study we combined mass spectrometry with cDNA sequencing to examine antimicrobial peptides in skin secretions from the Chinese frog Rana dybowskii. Thirteen peptides having precursor sequences that resemble known antimicrobial peptides from this genus were identified, ten of which were members of previously described peptide families based on their primary structures; i.e., brevinin-1, Japonicin-1, brevinin-2 and temporin. The other three peptides from R. dybowskii, which were named dybowskin-1CDYa, dybowskin-2 CDYa and dybowskin-2CDYb, had different amino acid compositions and little sequence similarity to known antimicrobial peptides. The carboxyl terminus of dybowskin-1CDY lacked amidation and is therefore clearly distinct from temporin peptides, whereas dybowskin-2CDYa and dybowskin-2CDYb consisted of 18 amino acids and were rich in Arg residues. Chemically synthesized peptides corresponding to mature dybowskin-1CDYa and dybowskin-2CDYa had strong antimicrobial activity and caused little hemolysis of human erythrocytes, suggesting they may serve as interesting templates for the development of novel antibiotics.