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Tracking antigen‐specific TCR clonotypes in SARS‐CoV‐2 infection reveals distinct severity trajectories

AbstractDespite the importance of antigen‐specific T cells in infectious disease, characterizing and tracking clonally amplified T cells during the progression of a patient's symptoms remain unclear. Here, we performed a longitudinal, in‐depth single‐cell multiomics analysis of samples from asymptomatic, mild, usual severe, and delayed severe patients of SARS‐CoV‐2 infection. Our in‐depth analysis revealed that hyperactive or improper T‐cell responses were more aggressive in delayed severe patients. Interestingly, tracking of antigen‐specific T‐cell receptor (TCR) clonotypes along the developmental trajectory indicated an attenuation in functional T cells upon severity. In addition, increased glycolysis and interleukin‐6 signaling in the cytotoxic T cells were markedly distinct in delayed severe patients compared to usual severe patients, particularly in the middle and late stages of infection. Tracking B‐cell receptor clonotypes also revealed distinct transitions and somatic hypermutations within B cells across different levels of disease severity. Our results suggest that single‐cell TCR clonotype tracking can distinguish the severity of patients through immunological hallmarks, leading to a better understanding of the severity differences in and improving the management of infectious diseases by analyzing the dynamics of immune responses over time.

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Ethnicity- and sex-specific genome wide association study on Parkinson’s disease

Most previous genome-wide association studies (GWASs) on Parkinson’s disease (PD) focus on the European population. There are several sex-specific clinical differences in PD, but little is known about its genetic background. We aimed to perform an ethnicity-specific and sex-specific GWAS on PD in the Korean population. A total of 1050 PD patients and 5000 controls were included. For primary analysis, we performed a GWAS using a logistic additive model adjusted for age and sex. The same statistical models were applied to sex-specific analyses. Genotyping was performed using a customized microarray chip optimized for the Korean population. Nine single nucleotide polymorphisms (SNPs) including four in the SNCA locus and three from the PARK16 locus were associated with PD in Koreans. The rs34778348 in the LRRK2 locus showed a strong association, though failed to pass cluster quality control. There were no notable genome-wide significant markers near the MAPT or GBA1 loci. In the female-only analysis, rs34778348 in LRRK2 and the four other SNPs in the SNCA showed a strong association with PD. In the male-only analysis, no SNP surpassed the genome-wide significance threshold under Bonferroni correction; however, the most significant signal was rs708726 in the PARK16 locus. This ethnicity- and sex-specific GWAS on PD implicate the pan-ethnic effect of SNCA, the universal but East-Asian inclined effect of PARK16, the East Asian-specific role of LRRK2 G2385R variants, and the possible disproportionate effect of SNCA and PARK16 between sexes for PD susceptibility. These findings suggest the different genetic contributions to sporadic PD in terms of ethnicity and sex.

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Concordance and deviations of the PDX tumors from the primary tumors of NSCLC patients: effects of murine fibroblasts on low engraftment rates

Abstract Patient-derived xenograft(PDX) models of primary lung cancer have been reported. However, varying engraftment rates and their underlying mechanisms for specific subtypes of lung cancer (adenocarcinoma, squamous cell carcinoma, and large cell neuroendocrine carcinoma) have not been studied. The authors prepared subcutaneous tumors grown in NSG™ mice with primary tumors of lung cancer patients to develop lung cancer PDX models. Pathological features of the subcutaneous tumors were compared with those of the patients. One hundred seventeen lung cancer PDX models retaining the original pathologic features were obtained from 642 primary lung cancer patients. Nineteen PDX tumors and the corresponding patient tumors, representing three subtypes of cell lung cancer, were selected and analyzed with in-depth genomic and transcriptomic profiling. Results showed the PDX tumors retained most of the somatic and oncogenic mutations with limited levels of additional xenograft-specific mutations. Significant downregulation of the genes involved in hypoxia-associated angiogenesis was found compared with the corresponding human tumors. This downregulation was associated with murine fibroblasts in the PDX tumor microenvironment, which might be an important factor in low engraftment rates in primary lung cancer PDX models.

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Analysis of antibiotic resistance gene cassettes in a newly identified Salmonella enterica serovar Gallinarum strain in Korea

Antimicrobial resistant pathogens are a global health threat driven by the indiscriminate use of antimicrobials. Antimicrobial resistance can be acquired by resistance genes encoded by mobile genetic elements. In this study, we identified a strain of Salmonella enterica serovar Gallinarum (SG4021) from an infected chicken in Korea and characterized the presence of resistance genes in its plasmid by whole genome sequencing. The sequence was then compared with that of a plasmid (P2) from strain SG_07Q015, the only other strain of S. Gallinarum isolated in Korea for which a genome sequence is available. The results revealed that both strains harbored nearly identical DNA carrying antibiotic resistance gene cassettes inserted into integron In2 of the transposable element Tn21, namely an aadA1 resistance gene conferring resistance to aminoglycosides and a sul1 resistance gene conferring resistance to sulfonamide. Interestingly, despite the presence of sul1 in SG4021, an antibiotic sensitivity test revealed that it was sensitive to sulfonamides. Further analysis revealed that this disparity was due to the insertion of a ~ 5 kb ISCR16 sequence downstream of the promoter driving sul1 expression in SG4021. Using various mutants, we showed that the insertion of ISCR16 blocked the expression of the sul1 gene from the upstream promoter. Therefore, the functionality of antimicrobial resistance genes determines phenotypic antimicrobial resistance.

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Ethnicity- and Sex-Specific Genome-Wide Association Study on Parkinson’s Disease

Abstract Most previous genome-wide association studies (GWASs) on Parkinson’s disease (PD) focus on the European population. There are several sex-specific clinical differences in PD, but little is known about its genetic background. In this study, we aimed to perform an ethnicity-specific, and sex-specific GWAS on PD in the Korean population. A total of 1,050 Korean PD patients and 5,000 controls were included. For primary analysis, we performed a GWAS using a logistic additive model adjusted for age and sex. Same statistical models were also applied to sex-specific analyses. Genotyping was performed using a customized microarray chip that is optimal for the Korean population. Nine single nucleotide polymorphisms (SNPs) including four in the SNCA locus and three from the PARK16 locus were associated with PD in Koreans. The rs34778348 in the LRRK2 locus showed a strong association, though failed to pass cluster quality control. There were no notable genome-wide significant markers near the MAPT or GBA loci. In the female-only analysis, rs34778348 in LRRK2 and the four other SNPs in the SNCA showed strong association with PD. In the male-only analysis, no SNP surpassed the genome-wide significance threshold under Bonferroni correction; however, the most significant signal was rs708726 in the PARK16 locus. This ethnicity- and sex-specific GWAS on PD implicates the pan-ethnic effect of SNCA, universal but East-Asian inclined effect of PARK16, East Asian-specific role of LRRK2 G2385R variants, and the possible disproportionate effect of SNCA and PARK16 between sexes for PD susceptibility. These findings suggest the different genetic contributions to sporadic PD in terms of ethnicity and sex.

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Haploid-resolved and chromosome-scale genome assembly in hexa-autoploid sweetpotato (<i>Ipomoea batatas</i>(L.) Lam)

AbstractSweetpotato (Ipomoea batatas(L.) Lam) is the world’s seventh most important food crop by production quantity. Cultivated sweetpotato is a hexaploid (2n = 6x = 90), and its genome (B1B1B2B2B2B2) is quite complex due to polyploidy, self-incompatibility, and high heterozygosity. Here we established a haploid-resolved and chromosome-scalede novoassembly of autohexaploid sweetpotato genome sequences. Before constructing the genome, we created chromosome-scale genome sequences inI. trifidausing a highly homozygous accession, Mx23Hm, with PacBio RSII and Hi-C reads. Haploid-resolved genome assembly was performed for a sweetpotato cultivar, Xushu18 by hybrid assembly with Illumina paired-end (PE) and mate-pair (MP) reads, 10X genomics reads, and PacBio RSII reads. Then, 90 chromosome-scale pseudomolecules were generated by aligning the scaffolds onto a sweetpotato linkage map.De novoassemblies were also performed for chloroplast and mitochondrial genomes inI. trifidaand sweetpotato. In total, 34,386 and 175,633 genes were identified on the assembled nucleic genomes ofI. trifidaand sweetpotato, respectively. Functional gene annotation and RNA-Seq analysis revealed locations of starch, anthocyanin, and carotenoid pathway genes on the sweetpotato genome. This is the first report of chromosome-scalede novoassembly of the sweetpotato genome. The results are expected to contribute to genomic and genetic analyses of sweetpotato.

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Monitoring Circulating Tumor DNA in Untreated Non-Small-Cell Lung Cancer Patients.

Circulating tumor DNA (ctDNA) has been utilized to monitor the clinical course of patients of non-small-cell lung cancer (NSCLC) who receive therapies targeting druggable mutations. However, despite providing valuable information on how NSCLC would naturally progress, the clinical utility of ctDNA for clinical-course monitoring and prediction of treatment-naïve NSCLC patients without druggable mutations remain unknown. We longitudinally followed a total of 12 treatment-naïve NSCLC patients, who did not harbor EGFR and ALK mutations, by collecting clinical information, radiological data, and plasma samples. Changes in ctDNA levels and tumor burden (TB) were compared with each other. New metastasis development, volume doubling time (VDT), and overall survival (OS) were analyzed regarding ctDNA detection at diagnosis. ctDNA was detected in the plasma of seven (58.3%) patients. Changes in ctDNA levels correlated with those in TB in a substantial fraction (57.1%) of patients and was also associated with brain metastasis, tumor necrosis, or pneumonia in other patients. All patients with ctDNA detection developed new metastasis during follow-ups in the organs that had been devoid of metastasis at diagnosis. The patients without ctDNA detection did not develop new metastasis (median duration of follow-ups: 9.8 months). In addition, patients with ctDNA detection had shorter VDT (p = 0.039) and worse OS (p = 0.019) than those without ctDNA detection. The natural course of NSCLC progression can be monitored by measuring ctDNA levels. Detection of ctDNA at diagnosis can predict development of new metastasis, rapid tumor growth and poor survival of NSCLC patients.

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Genetic Determinants of Visit-to-Visit Lipid Variability: Genome-Wide Association Study in Statin-Naïve Korean Population.

Background and AimThere is a growing evidence that fluctuation in lipid profiles is important in cardiovascular outcomes. We aimed to identify single nucleotide polymorphism (SNP) variants associated with low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) variability in statin-naïve Korean subjects and evaluate their associations with coronary atherosclerosis.MethodsIn statin-naïve subjects from Gene-Environment of Interaction and phenotype cohort, we performed genome-wide association studies of lipid variability; the discovery (first) and replication (second) sets included 4,287 and 1,086 subjects, respectively. Coronary artery calcium (CAC) score and degree of coronary artery stenosis were used as outcome measures. Cholesterol variability was determined by standard deviation and average successive variability, and significant coronary atherosclerosis was defined as CAC score ≥400 or coronary stenosis ≥70%.ResultsMean HDL-C and LDL-C level were 54 ± 12 and 123 ± 30 mg/dL in the first set and 53 ± 12 and 126 ± 29 mg/dL in the second set. APOA5 rs662799 and APOA5 rs2266788 were associated with LDL-C variability and PXDNL rs80056520, ALDH2 rs671, HECTD4 rs2074356, and CETP rs2303790 were SNPs associated for HDL-C variability. APOA5 rs662799 passed Bonferroni correction with p-value of 1.789 × 10−9. Among the SNPs associated with cholesterol variability, rs80056520 and rs2266788 variants were associated with CACS ≥400 and coronary stenosis ≥70% and rs662799 variant was associated with coronary stenosis ≥70%.ConclusionTwo SNPs associated with LDL-C variability (APOA5 rs662799 and rs2266788) and one SNP associated with HDL-C variability (PXDNL rs80056520) were significantly associated with advanced coronary artery stenosis. Combining GWAS results with imaging parameters, our study may provide a deeper understanding of underlying pathogenic basis of the link between lipid variability and coronary atherosclerosis.

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