Objective To investigate the correlation between HLA-DM gene polymorphism and antibody response induced by poliomyelitis vaccine.Methods 355 healthy infants aged 2 to 3 months in Guangxi Zhuang Autonomous Region were selected as the study objects,and 10 SNPs of DMA exon 3 and DMB exon 2/3 were genotyped by Sanger sequencing.The correlation between DMA and DMB genes and poliomyelitis vaccine-induced antibody response was analyzed at allele,genotype and haplotype levels.Results In the type Ⅰ antibody response induced by polio vaccine,the frequencies of DMA*01:02,DMB*01:01,DMB*01:01/DMB*01:01 and DMA*01:02-DMB*01:01 were higher in the non-seroconversion group than in the seroconversion group(P<0.05).In the polio type Ⅱ antibody response,the frequencies of DMA*01:02,DMA*01:02/DMA*01:02,DMB*01:01/DMB*01:01 and DMA*01:02-DMB*01:01 were higher in the non-seroconversion group than in the seroconversion group(P<0.05).Conclusion Alleles DMA*01:02 and DMB*01:01 may be associated with type Ⅰ and type Ⅱ antibody responses induced by poliomyelitis vaccine.

Objective:To analyze the epidemiological features of respiratory syncytial virus (RSV) infection in Beijing, and monitor the sequence variations in RSV glycoprotein (G) gene and clinical features of infected children.Methods:Respiratory tract specimens were collected from children with acute respiratory infection in the Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 1, 2023 to December 31, 2023. RSV-positive specimens screened by multiple nucleic acid testing were subjected to PCR to amplify the full-length RSV G gene. A phylogenetic tree was constructed after gene sequencing to analyze RSV subtypes and trace G gene variants. Clinical data were retrieved from the medical record system to analyze the clinical features of children with RSV infection in Beijing.Results:A total of 5 489 respiratory specimens were collected from 3 046 male patients and 2 443 female patients. The average age of the patients was 4.36 years. A total of 589 RSV-positive specimens (10.7%, 589/5 489) were detected with 349 from male patients and 240 from female patients. The average age of children with RSV infection was (2.51±2.78) years and the median age was 0.48 years. RSV had been circulating among children in Beijing since March 2023 with two epidemic peaks in May (24.6%, 122/496) and December (18.2%, 126/693). The predominant subtype of RSV in the first half of 2023 was subtype A, but it was replaced by subtype B from November 2023. Phylogenetic analysis revealed a novel G gene of RSV subtype B (RSV-B-BA9-954bp) with a length of 954 bp, which belonged to a new cluster in the phylogenetic tree. The percentage of patients admitted to the Intensive Care Unit (ICU) was higher in children with new variant of RSV subtype B infection than in those with common RSV subtype B infection [44.1% (15/34) vs 25.2% (31/123), χ 2=4.600, P=0.032], while the counts of white blood cells and the levels of C-reactive protein were lower in the children with new variant infection ( P<0.05). Conclusions:RSV has been prevalent among children in Beijing since March 2023 with two epidemic peaks. The predominant A subtype is gradually replaced by to B subtype. A new variant of RSV B G gene (RSV-B-BA9-954bp) is detected among the children.

Objective:To analyze the differentially expressed genes of human respiratory syncytial virus (RSV) subtype A genotype ON1, a predominant genotype in Beijing, after infecting A549 cells using transcriptomic sequencing, and provide potential targets for RSV prevention and treatment.Methods:A local strain (61397-ON1) identified by whole-genome sequencing as ON1 genotype of RSV subtype A was selected to infect A549 cells. Total mRNA was extracted, and the differentially expressed genes in infected and uninfected A549 cells were screened by transcriptomic sequencing. GO analysis and KEGG pathway analysis were performed. Besides, six genes with differential expression ratio greater than two times were randomly selected for qRT-PCR verification.Results:There were 1 632 differentially expressed genes between infected and uninfected A549 cells, of which 807 genes were up-regulated and 825 genes were down-regulated. The differentially expressed genes were mainly involved in immune response-related biological processes such as cytokine response and positive regulation of MAPK cascades, and were enriched in MAPK signaling pathway, NOD-like receptor signaling pathway, p53 signaling pathway, TNF signaling pathway, IL-17 signaling pathway and NF-κB signaling pathway. The results of qRT-PCR for six differentially expressed genes were consistent with the trend of transcriptome data.Conclusions:The differentially expressed genes of RSV A subtype ON1 genotype after infecting A549 cells are mainly involved in cytokine response and immune-related signaling pathways. This study provides basic data for further study of the molecular mechanism of RSV infection and the development of prevention and treatment strategies.