ABSTRACT
【Objective】 To establish RH gene mRNA sequencing method based on nanopores sequencing and to explore the RHD and RHCE mRNA transcripts in D positive and Del individuals. 【Methods】 From March 2021 to May 2022, 5 RhD positive samples and 5 Del samples screened out by hospitals in Chengdu were sent to our laboratory for futher examination. The erythrocytes and buff coat were isolated, then DNA and RNA were extracted.All 10 samples were genotyped by PCR-SSP. After the mRNA was reversely transcribed into cDNA, the full-length mRNA of RHD and RHCE genes were simultaneously amplified by a pair of primers. Sanger sequencing and third-generation sequencing technology based on Nanopore were used to sequence the amplified products, and the types and expressions of different splices of RHD and RHCE gene mRNA transcripts were analyzed. 【Results】 The method established in this study can simultaneously amplify the full length transcripts of RHD and RHCE. Ten different RHD gene mRNA transcripts and nine RHCE gene mRNA transcripts were detected in 10 samples. RHD full-length transcript (RHD-201) can be detected in RhD Del type, but the expression amount was significantly lower than that in RhD positive samples. The expression amount of transcript RHD-207 (Del789) in Del samples was significantly higher than that in RhD positive samples. The transcript RHD-208 (Del8910+ 213) was only detected in RhD Del type individuals, and no significant difference was found between other RHD transcripts and all RHCE transcripts in the two phenotypes. 【Conclusion】 In this study, an analytical method for sequencing full-length transcript isomers of RHD and RHCE mRNA via the third generation was successfully established, and complex alternative splicing patterns were found in RHD and RHCE genes, providing a new method for the study of alternative splicing of blood group gene variants mRNA.
ABSTRACT
【Objective】 To understand the memory phenotype and function of SARS-CoV-2 reactive CD4+ T cells in healthy individuals. 【Methods】 In this study, SARS-CoV-2-derived peptides were used to stimulate PBMC from participants.SARS-CoV-2 reactive memory T cells were detected by intracellular staining and flow cytometry, and memory phenotype analysis was performed.CBA was used to detect cytokine secretion after SARS-CoV-2-derived peptides stimulation to evaluate the function of SARS-CoV-2 reactive memory T cells. 【Results】 We found that SARS-CoV-2 reactive CD4+ memory T cells could be detected in 40% (6/15) healthy donors.Phenotypic analysis of memory showed that these T cells were mainly composed of central memory T cells(82.2%), and other memory cells accounted for 17.8%.Compared with negative control, IL-10 was significantly decreased after stimulation of SARS-CoV-2-derived peptides (P<0.05), while the secretion of IFNγ, TNFα, IL-2 and IL-4 showed no significant difference. 【Conclusions】 SARS-CoV-2 reactive CD4+ memory T cells are present in healthy individuals from China.