Expression of RAG and rearrangement of the secondary genes of BCR in
mature peripheral B lymphocytes in Takayasu arteritis
Abstract
Objective: To evalute the expression of RAG and BCR gene rearrangement
in mature peripheral B lymphocytes in Takayasu arteritis, reveal the
possible mechanism of humoral immune response in Takayasu arteritis.
Methods: Patients with Takayasu arteritis (10 cases) and healthy
volunteers with age and sex matching (10cases, as control group) from
Beijing Shijitan Hospital, Capital Medical University , and Peking Union
Medical College Hospital from 2022 to 2023 were included in this study.
The recombinant activating gene mRNA test uesd real-time quantitative
PCR (RT-PCR) . Western blot was used to detect the expression levels of
the RAG protein . The NGS gene sequencing technology was performed for
the B cell receptor (BCR) gene sequencing. Results: The expression level
of RAG1 mRNA and RAG2 mRNA in peripheral mature B lymphocytes in TA
patients was significantly higher than that of normal controls(RAG1
5.56±1.71 vs. 1.94±0.86, P<0.05; RAG2 5.26±1.59 vs. 1.65±0.64,
P<0.05), respectively; The expression level of the RAG1 protein
and the RAG2 protein in peripheral mature B lymphocytes in TA patients
was significantly higher than that of normal controls(RAG1 4.33±1.58
vs. 1.52±0.59, P<0.05; RAG2 4.67±1.88 vs. 1.59±0.56,
P<0.05), respectively. The number of peripheral B lymphocyte
BCR clonotypes in the group of patients with TA was significantly higher
than in the normal control group(1574±317.7 vs. 801.3±202.1,
P<0.05). The abundance of the BCR gene V region in TA patients
was higher than that in the normal control group(31.185% vs.
13.449%).The abundance of genes in the BCR V region was positively
correlated with RAG1 and RAG2 (correlation coefficient r=1.00,
P<0.05), respectively. Conclusion: High expression of
the RAG gene in mature peripheral B lymphocytes may cause BCR secondary
gene rearrangement in mature peripheral B lymphocytes in patients with
Takayasu arteritis, suggesting that there is a possibility of secondary
gene rearrangement in TA and providing important clues for the potential
diagnostic indicator and therapeutic target of Takayasu arteritis, and
further exploration and analysis is required for larger samples.