Recombinant human LAG3 lentiviral vector and its stable expression in mouse fibroblast cells
- Author:
LI Xinyue
;
JIN Yue
;
CAI Xiu
- Publication Type:Journal Article
- Keywords:
Recombinant lentiviral vector;
lymphocyte activation gene;
immunosuppressive receptor;
chronic viral infection
- From:
China Tropical Medicine
2025;25(3):328-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To construct a recombinant lentiviral expression vector for human lymphocyte activation gene 3 (LAG3) and generation of monoclonal cell lines that preferentially express LAG3 by transfection of the vector into mouse fibroblast cells 3T3. Methods After extracting total RNA extracted from human peripheral blood mononuclear cells, the RNA is reversely transcribed into cDNA. The LAG3 extracellular and transmembrane region sequences are amplified by PCR using high-fidelity DNA polymerase. The PCR products are double-digested with the restriction endonucleases EcoRⅠ and NotⅠ, then ligated with the lentiviral vector pTSB-copGFP to construct the recombinant expression vector pTSB-LAG3-copGFP, which is subsequently transformed into Escherichia coli DH5α. Positive clonal bacteria are selected by PCR, and the plasmids are extracted and sequenced for verification. The recombinant vector pTSB-LAG3-copGFP, along with packaging plasmids psPAX2 and pMD2.0G, are co-transfected into human embryonic kidney 293T cells to assemble and release virus particles, the virus infected 3T3 cells were collected. During the puromycin selection of infected 3T3 cells, the limited dilution method is used to obtain 3T3 monoclonal cells that stably express LAG3. Real-time fluorescent quantitative PCR, immunofluorescence and flow cytometry were utilized to verify the transcription of LAG3 mRNA and the expression of LAG3 protein respectively. Results Sequencing of the recombinant pTSB-LAG3-copGFP lentiviral vector plasmid reveals that the amplified LAG3 sequence contains a synonymous mutation in the His codon at nucleotide position 1 697 bp within the LAG3 transmembrane region, which aligns with the standard LAG3 sequence (accession number NM_002286.6) in GenBank. The 3T3 cells infected by pTSB-LAG3-copGFP packaging virus screened with puromycin. A total of 20 LAG3+copGFP+-3T3 monoclonal cell lines were obtained, all of which exhibited transcription of LAG3 mRNA. The monoclonal cell line MC-6 exhibits the highest transcriptional level of LAG3. Effective expression and distribution of LAG3 protein on the cell membrane and cytoplasmic organelle membranes in MC-6 indicated by immunofluorescence and flow cytometry. Conclusion The pTSB-LAG3-copGFP lentiviral vector was successfully constructed. LAG3+copGFP+-3T3 monoclonal cell lines overexpressing lymphocyte activating 3 were efficiently established, laying the foundation for subsequent studies on the relationship between LAG3 and the development of chronic infectious diseases such as hepatitis B, as well as the interventional treatment of LAG3.
- Full text:20251117172318599212.Recombinant human LAG3 lentiviral vector and its stable expression in mouse fibroblast cells.pdf
