Immortalized Human Cord Blood Mesenchymal Stromal Cells (cbMSC-hTERT)

Immortalized human cord‑blood mesenchymal stromal cells (cbMSC‑hTERT) are an extensively characterized, hTERT‑transduced MSC line with an origin in neonatal umbilical cord blood. Parental cells are extracted from the blood component of the umbilical cord, a fetal tissue that naturally harbors large quantities of primitive mesenchymal progenitors. Subsequent retroviral transduction with human telomerase reverse transcriptase (hTERT) confers the cells with unlimited proliferative capacity. The classic MSC phenotype is retained, including plastic adherence, fibroblast‑like morphology, and immunophenotype characterized by expression of CD29, CD44, CD73, CD90, CD105 and HLA‑ABC with lack of hematopoietic markers CD14, CD34 and CD45.

The line features a doubling time of ~24 h and can be passaged to >20 generations without evidence of senescence. Karyotype analysis and comparative genomic hybridization analysis have demonstrated stability of the genome. In vivo tumorigenicity assays in immunodeficient mice have not demonstrated evidence of malignant transformation and the line is considered a non‑tumorigenic, BSL‑2 research tool. Functionally, cbMSC‑hTERT demonstrates vigorous trilineage differentiation capacity to form mineralized matrix in osteogenic differentiation, lipid droplets in adipogenic differentiation, and proteoglycan rich matrix in chondrogenic differentiation culture conditions.

Due to its capacity for infinite expansion, stable phenotype, and non‑tumorigenic safety profile, cbMSC‑hTERT is a broadly useful tool for studies in basic MSC biology, tissue‑engineering scaffold seeding, high‑throughput drug screens, disease model construction, and in vivo cell tracking studies (e.g., RFP‑labelled derivatives in traumatic brain injury or multiple sclerosis models).