Adipogenic characterization of immortalized CD55⁺ progenitor cells from human white adipose tissue

Mature adipocytes are difficult to study ex vivo, prompting the use of human adipose progenitor cells (hAPCs). However, hAPCs undergo replicative senescence, limiting their utility in long-term studies. We inserted human telomerase reverse transcriptase (TERT) into the AAVS1 locus of CD55+ hAPCs derived from abdominal subcutaneous adipose tissue, and characterized the cells before and after adipogenic differentiation. TERT-hAPCs retained proliferative and adipogenic capacities for over 80 passages, comparable to early-passage wild type hAPCs. Transcriptomic and proteomic analyses confirmed strong adipocyte gene expression. Functionally, TERT-hAPCs responded to insulin and lipolytic stimuli (isoprenaline, dibutyryl cAMP, TNF-α). They adapted well to both 2D and 3D cultures, with improved adipogenesis under spheroid conditions. Immortalization of CD55+ hAPCs yields cells with stable proliferative and adipogenic capacity across passages. Being cryopreservable and suitable for both 2D and 3D cultures, TERT-hAPCs offer a reliable, reusable model system for adipocyte studies using cells with a consistent genetic background.