Immortalized Human hTert/KER-CT Keratinocytes a Model System for Research on Desmosomal Adhesion and Pathogenesis of Pemphigus Vulgaris.

Pemphigus Vulgaris is an autoimmune disease that results in blister formation in the epidermis and in mucosal tissues due to antibodies recognizing desmosomal cadherins, mainly desmoglein-3 and -1. Studies on the molecular mechanisms of Pemphigus have mainly been carried out using the spontaneously immortalized human keratinocyte cell line HaCaT or in primary keratinocytes. However, both cell systems have suboptimal features, with HaCaT cells exhibiting a large number of chromosomal aberrations and mutated p53 tumor suppressor, whereas primary keratinocytes are short-lived, heterogeneous and not susceptible to genetic modifications due to their restricted life-span. We have here tested the suitability of the commercially available human keratinocyte cell line hTert/KER-CT as a model system for research on epidermal cell adhesion and Pemphigus pathomechanisms. We here show that hTert cells exhibit a calcium dependent expression of desmosomal cadherins and are well suitable for typical assays used for studies on Pemphigus, such as sequential detergent extraction and Dispase-based dissociation assay. Treatment with Pemphigus auto-antibodies results in loss of monolayer integrity and altered localization of desmoglein-3, as well as loss of colocalization with flotillin-2. Our findings demonstrate that hTert cells are well suitable for studies on epidermal cell adhesion and Pemphigus pathomechanisms.