HUMAN PAPILLOMA-VIRUS E6 E7 GENES CAN EXPAND THE LIFE-SPAN OF HUMAN CORNEAL FIBROBLASTS/

Human corneal fibroblasts were infected with a retroviral delivery vec tor containing the E6 and E7 genes from human Papilloma virus type 16 in order to produce cell lines that have an expanded lifespan in cultu re. Morphologically, some of the trasfected corneal fibroblast lines a ppeared to have the normal spindle-shape morphology of diploid fibrobl asts, whereas other lines appeared to have a more elongated morphology . All the cell Lines were anchorage-dependent. Cells that had a normal morphology grew at a rate similar to normal diploid human corneal fib roblasts and had a population doubling time of 48 h. All E6/E7 express ing cell lines, regardless of morphology, produce types I, III, and V collagen, at levels similar to those observed in the parent corneal di ploid fibroblast. These corneal fibroblast lines will be a useful in v itro system to study collagen expression and fibril formation, as well as normal stroma development. These results also demonstrate that the use of E6/E7 genes to expand a cell's lifespan can be a powerful tool because it does not appear to alter either the growth rate of the cel l or collagen expression.