Selective expansion and long‐term culture of human schwann cells from sural nerve biopsies

Fragments of sural nerve biopsy specimens were cultured in the presence of the supernatant of lymphokine‐activated killer cells, resulting in the selective outgrowth of cells with bipolar or tripolar morphology, reminiscent of that of Schwann cells. Immunofluorescent staining with antibodies to the S‐100 protein, the low‐affinity nerve growth factor receptor, and the surface Thy‐1 antigen confirmed that these cultures contained more than 99% Schwann cells and no detectable fibroblasts. The mitotic activity of Schwann cells was measured by bromodeoxyuridine labeling, and was increased when the cells were grown in medium with lymphokine‐activated killer cell supernatant compared with medium without this supernatant. In the presence of lymphokine‐activated killer cell supernatant, Schwann cells could be maintained in continuous culture for a minimum of 8 months.