IGF-1 production by T cells in acute versus chronic wounds. (A) Ratio of αβ and Vδ1 T cells in acute (n = 4) versus chronic (n = 8) wounds. Data were compared using a two-tailed unpaired Student's t test. Horizontal bars represent means of the values from the different patients. (B) Cells were isolated from normal epidermis (top), acute wounds (middle), and chronic wounds (bottom) and examined for IGF-1 expression by flow cytometry. (top and bottom) Cells were also stimulated with PMA and ionomycin, and stained with anti–IGF-1. Cells isolated from acute wounds were not stimulated. The acute wound and the healthy epidermis shown were isolated from the same patient and were processed simultaneously. Data are representative of acute wounds obtained from four patients and chronic wounds obtained from eight patients. pt, patient. (C) IGF-1 production in circulating αβ⁺ and Vδ1⁺ T cells isolated from the blood of healthy (H; n = 5) and acutely wounded (W; n = 4) patients before and after stimulation with PMA and ionomycin. (D) IGF-1 production is greatly enhanced in acute wounds as compared with chronic wounds and healthy epidermis. There is a significant difference in IGF-1 expression in the αβ⁺ and the Vδ1⁺ subsets in acute wounds compared with normal epidermis and chronic wounds. Normal epidermis (n = 17), acute wounds (n = 4), and chronic wounds (n = 8) were examined in the absence of stimulation. Histograms show means ± SD. The GMFI of IGF-1 production by αβ⁺ and Vδ1⁺ cells is shown. In all graphs showing flow cytometry analysis, protein expression was determined by subtracting the GMFI of the control secondary antibody from the GMFI of cells treated with specific antibodies. Data are means ± SD.