IL-1 alpha or tumor necrosis factor-alpha stimulate release of three NAP-1/IL-8-related neutrophil chemotactic proteins in human dermal fibroblasts

Abstract

Human dermal fibroblasts in culture secrete three protein-like neutrophil chemotactic factors, when stimulated either with human rIL-1 alpha or IL-1 beta; not, however, after incubation with LPS. These three fibroblast-derived neutrophil-activating proteins (FINAP) could be purified by subsequently performed reversed phase and size exclusion HPLC. By high resolution SDS-PAGE, all the proteins were shown to migrate with an Mr of 6,700 (alpha-FINAP), 3,600 (beta-FINAP), and 5,300 (gamma-FINAP). All purified cytokine preparations were found to be chemotactic for human neutrophils. In addition, all FINAP induced release of lysosomal enzymes in neutrophils. Deactivation of chemotaxin-elicitable enzyme release showed cross-desensitization of all FINAP with NAP-1/IL-8. Western blot analysis of alpha-FINAP by using mAb against neutrophil-activating protein (NAP)-1/IL-8 reveals immunologic cross-reactivity with NAP-1/IL-8. By amino-terminal amino acid sequence analysis alpha-FINAP could be identified as the 77-residue extended form of NAP-1/IL-8 containing the 79-residue form as a minor contaminant. Whereas beta-FINAP has been found to be a truncation product of alpha-FINAP, gamma-FINAP shows identity with authentic melanoma growth stimulatory activity with respect to retention time upon reversed phase HPLC, high resolution SDS-PAGE, and biologic properties, as well as amino-terminal amino acid sequence. These data show that human dermal fibroblasts may actively participate in inflammatory reactions by secretion of proinflammatory cytokines.