Vascular injury has been induced in rat lung and dermis after deposition of
IgG immune complexes (BSA-anti-BSA complexes). By the use of
antibodies to
TNF-alpha and
IL-1 and employment of the IL-1R antagonist, the requirements for these
cytokines have been evaluated. In lung, both
TNF-alpha and
IL-1 were required for the full expression of injury. Protection was related to the dose of
cytokine-blocking agent employed and was directly correlated with diminished tissue content of
myeloperoxidase (MPO). In the dermis,
IL-1 was required for the full expression of injury; blocking of
IL-1 protected the tissue from injury in a manner that correlated with reduced MPO content. However, anti-
TNF-alpha provided no protection against dermal
vascular injury and failed to reduce MPO content. In contrast, the local injection of either
TNF-alpha or
IL-1 beta enhanced
IgG immune complex-induced dermal
vascular injury, proportional to the increased tissue content of MPO, indicating that the rat dermis is reactive to both
cytokines. By the employment of immunohistochemical approaches, it was demonstrated that, after deposition of
immune complexes,
TNF-alpha and
IL-1 were readily demonstrated in lung macrophages, whereas in the dermis
IL-1, but not
TNF-alpha, was present in a granular pattern within interstitial cells. The immunohistochemical data are consistent with the patterns of protective effects of anti-IL-1, IL-1R antagonist and anti-
TNF-alpha in the two organs. As expected, blocking of
TNF-alpha or
IL-1 had no protective effects on
acute lung injury produced by systemic C activation after i.v. infusion of the
cobra venom factor. The data suggest fundamental differences in the requirements for
cytokines in lung and dermal
vascular injury after deposition of
IgG immune complexes.