Lymph node permeability factor in the dinitrochlorobenzene skin hypersensitivity reaction in guinea-pigs.

The vascular permeability factor present in extracts of lymph node cells (LNPF) has been examined as a possible mediator of the cutaneous inflammation associated with the delayed hypersensitivity produced by painting the skin of guinea-pigs with 2:4-dinitrochlorobenzene. It has been found that during the development of the DNCB reaction it becomes possible to extract from the reaction site a substance indistinguishable from LNPF, the results being similar to those obtained previously in tuberculin sensitivity. Precipitating antibody to guinea-pig LNPF has been produced in rabbits. Pretreatment of animals with the antibody serum caused a marked diminution of the erythema and cellular infiltration seen after application of the challenging dose of DNCB. It is suggested that in the tuberculin and DNCB reactions, sensitized mononuclear cells may reach the reaction site as a result of non-specific stimuli, react with antigen and release LNPF which might bring about a major inflammatory response.