EXPERIMENTAL HYPERSENSITIVITY PNEUMONITIS - IN-VITRO EFFECTS OF INTERLEUKIN-2 AND INTERFERON-GAMMA

Cultured CD4(+) cells are responsible for transfer of adoptive murine experimental hypersensitivity pneumonitis (EHP)(ARRD 1992;146:1582-8), To characterize interactions that occur in vitro that result in cells able to transfer EHP, we added either antibody to IFN-gamma, antibody to IL-2, or 30 or 300 mu g/ml IFN-gamma at the onset of 72-hour cultu re of C3H/HeJ spleen cells from either M. faeni or ovalbumin (control) sensitized donors with 30 mu g/ml Micropolyspora faeni, We determined the phenotype of cells after culture and the amount of IL-2 or IFN-ga mma in the culture supernatants, transferred cells to naive recipients , challenged the recipients intratracheally with M, faeni, and determi ned the extent of pulmonary inflammatory changes 4 days thereafter, Su bstantial amounts of IL-2 and IFN-gamma were detected in supernatants of cultures from M, faeni-sensitized animals, and lesser amounts were detected in culture supernatants from ovalbumin-sensitized donors. Tre atment of cultures of M, faeni-sensitized cells with antibody to IL-2 or IFN-gamma blocked or reduced measurable IL-2 or IFN-gamma for the d uration of culture, Treatment with IFN-gamma blocked increased levels of IL-2 at 48 and 72 hours of culture, Cultured M, faeni-sensitized ce lls adoptively transfer EHP, Cells from cultures depleted of either IL -2 or lFN-gamma or supplemented with IFN-gamma could transfer EHP equa lly well, We conclude that in vitro maturation of cells capable of ado ptive EHP is not dependent on soluble IL-2 or IFN-gamma and is not alt ered by exogenous IFN-gamma.