Type 1-like helper T cell lines responsive to autologous peripheral blood monocytes established from two patients with sarcoidosis.

In the present study, T cell lines, designated TU/BAL and KC/LN, were established from bronchoalveolar lavage (BAL) fluid and an affected lymph node, respectively, obtained from patients with active sarcoidosis by cultivating in the presence of IL-2. These cell lines produced IL-2 and proliferated by stimulation with the patient's own peripheral blood mononuclear cells treated with mitomycin C, while three other T cell lines established from ConA-stimulated BAL cells of patients with non-sarcoid lung diseases did not show any proliferative responses. The proliferation was mediated by IL-2, because anti-IL-2R alpha-chain monoclonal antibody (mAb) inhibited this response in a dose-dependent fashion. The adherent cell was a main stimulator of the proliferation. Both CD4 and HLA-DR appeared to be involved, because mAbs against these molecules inhibited this response. These results suggest that T cells obtained from sarcoid patients respond to a certain unknown antigen associated with HLA-DR or some self antigen expressed on the monocytes. Furthermore, both TU/BAL and KN/LN represented a profile of Th1-like cells: they secreted IL-2 and IFN-gamma, but not IL-4, IL-5 and IL-6, when stimulated with PHA in the presence or absence of 12-O-tetradecanoylphorbol-13-acetate. Thus, Th1-like cells activated by some unknown antigen(s) might play roles in the pathogenesis of sarcoidosis.