1989 Volume 159 Issue 3 Pages 171-183
TOMURA, K., KANG, H., MITAMURA, K., TAKEI, M., KARASAKI, M., KOYASU, S. and SAWADA, S. IL-2 Enhancing Factor(s) in B Cell Supernatants from Patients with Rheumatoid Arthritis or Systemic Lupus Erythematosus. Tohoku J. Exp. Med., 1989, 159 (3), 171-183- Culture supernatants of B cells from patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) in the active stage enhanced interleukin 2 (IL-2) dependent proliferation of CTLL A/J cells. This activity, designated B cell-derived growth-enhancing factor-2 (BGEF-2), was recovered by gel filtration of a molecular weight between 15, 000 and 20, 000. BGEF-2 itself did not show IL-2 activity nor IL-1 activity, and BGEF-2 activity was not detected in the following cytokines: Interferon-α (IFN-α), interferon-γ (IFN-γ), tumor necrosis factor (TNF), interleukin 4 (IL-4), interleukin 5 (IL-5) and interleukin 6 (IL-6). Furthermore, BGEF-2 was distinguishable from B cell-derived growth-enhancing factor described in a previous paper [Kang et al. (1987) J. Immunol., 139, 1154-1160]. BGEF-2 was produced by B cells from patients with RA or SLE only when the patients were in the active stage. BGEF-2 enhanced IL-2-dependent growth of peripheral blood T cells from patients with active RA, but did not enhance the growth of T cells from healthy voluteers. These results suggest that BGEF-2 is a B cell-derived lymphokine which plays an important role in the pathogenesis of RA and SLE.