Production and usefulness of monoclonal antibodies against B cells

We have described new monoclonal antibodies (FUN-1, -2, FK61, FB1, FB21) which recognize B cells in the peripheral blood and lymphoid tissues. In preliminary reports FB1 and FUN-1 were described previously as anti-CD20 and -CD86 antibodies, respectively. FB1 and FB21 recognize an intracytoplasmic epitope (35, 38 kD) and a sialic acid-dependent carbohydrate epitope, respectively. FB1 reacts with pan B cells and FB21 with a subpopulation of B cells. In addition, FB21 shows relatively specific reaction with papillary or follicular carcinoma of the thyroid gland, but not with normal thyroid follicules and most benign thyroid gland tumors. Since FB1 and FB21 can be used with formalin-fixed paraffin-embedded tissue sections, they are useful for diagnosis of B cell lymphoma or thyroid carcinoma. FUN-1 recognizes surface antigen (CD86) on activated B cells, monocytes in peripheral blood and germinal center B cells in lymphoid tissues. CD86 has an important role in T cell activation and the antigen-specific T-cell dependent immune response.