Reticular fibroblasts in peripheral lymphoid organs identified by a monoclonal antibody.

TLDR

The study presents the reactivity of the monoclonal antibody ER‑TR7 and discusses its potential role in organizing peripheral lymphoid organs. ER‑TR7 detects reticular fibroblasts, the cellular framework of lymphoid and nonlymphoid organs, by binding an uncharacterized intracellular antigen. ER‑TR7 labeling clearly delineates the red and white pulp of the spleen and the capsule, sinuses, follicles, paracortex, and medullary cords of lymph nodes, but not specialized compartments in thymus or bone marrow, demonstrating its utility for mapping lymphoid organ architecture.

Abstract

We have produced a panel of monoclonal antibodies directed against nonlymphoid cells in central and peripheral lymphoid organs. In this paper we present the reactivity of one of these antibodies, ER-TR7. This antibody detects reticular fibroblasts, which constitute the cellular framework of lymphoid and nonlymphoid organs and their products. In frozen sections of the spleen incubated with this antibody, the red pulp and white pulp are clearly delineated. Furthermore, the major white pulp compartments--the follicles and periarteriolar lymphoid sheath as well as the marginal zone--are recognized by their characteristic labeling patterns. In lymph nodes, the capsule, sinuses, follicles, paracortex, and medullary cords are clearly delineated. In the thymus and bone marrow no such specialized compartments were demonstrated. ER-TR7 reacts with an intracellular component of fibroblasts. Since ER-TR7 does not react with purified laminin, collagen types I-V, fibronectin, heparan sulfate proteoglycan, entactin, or nidogen, it detects a hitherto uncharacterized antigen. The possible role of the ER-TR7 positive reticular fibroblasts in the cellular organization of peripheral lymphoid organs will be discussed.