Bone marrow stromal cells modulate both kappa light chain and Ly1 antigen
expression on Ly1+ pre-B cell lines in vitro
MG Kruger, RL Riley, EA Riley and JM Elia
Department of Microbiology and Immunology, University of Miami School of
Medicine, FL.
Murine Ly1+ pre-B cell lines, including 70Z/3 and three pre-B cell lines
derived from long-term bone marrow cultures, exhibited selective adherence
to bone marrow stromal cells. In contrast, splenic B cells, the A20 B-cell
lymphoma, and four Ly1- B cell lines derived from long- term bone marrow
cultures failed to adhere substiantially to bone marrow cultures failed to
adhere substiantially to bone marrow stroma. Ly1+ pre-B cell lines were
induced to express kappa light chains by exposure to either
lipopolysaccharide (LPS), recombinant interleukin-1 (IL-1), or stromal
cells. However, induction of kappa light chains failed to prevent pre-B
cell adherence to stromal cells. Supernatants derived from primary bone
marrow stromal cells decreased Ly1 expression on the Ly1+ pre-B cell lines.
These experiments suggest that (1) expression of immunoglobulin light
chains by developing Ly1+ pre-B cells is mediated by bone marrow stromal
cells; (2) loss of specific adherence to stroma is progressive and occurs
post-light chain induction; and (3) soluble products of stromal cells may
downregulate expression of surface Ly1 on otherwise Ly1+ pre-B cells. The
importance of these observations to the development of both the Ly1- and
Ly1+ B cell lineages in the mouse is discussed.
Volume 76,
Issue 2,
pp. 383-392,
07/15/1990
Copyright © 1990 by The American Society of Hematology
