Surface lymphotoxin alpha/beta complex is required for the development of peripheral lymphoid organs.

PD Rennert, JL Browning, R Mebius… - The Journal of …, 1996 - rupress.org
PD Rennert, JL Browning, R Mebius, F Mackay, PS Hochman
The Journal of experimental medicine, 1996rupress.org
For more than a decade, the biological roles and the apparent redundancy of the cytokines
tumor necrosis factor (TNF) and lymphotoxin (LT) have been debated. LT alpha exists in its
soluble form as a homotrimer, which like TNF only binds the TNF receptors, TNF-R55 or TNF-
R75. The cell surface form of LT exists as a heteromer of LT alpha and LT beta subunits and
this complex specifically binds the LT beta receptor (LT beta-R). To discriminate the
functions of the LT and TNF systems, soluble LT beta-R-immunoglobulin (Ig) or TNF-R-Ig …
For more than a decade, the biological roles and the apparent redundancy of the cytokines tumor necrosis factor (TNF) and lymphotoxin (LT) have been debated. LT alpha exists in its soluble form as a homotrimer, which like TNF only binds the TNF receptors, TNF-R55 or TNF-R75. The cell surface form of LT exists as a heteromer of LT alpha and LT beta subunits and this complex specifically binds the LT beta receptor (LT beta-R). To discriminate the functions of the LT and TNF systems, soluble LT beta-R-immunoglobulin (Ig) or TNF-R-Ig fusion proteins were introduced into embryonic circulation by injecting pregnant mice. Exposure to LT beta-R-Ig during gestation disrupted lymph node development and splenic architecture in the progeny indicating that both effects are mediated by the surface LT alpha/beta complex. These data are the first to identify a cell surface ligand involved in immune organ morphogenesis. Moreover, they unambiguously discriminate the functions of the various TNF/LT ligands, provide a unique model to study compartmentalization of immune responses and illustrate the generic utility of receptor-Ig fusion proteins for dissecting/ordering ontogenetic events in the absence of genetic modifications.
rupress.org