Molecular Neuroimmunology 
has some unique sequences characterized by pro- 
tease inhibitor domains. He has begun a study of 
the molecule's protease inhibitor activity to see if 
it plays a role during the remodeling process in 
neuronal development. We expect the studies re- 
garding receptor signal transduction mechanisms 
and early developmental remodeling processes in 
the nervous system to help us further understand 
how the immune and nervous systems develop 
and interact. 
Cell surface receptors on lymphocytes some- 
times share intracellular signaling mecha- 
nisms. In this case, the receptor for a T cell 
growth factor (interleukin-2 or IL-2) and the 
protein molecule CD4, which assists these cells 
in the recognition of foreign antigens, both in- 
teract with a lymphocyte- specific protein- 
tyrosine kinase, p56^'^^ — a potent signaling 
molecule that induces proliferation. A highly 
acidic region of the IL-2 receptor's fS-chain me- 
diates this interaction, while a very different 
domain in the CD4 protein, containing two 
critical cysteine residues (c ), performs a simi- 
lar function for this receptor. 
Diagram from Roger Perlmutter, based on 
work in his laboratory. 
IaCIDIC 
:- - =7/-- ' proline-rich 
\\ tv Signal 
V:~y Transduction 
320 
I 
