Diabetes, Vol 40, Issue 11 1555-1559, Copyright © 1991 by American Diabetes Association
Diabetes in NOD mice does not require T lymphocytes expressing V beta 8 or V beta 5
M McDuffie
Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver.
The incidence of destructive pancreatic infiltrates and overt diabetes in
animal models of insulin-dependent (type I) diabetes mellitus can be
greatly reduced by inactivating or eliminating most T lymphocytes early in
life. Because of theoretical and practical concerns about inducing
long-term pan-T-lymphocyte inactivation for prevention or treatment of type
I diabetes in humans, we hoped that more selective suppression of only the
diabetogenic T lymphocyte population might be possible. To this end, two
groups suggested that diabetogenic subpopulations of T lymphocytes in NOD
mice could be identified by the protein sequence of their T-lymphocyte
receptors. This assertion was based on experimental elimination of
candidate T-lymphocyte subpopulations in two different short-term models of
diabetes induction in NOD mice. For these experiments, identification and
elimination of T-lymphocyte subsets were accomplished with monoclonal
antibodies that bind specifically to the variable region of the beta-chain
(V beta) of the T-lymphocyte antigen receptor and divide the T-lymphocyte
pool of the NOD mouse into approximately 20 V beta subsets. To test the
relationship between the two T-lymphocyte V beta subsets implicated in
these studies and pancreatic beta-cell destruction in unmanipulated
animals, both T-lymphocyte subpopulations identified were genetically
eliminated from NOD-derived mice by introduction of a mutant T-lymphocyte
receptor V beta gene, from which these sequences are genomically deleted.
Histological evidence of severe beta-cell destruction and overt diabetes
was found in mice homozygous for the deleted V beta gene, indicating that
neither V beta gene segment identified in previous studies is required for
diabetogenesis in unmanipulated diabetes-prone mice.