K.P. Jensen,
A. Neale, P. Narendran, E. Jansen, L.C. Harrison, in collaboration with
A. Hodder, Infection and Immunity Division
Proinsulin is
a key autoantigen that drives immune responses to pancreatic beta cells
in type 1 diabetes. We developed a method for the production, refolding
and purification of recombinant human proinsulin from E.coli. Proinsulin
was used to identify and clone autoreactive T cells and to raise a panel
of mouse monoclonal antibodies. The antibodies have been used to isolate
proinsulin-expressing myeloid cells from human peripheral blood by FACS-based
sorting. Studies are underway to characterise these peripheral ‘self-antigen-expressing’
cells (see Narendran et al).
An
efficient method for cloning rare autoantigen-specific T cells from
human peripheral blood
S.I. Mannering,
J. Dromey, L.C.Harrison
The study of human autoimmune
disease, such as type 1 diabetes, has been hampered by our inability
to isolate autoantigen-specific T cells. We have developed a method
that allows us to isolate human CD4+ T-cell clones specific for glutamic
acid decarboxylase and proinsulin, two antigens implicated in type 1
diabetes. Using these clones we have identified a new epitope from proinsulin
that contains a novel posttranslational modification. T-cells that recognise
this epitope could be isolated from both pre-diabetic and diabetic donors.
This information will be useful for the prevention and diagnosis of
type 1 diabetes.
Myeloid
progenitor cells encoding proinsulin differentiate into resting dendritic
cells in vivo and inhibit autoimmune diabetes
R.J. Steptoe,
J.M. Ritchie, L.K. Jones, L.C. Harrison
We tested the hypothesis
that partially-differentiated myeloid cells expressing an autoantigen
would suppress autoimmune disease as they differentiated to resting
DC in vivo. Bone marrow (BM) was obtained from wild-type non-obese diabetic
(NOD) mice that develop spontaneous autoimmune diabetes and from NOD
mice in which proinsulin expression is transgenically driven by an MHC
class II promoter. BM was cultured in GM-CSF and TGF-beta-1, to yield
Gr-1+/CD11b+/CD11c- myeloid progenitors. These cells acquired resting
DC characteristics after transfer in vivo and inhibited diabetes development
after transfer into 4 week-old NOD mice. Thus myeloid DC progenitors
encoding a disease-specific autoantigen inhibit development of spontaneous
autoimmune disease.
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