Haematologica 2003 - Supplements

two HLA-A2+ myeloma patients with CD28-CD27- TCRVβ
expansions, it was demonstrated that only 2-3% of total CD8 T
cells were CMV-tetramer positive. As the expanded Vβ clones
contained 10 times as many cells as the tetramer positive
population and several patients with T cell clones had negative
CMV serology it was considered that the T cell clones were not
CMV specific. Patients whose expanded T cells expressed a
“late” T cell phenotype had a significantly improved survival
over those with an “intermediate” phenotype (p=0.013). The
survival of patients with an “intermediate” T cell phenotype was
not significantly better than those patients who had no detectable
T cell clones. Thus it is the expanded CD8+CD57+ cell clones
with a late memory/effector phenotype which are associated with
a good prognosis in patients with myeloma. Although this “late”
memory/effector phenotype is found in patients with chronic
CMV infection, the T cell clones in patients with myeloma were
not CMV specific but indicate a similar pattern of chronic antigen
presentation and T cell recognition.
1. Appay et al. 2002. Nature Medicine 8:379
065
Idiotype specific T cells detected with MHC Class I
Tetramers
Ross Brown, Daniel M Sze, Allan Murray, Shi Hong Yang,
P Joy Ho, John Gibson, Doug Joshua
Institute of Haematology, Royal Prince Alfred Hospital, Sydney,
Australia.
The extent to which idiotype-specific T cells have been either
deleted or tolerised in patients with multiple myeloma is
unknown. Previous attempts to detect these cells have
traditionally used a range of surrogate or functional markers of
the T cell response. As direct detection of antigen-specific T cells
can be demonstrated with MHC tetramers we sequenced the
hypervariable regions of both the heavy and light chain
hypervariable regions of 6 patients (HLA-A0201) with expanded
CD8+ clones and used bioinformatic programs (BIMAS
http://bimas.dcrt.nih.gov/molbio/hla_bind and SYFPEITHI
http://syfpeithi.bmiheidelberg.com/Scripts/MHCServer.dll/EpPredict.htm)
to
demonstrate the presence of immunodominant peptides in only 3
of the 6 patients. We then prepared tetrameric MHC class I
complexes containing CDR-derived immunodominant peptides to
search for idiotype-specific T cells in the blood of the 2 surviving
patients. CMV PP65 HLA-A*0201 tetramer and the CMVderived
peptide NLVPMVATV
were used to optimise the novel staining strategies. The standard
staining technique failed to detect tetramer positive cells in either
patient and suggested that idiotype-specific T cells were deleted.
Modified staining techniques, using different staining
temperatures, crossover controls and preincubation with free
peptide, demonstrated that low avidity tetramer positive T cells
comprised 1-10% of an IL-2 activated T cell population (