Haematologica 2003 - Supplements

CD80 and CD86, diminished their ability to activate allospecific
T cells and present recalled antigen (PPD) to autologous T cells
(p < 0.05 to p< 0.01). The generation of the type-1 T-cell
response induced in allogeneic mixed lymphocyte reaction was
also compromized when β2M-treated DCs were used as APCs.
Compared with control cells, ß2M-treated DCs produced much
more IL-6, IL-8 and IL-10 (p < 0.01). After additional 48-hour
culture in the presence of TNF-α and IL-1β (to induce DC
maturation), 2M-treated (in the first 7 days) DCs expressed
significantly fewer surface CD83, HLA-ABC, costimulatory and
adhesion molecules, and were less potent at stimulating
allospecific T cells (p < 0.05). During cell culture, β2M
downregulated the expression of phosphorylated MAP kinases
ERK and MEK, inhibited NF-B and activated STAT3 (p <
0.01) in treated cells, all of which are involved in cell
differentiation and proliferation. In conclusion, we demonstrate,
for the first time, that β2M at high concentrations retards the
generation of DCs, which may involve downregulation of the
MHC class-I molecules, inactivation of Raf/MEK/ERK cascade
and NF-κB, and activation of STAT3. Thus, our study identifies
ß2M as a negative regulator of the immune system, which is
compatible with the clinical arena in MM and merits further study
to examine its role on other components of the immune system.
063
PATIENTS WITH MONOCLONAL GAMMOPATHIES
DISPLAY ABNORMAL NUMBERS OF FUNCTIONALLY
ALTERED CIRCULATING DENDRITIC CELLS AND
MONOCYTES.
M. Martín-Ayuso1,2, M. Perez de Andrés1,2, J. Almeida1,2,
M.A. García-Marcos3, M.I.González-Fraile4, M.J. Moro4,
D.Borrego5, G. Martín-Núñez6, J.F. San Miguel3, A.
Orfao1,2
1.-Servicio de Citometría. Universidad de Salamanca. 2.-Centro de
Investigación del Cáncer. Salamanca. 3.-Servicio de Hematología.
Hospital Universitario de Salamanca. 4.-Servicio de Hematología.
Hospital Virgen Blanca. León. 4.-Servicio de Hematología.
Hospital Universitario de Valladolid. 5.-Servicio de Hematología.
Hospital Virgen del Puerto. Plasencia..Spain.
In the development and progression of monoclonal
gammopathies (MG) the plasma cell microenviroment including
inflammatory cells is believed to play a crucial role.
The aim of the present study was to cuantitatively analyze the
distribution and function of circulating monocytes and dendritic
cells (DC) in patients with MG in order to gain insight into their
potential role in the clinical behaviour of the disease.
PB samples corresponding to 34 untreated newly diagnosed
patients with MG of undetermined significance (MGUS), 27
multiple myelomas (MM) and 4 plasma cell leukemias (PCL)
were analyzed. PB samples from 12 healthy individuals aged >40
years, were studied in parallel.
As compared to normal PB, the absolute numbers of circulating
DC were decreased in MGUS, normal in MM, and increased in
PCL: overall number of circulating DC of normal individuals of
65±18 versus 54±32, 64±43 and 237±91 cells/µl respectively.
However, absolute monocyte levels were increased in all MG, the
highest values being found in PCL patients (509±523
monocytes/µl in MGUS, 482±345 in MM and 616±392 in PCL)
as compared to healthy individuals (308±114 monocytes/µl).
From the functional point of view, PB monocytes and DC from
healthy and MGUS individuals showed no spontaneous
production of inflammatory cytokines. In contrast, increased
spontaneous ex vivo IL6 and TNFα production was observed in a
variable proportion of MM and PCL, the percentage of cytokinesecreting
cells being higher in PCL, where 50% showed
spontaneous production. Overall, after in vitro stimulation with
LPS+IFNγ, production of inflammatory cytokines by PB
monocytes and DC was lower in MG than in healthy subjects.
Interestingly, monocytes from MGUS cases had a lower response
to LPS+IFNγ than patients with MM and PCL, as regards
production of IL1, IL6, IL8, IL12 and TNFα. In contrast, no
major differences were observed by the different subsets of PB
DC in the three disease groups, except for TNFα (table1).
Accordingly, a higher production of TNFα was observed in PCL
and MM as compared to MGUS.
Table1: Production of TNFα from stimulated DC in different MG
CONTROL
Myeloid
DC
316
(38-613)
Lymphoplasmocytoid
DC
18
(7-35)
CD16+
DC
2413
(536-
3232)
390
(11-2456)
517
(6-4178)
207
(30-673)
107 16
MGUS
(7-834) (5-227)
157 15
MM
(12-1212) (5-438)
194 30
PCL
(30-732) (13-153)
- Results expressed as median and range (in brackets) of the mean
fluorescence intensity/cell.
In summary, our results show that in MGUS and MM circulating
DC are decreased in numbers, but increased in PCL, as compared
to healthy individuals. In contrast, the absolute number of
circulating monocytes is increased in all groups of MG. From the
functional point of view circulating DC and monocytes from MM
and PCL but not MGUS showed increased spontaneous
production of inflammatory cytokines; this is associated in both
MM and PCL as well as in MGUS with a lower in vitro response
to LPS+IFNγ. The distinct subsets of DC and monocytes have an
impaired function in the different MG.
064
Clonally expanded T cells in myeloma with a “late”
memory/effector phenotype are associated with
improved survival.
DMY Sze, S Yang, RD Brown, J Gibson, J Ho, *B Fazekas
de St Groth, *A Basten, DE Joshua.
Institute of Haematology, Royal Prince Alfred Hospital; *Centenary
Institute of Cancer Medicine and Cell Biology, Sydney, NSW,
Australia.
We have previously demonstrated that the presence of an
expanded CD8+CD57+ T cell clone in patients with myeloma is
associated with a significantly prolonged overall survival.
Recently, it has been shown that a pair of differentially expressed
costimulatory receptors on CD8+ T cells, CD28 and CD27, can
be used to differentiate three distinct memory/effector
phenotypes: CD28+CD27+, CD28-CD27+ and CD28-CD27-
which correspond to “early”, “intermediate”, and “late” subsets
respectively on a putative linear differentiation pathway (1). We
have performed 5-color flow analysis on 22 patients with MM
with a total of 29 expanded T cell receptor Vβ (TCRVβ) clones
and found that the majority (73%) of patients had clonally
expanded CD8+CD57+TCRVβ+ T cells of the “late” subset;
while the remaining 27% were of the “intermediate” subset.
These results demonstrate that the phenotype of the clonal T cells
in myeloma is similar to the phenotype of the memory CD8 cells
seen in patients with CMV infection and dissimilar to the
phenotypic pattern seen in patients with hepatitis C, HIV and
EBV. Using a CMVPP65 (NLVPMVATV) HLA-A2-tetramer on
S116