Flow cytometry-based enumeration and functional characterization of CD8 T regulatory cells in patients with multiple myeloma before and after lenalidomide plus dexamethasone treatment.
BACKGROUND
Multiple myeloma (MM) is a malignancy of plasma cells frequently associated with immune abnormalities. Several studies have confirmed that in MM immune deregulation can be mediated by increased numbers of CD4 T regulatory (Treg) cells, and these cells were also associated with poor outcome. In this study, we aimed to study CD8 Treg cells before and after lenalidomide plus dexamethasone (len-dex) treatment in MM patients.


METHODS
Using flow cytometry, we enumerated and assessed suppressive function of CD8 Treg cells in 16 MM patients before and after len-dex treatment.


RESULTS
Numbers of CD8 Treg cells (CD8+CD25hi+FoxP3+) (P < 0.01) were significantly increased in MM patients (before treatment) compared to healthy donors. However, no significant changes were observed in CD4 and CD8 T cells. A significant increase in CD8 Treg cells was observed after len-dex treatment compared to pre-treatment but no significant difference was observed in CD4 and CD8 T cells. Proliferation assay data showed that CD8 Treg cells inhibited proliferation of CD4 T cells and IFN-γ secretion in a concentration dependent manner. Suppressive activity of CD8 Treg cells did not differ significantly between healthy donors, untreated and len-dex treated MM patients. A significant abnormal level of IL-10 was observed from proliferation assays of untreated and len-dex treated MM patients compared to healthy donors (P ≤ 0.03).


CONCLUSIONS
Using flow cytometry, we have shown that suppressive CD8 Treg cells are increased in MM patients and len-dex treatment is unable to control these suppressive CD8 Treg cells.
Department of Pathological Physiology, Babak Myeloma Group, Faculty of Medicine, Masaryk University, Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Karthick Raja Muthu
KR
Raja
Martin
M
Plasil
Lucie
L
Rihova
Jana
J
Pelcova
Zdenek
Z
Adam
Roman
R
Hajek
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D015331:Cohort Studies; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D000077269:Lenalidomide; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000188:drug therapy* / Q000276:immunology; D013792:Thalidomide / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
D013792:Thalidomide; D003907:Dexamethasone; D000077269:Lenalidomide
CD8 T regulatory cells; dexamethasone; flow cytometry and CFSE; immune suppression; lenalidomide; multiple myeloma