List of Titles

Testing the NKT cell hypothesis in lenalidomide-treated myelodysplastic syndrome patients

- Chan, Angela, Neeson, Paul, Leeansyah, Edwin, Tainton, K., Quach, Hang, Prince, Henry, Godfrey, Dale, Ritchie, David, Berzins, Stuart

Authors: Chan, Angela , Neeson, Paul , Leeansyah, Edwin , Tainton, K. , Quach, Hang , Prince, Henry , Godfrey, Dale , Ritchie, David , Berzins, Stuart
Date: 2010
Type: Text , Journal article
Relation: Leukemia Vol. 24, no. 3 (2010), p. 592-600
Full Text: false
Reviewed:
Description: Myelodysplastic syndrome (MDS) comprises a group of clonal bone marrow disorders characterized by ineffective hematopoiesis and increased predisposition to acute myeloid leukemia. The causes of MDS remain poorly defined, but several studies have reported the NKT cell compartment of patients with MDS is deficient in number and functionally defective. In support of a central role for NKT cells, a pilot clinical study reported that lenalidomide (an approved treatment for MDS) increased NKT cell numbers in patients with MDS, and several in vitro studies showed lenalidomide specifically promoted NKT cell proliferation and cytokine production. We tested this in a much larger study and confirm a moderate in vitro augmentation of some NKT cell functions by lenalidomide, but find no impact on the NKT cell compartment of patients treated with lenalidomide, despite a consistently positive clinical response. We further show that the frequency and cytokine production of NKT cells is normal in patients with MDS before treatment and remains stable throughout 10 months of lenalidomide therapy. Collectively, our data challenge the concept that NKT cell defects contribute to the development of MDS, and show that a clinical response to lenalidomide is not dependent on modulation of NKT cell frequency or function. © 2010 Macmillan Publishers Limited All rights reserved.

The glucocorticoid receptor 1A3 promoter correlates with high sensitivity to glucocorticoid-induced apoptosis in human lymphocytes

- Liddicoat, Douglas, Kyparissoudis, Konstantinos, Berzins, Stuart, Cole, Timothy, Godfrey, Dale

Authors: Liddicoat, Douglas , Kyparissoudis, Konstantinos , Berzins, Stuart , Cole, Timothy , Godfrey, Dale
Date: 2014
Type: Text , Journal article
Relation: Immunology and Cell Biology Vol. 92, no. 10 (2014), p. 825-836
Full Text: false
Reviewed:
Description: Glucocorticoids (GCs) are powerful inhibitors of inflammation and immunity. Although glucocorticoid-induced cell death (GICD) is an important part of GCs actions, the cell types and molecular mechanisms involved are not well understood. Untranslated exon 1A3 of the human glucocorticoid receptor (GR) gene is a major determinant of GICD in GICD-sensitive human cancer cell lines, operating to dynamically upregulate GR levels in response to GCs. We measured the GICD sensitivity of freshly isolated peripheral blood mononuclear cells and thymocytes to dexamethasone in vitro, relating this to GR exon 1A3 expression. A clear GICD sensitivity hierarchy was detected: B cells>thymocytes/natural killer (NK) cells>peripheral T cells. Within thymocyte populations, GICD sensitivity decreased with maturation. Interestingly, NK cell subsets were differentially sensitive to GICD, with CD16 + CD56 int (cytotoxic) NK cells being highly resistant to GICD, whereas CD16-CD56 hi (cytokine producing) NK cells were highly sensitive (similar to B cells). B-cell GICD was rescued by co-culture with interleukin-4. Strikingly, although no significant increases in GR protein were observed during 48 h of culture of GICD-sensitive and-resistant cells alike, GR 1A3 expression was increased over pre-culture levels in a manner directly proportional to the GICD sensitivity of each cell type. Accordingly, this is the first evidence that the GR exon 1A3 promoter is differentially regulated during thymic development and maturation of human T cells. Furthermore, human peripheral blood B cells are exquisitely GICD-sensitive in vitro, giving new insight into how GCs may downregulate immunity. Collectively, these data show that GR 1A3 expression is tied with GICD sensitivity in human lymphocytes, underscoring the potential for GR 1A3 expression to be used as a biomarker for sensitivity to GICD. © 2014 Australasian Society for Immunology Inc.

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