Publication details
Evaluation of Novel CD8 T Regulatory Cells in Patients with Multiple Myeloma at Baseline and after Len-Dex Treatment
| Authors | |
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| Year of publication | 2013 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Regulatory T cells (Tregs) play a significant role in maintaining immune homeostasis in healthy individuals. In cancer patients Tregs were considered as immune suppressors due to their expansion. In multiple myeloma (MM), we and others have shown the suppressive role of CD4 Tregs. In the present study, we investigated novel regulatory cells expressing CD8 marker (CD8 Tregs) in MM patients at baseline and after lenalidomide plus dexamethasone (LD) treatment. Peripheral blood (PB) samples were collected at baseline and after 4 cycles of LD treatment from a cohort of 16 MM patients. As a control group, 10 healthy donors (HDs) PB samples were also collected. CD8 Tregs were identified as CD8+CD25hi+FoxP3+. These CD8 Tregs share similar phenotypic features of CD4 Tregs in terms of expression of CD127 and CTLA-4. Baseline CD8 Treg numbers were significantly increased in MM patients compared to HDs (median: 0.51% vs. 0.12%; P=0.01), but no other significant differences were observed with respect to total lymphocytes, CD4 and CD8 T cell numbers. Analysis of CD8 Tregs at baseline and after LD treatment clearly showed a significant increase in CD8 Treg numbers after LD treatment (median: 1.35% vs. 0.51%; P=0.01). Functional studies revealed that CD8 Tregs from MM patients at baseline and after LD treatment were suppressive (inhibited CD4 T cell proliferation and IFN-gamma secretion) as similar to CD8 Tregs from HDs. These findings suggest that increase in CD8 Treg numbers might promote immune impairment, thereby, predisposing MM patients to infections and disease progression. |