Thalidomide maintenance therapy maturates the T cell compartment and compromises antigen-specific antitumor immunity in patients with multiple myeloma

What happens to regulatory T cells in multiple myeloma

Abnormal tumor microenvironment and immune escape in multiple myeloma (MM) are associated with regulatory T cells (Tregs), which play an important role in maintaining self-tolerance and regulating the overall immune response to infection or tumor cells. In patients with MM, there are abnormalities in the number, function and distribution of Tregs, and these abnormalities may be related to the disease stage, risk grade and prognosis of patients. During the treatment, Tregs have different responses to various treatment regiments, thus affecting the therapeutic effect of MM. It is also possible to predict the therapeutic response by observing the changes of Tregs. In addition to the above, we reviewed the application of Tregs in the treatment of MM. In conclusion, there is still much room for research on the mechanism and application of Tregs in MM.

Cellular immunity in the era of modern multiple myeloma therapy

Multiple myeloma (MM) is a relapsing clonal plasma cell malignancy and incurable thus far. With the increasing understanding of myeloma, highlighting the critical importance of the immune system in the pathogenesis of MM is essential. The immune changes in MM patients after treatment are associated with prognosis. In this review, we summarize currently available MM therapies and discuss how they affect cellular immunity. We find that the modern anti-MM treatments enhance antitumour immune responses. A deeper understanding of the therapeutic activity of individual drugs offers more effective treatment approaches that enhance the beneficial immunomodulatory effects. Furthermore, we show that the immune changes after treatment in MM patients can provide useful prognostic marker. Analysing cellular immune responses offers new perspectives for evaluating clinical data and making comprehensive predictions for applying novel therapies in MM patients.

Lenalidomide overcomes the immunosuppression of regulatory CD8+CD28- T-cells

Although lenalidomide and pomalidomide are well-established treatment options in patients with multiple myeloma, their immune-modulating effects are not fully understood. While CD8⁺CD28⁻ regulatory T-cells in patients with hematologic disorders display a known immune-escape mechanism, we show that lenalidomide can overcome the immunosuppressive impact of CD8⁺CD28⁻ T-cells.

We analyzed in vitro the antigen-specific T-cell responses of healthy donors and patients with multiple myeloma with or without the addition of autologous CD8⁺CD28⁻ T-cells in the absence and presence of lenalidomide. We found that lenalidomide enhances the antigen-specific secretion of IFN-γ and Granzyme B despite the addition of CD8⁺CD28⁻ T-cells. Furthermore, we showed that lenalidomide inhibits the IL-6 secretion of mononuclear cells, triggered by CD8⁺CD28⁻ T-cells. The addition of IL-6 counteracts the action of lenalidomide based stimulation of IFN-γ secretion and induction of T-cell maturation but not the secretion of Granzyme B. Surprisingly, pomalidomide failed to induce IL-6 suppression and displayed immunostimulating effects only after a prolonged incubation time. Analysis of the IL-6 modulating cereblon-binding protein KPNA2 showed the similar degradation capacity of lenalidomide and pomalidomide without explaining the divergent effects. In conclusion, we showed that IL-6 and lenalidomide, but not pomalidomide, are opponents in a myeloma-antigen specific T-cell model.

Lenalidomide enhances myeloma-specific T-cell responses in vivo and in vitro

Immunomodulation is an important part of lenalidomide's mode of action. We analyzed the impact of lenalidomide on T cells from patients with multiple myeloma during lenalidomide therapy in vivo and in patients with lenalidomide-refractory disease in vitro Patients enrolled in the German Speaking Myeloma Multicenter Group (GMMG) MM5 trial received a consolidation therapy with two cycles of lenalidomide after autologous stem cell transplantation (ASCT). Half of the study population continued treatment with lenalidomide maintenance therapy for 2 y, while the other patients received lenalidomide maintenance therapy until complete remission. We analyzed 58 patients with (n = 30) or without (n = 28) lenalidomide therapy and 12 patients refractory to lenalidomide with regards to their anti-myeloma-specific T-cell responses displayed by IFNγ, Granzyme B, and Perforin secretion. The immunophenotype of T-cells was investigated by flow cytometry. Significantly, more myeloma-specific T-cell responses were observed in patients during lenalidomide therapy, compared to patients without treatment. Furthermore, we found on T-cells from patients treated with lenalidomide a decreased CD45RA expression, indicating a maturated immunophenotype and a decreased expression of CD57, indicating functional T cells. An improved myeloma-specific T-cell response was observed in 6 out of 12 heavily pretreated patients (refractory to lenalidomide) after in vitro incubation with lenalidomide. Complementary to the results in vivo, lenalidomide decreased CD45RA expression on T cells in vitro.

Targeted therapy for HM1.24 (CD317) on multiple myeloma cells

Multiple myeloma (MM) still remains an incurable disease, at least because of the existence of cell-adhesion mediated drug-resistant MM cells and/or continuous recruitment of presumed MM cancer stem cell-like cells (CSCs). As a new alternative treatment modality, immunological approaches using monoclonal antibodies (mAbs) and/or cytotoxic T lymphocytes (CTLs) are now attracting much attention as a novel strategy attacking MM cells. We have identified that HM1.24 [also known as bone marrow stromal cell antigen 2 (BST2) or CD317] is overexpressed on not only mature MM cells but also MM CSCs. We then have developed a humanized mAb to HM1.24 and defucosylated version of the mAb to adapt to clinical practice. Moreover, we have successfully induced HM1.24-specific CTLs against MM cells. The combination of these innovative therapeutic modalities may likely exert an anti-MM activity by evading the drug resistance mechanism and eliminating presumed CSCs in MM.

Peripheral T-cell lymphoma complicated by immunoglobulin A pemphigus: A case report and literature review

Peripheral T-cell lymphomas (PTCLs) account for 12% of non-Hodgkin's lymphomas (NHLs). Immunoglobulin (Ig) A pemphigus is an autoimmune blistering disease characterized by tissue-bound and circulating IgA antibodies that target epidermal cell surface components. Malignant lymphomas are often linked with autoimmune disease and the autoimmune blistering disease, paraneoplastic pemphigus, has been associated with NHL. However, cases of PTCLs that are complicated by IgA pemphigus are particularly rare. The current study presents the first known case of PTCL complicated by IgA pemphigus. A 43-year-old male was admitted to the Union Hospital (Wuhan, China) in March 2012 with multiple swollen lymph nodes. Pathology examinations revealed PTCL. Immunohistochemical staining was positive for cluster of differentiation (CD)2, CD3, CD5, CD7 and CD47, and negative for CD20. Ki-67 was ~40% positive. The patient was treated with four cycles of cyclophosphamide, Adriamycin, vincristine and prednisone, and two cycles of gemcitabine, cisplatin and dexamethasone; in addition, the patient received radiation of the retroperitoneal region (total dose, 36 Gy). The patient underwent thalidomide maintenance therapy for 20 days before flaccid blisters appeared on the trunk and limbs. Histopathology and immunofluorescence indicated IgA pemphigus, and intravenous methylprednisolone was administered, followed by treatment with prednisone. Subsequently, no evidence of recurrent lymphoma or pemphigus has been observed.