Immune mobilization of autologous blood progenitor cells: direct influence on the cellular subsets collected

Incidence of Capillary Leak Syndrome as an Adverse Effect of Drugs in Cancer Patients: A Systematic Review and Meta-Analysis

Capillary leak syndrome (CLS) is a rare disease with profound vascular leakage, which can be associated with a high mortality. There have been several reports on CLS as an adverse effect of anti-cancer agents and therapy, but the incidence of CLS according to the kinds of anti-cancer drugs has not been systemically evaluated. Thus, the aim of our study was to comprehensively meta-analyze the incidence of CLS by different types of cancer treatment or after bone marrow transplantation (BMT). We searched the literatures (inception to July 2018) and among 4612 articles, 62 clinical trials (studies) were eligible. We extracted the number of patients with CLS, total cancer patients, name of therapeutic agent and dose, and type of cancer. We performed a meta-analysis to estimate the summary effects with 95% confidence interval and between-study heterogeneity. The reported incidence of CLS was categorized by causative drugs and BMT. The largest number of studies reported on CLS incidence during interleukin-2 (IL-2) treatment (n = 18), which yielded a pooled incidence of 34.7% by overall estimation and 43.9% by meta-analysis. The second largest number of studies reported on anti-cluster of differentiation (anti-CD) agents (n = 13) (incidence of 33.9% by overall estimation and 35.6% by meta-analysis) or undergoing BMT (n = 7 (21.1% by overall estimation and 21.7% by meta-analysis). Also, anti-cancer agents, including IL-2 + imatinib mesylate (three studies) and anti-CD22 monoclinal antibodies (mAb) (four studies), showed a dose-dependent increase in the incidence of CLS. Our study is the first to provide an informative overview on the incidence rate of reported CLS patients as an adverse event of anti-cancer treatment. This meta-analysis can lead to a better understanding of CLS and assist physicians in identifying the presence of CLS early in the disease course to improve the outcome and optimize management.

The natural killer-activating receptor, NKG2D, on CD3+CD8+ T cells plays a critical role in identifying and killing autologous myeloma cells

BACKGROUND

The NKG2D receptor, one of the natural killer (NK) cell-activating receptors, is expressed on the surface of CD3+CD8+ T cells, γδ+ T cells, NK cells, NKT cells, and a few CD4+ T cells. We show, for the first time, a critical role for the NKG2D receptor on CD3+CD8+ T cells isolated from myeloma patients, in identifying and killing autologous myeloma cells isolated from the same patients' marrow. We also show that blocking NKG2D using anti-NKG2D reverses the cytotoxicity while blocking HLA-I using antibodies does not have the same effect, showing that the autologous cytotoxicity is NKG2D dependent and major histocompatibility complex (MHC)-I independent. We further confirmed the NKG2D specificity by small interfering RNA (siRNA) down regulation of NKG2D receptor.

STUDY DESIGN AND METHODS

Using ex vivo expansion methods that enrich for NKG2D+CD3+CD8+ T cells, we investigated whether these ex vivo expanded NKG2D+CD3+CD8+ T cells would recognize and lyse autologous and allogeneic myeloma cells, independent of T-cell receptor or MHC-I expression.

RESULTS

Myeloma cell lysis by the NKG2D+CD3+CD8+ T cells correlated with the amount of NKG2D ligand expression. With receptor-ligand interaction, interferon-γ and tumor necrosis factor-α were released. Blocking the NKG2D receptor by using either monoclonal antibodies or siRNAs inhibited the receptor's function and prevented myeloma cell lysis.

CONCLUSION

Clinical trials are ongoing to determine a correlation with the number and function of NKG2D+CD3+CD8+ T cells and clinical outcomes in transplanted myeloma patients, including lymphocyte recovery following transplant and overall survival.

Achieving graft-versus-tumor effect in brain tumor patients: from autologous progenitor cell transplant to active immunotherapy

Success in treating aggressive brain tumors like glioblastoma multiforme and medulloblastoma remains challenging, in part because these malignancies overcome CNS immune surveillance. New insights into brain tumor immunology have led to a rational development of immunotherapeutic strategies, including cytotoxic Tlymphocyte therapies and dendritic cell vaccines. However, these therapies are most effective when applied in a setting of minimal residual disease, so require prior use of standard cytotoxic therapies or cytoreduction by surgery. Myeloablative chemotherapy with autologous hematopoietic cell transplantation (autoHCT) can offer a platform upon which different cellular therapies can be effectively instituted. Specifically, this approach provides an inherent 'chemical debulking' through high-dose chemotherapy and a graft-versus-tumor effect through an autologous T-cell replete graft. Furthermore, autoHCT may be beneficial in 'resetting' the body's immune system, potentially 'breaking' tumor tolerance, and in providing a 'boost' of immune effector cells (NK cells or cytotoxic T lymphocytes), which could augment desired anti-tumor effects. As literature on the use of autoHCT in brain tumors is scarce, aspects of immunotherapies applied in non-CNS malignancies are reviewed as potential therapies that could be used in conjunction with autoHCT to eradicate brain tumors.

Adoptive cellular therapy using cells enriched for NKG2D+CD3+CD8+T cells after autologous transplantation for myeloma

The number of circulating lymphocytes on day 15 after transplantation correlates with improved survival in patients with myeloma, but the lymphocyte subset responsible is unknown. NKG2D is a natural killer (NK) cell activating receptor that mediates non-MHC restricted and TCR-independent cell lysis. Our preliminary results indicate that CD3(+)CD8(+) T cells expressing NKG2D may be a critical lymphocyte population. A phase II trial examined the feasibility of infusing ex vivo-expanded cells enriched for NKG2D(+)CD3(+)CD8(+) T cells at weeks 1, 2, 4, and 8 after an autologous transplantation. In addition, low-dose IL-2 (6 × 10(5) IU/m(2)/day) was administered for 4 weeks, beginning on the day of transplantation. Twenty-three patients were accrued and 19 patients are evaluable. There were no treatment-related deaths. All patients completed their course of IL-2 and demonstrated normal engraftment. When compared with patients with myeloma who underwent transplantation not receiving posttransplantation immune therapy, the treated patients demonstrated an increase in the number of circulating NKG2D(+)CD3(+)CD8(+) T cells/μL (P < .004), CD3(+)CD8(+) T cells/μL (P < .04), CD3(+)CD8(+)CD56(+) T cells/μL (P < .004), and NKG2D(+)CD3(-)CD56(+) T cells/μL (P < .003). Myeloma cell-directed cytotoxicity by the circulating mononuclear cells increased after transplantation (P < .002). When compared to posttransplantation IL-2 therapy alone in this patient population, the addition of cells enriched for NKG2D(+)CD3(+)CD8(+) T cells increased tumor-specific immunity, as demonstrated by enhanced lysis of autologous myeloma cells (P = .02). We postulate that this regimen that increased the number and function of the NKG2D(+)CD3(+)CD8(+) T cells after transplantation may improve clinical outcomes by eliminating residual malignant cells in vivo.

Mobilisation strategies for normal and malignant cells

This review evaluates the latest information on the mobilisation of haemopoietic stem cells for transplantation, with the focus on what is the current best practice and how new understanding of the bone marrow stem cell niche provides new insights into optimising mobilisation regimens. The review then looks at the mobilisation of mesenchymal stromal cells, immune cells as well as malignant cells and what clinical implications there are.

Novel mobilization strategies to enhance autologous immune effector cells in multiple myeloma

The immune system plays a critical role determining the outcomes in transplanted multiple myeloma patients, since enhanced lymphocyte recovery results in improved survival. Since mobilization regimens influence the cellular subsets collected and infused for transplant, these regimens may determine immune recovery following transplant. We hypothesized that a mobilized stem cell product harboring an increased number of lymphocytes would enhance immune recovery following autologous stem cell infusion, increase lymphocyte recovery, and improve clinical outcomes. We designed a phase I immune mobilization trial using IL-2 and growth factors to increase the number of lymphocytes within the stem cell product. This regimen efficiently mobilized CD34+ progenitor cells (median: 3.6 x 10(6) cells/kg; range 1.9-6.6 x 10(6) cells/kg) and improved the immune properties of the mobilized stem cells, including an increase in CD8+ T cells expressing an NK activating receptor called NKG2D (P less than 0.004), cells that are extremely potent at killing myeloma cells using non-MHC-I restricted and TCR-independent mechanisms. Novel mobilization techniques can improve the mobilized graft and may improve clinical outcomes in myeloma patients.