IntroductionPeripheral blood mononuclear cells (PBMC) concentrates collected by apheresis are frequently used as starting material for cellular therapies, but the cell of interest must often be isolated prior to initiating manufacturing.Study design and methodsThe results of enriching 59 clinical PBMC concentrates for monocytes or lymphocytes from patients with solid tumors or multiple myeloma using a commercial closed system semi-automated counter-flow elutriation instrument (Elutra, Terumo BCT) were evaluated for quality and consistency. Elutriated monocytes (n = 35) were used to manufacture autologous dendritic cells and elutriated lymphocytes (n = 24) were used manufacture autologous T cell therapies. Elutriated monocytes with >10% neutrophils were subjected to density gradient sedimentation to reduce neutrophil contamination and elutriated lymphocytes to RBC lysis.ResultsElutriation separated the PBMC concentrates into 5 fractions. Almost all of the lymphocytes, platelets and red cells were found in fractions 1 and 2; in contrast, most of the monocytes, 88.6 ± 43.0%, and neutrophils, 74.8 ± 64.3%, were in fraction 5. In addition, elutriation of 6 PBMCs resulted in relatively large quantities of monocytes in fractions 1 or 2. These 6 PBMCs contained greater quantities of monocytes than the other 53 PBMCs. Among fraction 5 isolates 38 of 59 contained >10% neutrophils. High neutrophil content of fraction 5 was associated with greater quantities of neutrophils in the PBMC concentrate. Following density gradient separation the neutrophil counts fell to 3.6 ± 3.4% (all products contained <10% neutrophils). Following red cell lysis of the elutriated lymphocyte fraction the lymphocyte recovery was 86.7 ± 24.0% and 34.3 ± 37.4% of red blood cells remained.ConclusionsElutriation was consistent and effective for isolating monocytes and lymphocytes from PBMC concentrates for manufacturing clinical cell therapies, but further processing is often required.
BackgroundMonocytes are myeloid cells that reside in the blood and bone marrow and respond to inflammation. At the site of inflammation, monocytes express cytokines and chemokines. Monocytes have been shown to be cytotoxic to tumor cells in the presence of pro-inflammatory cytokines such as Interferon Alpha, Interferon Gamma, and IL-6. We have previously shown that monocytes stimulated with both interferons (IFNs) results in synergistic killing of ovarian cancer cells. We translated these observations to an ongoing clinical trial using adoptive cell transfer of autologous monocytes stimulated ex vivo with IFNs and infused into the peritoneal cavity of patients with advanced, chemotherapy resistant, ovarian cancer. Here we describe the optimization of the monocyte elutriation protocol and a cryopreservation protocol of the monocytes isolated from peripheral blood.MethodsCounter flow elutriation was performed on healthy donors or women with ovarian cancer. The monocyte-containing, RO-fraction was assessed for total monocyte number, purity, viability, and cytotoxicity with and without a cryopreservation step. All five fractions obtained from the elutriation procedure were also assessed by flow cytometry to measure the percent of immune cell subsets in each fraction.ResultsBoth iterative monocyte isolation using counter flow elutriation or cryopreservation following counter flow elutriation can yield over 2 billion monocytes for each donor with high purity. We also show that the monocytes are stable, viable, and retain cytotoxic functions when cultured with IFNs.ConclusionLarge scale isolation of monocytes from both healthy donors and patients with advanced, chemotherapy resistant ovarian cancer, can be achieved with high total number of monocytes. These monocytes can be cryopreserved and maintain viability and cytotoxic function. All of the elutriated cell fractions contain ample immune cells which could be used for other cell therapy-based applications.Electronic supplementary materialThe online version of this article (10.1186/s12967-019-1822-6) contains supplementary material, which is available to authorized users.
Purpose: Ovarian cancer is the most lethal gynecologic cancer and intrinsically resistant to checkpoint immunotherapies. We sought to augment innate immunity, building on previous work with interferons and monocytes. Experimental Design: Preclinical experiments were designed to define the mechanisms of cancer cell death mediated by the combination of interferons alpha and gamma with monocytes. We translated these preclinical findings into a phase I trial of autologous IFN-activated monocytes administered intraperitoneally to platinum-resistant or -refractory ovarian cancer patients. Results: Interferon (IFN)-treated monocytes induced caspase 8-dependent apoptosis by the proapoptotic tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and mediated by the death receptors 4 and 5 (DR4 and DR5, respectively) on cancer cells. Therapy was well tolerated with evidence of clinical activity, as 2/9 evaluable patients had a partial response (PR) by RECIST criteria, and 1 additional patient had a CA-125 response. Upregulation of monocyte-produced TRAIL and cytokines was confirmed in peripheral blood. Long-term responders had alterations in innate and adaptive immune compartments. Conclusions: Given the mechanism of cancer cell death, and the acceptable tolerability of the clinical regimen, this platform presents a possibility for future combination therapies to augment anti-cancer immunity.
The manufacture of adHER2/neu DC using autologous plasma as a media supplement resulted in inconsistent HER2/neu expression. It is likely that variability in the levels of multiple proteins in autologous plasma contributed to low HER2/neu expression.
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