Clinical-Grade Expanded Regulatory T Cells Are Enriched with Highly Suppressive Cells Producing IL-10, Granzyme B, and IL-35.

In the setting of T cell-depleted, full-haplotype mismatched transplantation, adoptive immunotherapy with regulatory T cells (Tregs) and conventional T cells (Tcons) can prevent graft-versus-host disease (GVHD) and improve post-transplantation immunologic reconstitution and is associated with a powerful graft-versus-leukemia effect. To improve the purity and the quantity of the infused Tregs, good manufacturing practices (GMP)-compatible expansion protocols are needed. Here we expanded Tregs using an automated, clinical-grade protocol. Cells were extensively characterized in vitro, and their efficiency was tested in vivo in a mouse model. Tregs were selected by CliniMacs (CD4+CD25+, 94.5 ± 6.3%; FoxP3+, 63.7 ± 11.5%; CD127+, 20 ± 3%; suppressive activity, 60 ± 7%), and an aliquot of 100 × 106 was expanded for 14 days using the CliniMACS Prodigy System, obtaining 684 ± 279 × 106 cells (CD4+CD25+, 99.6 ± 0.2%; FoxP3+, 82 ± 8%; CD127+, 1.1 ± 0.8%; suppressive activity, 75 ± 12%). CD39 and CTLA4 expression levels increased from 22.4 ± 12% to 58.1 ± 13.3% (P < .05) and from 20.4 ± 6.7% to 85.4 ± 9.8% (P < .01), respectively. TIM3 levels increased from .4 ± .05% to 29 ± 16% (P < .05). Memory Tregs were the prevalent population, whereas naive Tregs almost disappeared at the end of the culture. mRNA analysis displayed significant increases in CD39, IL-10, granzyme B, and IL-35 levels at the end of culture period (P < .05). Conversely, IFNγ expression decreased significantly by day +14. Expanded Tregs were sorted according to TIM3, CD39, and CD62L expression levels (purity >95%). When sorted populations were analyzed, TIM3+ cells showed significant increases in IL-10 and granzyme B (P < .01) .When expanded Tregs were infused in an NSG murine model, mice that received Tcons only died of GVHD, whereas mice that received both Tcons and Tregs survived without GVHD. GMP grade expanded cells that display phenotypic and functional Treg characteristics can be obtained using a fully automated system. Treg suppression is mediated by multiple overlapping mechanisms (eg, CTLA-4, CD39, IL-10, IL-35, TGF-ß, granzyme B). TIM3+ cells emerge as a potentially highly suppressive population. © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Immunotherapy with cytokine induced killer cells in solid and hematopoietic tumours: a pilot clinical trial.

BACKGROUND AND OBJECTIVES: CIK cells are a novel population of efficient immune effector cells with high antitumour activity mainly due to the high proliferation of CD3(+)CD56(+) cells, so may play a role in the development of new forms of adoptive cellular immunotherapy. We started a pilot clinical trial with autologous CIK cells in patients with refractory lymphoma and metastatic solid tumours. This study was aimed at determining the feasibility of generating a sufficient number of CIK cells in heavily pretreated patients and at assessing treatment toxicity. DESIGN AND METHODS: CIK cells were generated from peripheral blood mononuclear cells (MNC) and incubated in the presence of IFN-gamma followed by OKT3 and IL-2. Treatment schedule consisted of three cycles of CIK cells infusions at an interval of 3 weeks. RESULTS: At present 12 patients were enrolled: 6 advanced lymphomas, 5 metastatic kidney carcinoma and 1 hepatocellular carcinoma (HCC). The median number of transferred cells per patient was 28 x 10(9) (range, 6-61). Protocol adherence was excellent and the toxicity profile was favourable. After CIK cells infusion, the absolute median count of lymphocytes, CD3(+), CD8(+) and CD3(+)CD56(+) cells significantly increased in patient's peripheral blood. Clinical outcome appeared promising: three patients had complete response (CR) and two patients had stabilization of disease with a median follow-up of 33 months (range, 9-44). INTERPRETATIONS AND CONCLUSIONS: These preliminary data showed that adoptive immunotherapy with CIK cells is a safe therapy with some suggestion of efficacy that significantly enhances immune functions increasing absolute numbers of effector cells without side effects. If confirmed in larger scale studies, these promising results may have a favourable impact on conventional treatment strategy of malignancies.

Long-term results of survival in patients with thalassemia major treated with bone marrow transplantation.

Allogeneic bone marrow transplantation (BMT) is the only available curative approach for thalassemia major, although long-term morbidity and mortality are not established. The aim of this study was to assess the long-term clinical and hematological results in children and adults with thalassemia major treated with BMT. We analyzed the outcome of 115 patients (median age 9 years, range 11 months to 28 years) with thalassemia major undergoing BMT from a related donor between 1983 and 2006. All patients received the same protocol, consisting of busulfan and cyclophoshamide as conditioning therapy and cyclosporin (CSA) alone or CSA and methotrexate for graft-versus-host disease (GvHD) prophylaxis. The cumulative probability of graft rejection was 6.7%. The transplant-related mortality at 1 year was 8.7%. The 20-year Kaplan-Meier estimate of overall survival and disease-free survival was 89.2% and 85.7%, respectively. Ninety-nine patients out of 103 survivors were in excellent clinical and hematological conditions at last visit following a median follow-up of 15 years (range, 1-24 years) with the exception of two patients who had invalidating chronic GvHD. This study conducted with a large cohort of patients and covering a long period of observation time, showed BMT to be curative for the majority of patients with thalassemia major. The impact of long-term transplant-related sequelae was very limited.

NOTCH and Graft-Versus-Host Disease.

In allogeneic hematopoietic stem cell transplantation, which is the major curative therapy for hematological malignancies, T cells play a key role in the development of graft-versus-host disease (GvHD). NOTCH pathway is a conserved signal transduction system that regulates T cell development and differentiation. The present review analyses the role of the NOTCH signaling as a new regulator of acute GvHD. NOTCH signaling could also represent a new therapeutic target for GvHD.

Treg-protected donor lymphocyte infusions: a new tool to address the graft-versus-leukemia effect in the absence of graft-versus-host disease in patients relapsed after HSCT.

In high-risk acute leukemia patients undergoing haploidentical hematopoietic stem cell transplantation (HSCT), adoptive immunotherapy with T regulatory cells (Tregs) and T conventional cells (Tcons) prevented acute and chronic graft-versus-host disease (GvHD), favored post-transplant immunological reconstitution and was associated with a powerful graft-versus-leukemia (GvL) effect. With a particularly innovative approach, we developed a treatment with a Treg-protected donor lymphocyte infusion (DLI) for patients with early relapse after HSCT and we report here the results obtained in the first patient with APL (M3v) relapsed after a second matched allogeneic HSCT (15% blasts and 75% of donor cells in bone marrow). The patient received a first infusion of 2.5 × 106/kg Tregs derived from matched donor followed 7 days later by 5 × 106/kg Tcons. GvL effect was strongly evident as the percentage of leukemic cells decreased to 5%. A second infusion of Tregs (2.5 × 106/kg) and Tcons (2 × 106/kg) was performed. No GvHD was observed. Disease evaluation showed the absence of blastic cells at flow-cytometry, a normal caryotype and full donor chimerism. We also observed NOTCH1 down-regulation in peripheral blood. This new immunotherapy approach showed that Treg-protected DLI is effective in preventing GvHD and is associated with a strong GvL effect.

Evaluation of an automated closed fluid management device for processing expanded cytokine-induced killer cells to use in immunotherapy programs for cancer.

BACKGROUND: Cytokine-induced killer (CIK) cells are a heterogeneous population of immune cells derived from peripheral blood lymphocytes with a high proliferative potential ex vivo. This study shows a rapid and reproducible protocol for adoptive immunotherapy with CIK cells in patients with hematologic malignancies. For this purpose a new automatic cell processing device (CytoMate, Baxter Oncology) was tested to improve extensive manipulations of these cells. STUDY DESIGN AND METHODS: Twenty CIK expansions obtained from healthy donors and patients with hematologic malignancies were washed and refilled with fresh medium during culture with the CytoMate. Recovery, viability, and cytotoxic activity were evaluated. Six cryopreserved CIK procedures were thawed and processed for washing out dimethyl sulfoxide automatically. Recovery of cells, viability, and early apoptosis were measured immediately after washing, and cytotoxic activity against target cell lines K562 and Daudi was tested after short culture. RESULTS: Prewash volume of CIK cultures was 3600 mL (range, 1970-6000 mL). After automatic wash, the total CIK cell recovery was 85.3 percent (range, 78.5%-97.5%), and living cells were greater than 95 percent. After thawing, the median recoveries of total nucleated cells and natural killer T (NKT) cells were, respectively, 80.7 percent (range, 65%-95.5%) and 90.5 percent (range, 70.5%-98.5%). Thawed cells preserved their cytotoxic activity after cryopreservation (approx. 50% lysis at effector:target ratio of 40:1). CONCLUSION: The automatic wash with the CytoMate showed a good recovery of viable CIK cells during expansion and allowed an efficient manipulation of thawed cells. The use of this simple and efficient washing technique is suitable for clinical-grade processing in cellular therapy protocols.

Catheter-related candidemia caused by Candida lipolytica in a patient receiving allogeneic bone marrow transplantation.

Candida lipolytica was recovered from the blood and the central venous catheter in a patient receiving allogeneic bone marrow transplantation. Two C. lipolytica strains from different geographical areas and the ATCC 9773 strain of C. lipolytica were used as controls. C. lipolytica was identified by standard methods. MICs indicated antifungal susceptibilities to amphotericin B, fluconazole, and itraconazole for all strains. In vitro testing and scanning electron microscopy showed that C. lipolytica was capable of producing large amounts of viscid slime material in glucose-containing solution, likely responsible for the ability of the yeast to adhere to catheter surfaces. Restriction fragment length polymorphisms revealed an identical profile for all clinical isolates, unrelated to those observed for the control strains. This finding suggested the absence of microevolutionary changes in the population of the infecting strain, despite the length of the sepsis and the potential selective pressure of amphotericin B, which had been administered to the patient for about 20 days. The genomic differences that emerged between the isolates and the control strains were indicative of a certain degree of genetic diversity between C. lipolytica isolates from different geographical areas.