Combination of cytokine-induced killer and dendritic cells pulsed with antigenic α-1,3-galactosyl epitope-enhanced lymphoma cell membrane for effective B-cell lymphoma immunotherapy.

BACKGROUND AIMS: Refractory B-cell lymphomas are difficult to successfully treat with current chemotherapeutic regimens; however, immunotherapy may be an effective form of treatment for these patients. METHODS: Fourteen refractory lymphoma patients (age, 29-74 y) were enrolled in the trial. α-1,3-galactosyl (α-Gal) epitopes were synthesized on lymphoma cell membranes with the use of bovine recombinant α-1,3-galactosyltransferase (α-GT) and neuraminidase to enhance tumor immunogenicity. Subsequent incubation of processed cell membranes with autologous dendritic cells (DCs) in the presence of human serum containing abundant natural anti-α-Gal immunoglobulin G led to the effective phagocytosis of tumor membranes by DCs. The pulsed DCs and autologous cytokine-induced killer cells were then co-cultured to promote maximum cytotoxicity to lymphoma cells and were infused back into the donor lymphoma patients. Therapeutic responses were assessed by clinical observation, laboratory tests and a computed tomography scan at 6 months after treatment. RESULTS: Complete and partial remission occurred in four and three patients, respectively. The disease status remained unchanged in five patients, and disease progression was observed in two patients. No serious side effects or autoimmune diseases were observed in any participants. Serum lactate dehydrogenase and ß2-macroglobulin decreased in 11 and 14 patients, respectively. All patients showed robust systemic cytotoxicity in response to tumor lysate as measured by interferon-γ expression in peripheral blood mononuclear cells after treatment (P < 0.001). The number of peripheral immune effector cells (CD3(+)/CD4(+), CD8(+)/CD28(+) and CD16(+)/CD56(+) cells) increased significantly (P < 0.05) 3 months after treatment. CONCLUSIONS: Lymphoma cell-specific α-Gal immunotherapy is safe, effective and has great potential for the treatment of refractory B-cell lymphoma.

Pancreatic carcinoma-specific immunotherapy using synthesised alpha-galactosyl epitope-activated immune responders: findings from a pilot study.

BACKGROUND: Dendritic cell (DC)-based and cytokine-induced killer cell (CIK)-based therapy can induce specific antitumor T-cell responses. This clinical pilot study examined the safety, the feasibility, and the outcome of tumor-specific immunotherapy for patients with advanced pancreatic adenocarcinoma. METHODS: Alpha-Gal epitopes were synthesised on pancreatic carcinoma cell membranes with α1,3-galactosyltransferase in vitro. Subsequently, the addition of natural human anti-Gal IgG to the processed membranes resulted in opsonization and effective phagocytosis by DCs, which were co-cultured with newly differentiated CIKs from bone marrow stem cells to generate tumor-specific immune responders ex vivo. Fourteen patients with inoperable stage III/IV pancreatic adenocarcinoma were enrolled in the study; the treatment procedure consisted of injections of DCs and CIKs. RESULTS: Clinical observation showed that the procedure was safe and lacked serious side effects. Tests showed that 12 patients had strong positive delayed-type IV hypersensitivity to the autologous cancer cell lysate; robust systemic cytotoxicity elicited by interferon (IFN)γ expression by peripheral blood mononuclear cells; and significant increases in CD3+CD8+, CD3+CD45RO+, and CD3+CD56+ cells in peripheral blood lymphocytes after 3 injections. During the follow up, the percentages of CD3+CD8+, CD3+CD45RO+, and CD3+CD56+ cells returned to the normal range at 6 to 9 months after the third injection and IFNγ expression in the cells stayed at the higher level from the third injection to 24 months after the treatment. CONCLUSIONS: This new tumor-specific immunotherapy is safe, feasible, and has great potential for pancreatic carcinoma treatment.

Immunity Enhancement in Immunocompromised Gastrointestinal Cancer Patients with Allogeneic Umbilical Cord Blood Mononuclear Cell Transfusion.

Objectives. In order to enhance the immunity of cancer patients to prevent relapse or to prolong survival time, umbilical cord blood mononuclear cells (UCMCs) were transplanted to cancer patients. Patients and Methods. UCMCs were transfused to 63 immunocompromised gastrointestinal cancer patients with nonmyeloablative (NMA) conditioning regimen. Results. The clinical study showed that the number of both T and B cells increased much more rapidly after transfusion of UCMCs than that of the control group without transplantation (p < 0.01). Proinflammation cytokines IFNγ and TNFα in serum increased to or above the normal range in 80.9% of patients at 12 weeks after UCMC transfusion. However, they recovered to the normal range in 21.7% of patients at the same time point in the control group only. In addition, the clinical investigation also showed that the transfusion of UCMC increased stable disease (SD) and reduced progressive disease (PD) significantly (p < 0.01); however, it did not have significant effects on complete response (CR), partial response (PR), or mortality rates compared with the control group (p > 0.05). Conclusions. UCMCs have powerful repairing effects on damaged cells and tissues and may reconstruct the impaired immunity. Transfusion of UCMCs could reconstruct the immunity of cancer patients with immunosuppression.

Human umbilical cord mesenchymal stromal cells suppress MHC class II expression on rat vascular endothelium and prolong survival time of cardiac allograft.

BACKGROUND: Human umbilical cord mesenchymal stromal cells (UC-MSCs) have low immunogenicity and immune regulation. To investigate immunomodulatory effects of human UC-MSCs on MHC class II expression and allograft, we transplanted heart of transgenic rats with MHC class II expression on vascular endothelium. METHODS: UC-MSCs were obtained from human umbilical cords and confirmed with flow cytometry analysis. Transgenic rat line was established using the construct of human MHC class II transactivator gene (CIITA) under mouse ICAM-2 promoter control. The induced MHC class II expression on transgenic rat vascular endothelial cells (VECs) was assessed with immunohistological staining. And the survival time of cardiac allograft was compared between the recipients with and without UC-MSC transfusion. RESULTS: Flow cytometry confirmed that the human UC-MSCs were positive for CD29, CD44, CD73, CD90, CD105, CD271, and negative for CD34 and HLA-DR. Repeated infusion of human UC-MSCs reduced MHC class II expression on vascular endothelia of transplanted hearts, and increased survival time of allograft. The UC-MSCs increased regulatory cytokines IL10, transforming growth factor (TGF)-ß1 and suppressed proinflammatory cytokines IL2 and IFN-γ in vivo. The UC-MSC culture supernatant had similar effects on cytokine expression, and decreased lymphocyte proliferation in vitro. CONCLUSIONS: Repeated transfusion of the human UC-MSCs reduced MHC class II expression on vascular endothelia and prolonged the survival time of rat cardiac allograft.

Hepatocellular carcinoma-specific immunotherapy with synthesized α1,3- galactosyl epitope-pulsed dendritic cells and cytokine-induced killer cells.

AIM: To evaluate the safety and clinical efficacy of a new immunotherapy using both α-Gal epitope-pulsed dendritic cells (DCs) and cytokine-induced killer cells. METHODS: Freshly collected hepatocellular carcinoma (HCC) tumor tissues were incubated with a mixture of neuraminidase and recombinant α1,3-galactosyltransferase (α1,3GT) to synthesize α-Gal epitopes on carbohydrate chains of the glycoproteins of tumor membranes. The subsequent incubation of the processed membranes in the presence of human natural anti-Gal IgG resulted in the effective phagocytosis to the tumor membrane by DCs. Eighteen patients aged 38-78 years with stage III primary HCC were randomLy chosen for the study; 9 patients served as controls, and 9 patients were enrolled in the study group. RESULTS: The evaluation demonstrated that the procedure was safe; no serious side effects or autoimmune diseases were observed. The therapy significantly prolonged the survival of treated patients as compared with the controls (17.1 ± 2.01 mo vs 10.1 ± 4.5 mo, P = 0.00121). After treatment, all patients in the study group had positive delayed hypersensitivity and robust systemic cytotoxicity in response to tumor lysate as measured by interferon-γ-expression in peripheral blood mononuclear cells using enzyme-linked immunosorbent spot assay. They also displayed increased numbers of CD8-, CD45RO- and CD56-positive cells in the peripheral blood and decreased α-fetoprotein level in the serum. CONCLUSION: This new tumor-specific immunotherapy is safe, effective and has a great potential for the treatment of tumors.