Deeds, Michael

Abstract Introduction: Immune suppression is a major component of lymphoma pathogenesis. Recent advances in lymphoma treatment have been immunotherapy. We present the preliminary results of our clinical trial testing 2 vaccine strategies in patients with indolent B-cell non-Hodgkin lymphoma (NHL). The primary objective is to determine the safety and feasibility of the vaccine approaches and secondary objectives are to describe clinical responses and identify corresponding immune changes. Methods: Autologous mature dendritic cells (mDC) were manufactured from leukapheresed cells of NHL pts. For patients with tumor lymph nodes deemed amenable to cryoablation by interventional radiologist (arm A), they received cryoablation of a node and injection of mDC into the cryoablated node followed by another 1 to 7 intratumoral mDC injections. Remaining patients had a tumor excised to generate tumor lysate ex vivo. mDC were pulsed with tumor lysate during DC maturation (arm B; DC-TL). The DC-TL vaccines were injected intradermally for 4 to 8 doses. Patients are monitored for one year after vaccines for adverse events and systemic tumor response. Correlative studies include cellular immune phenotype of peripheral blood and T cell intracellular cytokine productions. Planned accrual is 10 patients per arm (total = 20). Results: To date, 10 patients have accrued to arm A and 5 patients to arm B (Table 1). All pts tolerated vaccine treatments without major adverse events. Of the 10 evaluable patients, there were 1 CR (arm B: 1 / 4; total: 1/6) and 4 PR (arm A: 3/6; arm B: 1 / 4; total: 4/10) for an ORR of 50% for both arms (Figure 1). Time to next treatment ranged from 6.5 to 25 months (Figure 2). Correlative studies suggest that immune changes can be used as prognostic biomarkers to predict response. These include changes in vaccine induced cytokine secretion, and in the number and composition of the immune system. In addition, preliminary analysis of >40 immune phenotypes using flow cytometry and hierarchical clustering suggest there are characteristic immune system responses in patients responding to vaccine. Conclusions: Both cryoablation and intratumoral mDC vaccination are feasible and safe in NHL. Treatment responses may correlate with immune system changes. Biosystems analysis method can be used to develop novel assays as predictive biomarkers of treatment response and used to develop novel protocols that allow treating to response. Table 1. Patient Demographics Arm A (n = 10) Arm B (n = 5) Total (n = 15) Age (median, rage) 64 (55 – 80) 60 (31 – 86) 63 (31 – 86) Gender (M/F) 6/4 2/3 8/7 Histology (n, %) Follicular Marginal zone DLBCL 10 (100%) 0 (0%) 0 (0%) 3 (60%) 1 (20%) 1(20%) 13 (86.6%) 1 (6.7%) 1 (6.7%) Stage (N, %) II III IV 1 (10%) 1 (10%) 8 (80%) 2 (40%) 1 (20%) 2 (40%) 3 (20%) 2 (13.3%) 10 (66.7%) No of prior Tx (mean, range) 2.4 (0-8) 3.2 (0-7) 2.7 (0-8) FLIPI (n, %) 0-1 2 ≥ 3 1 (10%) 2 (20%) 7 (70%) 1 (20%) 2 (40%) 2 (45%) 2 (13.3%) 4 (26.7%) 9 (60%) Positive GELF criteria (n, %) 4 (40%) 1 (20%) 5 (30%) Figure 1. Waterfall plot. Figure 1. Waterfall plot. Figure 2. Time to next treatment. Figure 2. Time to next treatment. Disclosures No relevant conflicts of interest to declare.

Summary Streptozotocin (STZ), a glucosamine-nitrosourea compound, has potent genotoxic effects on pancreatic β-cells and is frequently used to induce diabetes in experimental animals. Glucagon-like peptide-1 (GLP-1) has β-cell protective effects and is known to preserve β-cells from STZ treatment. In this study, we analyzed the mechanisms of STZ-induced diabetes and GLP-1-mediated β-cell protection in STZ-treated mice. At 1 week after multiple low-dose STZ administrations, pancreatic β-cells showed impaired insulin expression, while maintaining expression of nuclear Nkx6.1. This was accompanied by significant upregulation of p53-responsive genes in islets, including a mediator of cell cycle arrest, p21 (also known as Waf1 and Cip1). STZ treatment also suppressed expression of a wide range of genes linked with key β-cell functions or diabetes development, such as G6pc2, Slc2a2 (Glut2), Slc30a8, Neurod1, Ucn3, Gad1, Isl1, Foxa2, Vdr, Pdx1, Fkbp1b and Abcc8, suggesting global β-cell defects in STZ-treated islets. The Tmem229B, Prss53 and Ttc28 genes were highly expressed in untreated islets and strongly suppressed by STZ, suggesting their potential roles in β-cell function. When a pancreas-targeted adeno-associated virus (AAV) vector was employed for long-term Glp-1 gene delivery, pancreatic GLP-1 expression protected mice from STZ-induced diabetes through preservation of the β-cell mass. Despite its potent β-cell protective effects, however, pancreatic GLP-1 overexpression showed limited effects on the global gene expression profiles in the islets. Network analysis identified the programmed-cell-death-associated pathways as the most relevant network in Glp-1 gene therapy. Upon pancreatic GLP-1 expression, upregulation of Cxcl13 and Nptx2 was observed in STZ-damaged islets, but not in untreated normal islets. Given the pro-β-cell-survival effects of Cxcl12 (Sdf-1) in inducing GLP-1 production in α-cells, pancreatic GLP-1-mediated Cxcl13 induction might also play a crucial role in maintaining the integrity of β-cells in damaged islets.

Streptozotocin (STZ)-induced diabetes mellitus (DM) offers a very cost-effective and expeditious technique that can be used in most strains of rodents, opening the field of DM research to an array of genotypic and phenotypic options that would otherwise be inaccessible. Despite widespread use of STZ in small animal models, the data available concerning drug preparation, dosing and administration, time to onset and severity of DM, and any resulting moribundity and mortality are often limited and inconsistent. Because of this, investigators inexperienced with STZ-induced diabetes may find it difficult to precisely design new studies with this potentially toxic chemical and account for the severity of DM it is capable of inducing. Until a better option becomes available, attempts need to be made to address shortcomings with current STZ-induced DM models. In this paper we review the literature and provide data from our pancreatic islet transplantation experiments using single high-dose STZ-induced DM in NCr athymic nude mice with hopes of providing clarification for study design, suggesting refinements to the process, and developing a more humane process of chemical diabetes induction.