Simultaneous targeting of PD-1 and IL-2Rßγ with radiation therapy inhibits pancreatic cancer growth and metastasis.

In pancreatic ductal adenocarcinoma (PDAC) patients, we show that response to radiation therapy (RT) is characterized by increased IL-2Rß and IL-2Rγ along with decreased IL-2Rα expression. The bispecific PD1-IL2v is a PD-1-targeted IL-2 variant (IL-2v) immunocytokine with engineered IL-2 cis targeted to PD-1 and abolished IL-2Rα binding, which enhances tumor-antigen-specific T cell activation while reducing regulatory T cell (Treg) suppression. Using PD1-IL2v in orthotopic PDAC KPC-driven tumor models, we show marked improvement in local and metastatic survival, along with a profound increase in tumor-infiltrating CD8+ T cell subsets with a transcriptionally and metabolically active phenotype and preferential activation of antigen-specific CD8+ T cells. In combination with single-dose RT, PD1-IL2v treatment results in a robust, durable expansion of polyfunctional CD8+ T cells, T cell stemness, tumor-specific memory immune response, natural killer (NK) cell activation, and decreased Tregs. These data show that PD1-IL2v leads to profound local and distant response in PDAC.

IL-2/IL-2R signaling and IL-2Rα-targeted therapy in anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) is a CD30-positive non-Hodgkin's T­cell lymphoma. Despite the implementation of CD30 antibody-drug conjugate-targeted therapy into front-line treatment regimens, the prognosis of some subtypes of the disease remains unsatisfactory. In the relapsed/refractory setting, effective second-line treatment options are still lacking. However, it has been reported that blockade of direct downstream targets of activator protein­1 (AP-1) transcription factors, which are highly dysregulated in ALCL, results in complete and sustained remission in late-stage relapsed/refractory anaplastic lymphoma kinase (ALK)-positive ALCL patients. Moreover, it has been identified that involvement of the BATF3/AP­1 module promotes lymphomagenesis via oncogenic BATF3/IL-2/IL-2R signaling through hyperphosphorylation of ERK1/2, STAT1, and STAT5 in ALCL cells regardless of their ALK status. Therefore, targeting BATF3/IL-2/IL-2R signaling may represent a novel therapeutic alternative for ALCL patients.

Efficient Non-Viral T-Cell Engineering by Sleeping Beauty Minicircles Diminishing DNA Toxicity and miRNAs Silencing the Endogenous T-Cell Receptors.

Transposon-based vectors have entered clinical trials as an alternative to viral vectors for genetic engineering of T cells. However, transposon vectors require DNA transfection into T cells, which were found to cause adverse effects. T-cell viability was decreased in a dose-dependent manner, and DNA-transfected T cells showed a delayed response upon T-cell receptor (TCR) stimulation with regard to blast formation, proliferation, and surface expression of CD25 and CD28. Gene expression analysis demonstrated a DNA-dependent induction of a type I interferon response and interferon-ß upregulation. By combining Sleeping Beauty transposon minicircle vectors with SB100X transposase-encoding RNA, it was possible to reduce the amount of total DNA required, and stable expression of therapeutic TCRs was achieved in >50% of human T cells without enrichment. The TCR-engineered T cells mediated effective tumor cell killing and cytokine secretion upon antigen-specific stimulation. Additionally, the Sleeping Beauty transposon system was further improved by miRNAs silencing the endogenous TCR chains. These miRNAs increased the surface expression of the transgenic TCR, diminished mispairing with endogenous TCR chains, and enhanced antigen-specific T-cell functionality. This approach facilitates the rapid non-viral generation of highly functional, engineered T cells for immunotherapy.

CD25 siRNA induces Treg/Th1 cytokine expression in rat corneal transplantation models.

Corneal graft rejection is the major reason for transplant failure. CD25 plays an important role in the induction of corneal graft rejection by regulating CD4(+) T cell function. Furthermore, CD25-mediated signaling is closely associated with the expression of Treg cytokines (IL-10, TGF-ß) and Th1 cytokines (IFN-γ, IL-1ß, and TNF-α). In the current study, corneal transplantation was performed on Wistar rats as donors and Sprague-Dawley rats as recipients. The survival curves indicated that CD25 siRNA treatment significantly prolonged graft survival time (mean survival time [MST], 14.8 ± 0.7 days) as compared with controls (MST, 7.6 ± 0.7 days; n = 12, p < 0.01). HE staining showed that CD25 siRNA alleviated inflammatory cell infiltration. At days 3, 7, 14, and 21, the mRNA and protein expression of CD25 in the CD25 siRNA groups were less than those of the control group, although the most significant decrease of CD25 protein was at day 3. The expression of IL-10 and TGF-ß in the CD25 siRNA group increased, while IFN-γ, IL-1ß, and TNF-α expression decreased, as well as no significant changes in Foxp3 expression were observed at day 14 post-operation. In conclusion, CD25 siRNA gene therapy played a protective role in corneal graft rejection via up-regulation of Treg cytokine expression and down-regulation of Th1 cytokine expression.

Safety and efficacy of daclizumab in relapsing-remitting multiple sclerosis: 3-year results from the SELECTED open-label extension study.

BACKGROUND: Daclizumab is a humanized monoclonal antibody against CD25 that modulates interleukin 2 signaling. The SELECT TRILOGY of clinical studies (SELECT/SELECTION/SELECTED) evaluated the safety and efficacy of daclizumab in patients with relapsing-remitting multiple sclerosis (RRMS). We report the long-term safety and efficacy of daclizumab 150 mg subcutaneous every 4 weeks in patients with RRMS in the SELECTED open-label extension study. METHODS: An interim intent-to-treat analysis of all enrolled patients was performed in January 2014 for this ongoing study. RESULTS: The SELECTED study enrolled 90% of patients who completed SELECTION. In the safety and efficacy analysis (N = 410), median treatment time in SELECTED was 25 months (range, <1-45). Adverse events (AEs) were reported in 76% of patients, serious AEs (SAEs) excluding MS relapse in 16%, and treatment discontinuation due to AEs including multiple sclerosis (MS) relapse in 12%. AEs were primarily of mild to moderate severity, and common AEs (≥10%), excluding MS relapse, were nasopharyngitis (12%) and upper respiratory tract infection (12%). Most commonly reported SAEs (in ≥3 patients), excluding MS relapses, were increased serum hepatic enzymes, pneumonia, ulcerative colitis, and urinary tract infection (<1% each). Incidences of AE groups of interest include cutaneous events (28%), cutaneous SAEs (2%), gastrointestinal SAEs (2%), hepatic SAEs, (1%) and malignancies (1%). The incidence of AEs, SAEs, and treatment-related study discontinuations did not increase over time and no deaths were reported. The adjusted annualized relapse rate (95% confidence interval (CI)) analyzed at 6-month intervals was 0.15 (0.10-0.22) for weeks 97-120 and 0.15 (0.10-0.21) for weeks 121-144. In year 3, the adjusted mean (95% CI) number of new/newly enlarging T2 hyperintense lesions was 1.26 (0.93-1.72) and the mean (median) annualized change in brain volume was -0.32% (-0.34%). CONCLUSIONS: The AE incidence did not increase with extension of therapy into year 3 in SELECTED; the safety profile was similar to that previously observed. The clinical efficacy of daclizumab was sustained over the 3 years comprising the SELECT TRILOGY, although potential selection bias cannot be excluded. TRIAL REGISTRATION: Clinicaltrials.gov NCT01051349; first registered January 15, 2010.

[The treatment by expanded ex vivo autologous regulatory T-cells CD4+CD25+FoxP3+CD127low restores the balance of immune system in patients with remitting-relapsing multiple sclerosis]. / Lechenie vyrashchennymi ex vivo autologichnymi regulyatornymi T-kletkami CD4+CD25+FOXP3+CD127low vosstanavlivaet balans immunnoi sistemy patsientov s remittiruyushchim rasseyannym sklerozom.

AIM: To assess clinical efficacy and safety of the autologous (own) regulatory T-cells (Tregs)CD4+CD25+Foxp3+CD127low isolated from the blood of patients with remitting-relapsing multiple sclerosis. Patients with autoimmune diseases have the decreased number of peripheral Tregs (pTreg) and impaired suppressive ability. In order to restore levels of pTreg, it is possible to isolate precursor cells, enter expanded ex vivo autologous Treg cells and introduce an expanded amount of autologous cells as Treg vaccine. MATERIAL AND METHODS: A method of ex vivo Tregs expansion by 30-40 times within 5-7 days has been developed. Expanded ex vivo Tregs are more than 90% CD4+CD25+Foxp3+CD127low and have high suppressor activity. Fourteen patients with remitting-relapsing multiple sclerosis were included in pilot studies.Ex vivoTregs were introduced subcutaneously in dosefrom 2.8 to 4.5 108 cell per injection. The duration of follow-up was 1 year. RESULTS AND CONCLUSION: The numbers of pTregs in the blood of these patients elevated by 1.5-2 times. No adverse-effects, a decrease of relapses and stabilization of disability index were observed. It has been suggested that ex vivo expanded Tregs can compensate the impaired function of pTregs and can be used for adoptive immunotherapyof multiple sclerosis.

Induction immunosuppressive therapy in the elderly kidney transplant recipient in the United States.

BACKGROUND AND OBJECTIVES: The choice of induction agent in the elderly kidney transplant recipient is unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The risks of rejection at 1 year, functional graft loss, and death by induction agent (IL2 receptor antibodies [IL2RA], alemtuzumab, and rabbit antithymocyte globulin [rATG]) were compared among five groups of elderly (≥60 years) deceased-donor kidney transplant recipients on the basis of recipient risk and donor risk using United Network of Organ Sharing data from 2003 to 2008. RESULTS: In high-risk recipients with high-risk donors there was a higher risk of rejection and functional graft loss with IL2RA versus rATG. Among low-risk recipients with low-risk donors there was no difference in outcomes between IL2RA and rATG. In the two groups in which donor or recipient was high risk, there was a higher risk of rejection but not functional graft loss with IL2RA. Among low-risk recipients with high-risk donors, there was a trend toward a higher risk of death with IL2RA. CONCLUSIONS: rATG may be preferable in high-risk recipients with high-risk donors and possibly low-risk recipients with high-risk donors. In the remaining groups, although rATG is associated with a lower risk of acute rejection, long-term outcomes do not appear to differ. Prospective comparison of these agents in an elderly cohort is warranted to compare the efficacy and adverse consequences of these agents to refine the use of induction immunosuppressive therapy in the elderly population.

Interleukin-2 receptor antagonists in liver transplantation: a meta-analysis of randomized trials.

BACKGROUND: The efficacy and safety of interleukin-2 receptor antagonist (IL-2Ra) induction therapy in liver transplantation has not reached a final conclusion. This study sought to explore the effects of IL-2Ra therapy on occurrence of biopsy-proven acute rejection (BPAR), risk of infection, and other adverse events by using meta-analysis. METHODS: We reviewed randomized trials assessing IL-2Ra therapeutic effects in liver transplantation. We synthesized published data using the random-effects and fixed-effect models, expressing results as relative risk (RR) with 95% confidence intervals (CI). RESULTS: Among 12 trials including 3,251 participants, IL-2Ra significantly reduced the incidence of BPAR (RR 0.82, 95% CI 0.68-0.99) and de novo diabetes mellitus (RR 0.75, 95% CI 0.62-0.91) within 1 year. Subgroup analysis showed only daclizumab but not basiliximab treatment to significantly benefit BPAR and de novo diabetes mellitus. There were no significant differences in the graft losses (RR 1.05, 95% CI 0.85-1.31), mortality rates (RR 0.89, 95% CI 0.70-1.13), overall incidences of infection (RR 0.95, 95% CI 0.87-1.04), incidences of cytomegalovirus infections (RR 0.96, 95% CI 0.65-1.44), risks of malignancies (RR 1.06, 95% CI 0.56-2.01), or de novo hypertension (RR 0.90, 95% CI 0.79-1.03) or and renal insufficiency (RR 0.81, 95% CI 0.56-1.17, P = .26) within 1 year. CONCLUSIONS: The IL-2Ra daclizumab, but not basiliximab, shows significant benefit to reduce acute rejection episodes and de novo diabetes mellitus within 1 year among patients undergoing liver transplantation. There was no evidence of an increased risk of infection or other side effects.

The impact of IL2ra induction therapy in kidney transplantation using tacrolimus- and mycophenolate-based immunosuppression.

BACKGROUND: IL2 receptor antagonist (IL2ra) induction therapy has gained favor due to an excellent safety profile and improved outcomes in randomized trials using cyclosporine-based immunosuppression. However, there have been no large randomized trials or retrospective analyses examining the effect of IL2ra versus no induction using tacrolimus and mycophenolate (TAC/MPA)-based therapy. METHODS: A retrospective analysis from the Scientific Renal Transplant Registry of adult, primary kidney transplant recipients from 2000 to 2008 with initial immunosuppression of TAC/MPA and prednisone, who received IL2ra induction therapy or no induction therapy (n=28,686) was performed. The primary outcome was acute rejection at 1 year, and secondary outcomes were graft and patient survival at 1 and 3 years. Multivariable analysis was used to control for factors shown to influence the incidence of acute rejection, and separate analyses were performed for deceased versus living donors. RESULTS: Acute rejection at 1 year was significantly lower with IL2ra (11.6%) versus no induction therapy (13.0%; P=0.001). One-year (95.7% vs. 95.8%) and 3-year (87.5% vs. 87.8%) graft survival, and 1-year (97.4% vs. 97.5%) and 3-year (92.8% vs. 93.2%) patient survival, was not different between those receiving IL2ra and no induction therapy. On multivariable analysis, the relative risk of acute rejection with IL2ra was 0.90 (95% CI, 0.85-0.96; P=0.001), and the effect was greater in living donors (relative risk, 0.82; P<0.001) than deceased donors (relative risk, 0.95; P=0.23). CONCLUSION: The benefit of IL2ra induction with TAC/MPA/prednisone maintenance immunosuppression is less than previously reported due to a low baseline incidence of acute rejection.

A review of the evidence for use of thymoglobulin induction in renal transplantation.

Depleting antilymphocyte, or antithymocyte antibodies, have long been an integral part of induction regimens and continue today to be used in the management of patients at risk of early rejection or those in whom the introduction of calcineurins or other immune suppressants must be delayed. Registry data demonstrate that the most commonly used depleting antibody, rabbit anti-human thymocyte globulin (rATG), is associated with improved outcomes following renal transplantation in high-risk patients, particularly in conjunction with steroid-avoidance regimens. Two prospective randomized trials in high-risk renal allograft patients have also demonstrated an advantage of r-ATG induction compared to the nondepleting interleukin receptor (IL2RA) antibodies. In low-immunologic-risk patients, however, r-ATG induction and IL2RA induction appear to be equivalent in terms of rejection prophylaxis and long-term function. Other studies have shown that sequential rATG-containing regimens were superior to no induction and allowed for successful late introduction of calcineurin inhibitors. The side effect profile of the depleting antibody included increased incidence of fever, hematologic abnormalities, cytomegalovirus infections when prophylaxis was not employed, and in some studies, increased incidence of posttransplant lymphoproliferative disease. This review describes the evidence supporting the use of depleting ATGs in kidney transplantation.

Phase II trial of subcutaneous injections of human recombinant interleukin-2 for the treatment of mycosis fungoides and Sézary syndrome.

We conducted a phase II trial to evaluate the efficacy and toxicity of subcutaneous injections of recombinant interleukin (IL)-2 in 22 heavily pretreated patients with advanced cutaneous T-cell lymphoma. We observed modest response rates (18%) with a reasonable toxicity profile. The role of IL-2 in vivo for expansion of cytotoxic CD8(+) T cells, CD4(+) T cells, regulatory CD25(+) T cells, or a combination of these has not been elucidated. There was no evidence of expansion of CD8(+) T cells in peripheral blood of patients during treatment. Immunophenotypic analysis revealed an increase of CD25(+) cells in CD3(+) and CD4(+) populations after treatment in a subset of patients possibly reflecting activation of reactive helper T cells, proliferation of neoplastic T cells, or proliferation of T-regulatory cells. In summary, at this dose and schedule recombinant IL-2 is largely ineffective as therapy in patients with advanced cutaneous T-cell lymphoma. Whether IL-2 has the potential to suppress antitumor activity by stimulation of regulatory T cells needs to be clarified.