Conditional IL-2 Gene Deletion: Consequences for T Cell Proliferation

To explore the role of interleukin-2 (IL-2) in T cell proliferation, and to circumvent the IL-2 deficiency autoimmune syndrome of conventional il2 gene deletion, mice were created to allow conditional il2 gene deletion when treated with the estrogen analog, tamoxifen (TAM) as adults. Splenocytes from four different mouse strains, C57Bl/6 wild type (WT), conventional IL-2(−/−), TAM-treated Cre recombinase-negative (Cre−)/IL2fl/fl, and Cre recombinase-positive (Cre+)/IL2fl/fl, were activated with anti-CD3 and anti-CD28, and monitored for CD4+ and CD8+ T cell lymphocyte blastogenesis, aerobic glycolysis, BrdU incorporation into newly synthesized DNA, and CFSE dye dilution to monitor cell division. IL-2 production was monitored by quantitative ELISA and multiple additional cytokines were monitored by quantitative protein-bead arrays. Splenocytes from conventional IL-2(−/−) and TAM-treated Cre+ mice resulted in undetectable IL-2 production by ELISA, so that both strains were IL-2-deficient. As monitored by flow cytometry, activated CD4+ and CD8+ T cells from WT, Cre+, and Cre− mice all underwent blastogenesis, whereas far fewer cells from conventional IL-2(−/−) mice did so. By comparison, only cells from IL-2 sufficient WT and Cre− mice switched to aerobic glycolysis as evidenced by a drop in media pH. Blastogenesis was mirrored by BrdU incorporation and CFSE dye dilution by CD4+ and CD8+ T cells from WT, Cre+, and Cre− mice, which were all equivalent, while proliferation of cells from conventional IL-2(−/−) mice was compromised. Splenocytes from IL-2 deficient conventional IL-2(−/−) mice produced low or undetectable other γc-chain cytokines (IL-4, IL-7, IL-9, IL-13, IL-15, and IL-21), whereas production of these γc-chain cytokines from IL-2-deficient conditional IL-2(−/−) Cre+ mice were comparable with WT and Cre− mice. These results indicate that CD4+ and CD8+ T cell blastogenesis cannot be attributable to IL-2 alone, but a switch to aerobic glycolysis was attributable to IL-2, and proliferation after CD3/CD28 activation is dependent on γc-chain cytokines, and not CD3/28 triggering per se

Evaluation of two doses of etoricoxib, a COX-2 selective non-steroidal anti-inflammatory drug (NSAID), in the treatment of Rheumatoid Arthritis in a double-blind, randomized controlled trial

List of Ethics Committees. (DOCX 38 kb

A randomized, clinical trial to assess the relative efficacy and tolerability of two doses of etoricoxib versus naproxen in patients with ankylosing spondylitis

Background This study evaluated two doses of etoricoxib (60 and 90 mg) vs. naproxen 1000 mg in subjects with ankylosing spondylitis (AS). Methods This was a 2-part, double-blind, active comparator-controlled non-inferiority study in subjects ≥18 years of age with AS. In Part I, subjects were randomized to naproxen 1000 mg; etoricoxib 60 mg, and 90 mg. In Part II, naproxen and etoricoxib 90 mg subjects continued on the same treatment; subjects on etoricoxib 60 mg either continued on 60 mg or escalated to 90 mg. Part I (6 weeks) assessed the efficacy of A) etoricoxib 60 mg vs. naproxen and B) 90 mg vs. naproxen according to the time-weighted average change from baseline in Spinal Pain Intensity (SPI; 0–100 mm VAS) (primary endpoint). The non- inferiority margin was set at 8 mm for SPI. In Part II (20 weeks) we evaluated the potential benefit of increasing from 60 to 90 mg (predefined minimum clinically important difference = 6 mm in SPI) for inadequate responders (<50 % improvement from baseline in SPI) onetoricoxib 60 mg in Part I. Results In total, 1015 subjects were randomized to receive etoricoxib 60 mg (N = 702), etoricoxib 90 mg (N = 156), and naproxen 1000 mg (N = 157); 70.9 % were male and the mean age was 45.2 years. There were 919 subjects who completed Part I and all continued to Part II. In Part I, SPI change was non-inferior for both etoricoxib doses vs. naproxen. In both Part I and II, the incidence of adverse events (AEs), drug-related AEs, and serious adverse events (SAEs) were similar between the 3 treatment groups. Conclusion Both doses of etoricoxib were non- inferior to naproxen. All treatments were well tolerated. Etoricoxib 60 and 90 mg effectively control pain in patients with AS, with 60 mg once daily as the lowest effective dose for most patients. Trial registration Clinical Trials Registry # NCT01208207. Registered on 22 September 2010

Immunotherapy with Canarypox Vaccine and Interleukin-2 for HIV-1 Infection: Termination of a Randomized Trial

OBJECTIVES: To determine whether immunotherapy of chronic HIV-1 infection can prevent or attenuate viremia upon antiviral discontinuation. DESIGN: This was a Phase II randomized, partially double blinded, 2×2 factorial study of three steps of 12 wk/step. Step I involved four groups: (1) vaccine placebo, (2) vaccine (ALVAC, vCP1452), (3) placebo + interleukin 2 (IL-2), and (4) vaccine + IL-2. Step II involved a 12-wk diagnostic treatment interruption (DTI). Step III involved an extension of the DTI for an additional 12 wk. SETTING: The Weill-Cornell General Clinical Research Center. PARTICIPANTS: Chronically infected HIV-1 positive adults with undetectable HIV-1 levels and > 400 CD4(+) T cells/μl. INTERVENTIONS: An HIV canarypox vaccine (vCP1452) and vaccine placebo, administered every 4 wk for four doses, and low-dose IL-2 administered daily for 12–24 wk. OUTCOME MEASURES: Primary endpoints: (1) Proportion of participants with undetectable plasma HIV RNA during trial Step II, (2) mean log(10) HIV RNA copies/ml ([HIV]) from weeks 21–25, and (3) proportion of individuals eligible for trial Step III. RESULTS: 44 participants were randomized, but 16 withdrew or were withdrawn before completing Step II. As all participants underwent viral relapse in Step II, the study was terminated after 28 participants completed Step II. Among the four groups, there was no difference in mean [HIV] or the proportion of individuals with < log(10) 4.48 HIV; no difference between the mean [HIV] of the two groups that received ALVAC (n = 17) versus placebo (n = 11); and no significant difference between the mean [HIV] of the two groups that received IL-2 (n = 11) versus placebo (n = 17). CONCLUSIONS: Neither ALVAC (vCP1452) nor low-dose daily IL-2 nor their combination prevented the relapse of viremia upon discontinuation of antiviral therapy

Negative Feedback Regulation of T Cells via Interleukin-2 and FOXP3 Reciprocity

As interleukin-2 (IL2) is central to the clonal expansion of antigen-selected T cells, we investigated the relationship between IL2 and the negative regulatory transcription factor FOXP3. We found IL2 to be responsible for T cell antigen receptor (TCR)-activated FOXP3 expression by both CD4+ and CD8+ human T cells, and as anticipated, FOXP3 expression restricted TCR-stimulated IL2 expression. However, no evidence could be found that FOXP3+ cells actively suppress IL2 expression by FOXP3- cells. These data are consistent with an IL2/FOXP3-dependent negative feedback loop that normally regulates the T cell immune response. It follows that a defect in this negative feedback loop as a result of a deficiency of either IL2 or FOXP3 will lead to a hyperproliferative autoimmune syndrome, without the necessity of invoking an active suppressive function for FOXP3+ T cells

Studies with herpes zoster vaccines in immune compromised patients

Introduction: The active component of the herpes zoster vaccine (ZVL), licensed for people ≥50 years of age, is a live attenuated varicella-zoster virus. ZVL is contraindicated for immune compromised individuals, with limited regard to the degree of immunosuppression. Areas covered: This review evaluates phase I and II and observational studies for ZVL, and published reports of the off-label use of ZVL, for conditions and therapies for which investigators considered the risk-benefit for using ZVL to be favorable. It also discusses exploratory trials of ZVL for additional immune compromising conditions, and summarizes clinical guidelines from many countries and professional societies that are based upon recent investigations. Studies in immune compromised patients of investigational vaccines that do not contain live virus are reviewed. Expert commentary: It is likely that past and ongoing research with ZVL will define immune compromising diseases and/or therapies for which the risk-benefit for using ZVL vaccine is favorable. The main variables to consider in this assessment in immune compromised patients are safety, immunogenicity, protection against herpes zoster, and persistence of protection. Vaccination against herpes zoster prior to suppressing immunity is an important clinical strategy, although efficacy of this approach has not been evaluated in a clinical trial

A post hoc analysis utilizing the FDA toxicity grading scale to assess injection site adverse events following immunization with the live attenuated Zoster Vaccine (ZVL)

Background: ZOSTAVAX (ZVL; Zoster Virus Live), is a single dose, live, attenuated vaccine licensed for the prevention of herpes zoster (HZ) and post herpetic neuralgia (PHN) in adults ≥50 years of age. Injection site adverse events (AEs) of erythema, swelling and pain were solicited within 5 days post vaccination in the 2 pivotal studies of ZVL; ZEST (ZOSTAVAX Efficacy and Safety Trial) and SPS (Shingles Prevention Study). Protocol specified criteria were used to report the frequency and intensity of injection site AEs in ZEST and SPS studies. Subsequently, the FDA Toxicity Grading Scale provided guidance for uniform assessment of AEs across all adult vaccine clinical trials. The objective of this post-hoc analysis was to categorize the previously reported injection site AEs in two pivotal trials of ZVL according to the current FDA Toxicity Grading Scale. Methods: The current FDA Toxicity Grading Scale provides a measure for classifying injection site AEs by four grades [Grade 1 (mild); Grade 2 (moderate); Grade 3 (severe) and Grade 4 (life threatening)]. Injection site erythema, swelling, and pain intensity gradings were assigned to the respective FDA Toxicity Grade based on this appropriation. A descriptive analysis of the proportion and risk difference (within 95% confidence intervals) of injection site AEs per the FDA Toxicity Grading Scale is provided. Results: The frequency of injection site AEs (erythema, swelling, pain) after subcutaneous vaccination with ZVL were higher in recipients of ZVL compared with placebo. Majority of the injection site AEs observed were Grade 1 (mild) or Grade 2 (moderate) in intensity. Additionally, Grade 3 (severe) injection site AEs were observed infrequently. Conclusions: Application of the FDA Toxicity Grading Scale provides a uniform AE assessment tool across different adult vaccines. This post hoc summary of injection site AEs using FDA Toxicity Grading Scale provides further evidence of low frequency of severe injection site AEs post ZVL vaccination