Helper cell-independent antitumor activity of potent CD8+ T cell epitope peptide vaccines is dependent upon CD40L

Peptide vaccines derived from CD8+ T-cell epitopes have shown variable efficacy in cancer patients. Thus, some peptide vaccines are capable of activating CD8+ T-cell responses, even in the absence of CD4+ T-cell epitopes or dendritic cell (DC)-activating adjuvants. However, the mechanisms underlying the clinical activity of these potent peptides are poorly understood. Using CT26 and ovalbumin-expressing B16 murine allograft tumor models, we found that the antitumor effect of helper cell-independent CD8 T-cell peptide vaccines is inhibited by the blockade of CD40 ligand (CD40L) in vivo. Furthermore, in vitro stimulation with antigenic peptides of cells derived from immunized mice induced the expression of CD40L on the surface of CD8+ T cells and fostered DC maturation, an effect that was partially inhibited by CD40L-blocking antibodies. Interestingly, CD40L blockade also inhibited CD8+ T-cell responses, even in the presence of fully mature DCs, suggesting a role for CD40L not only in promoting DC maturation but also in mediating CD8+ T-cell co-stimulation. Importantly, these potent peptides share features with bona fide CD4 epitopes, since they foster responses against less immunogenic CD8+ T-cell epitopes in a CD40L-dependent manner. The analysis of peptides used for the vaccination of cancer patients in clinical trials showed that these peptides also induce the expression of CD40L on the surface of CD8+ T cells. Taken together, these results suggest that CD40L expression induced by potent CD8+ T-cell epitopes can activate antitumor CD8+ T-cell responses, potentially amplifying the immunological responses to less immunogenic CD8+ T-cell epitopes and bypassing the requirement for CD4+ helper T cells in vaccination protocols

Tumor therapy in mice by using a tumor antigen linked to modulin peptides from Staphylococcus epidermidis

Staphylococcus epidermidis releases a complex of at least four peptides, termed phenol-soluble modulins (PSM), which stimulate macrophages to produce proinflammatory cytokines via activation of TLR2 signalling pathway. We demonstrated that covalent linkage of PSM peptides to an antigen facilitate its capture by dendritic cells and, in combination with different TLR ligands, can favour the in vivo induction of strong and persistent antigen-specific immune responses. Treatment of mice grafted with HPV16-E7-expressing tumor cells (TC-1) with poly(I:C) and a peptide containing αMod linked to the H-2D(b)-restricted cytotoxic T-cell epitope E7(49-57) from HPV16-E7 protein allowed complete tumor regression in 100% of the animals. Surprisingly, this immunomodulatory property of modulin-derived peptides was TLR2 independent and partially dependent upon the EGF-receptor signalling pathway. Our results suggest that alpha or gamma modulin peptides may serve as a suitable antigen carrier for the development of anti-tumoral or anti-viral vaccines

Improved dendritic cell-based immunization against hepatitis C virus using peptide inhibitors of interleukin 10

The high levels of interleukin 10 (IL-10) present in chronic hepatitis C virus (HCV) infection have been suggested as responsible for the poor antiviral cellular immune responses found in these patients. To overcome the immunosuppressive effect of IL-10 on antigen-presenting cells such as dendritic cells (DCs), we developed peptide inhibitors of IL-10 to restore DC functions and concomitantly induce efficient antiviral immune responses. Two IL-10-binding peptides (p9 and p13) were selected using a phage-displayed library and their capacity to inhibit IL-10 was assessed in a bioassay and in STAT-3 (signal transducer and activator of transcription 3) phosphorylation experiments in vitro. In cultures of human leukocytes where HCV core protein induces the production of IL-10, p13 restored the ability of plasmacytoid DC to produce interferon alpha (IFN-α) after Toll-like receptor 9 (TLR9) stimulation. Similarly, when myeloid DCs were stimulated with CD40L in the presence of HCV core, p9 enhanced IL-12 production by inhibiting HCV core-induced as well as CD40L-induced IL-10. Moreover, in vitro, p13 potentiated the effect of maturation stimuli on human and murine DC, increasing their IL-12 production and stimulatory activity, which resulted in enhanced proliferation and IFN-γ production by responding T-cells. Finally, immunization with p13-treated murine DC induced stronger anti-HCV T-cell responses not only in wildtype mice but also in HCV transgenic mice and in mice transiently expressing HCV core in the liver. CONCLUSION: These results suggest that IL-10 inhibiting peptides may have important applications to enhance anti-HCV immune responses by restoring the immunostimulatory capabilities of DC

Improved dendritic cell-based immunization against hepatitis C virus using peptide inhibitors of interleukin 10

The high levels of interleukin 10 (IL-10) present in chronic hepatitis C virus (HCV) infection have been suggested as responsible for the poor antiviral cellular immune responses found in these patients. To overcome the immunosuppressive effect of IL-10 on antigen-presenting cells such as dendritic cells (DCs), we developed peptide inhibitors of IL-10 to restore DC functions and concomitantly induce efficient antiviral immune responses. Two IL-10-binding peptides (p9 and p13) were selected using a phage-displayed library and their capacity to inhibit IL-10 was assessed in a bioassay and in STAT-3 (signal transducer and activator of transcription 3) phosphorylation experiments in vitro. In cultures of human leukocytes where HCV core protein induces the production of IL-10, p13 restored the ability of plasmacytoid DC to produce interferon alpha (IFN-α) after Toll-like receptor 9 (TLR9) stimulation. Similarly, when myeloid DCs were stimulated with CD40L in the presence of HCV core, p9 enhanced IL-12 production by inhibiting HCV core-induced as well as CD40L-induced IL-10. Moreover, in vitro, p13 potentiated the effect of maturation stimuli on human and murine DC, increasing their IL-12 production and stimulatory activity, which resulted in enhanced proliferation and IFN-γ production by responding T-cells. Finally, immunization with p13-treated murine DC induced stronger anti-HCV T-cell responses not only in wildtype mice but also in HCV transgenic mice and in mice transiently expressing HCV core in the liver. CONCLUSION: These results suggest that IL-10 inhibiting peptides may have important applications to enhance anti-HCV immune responses by restoring the immunostimulatory capabilities of DC

The prevalence of abnormal glucose regulation in patients with coronary artery disease across Europe: The Euro Heart Survey on diabetes and the heart

Aim The objective behind the Euro Heart Survey on diabetes and the heart was to study the prevalence of abnormal glucose regulation in adult patients with coronary artery disease (CAD). Methods and results The survey engaged 110 centres in 25 countries recruiting 4196 patients referred to a cardiologist due to CAD out of whom 2107 were admitted on an acute basis and 2854 had an elective consultation. Patient data were collected via a web-based case record form. An oral glucose tolerance test (OGTT) was used for the characterisation of the glucose metabolism. Thirty-one per cent of the patients had diabetes. An OGTT was performed on the 1920 patients without known diabetes, of whom 923 had acute and 997 had a stable manifestation of CAD, respectively. In patients with acute CAD, 36% had impaired glucose regulation and 22% newly detected diabetes. In the stable group these proportions were 37% and 14%. Conclusion This survey demonstrates that normal glucose regulation is less common than abnormal glucose regulation in patients with CAD. OGTT easily discloses the glucometabolic state and should be a routine procedure. The knowledge of glucometabolic state among these patients should influence their future management because it has great potential to improve the outcome

PERTINENT - PERindopril-Thrombosis, InflammatioN, endothelial dysfunction and neurohormonal activation trial: A sub-study of the EUROPA study

BACKGROUND: Markers of thrombosis, inflammation, endothelial dysfunction and neurohumoral activation such as fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A are reported to be linked to the increase of cardiovascular risk for atherosclerosis progression and events in patients with cardiovascular diseases. METHODS: EUROPA is a double blind, placebo-controlled trial on 12,231 patients that evaluates the effect of an angiotensin converting enzyme inhibitor--perindopril--on prevention of cardiovascular events in patients with coronary artery disease. PERTINENT is a sub-study of EUROPA that evaluates (a) in Part A (300 patients): the influence of perindopril vs. placebo on fibrinogen, D-dimer, C-reactive protein, von Willebrand factor, tumour necrosis factor-alpha and chromogranin-A. In addition, NOS expression and induction of apoptosis on human umbilical vein endothelial cells and angiotensin converting enzyme levels are also studied; (b) in Part B (about 1200 patients): the predictive role of plasma levels of C-reactive protein and von Willebrand factor on the occurrence of cardiovascular events. To this end, matched case-control analyses are planned (patients with vs. patients without events). STATUS OF PERTINENT: Blood analyses are in progress in four specialised laboratories: (a) Gaubius Laboratory, Leiden, TNO-PG, The Netherlands; (b) University Department of Medicine, Birmingham, UK; (c) University of Pavia, Italy; (d) Fondazione Salvatore Maugeri, Cardiovascular Research Centre, Gussago, Italy. CONCLUSIONS: The PERTINENT sub-study might help elucidating the phenomena contributing to the pathophysiology of cardiovascular events in patients with coronary artery disease and the role of perindopril in such context

the European trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease Investigators. Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA trial).

Background Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. Methods We recruited patients from October, 1997, to June, 2000. 13 655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12 218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4·2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. Findings Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% CI 9–29, p=0·0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. Interpretation Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease

Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA study)

BACKGROUND: Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. METHODS: We recruited patients from October, 1997, to June, 2000. 13655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4.2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. FINDINGS: Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% beta blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% CI 9-29, p=0.0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. INTERPRETATION: Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease