Athanassios S. Galanis

Vaccination of Patients With Advanced Non–Small-Cell Lung Cancer With an Optimized Cryptic Human Telomerase Reverse Transcriptase Peptide

PURPOSE To evaluate the immunological and clinical response as well as the safety of the optimized peptide telomerase reverse transcriptase p572Y (TERT572Y) presented by HLA-A*0201 in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Twenty-two patients with advanced NSCLC and residual (n = 8) or progressive disease (PD; n = 14) following chemotherapy and/or radiotherapy received two subcutaneous injections of the optimized TERT572Y peptide followed by four injections of the native TERT572 peptide administered every 3 weeks. Peptide-specific immune responses were monitored by enzyme-linked immunosorbent spot assay and/or TERT572Y pentamer staining. RESULTS Twelve (54.5%) of 22 patients completed the vaccination program. Toxicity consisted primarily of local skin reactions. TERT572-specific CD8+ cells were detected in 16 (76.2%) of 21 patients after the second vaccination, and 10 (90.9%) of 11 patients after the sixth vaccination. Stable disease (SD) occurred in eight (36.4%) of 22 vaccinated patients, with three (13.6%) having had PD before entering the study. The median duration of SD was 11.2 months. After a median follow-up of 10.0 months, patients with early developed immunological response (n = 16) had a significantly longer time to progression and overall survival (OS) than nonresponders (n = 5; log-rank tests P = .046 and P = .012, respectively). The estimated median OS was 30.0 months (range, 2.8 to 40.0 months) and 4.1 months (range, 2.4 to 10.9 months) for responders and nonresponders, respectively. CONCLUSION TERT572Y peptide vaccine is well tolerated and effective in eliciting a specific T cell immunity. Immunological response is associated with prolonged survival. These results are encouraging and warrant further evaluation in a randomized study.

Manufacturing peptides as active pharmaceutical ingredients

BACKGROUND Today, there are more than 40 peptides on the pharmaceutical world market and more than 100 in several clinical phases. Although in the past the pharmaceutical industries had reduced their interest in peptides research, in recent decades, they have rekindled their interest in peptides as a result of contemporary novel technological accomplishments, strategic developments, advances in the areas of formulation and enhanced drug delivery technology of peptides. Thus, eight new peptide drugs that could previously have been characterized as difficult to prepare on the large scale required by industry, have entered the pharmaceutical market at the new millennium. DISCUSSION The manufacturing of most of these drugs has benefited from new technological advances. Traditional and most modern techniques have been applied to the manufacture of these new entries. CONCLUSION Recent accomplishments, together with the traditional benefits of peptides (high biological activity, high specificity and low toxicity), have led pharmaceutical companies to re-focus their attention on peptide-based agents. Therefore, several serious diseases can be treated using the potential next generation of peptide drugs.

Solid-Phase Peptide Synthesis in Water Using Microwave-Assisted Heating

An approach using water as a solvent (coupling and deprotection) was developed for the solid-phase synthesis of peptides using the most common Boc-amino acid derivatives. Key aspects of this methodology are the use of a PEG-based resin, EDC-HONB as a coupling method, and microwave irradiation as an energy source.

Structural features of angiotensin-I converting enzyme catalytic sites: conformational studies in solution, homology models and comparison with other zinc metallopeptidases.

Angiotensin-I Converting Enzyme (ACE) is a Zinc Metallopeptidase of which the three-dimensional structure was unknown until recently, when the X-ray structure of testis isoform (C-terminal domain of somatic) was determined. ACE plays an important role in the regulation of blood pressure due to its action in the frame of the Renin-Angiotensin System. Efforts for the specific inhibition of the catalytic function of this enzyme have been made on the basis of the X-ray structures of other enzymes with analogous efficacy in the hydrolytic cleavage of peptide substrate terminal fragments. Angiotensin-I Converting Enzyme bears the sequence and topology characteristics of the well-known gluzincins, a sub-family of zincins metallopeptidases and these similarities are exploited in order to reveal common structural elements among these enzymes. 3D homology models are also built using the X-ray structure of Thermolysin as template and peptide models that represent the amino acid sequence of the ACEs two catalytic, zinc-containing sites are designed and synthesized. Conformational analysis of the zinc-free and zinc-bound peptides through high resolution 1H NMR Spectroscopy provides new insights into the solution structure of ACE catalytic centers. Structural properties of these peptides could provide valuable information towards the design and preparation of new potent ACE inhibitors.

Synthetic Peptides as Structural Maquettes of Angiotensin-I Converting Enzyme Catalytic Sites

The rational design of synthetic peptides is proposed as an efficient strategy for the structural investigation of crucial protein domains difficult to be produced. Only after half a century since the function of ACE was first reported, was its crystal structure solved. The main obstacle to be overcome for the determination of the high resolution structure was the crystallization of the highly hydrophobic transmembrane domain. Following our previous work, synthetic peptides and Zinc(II) metal ions are used to build structural maquettes of the two Zn-catalytic active sites of the ACE somatic isoform. Structural investigations of the synthetic peptides, representing the two different somatic isoform active sites, through circular dichroism and NMR experiments are reported.