Developing Monoclonal Antibodies for Immunohistochemistry

The experiences of a laboratory which pioneered the application of monoclonal antibodies to diagnostic histochemistry is described. This was achieved in four key steps: (1) Monoclonal antibodies were successfully produced to replace the difficult-to-produce and limited polyclonal antibodies available for immunohistochemistry. (2) Monoclonal antibodies were produced to improve the immunoenzymatic detection of bound antibodies, using immunoperoxidase or alkaline phosphatase, increasing sensitivity and allowing the use of two chromogens when applied together. The availability of a reliable alkaline phosphatase-based detection allowed the detection of antigens in tissues with high endogenous peroxidase. (3) Methodologies were developed to unmask antigens not detected in routinely processed paraffin-embedded tissue. (4) Synthetic peptides were used as immunising antigens for the direct production of specific molecules of diagnostic interest. This was expanded to include recombinant proteins. Many reacted with fixed tissue and recognised homologous molecules in other species. In addition to these developments, the laboratory promoted the collaboration and training of researchers to spread the expertise of monoclonal production for diagnosis.

Disrupting GPCR Complexes with Smart Drug-like Peptides

G protein-coupled receptors (GPCRs) are a superfamily of proteins classically described as monomeric transmembrane (TM) receptors. However, increasing evidence indicates that many GPCRs form higher-order assemblies made up of monomers pertaining to identical (homo) or to various (hetero) receptors. The formation and structure of these oligomers, their physiological role and possible therapeutic applications raise a variety of issues that are currently being actively explored. In this context, synthetic peptides derived from TM domains stand out as powerful tools that can be predictably targeted to disrupt GPCR oligomers, especially at the interface level, eventually impairing their action. However, despite such potential, TM-derived, GPCR-disrupting peptides often suffer from inadequate pharmacokinetic properties, such as low bioavailability, a short half-life or rapid clearance, which put into question their therapeutic relevance and promise. In this review, we provide a comprehensive overview of GPCR complexes, with an emphasis on current studies using GPCR-disrupting peptides mimicking TM domains involved in multimerization, and we also highlight recent strategies used to achieve drug-like versions of such TM peptide candidates for therapeutic application.

Modification of Alginates to Modulate Their Physic-Chemical Properties and Obtain Biomaterials with Different Functional Properties

Modified alginates have a wide range of applications, including in the manufacture of dressings and scaffolds used for regenerative medicine, in systems for selective drug delivery, and as hydrogel materials. This literature review discusses the methods used to modify alginates and obtain materials with new or improved functional properties. It discusses the diverse biological and functional activity of alginates. It presents methods of modification that utilize both natural and synthetic peptides, and describes their influence on the biological properties of the alginates. The success of functionalization depends on the reaction conditions being sufficient to guarantee the desired transformations and provide modified alginates with new desirable properties, but mild enough to prevent degradation of the alginates. This review is a literature description of efficient methods of alginate functionalization using biologically active ligands. Particular attention was paid to methods of alginate functionalization with peptides, because the combination of the properties of alginates and peptides leads to the obtaining of conjugates with properties resulting from both components as well as a completely new, different functionality.

Immunobiological properties of granulocytemacrophage colony-stimulating factor and synthetic peptides of his active center

Granulocyte-macrophage colony-stimulating factor (GM-CSF) belongs to the group of growth cytokines (hematopoietins) that regulate proliferation and differentiation of myeloid lineage cells. Recently, a lot of new data have accumulated, indicating the presence of a number of previously unknown biological effects in GM-CSF and synthetic peptides of its active center, which open up new prospects for their wide clinical use.The review outlines current understanding of the structure, functions, and mechanisms of GM-CSF action and concerns the structure of its receptor. The GM-CSF producer cells are characterized, as well as target cells (effector cells) responding to this cytokine are also presented. The known mechanisms of intracellular signaling involved into the GM-CSF/receptor interaction are described. The main pleiotropic effects of this cytokine as a factor of hematopoiesis and an immunostimulating agent are characterized. The previously known and recently found immunobiological effects of this cytokine, its recombinant forms and synthetic analogues of its active center are discussed.Participation of GM-CSF in hematopoiesis and differentiation of myeloid cells, the effects of this cytokine on the functional activity of immunocompetent populations (lymphocytes, macrophages, neutrophils, dendritic cells) and tissue cells were characterized. The influence of GM-CSF on the development and course of infectious and inflammatory processes, its role in the creation of combined vaccines is reviewed. Clinical data on usage of GM-CSF and its recombinant forms in hematology, immunology, oncology, reproductive medicine and in the treatment of systemic autoimmune processes and infectious diseases are presented.The recently discovered immunobiological properties of synthetic peptides derived from active center of GM-CSF are summarized, indicating that they exhibit immunotropic and hematopoietic effects, as well as antimicrobial activity against Gram-negative and Gram-positive bacteria, viruses, and tissue repair (effect on the rate of wound healing), which is not typical to the whole GM-CSF molecule. We discuss the prospects for clinical applications of synthetic GM-CSF analogue (ZP2 peptide), and an opportunity of creating new cosmetics and pharmaceuticals with combined immunostimulating, antimicrobial and reparative properties on its basis.The review expands the view on potential usage of cytokine therapy in the treatment of various infectious and non-infectious diseases in humans, and is addressing a wide range of specialists working in the field of allergology and immunology, infectology and regenerative medicine.

Synthetic peptides as promising antiviral molecules

Tweetable abstract Synthetic antiviral peptides are a promising option to overcome future viral diseases.

Light contamination in stable isotope-labelled internal peptide standards is frequent and a potential source of false discovery and quantitation error in proteomics

In mass spectrometry-based proteomics, heavy internal standards are used to validate target peptide detections and to calibrate peptide quantification. Here we report light contamination present in heavy labelled synthetic peptides of high isotopic enrichment. Application of such peptides as assay-internal standards potentially compromises the detection and quantification especially of low abundant cellular peptides. Therefore, it is important to adopt guidelines to prevent false-positive identifications of endogenous light peptides as well as errors in their quantification from biological samples.