Biotechnology Approach to Mineral Separation via Phage Flotation Collectors

A long-standing challenge in the mining industry is the separation of mineral particles that have similar surface characteristics for which surfactant-based flotation collectors cannot discriminate. In Florida phosphate mining, this problem occurs in the separation of dolomite [CaMg(CO₃)₂] contaminants from the desired francolite mineral {a fluorapatite [Ca₅(PO₄)₃(F,OH)]}. In this study, phage display techniques were used to select phage clones with specific binding affinity to francolite, which were then tested in a benchtop bubbler flotation apparatus for their ability to selectively float francolite particles from mixtures containing dolomite. Contact angles measured with the captive bubble technique were used to examine changes in the surface character of the mineral particles upon adsorption of the phage, which showed that the most selective phage led to an increase in the contact angle from 16 to 50°. Although this is below the level considered hydrophobic, the correlation between contact angles and increased flotation recovery suggests that the phage coat proteins are behaving as efficient bioamphiphiles for the attachment of the particles to air bubbles, demonstrating a new and environmentally friendly type of biocollector system. The chemical and physical characteristics of the phage "tail" peptides were evaluated to offer an explanation for the specificity of phage binding. We conclude with a discussion of the potential benefits of this biotechnology approach, even for commodity industries such as mining or other particle separation systems, when costs and sustainability are considered.

Generation of avian-derived anti-B7-H4 antibodies exerts a blockade effect on the immunosuppressive response

For highly conserved mammalian protein, chicken is a suitable immune host to generate antibodies. Monoclonal antibodies have been successfully targeted with immunity checkpoint proteins as a means of cancer treatment; this treatment enhances tumor-specific immunity responses through immunoregulation. Studies have identified the importance of B7-H4 in immunoregulation and its use as a potential target for cancer treatment. High levels of B7-H4 expression are found in tumor tissues and are associated with adverse clinical and pathological characteristics. Using the phage display technique, this study isolated specific single-chain antibody fragments (scFvs) against B7-H4 from chickens. Our experiment proved that B7-H4 clearly induced the inhibition of T-cell activation. Therefore, use of anti-B7-H4 scFvs can effectively block the exhaustion of immunity cells and also stimulate and activate T-cells in peripheral blood mononuclear cells. Sequence analysis revealed that two isolated scFv S2 and S4 have the same VH complementarity-determining regions (CDRs) sequence. Molecule docking was employed to simulate the complex structures of scFv with B7-H4 to analyze the interaction. Our findings revealed that both scFvs employed CDR-H1 and CDR-H3 as main driving forces and had strong binding effects with the B7-H4. The affinity of scFv S2 was better because the CDR-L2 loop of the scFv S2 had three more hydrogen bond interactions with B7-H4. The results of this experiment suggest the usefulness of B7-H4 as a target for immunity checkpoints; the isolated B7-H4-specific chicken antibodies have the potential for use in future cancer immunotherapy applications.

Preclinical discovery and development of adalimumab for the treatment of rheumatoid arthritis

Introduction: Rheumatoid arthritis (RA) is an autoimmune disease that is characterized by progressive joint disorders with significant pain and stiffness. In the past, RA was a difficult -to-treat ailment, but nowadays with the advent of biologics and better treatment strategies, disease remission is an achievable goal. Tumor necrosis factor α (TNFα) inhibitors were the first category of biologics to emerge with adalimumab being the first fully human TNFα.Areas covered: the authors provide an overview of the historical events that led to the discovery of TNFα inhibitors and more specifically the drug adalimumab. Several key trials are presented regarding the safety of the drug as well as its successful journey, but there is also a narrative description of the drug's future after patent expiration.Expert opinion: Adalimumab is a fully human TNFα inhibitor with a fairly rapid onset of action. It has a generally good safety and efficacy profile. Clinicians must be aware of the possible side effects and treat them in a timely manner or discontinue the drug where appropriate. Due to the success of the bio-originator adalimumab, a multitude of biosimilars have emerged but not, thus far, for all of the indications of the bio-originator.

Phage-based Electrochemical Sensors: A Review

Phages based electrochemical sensors have received much attention due to their high specificity, sensitivity and simplicity. Phages or bacteriophages provide natural affinity to their host bacteria cells and can serve as the recognition element for electrochemical sensors. It can also act as a tool for bacteria infection and lysis followed by detection of the released cell contents, such as enzymes and ions. In addition, possible detection of the other desired targets, such as antibodies have been demonstrated with phage display techniques. In this paper, the recent development of phage-based electrochemical sensors has been reviewed in terms of the different immobilization protocols and electrochemical detection techniques.

Isolation and characterization of anti ROR1 single chain fragment variable antibodies using phage display technique

Receptor tyrosine kinase-like orphan receptor (ROR1) belongs to one of the families of receptor tyrosine kinases (RTKs). RTKs are involved in the various physiologic cellular functions including proliferation, migration, survival, signaling and differentiation. Several RTKs are deregulated in various cancers implying the targeting potential of these molecules in cancer therapy. ROR1 has recently been shown to be expressed in various types of cancer cells but not in normal adult cells. Hence a molecular inhibitor of extracellular domain of ROR1 that inhibits ROR1-cell surface interaction is of great therapeutic importance. In an attempt to develop molecular inhibitors of ROR1, we screened single chain variable fragment (scFv) phage display libraries, Tomlinson I + J, against one specific synthetic oligopeptide from extracellular domain of ROR1 and selected scFvs were characterized using various immunological techniques. Several ROR1 specific scFvs were selected following five rounds of panning procedure. The scFvs showed specific binding to ROR1 using immunological techniques. Our results demonstrate successful isolation and characterization of specific ROR1 scFvs that may have great therapeutic potential in cancer immunotherapy.

Identification of conformational antigenic epitopes and dominant amino acids of buffalo β-lactoglobulin

Major allergen β-lactoglobulin exists in many mammalian types of milk except human breast. Buffalo milk also contains this major allergen but the detailed information on its epitopes is not available. The aim of this work was to map and characterize its conformational antigenic epitopes. Sixty mimotopes of buffalo β-lactoglobulin were produced by biopanning of phage display peptide library and then 2 mimotopes, specific for sera from rabbit 1 and 2, respectively, were predicted to be conformational epitope candidates by the use of DNAStar and web tool of MIMOX. On the basis of bioinformation analysis, 5 conserved amino acid residues PL-ENK were identified in 2 conformational epitope sequences and 7 conformational epitopes were derived from 2 mimotopes by molecular modeling. The result showed that these conformational epitopes were located in the 2 regions on buffalo β-lactoglobulin and composed of 5 hydrophilic and 2 hydrophobic amino acids.