Improved sensitivity of the anti-microcystin-LR ELISA using phage-displayed alpha-type anti-idiotypic nanobody

Microcystin-LR in drinking water: An emerging role of mitochondrial-induced epigenetic modifications and possible mitigation strategies

Algal blooms are a serious menace to freshwater bodies all over the world. These blooms typically comprise cyanobacterial outgrowths that produce a heptapeptide toxin, Microcystin-LR (MC-LR). Chronic MC-LR exposure impairs mitochondrial-nuclear crosstalk, ROS generation, activation of DNA damage repair pathways, apoptosis, and calcium homeostasis by interfering with PC/MAPK/RTK/PI3K signaling. The discovery of the toxin's biosynthesis pathways paved the way for the development of molecular techniques for the early detection of microcystin. Phosphatase inhibition-based bioassays, high-performance liquid chromatography, and enzyme-linked immunosorbent tests have recently been employed to identify MC-LR in aquatic ecosystems. Biosensors are an exciting alternative for effective on-site analysis and field-based characterization. Here, we present a synthesis of evidence supporting MC-LR as a mitotoxicant, examine various detection methods, and propose a novel theory for the relevance of MC-LR-induced breakdown of mitochondrial machinery and its myriad biological ramifications in human health and disease.

Discovery of nanobodies: a comprehensive review of their applications and potential over the past five years

Nanobodies (Nbs) are antibody fragments derived from heavy-chain-only IgG antibodies found in the Camelidae family as well as cartilaginous fish. Their unique structural and functional properties, such as their small size, the ability to be engineered for high antigen-binding affinity, stability under extreme conditions, and ease of production, have made them promising tools for diagnostics and therapeutics. This potential was realized in 2018 with the approval of caplacizumab, the world's first Nb-based drug. Currently, Nbs are being investigated in clinical trials for a broad range of treatments, including targeted therapies against PDL1 and Epidermal Growth Factor Receptor (EGFR), cardiovascular diseases, inflammatory conditions, and neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. They are also being studied for their potential for detecting and imaging autoimmune conditions and infectious diseases such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A variety of methods are now available to generate target-specific Nbs quickly and efficiently at low costs, increasing their accessibility. This article examines these diverse applications of Nbs and their promising roles. Only the most recent articles published in the last five years have been used to summarize the most advanced developments in the field.

Anti-Idiotypic Nanobodies Mimicking an Epitope of the Needle Protein of the Chlamydial Type III Secretion System for Targeted Immune Stimulation

The development of new approaches and drugs for effective control of the chronic and complicated forms of urogenital chlamydia caused by Chlamydia trachomatis, which is suspected to be one of the main causes of infertility in both women and men, is an urgent task. We used the technology of single-domain antibody (nanobody) generation both for the production of targeting anti-chlamydia molecules and for the subsequent acquisition of anti-idiotypic nanobodies (ai-Nbs) mimicking the structure of a given epitope of the pathogen (the epitope of the Chlamydial Type III Secretion System Needle Protein). In a mouse model, we have shown that the obtained ai-Nbs are able to induce a narrowly specific humoral immune response in the host, leading to the generation of intrinsic anti-Chlamydia antibodies, potentially therapeutic, specifically recognizing a given antigenic epitope of Chlamydia. The immune sera derived from mice immunized with ai-Nbs are able to suppress chlamydial infection in vitro. We hypothesize that the proposed method of the creation and use of ai-Nbs, which mimic and present to the host immune system exactly the desired region of the antigen, create a fundamentally new universal approach to generating molecular structures as a part of specific vaccine for the targeted induction of immune response, especially useful in cases where it is difficult to prepare an antigen preserving the desired epitope in its native conformation.

Cladosporium sphaerospermum extract inhibits quorum sensing associated virulence factors of Serratia marcescens

Serratia marcescens is now becoming a propensity for its highly antimicrobial-resistant clinical infections. Currently, it provides a novel strategy to prevent and control microbial infection by regulating S. marcescens quorum sensing (QS). Deep-sea-derived fungi are rich in QS bioactive constituents. In this work, the extracts from Cladosporium sphaerospermum SCSGAF0054 showed potent QS-related virulence factors and biofilm-inhibiting activities against S. marcescens NJ01. The swimming motility and multiple virulence factors such as prodigiosin, exopolysaccharide (EPS), lipase, protease and hemolysin were moderately inhibited by the extracts at varied concentrations. The confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) images revealed that C. sphaerospermum extracts moderately arrested biofilm formation and cell viability. Further, real-time quantitative PCR (RT-qPCR) analysis revealed that expressions of genes associated with virulence factors, flhD, fimA, fimC, bsmA, bsmB, pigA, pigC, and shlA, were significantly down-regulated compared with control. In addition, the extracts combined with imipenem inhibited the QS system of S. marcescens NJ01, disrupted its preformed biofilm, released the intra-biofilm bacteria and killed the bacteria gradually. Therefore, the extracts combined with imipenem can partially restore bacterial drug sensitivity. These results suggest that the extracts from SCSGAF0054 effectively interfere with the QS system to treat S. marcescens infection alone or combining with classical antimicrobial drugs.