Nanobody-based heavy chain antibodies and chimeric antibodies

Future of bNAbs in HIV Treatment

PURPOSE OF REVIEW

Broadly neutralizing antibodies (bNAbs) represent a novel approach to HIV treatment, prevention, and cure strategies. As research advances, the clinical application of bNAbs continues to evolve. This review explores the potential role of bNAbs in HIV management, addressing their mechanisms of action, current limitations, and future directions.

RECENT FINDINGS

Recent studies have demonstrated that bNAbs can effectively neutralize a broad range of HIV strains by targeting conserved epitopes on the viral envelope. Clinical trials have shown that bNAb combinations can maintain viral supression in the absence of antiretroviral therapy (ART), though pre-existing resistance remains a major challenge. Strategies such as Fc engineering and alternative delivery mechanisms (e.g., AAV, mRNA, DNA) are being explored to enhance bNAb efficacy and durability. Despite promising data, bNAbs have not yet demonstrated superior effectiveness compared to existing ART or pre-exposure prophylaxis (PrEP) options. While bNAbs offer exciting possibilities for long-acting HIV therapy, their widespread use is limited by logistical challenges, high production costs, and pre-existing viral resistance. The future of bNAbs may lie in combination strategies with small-molecule antiretrovirals in maintenance strategies, genetic delivery systems, and vaccine-based approaches to induce endogenous bNAb production. Further research is needed to refine these strategies and determine the optimal role of bNAbs in HIV care.

Nanobodies: From Discovery to AI-Driven Design

Nanobodies, derived from naturally occurring heavy-chain antibodies in camelids (VHHs) and sharks (VNARs), are unique single-domain antibodies that have garnered significant attention in therapeutic, diagnostic, and biotechnological applications due to their small size, stability, and high specificity. This review first traces the historical discovery of nanobodies, highlighting key milestones in their isolation, characterization, and therapeutic development. We then explore their structure-function relationship, emphasizing features like their single-domain architecture and long CDR3 loop that contribute to their binding versatility. Additionally, we examine the growing interest in multiepitope nanobodies, in which binding to different epitopes on the same antigen not only enhances neutralization and specificity but also allows these nanobodies to be used as controllable modules for precise antigen manipulation. This review also discusses the integration of AI in nanobody design and optimization, showcasing how machine learning and deep learning approaches are revolutionizing rational design, humanization, and affinity maturation processes. With continued advancements in structural biology and computational design, nanobodies are poised to play an increasingly vital role in addressing both existing and emerging biomedical challenges.

Dysregulation of Astrocytic ATP/Adenosine Release in the Hippocampus Cause Cognitive and Affective Disorders: Molecular Mechanisms, Diagnosis, and Therapy

The gliotransmitter adenosine 5'-triphosphate (ATP) and its enzymatic degradation product adenosine play a major role in orchestrating in the hippocampus cognitive and affective functions via P2 purinoceptors (P2X, P2Y) and P1 adenosine receptors (A1, A2A). Although numerous reviews exist on purinoceptors that modulate these functions, there is an apparent gap relating to the involvement of astrocyte-derived extracellular ATP. Our review focuses on the following issues: An impeded release of ATP from hippocampal astrocytes through vesicular mechanisms or connexin hemichannels and pannexin channels interferes with spatial working memory in rodents. The pharmacological blockade of P2Y1 receptors (P2Y1Rs) reverses the deficits in learning/memory performance in mouse models of familial Alzheimer's disease (AD). Similarly, in mouse models of major depressive disorder (MDD), based on acute or chronic stress-induced development of depressive-like behavior, a reduced exocytotic/channel-mediated ATP release from hippocampal astrocytes results in the deterioration of these behavioral responses. However, on the opposite, the increased stimulation of the microglial/astrocytic P2X7R-channel by ATP causes neuroinflammation and in consequence depressive-like behavior. In conclusion, there is strong evidence for the assumption that gliotransmitter ATP is intimately involved in the pathophysiology of cognitive and affective neuron/astrocyte-based human illnesses opening new diagnostic and therapeutic vistas for AD and MDD.

Advances in immunological sorting of X and Y chromosome-bearing sperm: from proteome to sex-specific proteins

Sex determination is the developmental assignment that results from genetic factors. The sexual characters were the specific manifestations of male and female individuals under stimulation of sexual hormonal production. The fusion of an oocyte with an X chromosome-bearing sperm will lead to a female (XX), while fusion with a Y chromosome-bearing sperm will develop into a male (XY) in mammals. Sexing technology has been developed to fertilize eggs with sorted sperm, producing offspring of the desired sex. Sperm sorting enables the sex pre-determination of offspring via in vitro fertilization (IVF) or artificial insemination (AI) in domestic animals. Flow cytometric sorting of X and Y sperm is widely considered the most applied method for sperm sorting and has been commercially applied in cattle. However, a non-invasive, immunological method for screening X and Y sperm is considered to be a feasible approach. This review summarizes the current knowledge and techniques of sperm immunological sorting, including the preparation of antibodies, application of immunomodulators, and immunoisolation. Additionally, we focus on identifying sex-specifically expressed proteins in X and Y sperm through proteomic analysis, and verifying the sex-specific proteins using experimental techniques. Furthermore, several housekeeping proteins as loading control were discussed in immunoblotting of sperm proteins. Immunological sorting of X and Y sperm could provide a convenient, cost-effective, and highly efficient technique that can improve economic benefits and achieve an advanced level of sexing technology. This review provides insight into immunological sorting of sperm and the pre-determination of sex in farm animals.

A versatile cohesion manipulation system reveals CENP-A dysfunction accelerates female reproductive age-related egg aneuploidy

Female reproductive aging is accompanied by a dramatic rise in the incidence of egg aneuploidy. Premature loss of chromosome cohesion proteins and untimely separation of chromosomes is thought to underly high rates egg aneuploidy during maternal aging. However, because chromosome cohesion loss occurs gradually over female reproductive lifespan and cytoskeletal defects alone can predispose eggs to chromosomal abnormalities, the root causes of exponential rise in egg aneuploidy at advanced reproductive ages remain a mystery. Here, we applied high-resolution live imaging to visualize for the first time cohesion protein dynamics underpinning meiotic chromosome segregation. To discover proteins whose dysfunction accelerates aneuploidies associated with female reproductive aging, we innovated the first experimental system in which chemically induced cohesion reduction rapidly triggers aging-like chromosomal abnormalities in young eggs. By integrating this direct cohesion manipulation system with quantitative high-resolution microscopy and targeted protein degradation tools, we identified the centromeric protein CENP-A as a new factor whose aging-like depletion causes a dramatic rise in premature separation of sister chromatids. Our work illuminates cohesion loss-independent origins of age-related egg aneuploidy and provides new avenues to discover therapeutic targets for extending the female reproductive lifespan.

Visual and High-Efficiency Secretion of SARS-CoV-2 Nanobodies with Escherichia coli

Nanobodies have gained attention as potential therapeutic and diagnostic agents for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to their ability to bind and neutralize the virus. However, rapid, scalable, and robust production of nanobodies for SARS-CoV-2 remains a crucial challenge. In this study, we developed a visual and high-efficiency biomanufacturing method for nanobodies with Escherichia coli by fusing the super-folder green fluorescent protein (sfGFP) to the N-terminus or C-terminus of the nanobody. Several receptor-binding domain (RBD)-specific nanobodies of the SARS-CoV-2 spike protein (S) were secreted onto the surface of E. coli cells and even into the culture medium, including Fu2, ANTE, mNb6, MR3-MR3, and n3113.1. The nanobodies secreted by E. coli retained equal activity as prior research, regardless of whether sfGFP was removed. Since some of the nanobodies bound to different regions of the RBD, we combined two nanobodies to improve the affinity. Fu2-sfGFP-ANTE was constructed to be bispecific for the RBD, and the bispecific nanobody exhibited significantly higher affinity than Fu2 (35.0-fold), ANTE (7.3-fold), and the combination of the two nanobodies (3.3-fold). Notably, Fu2-sfGFP-ANTE can be normally secreted into the culture medium and outer membrane. The novel nanobody production system enhances the efficiency of nanobody expression and streamlines the downstream purification process, enabling large-scale, cost-effective nanobody production. In addition, E. coli cells secreting the nanobodies on their surface facilitates screening and characterization of antigen-binding clones.

In vivo gene editing and in situ generation of chimeric antigen receptor cells for next-generation cancer immunotherapy

Chimeric antigen receptor (CAR) cell therapy has achieved groundbreaking success in treating hematological malignancies. However, its application to solid tumors remains challenging due to complex manufacturing processes, limited in vivo persistence, and transient therapeutic effects. In vivo CAR-immune cells induced by gene delivery systems loaded with CAR genes and gene-editing tools have shown efficiency for anti-tumor immunotherapy. In situ programming of autologous immune cells avoids the safety concerns of allogeneic immune cells, and the manufacture of gene delivery systems could be standardized. Therefore, the in vivo editing and in situ generation of CAR-immune cells might potentially overcome the abovementioned limitations of current CAR cell therapy. This review mainly focuses on CAR structures, gene-editing tools, and gene delivery techniques applied in anti-tumor immunotherapy to help design and develop in situ CAR-immune cell therapy. The recent applications of in vivo CAR-immune cell therapy in both hematologic malignancies and solid tumors are investigated. To sum up, the in vivo editing and in situ generation of CAR therapy holds promise for offering a practical, cost-effective, efficient, safe, and widely applicable approach to the next-generation anti-tumor immunotherapy.