Effect of Interleukins on Antibody Production by Epstein-Barr Virus Transformed B Cells

Development of therapeutic antibodies for the treatment of diseases

Since the first monoclonal antibody drug, muromonab-CD3, was approved for marketing in 1986, 165 antibody drugs have been approved or are under regulatory review worldwide. With the approval of new drugs for treating a wide range of diseases, including cancer and autoimmune and metabolic disorders, the therapeutic antibody drug market has experienced explosive growth. Monoclonal antibodies have been sought after by many biopharmaceutical companies and scientific research institutes due to their high specificity, strong targeting abilities, low toxicity, side effects, and high development success rate. The related industries and markets are growing rapidly, and therapeutic antibodies are one of the most important research and development areas in the field of biology and medicine. In recent years, great progress has been made in the key technologies and theoretical innovations provided by therapeutic antibodies, including antibody-drug conjugates, antibody-conjugated nuclides, bispecific antibodies, nanobodies, and other antibody analogs. Additionally, therapeutic antibodies can be combined with technologies used in other fields to create new cross-fields, such as chimeric antigen receptor T cells (CAR-T), CAR-natural killer cells (CAR-NK), and other cell therapy. This review summarizes the latest approved or in regulatory review therapeutic antibodies that have been approved or that are under regulatory review worldwide, as well as clinical research on these approaches and their development, and outlines antibody discovery strategies that have emerged during the development of therapeutic antibodies, such as hybridoma technology, phage display, preparation of fully human antibody from transgenic mice, single B-cell antibody technology, and artificial intelligence-assisted antibody discovery.

Detection of antibody-secreting cells specific for the cytomegalovirus and herpes simplex virus surface antigens

Infections with the herpes simplex virus (HSV) and the human cytomegalovirus (HCMV) can lead to life-threatening diseases, particularly in immunosuppressed patients. Furthermore, HSV infections at birth (herpes neonatorum) can result in a disseminated disease associated with a fatal multiorgan failure. Congenital HCMV infections can result in miscarriage, serious birth defects or developmental disabilities. Antibody-based interventions with hyperimmunoglobulins showed encouraging results in clinical studies, but clearly need to be improved. The isolation of highly neutralizing monoclonal antibodies is a promising strategy to establish potent therapy options against HSV and HCMV infections.

Monoclonal antibodies are commonly isolated from hybridomas or EBV-immortalized B-cell clones. The screening procedure to identify virus-specific cells from a cell mixture is a challenging step, since most of the highly neutralizing antibodies target complex conformational epitopes on the virus surface. Conventional assays such as ELISA are based on purified viral proteins and inappropriate to display complex epitopes.

To overcome this obstacle, we have established two full-virus based methods that allow screening for cells and antibodies targeting complex conformational epitopes on viral surface antigens. The methods are suitable to detect surface antigen-specific cells from a cell mixture and may facilitate the isolation of highly neutralizing antibodies against HSV and HCMV.

Co-delivery of doxorubicin and interleukin-2 via chitosan based nanoparticles for enhanced antitumor efficacy

In order to reduce toxicity and improve antitumor therapeutic effects of doxorubicin (DOX) and recombinant human interleukin-2 (rhIL-2), we developed a hydrophilic cationic polymer (N,N,N-trimethyl chitosan, TMC) based nanocomplexes (FTCD/rhIL-2) which could efficiently mediate systemic co-delivery of hydrophobic DOX and water-soluble rhIL-2 to achieve the purpose of combination therapy. DOX was covalently conjugated to TMC through cis-aconitic anhydride (CA) which endowed nanocomplexes a pH-sensitive release of DOX, while rhIL-2 was loaded through electrostatic adsorption without compromise of bioactivity. The resultant nanocomplexes exhibited sub-spherical shape (∼200nm) and positive charge (>20mV). Folate (FA) modification was utilized with the intention of active targeting, which was however correlated with weakened tumor growth inhibition, emphasizing the importance of balance in overcoming diverse delivery barriers for efficacious antitumor therapy. Compared with free drugs, FTCD/rhIL-2 nanocomplexes significantly delayed tumor growth, increased the serum immunoglobulin G (IgG) level and the amount of tumor infiltrated cytotoxic T lymphocytes. These results indicated that the combinational administration of DOX and rhIL-2 based on polymer nanoparticles could serve as an effective strategy in antitumor therapy.

STATEMENT OF SIGNIFICANCE

Combined administration of doxorubicin (DOX) and recombinant human interleukin-2 (rhIL-2) has been utilized for the treatment of tumors. However the traditional administration brought to severe side effects, and the efficiency of current delivery systems were unsatisfactory. Herein we developed a hydrophilic cationic polymer based nanoparticle delivery system which facilitated simultaneous and systemic co-delivery of hydrophobic DOX and water-soluble rhIL-2. This system achieved pH-sensitive release of DOX and sustained release of rhIL-2 in vitro, meanwhile, improved anti-tumor efficacy and reduced side-effect in vivo. Thus, our study provided a solution for combinational administration of DOX and rhIL-2 and could serve as an effective strategy in antitumor therapy.