Reversing stage III oral adenocarcinoma in a dog treated with anti-canine PD-1 therapeutic antibody: a case report.

Monoclonal antibody targeting programmed cell death-1 (PD-1) is one of the most promising treatment therapies for human cancers. Canine PD-1 antibodies used in clinical trials have also shown efficacy in treating canine cancers. An 11-year-old male intact border collie presented to us for evaluation of left cervical mass. Computed tomography (CT) examination revealed an irregular pharyngeal mass invading the surrounding soft tissue. Histological and immunohistochemical results were consistent with a diagnosis of adenocarcinoma, most likely originating from the minor salivary gland. An anti-canine PD-1 monoclonal antibody was administered. Two months after the initial treatment, the tumor reached partial remission and maintained as such for 6 months. Finally, the patient was euthanized due to reasons unrelated to cancer, with a survival time of 316 days. To our knowledge, this is the first report of response to PD-1 blockade treatment in canine adenocarcinoma.

The establishment of humanized IL-4/IL-4RA mouse model by gene editing and efficacy evaluation.

Asthma is a common respiratory immune disease in children and adults, and interleukin-4 (IL-4) is one of the key factors for the onset of asthma. Therefore, targeting human IL-4 and IL-4 receptor alpha (IL-4RA) has become one of the strategies for targeted therapy of cytokines. Herein, we established an animal model of asthmatic airway inflammation using double humanized IL-4/IL-4RA (hIL-4/hIL-4RA) mice, where human IL-4 and IL-4RA replaced their murine counterparts, respectively. We successfully identified the phenotype by Southern blotting, ELISA, and flow cytometry. The hIL-4/hIL-4RA mice induced by ovalbumin (OVA) exhibited several important features of asthma, such as inflammatory cell infiltration, IgE release, goblet cell hyperplasia, and Th2 cytokine secretion. Furthermore, treatment of these humanized mice with anti-human IL-4RA antibodies significantly inhibited level of these pathological indicators. Thus, hIL-4/hIL-4RA mice provide a validated preclinical mouse model to interrogate new therapeutic agents targeting this specific cytokine pathway in asthma.

Molecular imprint of enzyme active site by camel nanobodies: rapid and efficient approach to produce abzymes with alliinase activity.

Screening of inhibitory Ab1 antibodies is a critical step for producing catalytic antibodies in the anti-idiotypic approach. However, the incompatible surface of the active site of the enzyme and the antigen-binding site of heterotetrameric conventional antibodies become the limiting step. Because camelid-derived nanobodies possess the potential to preferentially bind to the active site of enzymes due to their small size and long CDR3, we have developed a novel approach to produce antibodies with alliinase activities by exploiting the molecular mimicry of camel nanobodies. By screening the camelid-derived variable region of the heavy chain cDNA phage display library with alliinase, we obtained an inhibitory nanobody VHHA4 that recognizes the active site. Further screening with VHHA4 from the same variable domain of the heavy chain of a heavy-chain antibody library led to a higher incidence of anti-idiotypic Ab2 abzymes with alliinase activities. One of the abzymes, VHHC10, showed the highest activity that can be inhibited by Ab1 VHHA4 and alliinase competitive inhibitor penicillamine and significantly suppressed the B16 tumor cell growth in the presence of alliin in vitro. The results highlight the feasibility of producing abzymes via anti-idiotypic nanobody approach.