Angiogenesis is crucial for tumor development, growth and metastasis. Vascular endothelial growth factor (VEGF) has been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis, and blocking the activity of VEGF can starve tumors. Avastin, which is a humanized anti-VEGF antibody, has been successfully applied in clinics since 2004. However, the price of Avastin is extremely high for Chinese people. Here, we report a novel human anti-VEGF neutralizing antibody, MIL60, which shows an affinity comparable to that of Avastin (the K_D value of MIL60 was 44.5 pM, while that of Avastin was 42.7 pM). MIL60 displays favorable actions in inhibiting VEGF-triggered endothelial cell proliferation (the IC₅₀ value of MIL60 was 31±6.4 ng/ml and that of Avastin was 47±8.1 ng/ml), migration (8 µg/ml or 0.8 µg/ml MIL60 versus the control: P<0.05) and tube formation (2 µg/ml or 0.2 µg/ml MIL60 versus the control: P<0.05) via the VEGFR2 signaling pathway. Moreover, MIL60 was shown to inhibit tumor growth and angiogenesis in vivo in xenograft models of human colon carcinoma and ovarian cancer using immunotherapy and immunohistochemistry analysis (MIL60 versus N.S.: P=0.0007; Avastin versus N.S.: P=0.00046). These data suggest that MIL60 is a potential therapeutic, anti-angiogenic agent. Our work provides a novel anti-VEGF antibody, which can be considered an anti-tumor antibody candidate and a new option for patients with various cancers.

Smallpox is an infectious disease caused by the variola virus, and it has a high mortality rate. Historically it has broken out in many countries and it was a great threat to human health. Smallpox was declared eradicated in 1980, and Many countries stopped nation-wide smallpox vaccinations at that time. In recent years the potential threat of bioterrorism using smallpox has led to resumed research on the treatment and prevention of smallpox. Effective ways of preventing and treating smallpox infection have been reported, including vaccination, chemical drugs, neutralizing antibodies, and clinical symptomatic therapies. Antibody treatments include anti-sera, murine monoclonal antibodies, and engineered humanized or human antibodies. Engineered antibodies are homologous, safe, and effective. The development of humanized and genetically engineered antibodies against variola virus via molecular biology and bioinformatics is therefore a potentially fruitful prospect with respect to field application. Natural smallpox virus is inaccessible, therefore most research about prevention and/or treatment of smallpox were done using vaccinia virus, which is much safer and highly homologous to smallpox. Herein we summarize vaccinia virus epitope information reported to date, and discuss neutralizing antibodies with potential value for field application.

Botulinum neurotoxin (BoNT) is a highly lethal toxin produced by the anaerobic bacterium Clostridium botulinum, which leads to nerve paralysis following poisoning. At present, there is no specific drug officially approved. Antibodies, particularly single-domain antibodies, represent safe and effective candidates for specific drugs against BoNT. In this study, the receptor-binding domain of botulinum toxin (BoNT/AHC_C) was utilized to immunize Bactrian camels, resulting in the generation of a nanobody phage library. From this library, a high-affinity binding antibody, designated A1, and a neutralizing antibody, named HM, were successfully obtained through SPR-based screening. The affinity constant of HM for botulinum toxin is 1.08E-11 M. Results from computer simulations indicate that HM binds at the same site as SV2C. Furthermore, experimental findings demonstrate that HM exhibits significant blocking activity at both the in vitro binding level and the cellular level. In mouse toxicity experiments, HM has been shown to offer protection against a 20 LD₅₀ dose of BoNT/A. Consequently, HM mitigates botulinum toxin poisoning in mice by obstructing the binding of AHC_C to SV2C.