Recombinant Human Papilloma Virus type 18 L1 protein (VLP)

Human papillomavirus (HPV) is a DNA virus spread through close contact. In human tissues, HPV mainly infects skin and mucosal tissues. HPV is mainly transmitted through close human contact, such as sexually transmitted viruses, and can cause a variety of proliferative epithelial lesions in humans, including papillomas (warts) and tumor-like lesions. Specifically, HPV-induced diseases mainly include three categories. Category 1: cancers of the cervix, vagina, female vulva, penis and anus, and certain types of head and neck tumors and other malignant lesions. Among them, these lesions are caused by Caused by high-risk HPV infection, such as: HPV16 and HPV18; Category 2: Benign lesions such as flat warts, genital warts and other genital warts. It is a sexually transmitted disease and is very common among people who are sexually active. Although genital warts do not cause serious consequences like cancer, the lesions often cause painful clinical symptoms to patients, such as burning, bleeding, and pain, and the repeated treatment process wastes a lot of medical resources. It is estimated that there are 30 million genital warts caused by non-carcinogenic HPV (mainly types 6 and 11) worldwide, and 20 to 50% of these lesions also contain mixed infections with high-risk HPV types. Category 3: HPV infection can also cause recurrent respiratory papilloma (RRP), a rare and potentially fatal disease that occurs mainly in adolescence. Sometimes, large numbers of papillomas can cause difficulty breathing and lead to younger children died.

Figure 1. The life cycle of HPV. (Source: Roden RBS, et al., 2018)

Among these diseases caused by HPV, cervical cancer, the second most common malignant tumor in women, is the most serious health threat. Fortunately, cervical cancer is the only cancer for which a vaccine has been developed. On June 8, 2006, the U.S. Food and Drug Administration (FDA) officially approved the launch of Gardasil HPV preventive vaccine; it is an HPV16/18/6/11 L1 VLP quadrivalent cervical cancer preventive vaccine expressed and purified from Saccharomyces cerevisiae. It is approved to prevent cervical cancer, precancerous lesions and genital warts caused by HPV16, 18, 6 and 11 infections in girls and women aged 6 to 26 years old. This is the world's first tumor vaccine approved by the FDA. Subsequently, Cervarix's HPV preventive vaccine was also successfully launched. It is a bivalent cervical cancer preventive vaccine derived from the HPV16/18 L1 VLP derived from an insect expression system. HPV belongs to the genus Papillomavirus of the family Papovaviridae and is a non-enveloped DNA virus. The viral genome is a double-stranded closed circular DNA with a size of approximately 7.2~8kb and 8 open frames. The genome can be divided into three regions according to different functions: the early region (E), about 4.5 kb, encoding E1, E2, E4~E7, a total of 6 non-structural proteins related to virus replication, transcription and transformation; the late region ( L), about 2.5 kb, encoding the major capsid protein L1 and the minor capsid protein L2; the long regulatory region (LCR), located between the end of the L region and the beginning of the E region, is about 800 to 900 bp long, and does not encode any Protein, containing DNA replication and expression regulatory elements.

HPV18 is the second most common high-risk HPV in cervical cancer patients after HPV16, but HPV18 has a stronger malignant transformation ability than HPV16. Since HPV is difficult to cultivate in vitro and is potentially carcinogenic, traditional inactivated vaccine and live attenuated vaccine technologies are not suitable for developing HPV18 vaccines, so genetically engineered protein expression has become the main method of research. The L1 protein has a conserved structure and contains multiple antigenic epitopes. It can self-assemble into virus-like particles (VLP) after expression in eukaryotic and prokaryotic systems. Its structure and antigenic epitopes are very similar to natural virus particles and can stimulate the body to produce protection.

HPV-18 Shell Protein
HPV-18 Capsid Protein
HPV-18 Coat Protein
HPV-18 Major Capsid Protein
HPV-18 Structural Protein
HPV-18 Viral Capsid Protein L1
HPV-18 Outer Capsid Protein
HPV-18 Shell Component L1
HPV-18 Capsomer Protein L1
HPV-18 Surface Antigen L1