Here, we presented a method to bacterially express the major structural protein L1 of Human Papillomavirus type 18 (HPV18) as soluble form. We found that the purified L1 could self-assemble to virus-like particles (VLPs). Further, we investigated the immunogenicity and the induced level of neutralizing antibody using these VLPs. First, the genome of HPV18 was cloned from a patient in Xiamen. It was used as template for PCR amplification of HPV18 L1 gene. The resultant DNA fragment was inserted into expression vector pTrxFus and expressed in Escherichia coli GI724. Second, L1 protein was purified by ammonium sulfate precipitation, ion-exchange chromatography and hydrophobic interaction chromatography; and the purified L1 was subjected to self-assembly to form VLPs with the removal of premixed reductant DTT. Finally, the size and morphology of these VLPs was investigated by Dynamic Light Scattering and Transmission Electronic Microscopy as 29.34 nm in hydrated radius and globular particles similar with native HPV18. The half effective dosage (ED50) and maximum level of neutralizing antibody elicitation were measured by vaccinations on mice, rabbit and goat using pseudovirus neutralization cell model. The results showed that the ED50 of HPV18 VLPs is 0.006 microg in mice, and the maximum titer of neutralizing antibody elicited in rabbit and goat is up to 10(7). As a conclusion, we can provide HPV18 VLPs with highly immunogenicity from prokaryote expression system, which may pave a new way for research and development of prophylactic vaccine for HPV18.
Animals ; Capsid Proteins ; biosynthesis ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Goats ; Human papillomavirus 18 ; immunology ; isolation & purification ; Mice ; Oncogene Proteins, Viral ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Virion ; genetics ; immunology

ObjectiveTo analyze the clinical and epidemiological characteristics of confirmed cases of human monkeypox infection in Changning District， Shanghai， and to explore their clinical and epidemiological characteristics. MethodsClinical data from 10 reported cases of monkeypox in individuals residing in Changning District or identified by local medical institutions between July 20 and September 30， 2023， were collected. Epidemiological case investigations were conducted， and throat swabs， anal swabs， and rash swabs were collected by the treating medical institutions. Real-time fluorescence quantitative PCR was used for monkeypox virus nucleic acid testing， and descriptive epidemiological analysis was applied to analyze the epidemiological characteristics of the cases. ResultsAll 10 confirmed cases of human monkeypox infection were all young males with an average age of 35.4 years， all of whom belonged to the men who have sex with men （MSM） population， with no occupational clustering. The primary clinical symptoms included fever， rash， enlarged inguinal lymph nodes， and muscle soreness. Nine cases presented with a rash， and seven cases experienced fever symptoms. Among the 10 cases， one experienced fever， rash， enlarged lymph nodes， and muscle soreness； two had fever， rash， and enlarged lymph nodes； two had fever， rash， and systemic soreness； two had only a rash； one had fever or rash； and one was asymptomatic. Among the nine cases with a rash， the rash was mainly localized to the genital or anal area， with fewer cases presenting rashes on the limbs or trunk simultaneously. All cases reported a history of non-exclusive MSM behavior within 21 days before the onset of the disease. The interval between the last suspected high-risk exposure and the onset of symptoms was 4 to 10 days， with an average interval of 6.9 days. The time from the onset of fever to the appearance of a rash was 0 to 5 days， with an average of 1.87 days. ConclusionThe main clinical manifestations of human infection with monkeypox are fever， rash， and enlarged inguinal lymph nodes. The MSM population is a high-risk group for monkeypox infection， and its source of infection may be associated with MSM exposure. Early-stage symptoms are mild， leading to potential underdiagnosis. Additionally， patients may conceal information during the investigation process， which increases the difficulty of epidemic prevention and control.