Clonación y expresión en Escherichia coli de un gen L1 completo del virus del papiloma humano 18 aislado de una paciente cubana y variantes delecionadas / Cloning and expression in Escherichia coli of the full-length and deletion variants of a human papillomavirus 18 L1 gene isolated from a Cuban patients

Introduction: Human papillomavirus (HPV) vaccines are based on the L1 major capsid protein. Objectives: To clone the HPV-18 L1 gene from a Cuban female HPV-18-infected patient and to express the full-length and deletion variants of the cloned HPV-18 L1 gene in Escherichia coli. Methods: The full-length HPV-18 L1 gene was PCR-amplified from total DNA isolated from a Cuban patient, cloned and finally subcloned into the E. coli expression vector pET26b. Three deletion mutants were constructed, which encode truncated proteins lacking 30 amino acids at the C-terminus in combination with 5, 6 or none deleted residue at the N-terminus. Production of L1 proteins in E. coli BL21(DE3) and E. coli SHuffle T7 was assessed by SDS-PAGE and Western blotting. Results: The cloned HPV-18 L1 gene was 99.9 por ciento similar to the African variant EF202152 and probably shares a common origin with the B lineage of genotype 18. The three truncated variants of HPV-18 L1 were produced at higher levels than the full-length HPV-18 L1 protein, attaining higher levels in E. coli BL21(DE3) and higher solubility in E. coli SHuffle. The C-terminus-only truncated variant, L1∆C30, was produced at similar levels to the HPV-18 L1s truncated at both termini. E. coli SHuffle produced about three times more amounts of L1∆C30 when grown under autoinduction conditions with respect to conventional induction and thus, amounts were comparable to those obtained in E. coli BL21(DE3) under conventional induction. Conclusions: Truncation of thirty amino acid residues at the carboxy-terminus of the HPV-18 L1 made a major contribution to the production and solubility of this wild-type protein in E. coli. This is the first report about soluble production of HPV-18 L1 protein in an E. coli SHuffle strain. However, higher amounts of L1 are needed to scale-up its production for developing an HPV vaccine candidate(AU)

Introducción: Las vacunas contra el virus del papiloma humano (VPH) se fundamentan en la proteína principal de la cápsida L1. Objetivo: Clonar el gen L1 del VPH-18 a partir de una paciente cubana infectada con VPH-18 y expresar las variantes de longitud completa y delecionadas del gen L1 del VPH-18 en Escherichia coli. Métodos: El gen L1 del VPH-18 de longitud completa se amplificó por PCR a partir de ADN total aislado de un paciente cubana, se clonó y finalmente se subclonó en el vector de expresión de E. coli pET26b. Se construyeron tres mutantes de deleción, que codifican para proteínas truncadas que carecen de 30 aminoácidos por el extremo carboxilo, en combinación con 5, 6 o ningún residuo delecionado por el extremo amino. La producción de las proteínas L1 en E. coli BL21(DE3) y E. coli SHuffle T7 se evaluó mediante SDS-PAGE y Western blot. Resultados: El gen L1 del VPH-18 clonado fue 99.9 percent similar a la variante africana EF202152 y probablemente comparte un origen común con el linaje B del genotipo 18. Las tres variantes truncadas de la proteína L1 del VPH-18 se produjeron a mayores niveles que la proteína L1 del VPH-18 de longitud completa, alcanzando mayores niveles en E. coli BL21(DE3) y mayor solubilidad en E. coli SHuffle. La variante truncada solo por el extremo carboxilo, L1(C30, se produjo a niveles similares a las proteínas L1 del VPH-18 truncadas por ambos extremos. E. coli SHuffle produjo aproximadamente tres veces más cantidades de L1(C30 cuando creció en condiciones de autoinducción, con respecto a la inducción convencional y, por ende, las cantidades fueron comparables a las obtenidas por E. coli BL21(DE3) bajo inducción convencional. Conclusiones: La truncación de treinta residuos de aminoácidos por el extremo carboxilo de la proteína L1 del VPH-18 tuvo una importante contribución a la producción y solubilidad de la proteína L1 nativa en E. coli. Este es el primer informe sobre la producción soluble de la proteína L1 del VPH-18 en una cepa de E. coli SHuffle. Sin embargo, se necesitan mayores cantidades de la proteína L1 para escalar su producción para desarrollar un candidato vacunal contra el VPH(AU)

Advance in human papillomavirus major capsid protein L1-based vaccines / 中华微生物学和免疫学杂志

L1 is the major capsid protein of human papillomavirus (HPV) encoded by late gene 1. Based on the fact that L1 can self-assemble into virus like particle (VLP) with good immunogenicity, it has aroused wide concern in studying the pathogenesis of and vaccines against HPV. Nevertheless, there are a few limitations of present L1-based HPV vaccines. For instance, low expression of the protein and the complexity of purification result in the relatively low yield of vaccines. Type-specific antibody induced by L1 also results in the unsatisfactory cross-protection rate. Furthermore, there is no reported therapeutic effect against HPV-related diseases because of its undefined role in virus eliminating. This review focused on the structure, immunogenicity and role in immune response of L1 and the development of and latest progress in HPV vaccines.

Advance in human papillomavirus major capsid protein L1-based vaccines / 中华微生物学和免疫学杂志

L1 is the major capsid protein of human papillomavirus (HPV) encoded by late gene 1. Based on the fact that L1 can self-assemble into virus like particle (VLP) with good immunogenicity, it has aroused wide concern in studying the pathogenesis of and vaccines against HPV. Nevertheless, there are a few limitations of present L1-based HPV vaccines. For instance, low expression of the protein and the com-plexity of purification result in the relatively low yield of vaccines. Type-specific antibody induced by L1 also results in the unsatisfactory cross-protection rate. Furthermore, there is no reported therapeutic effect against HPV-related diseases because of its undefined role in virus eliminating. This review focused on the struc-ture, immunogenicity and role in immune response of L1 and the development of and latest progress in HPV vaccines.

Neutralizing epitopes and intragenotypic variants of human papillomavirus 16 (HPV16) / 中华微生物学和免疫学杂志

Cervical cancer is the second most common cancer in women worldwide. It is clear that persistent infection of high-risk human papillomaviruses (HR-HPVs) is the main cause for this disease. Among the several HPV types associated with carcinoma, HPV-16 is the most prevalent type and present in about 50% of tumor specimens. The major capsid protein (L1) of HPV can self-assemble into virus-like particles (VLPs) with immunogenicity similar to infectious virions. Neutralizing epitopes are the structural basis of the current prophylactic HPV vaccines. The efficacy of HPV vaccines is critically dependent upon the integrity of type-specific neutralizing epitopes. Recently, considerable headway has been made in studying the epitopes of HPV16 based on neutralizing antibodies. Notably, more and more HPV16 variants have appeared along with increasing immune pressure. To study the phenotypic variations in HPV16 L1 protein, 1 204 naturally occurring sequences were analyzed and a phylogenetic tree was then constructed including four clades. Moreover, after compared the aforementioned sequences with the 114K reference sequence, eight "hot mutation sites" , six "specialized mutation sites" and 20 "epitope-related mutation sites" were found. Generally, sera raised against VLPs can neutralize the corresponding HPV types, but not other types. However, it is not known whether intragenotypic variants of human papillomavirus type 16 (HPV-16) can be neutralized by sera vaccinated with a single variant VLPs. It is, therefore, imperative to understand the neutralizing epitopes and intragenotypic variants of HPV-16 for the production of prophylactic vaccines with high potency and broad coverage.

Review for progress and current status of human papillomavirus prophylactic vaccine / 中国生化药物杂志

Persistant infection of high-risk human papillomavirus (HPV) is the primary cause leading to cervical cancer, which is ranked as second cancer threatening the health of women following breast cancer.Development of HPV vaccine is very important because there is no effective therapeutics for cervical cancer.Three currently licensed HPV vaccines based on major capsid protein L1 in the foreign market confered good safety and efficacy in clinical trials, but the current price is expensive due to high cost, which limits the wide application in developing countries.So far, the vaccines have not been launced in China market.Here, we review the progress and the current status of the HPV vaccine, which will attract the readers’ interest on the forthcoming emergence of HPV vaccine in China.

L1 C-terminal common sequence polypeptide antibody in detecting human papillomavirus in liquid-based cervical cytology specimens / 第二军医大学学报

Objective To determine whether the polypeptide antibody induced by human papillomavirus (HPV)L1 C-terminal conserved sequence polypeptide can be used to detect HPV in cervical exfoliated cell specimens. Methods Cervical exfoliated cell specimens were collected and divided into two groups: one was subjected to nested polymerase chain reaction (Nest-PCR) for detection of HPV DNA, and the other was subjected to sandwich enzyme-linked immunosorbent assay (ELISA), in which rabbit anti-polypeptide purified antibody and mice anti-polypeptide antiserum were used to determine HPV L1 in specimens. The detection rates of HPV were compared between the two groups. Part of the specimens were used for immunocytochemistry detection. Results Nest-PCR with primer MY09/11 detected 30 HPV DNA positive specimens out of a total of 296 ones, with a detection rate of 11.15%. Then the HPV DNA negative specimens were further amplified with primer GP5+/6, and 51 (21.34%) more positive cases were identified, making the total detection rate of Nest-PCR being 30.11% (totally 81 cases). ELISA identified 91 positive cases out of 263 specimens, with a detection rate of 34.60%, which was not significantly different from that by Nest-PCR. Immunocytochemistry detection results displayed that the polypeptide antibody could specifically reveal cervical exfoliated cells infected with HPV. Conclusion The HPV L1 polypeptide antibody can satisfactorily detect the HPV infection in cervical exfoliated cells, indicating that HPV L1 polypeptide antibody has great potential in developing HPV detection kit for cervical cancer preventive screening.

Production of immunogenic human papillomavirus-16 major capsid protein derived virus like particles.

Background & objective: Recombinant DNA technology allows expression of the human papillomavirus (HPV) major capsid protein (L1) in heterologous expression systems and the recombinant protein self assembles to virus-like particles (VLP). We took up this study to produce recombinant HPV-16 L1 in yeast, establish the process of recombinant L1 derived VLP preparation and develop an ELISA using VLP as the antigen for serological evaluation of anti HPV-16 L1 antibody status. Methods: Complete HPV-16 L1 was amplified from genomic DNA of an esophageal cancer biopsy, cloned and the protein was expressed in a galactose-inducible Saccharomyces cerevisiae expression system. Self assembled VLP was purified by a two-step density gradient centrifugation process and the VLP preparation used to test its suitability in developing an ELISA. Results: The recombinant protein was predominantly a ~55 KD species with distinct immunoreactivity and formed VLP as confirmed by electron microscopy. An ELISA using the VLP showed its efficacy in appropriate immunoreactivity to serum/plasma IgG. Interpretation & conclusions: Recombinant HPV-16 capsid protein derived VLP was produced and the VLP antigen based ELISA can be used to probe serological association of HPV with different clinical conditions. The VLP technology can be improved further and harnessed for future vaccine development efforts in the country.