ヒトパピローマウイルスワクチン開発に関する研究 : 子宮頸癌の発生制御をめざして(1 子宮頸癌の発生と進展 : その制御を目指して)

概要

論文の詳細を見る
[Objects] Human papillomavirus (HPV) is a major risk factor for cervical cancer. The prophylactic vaccine against HPV infection is a favorable strategy for prevention of the cervical cancer. The purpose of this study is the development of a type-common prophylactic vaccine to protect against more than ten types of oncogenic HPV infection. [Methods & Results] To measure neutralizing antibodies (NAs) against HPV 6,16, and 52 infection, we established an in vitro neutralization assay system using corresponding HPV pseudovirion. Neutralizing activity of serum was determined as an activity to inhibit the infection of cultured cells with pseudovirions containing expression plasmid for β-galactosidase. First, we examined the positive rate of the NAs against HPV16 in non-CIN women, CIN cases and cervical cancer cases with HPV16-DNA. The NAs were detected in 6 out of 7 non-CIN cases (85.7%). On the other hand, in women with cervical pathologies, the NAs were found in 8 out of 37 CIN 1 cases (21.6%), 3 out of 19 CIN 2/3 cases(15.8%)and in none of 13 invasive cancers (0%). In our cohort study for the CIN1 cases, Kaplan-Meier curves showed that the regression of CIN 1 occurred more frequently in the NA positive group against HPV compared with the negative group. These data suggest that the NAs against oncogenic HPV are associated with the regression of CIN 1. Second, we tried to identify type-common neutralization epitopes of minor capsid protein L2, whose amino acid (aa) sequences are well conserved among genital HPV. We demonstrated that the 70-135 aa region of HPV16-L2 display on the surface of HPV virions and contain the neutralization epitopes against several genital HPVs. In comparison of the neutralizing titers between the antisera to four L2 peptides with amino acid sequences of 70-85, 86-107, 108-120, and 121-135 aa, the antisera against 108-120 an region of HPV16-L2 had the strongest titer. Moreover, we investigate the region's involvement in adsorption and penetration of HPV to host cells by confocal microscopy and flow cytometry using green fluorescent protein (GFP) fused with the L2 peptide 108-126 aa. The fused GFP was found to bind to the surface of HeLa cells at 4C and to enter the cytoplasm after subsequent incubation at 37C. Substitutions at an 108-111 inhibited the fused GFP from binding to cells. The results suggest that the L2 region play an essential role in HPV infection through facilitating penetraion of the virions. Therefore, we decided that the L2 peptide corresponding to 108-120aa of HPV16-L2 is a type-common vaccine for protection against genital HPVs infection. Third, we nasally immunized mice with the L2 peptide and examined the antibodies elicited. Moreover, we designed a double-blind, placebo-controlled, dose-escalation small vaccine trial to evaluate the safety and immunogenicity of the L2 peptide vaccine through the nasal vaccination in healthy volunteers. The nasal vaccination of Balb/c mice with the L2 peptide elicited IgG antibodies in sera and IgA antibodies in vaginal washes binding to several types of HPV. In the trial in healthy volunteer, there was no complication by the nasal vaccination with the peptide compared with placebo group. The NAs against HPV16 in sera could be induced by the two times vaccination with 500μg of the peptide in the two volunteers (2/5 =40%). [Conclusions] We identified the L2 region, 108-120 aa of HPV16 L2, the synthetic peptide with whose amino acid sequence can elicit the type-common NAs against genital HPV. The L2 peptide is available for HPV prophylactic vaccine against any genital HPV infection, because of the safety and immunogenicity of the vaccine in healthy volunteers. And the type-common L2 vaccine is the most fundamentally strategy for prevention of the development of cervical cancer.
社団法人日本産科婦人科学会の論文
2002-08-01

ヒトパピローマウイルスワクチン開発に関する研究 : 子宮頸癌の発生制御をめざして(1 子宮頸癌の発生と進展 : その制御を目指して)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク