Characterization of Immunoglobulin A/G Responses During 3 Doses of the Human Papillomavirus-16/18 ASO4-Adjuvanted Vaccine

Immune Responses in Oral Papillomavirus Clearance in the MmuPV1 Mouse Model

Human papillomavirus (HPV)-induced oropharyngeal cancer now exceeds HPV-induced cervical cancer, with a noticeable sex bias. Although it is well established that women have a more proficient immune system, it remains unclear whether immune control of oral papillomavirus infections differs between sexes. In the current study, we use genetically modified mice to target CCR2 and Stat1 pathways, with the aim of investigating the role of both innate and adaptive immune responses in clearing oral papillomavirus, using our established papillomavirus (MmuPV1) infection model. Persistent oral MmuPV1 infection was detected in Rag1ko mice with T and B cell deficiencies. Meanwhile, other tested mice were susceptible to MmuPV1 infections but were able to clear the virus. We found sex differences in key myeloid cells, including macrophages, neutrophils, and dendritic cells in the infected tongues of wild type and Stat1ko mice but these differences were not observed in CCR2ko mice. Intriguingly, we also observed a sex difference in anti-MmuPV1 E4 antibody levels, especially for two IgG isotypes: IgG2b and IgG3. However, we found comparable numbers of interferon-gamma-producing CD8 T cells stimulated by E6 and E7 in both sexes. These findings suggest that males and females may use different components of innate and adaptive immune responses to control papillomavirus infections in the MmuPV1 mouse model. The observed sex difference in immune responses, especially in myeloid cells including dendritic cell (DC) subsets, may have potential diagnostic and prognostic values for HPV-associated oropharyngeal cancer.

Natural and vaccine-induced B cell-derived systemic and mucosal humoral immunity to human papillomavirus

Introduction: Human papillomavirus (HPV) are the causative agent of mucosal neoplasia. Both cervical, anal and oropharyngeal cancers incidence is constantly increasing, making the HPV infection, a significant worldwide concern. Together, the CD8+ T cytotoxic cell-mediated response and the HPV-specific antibody response control most of the HPV infections before the development of cancers.Areas covered: We searched the MEDLINE and EMBASE databases and identified 228 eligible studies from 1987 to 2019 which examines both naturally acquired and vaccine induced humoral immunity against HPV infection in female and male subjects from worldwide origin. Herein, we synthesize current knowledge on the features of systemic and mucosal humoral immunity against HPV. We discuss the issues of the balance between the viral clearance or the escape to the host immune response, the differences between natural and vaccine-induced HPV-specific antibodies and their neutralizing capability. We also discuss the protection afforded after natural infection or following prophylactic vaccination.Expert opinion: Understanding the antibody response induced by HPV infection has led to the design of first-generation prophylactic vaccines. Now, prophylactic vaccination induces protective and long-lasting antibody response which would also strengthened the natural moderate humoral response in people previously exposed to the virus.

Infection and vaccine-induced HPV-specific antibodies in cervicovaginal secretions. A review of the literature

Background

Human papillomavirus (HPV) infects and propagates in the cervical mucosal epithelium. Hence, in addition to assessing systemic immunity, the accurate measurement of cervical immunity is important to evaluate local immune responses to HPV infection and vaccination. This review discusses studies that investigated the presence of infection and vaccine-induced HPV-specific antibodies in cervicovaginal secretions (CVS).

Methods

We searched the two main health sciences databases, PubMed and the ISI Web of Science, from the earliest dates available to March 2019. From the eligible publications, information was extracted regarding: (i) study design, (ii) the reported HPV-specific antibody concentrations in CVS (and the associated serum levels, when provided), (iii) the CVS collection method, and (iv) the immunoassays used.

Results

The systematic search and selection process yielded 44 articles. The evidence of HPV-specific antibodies in CVS after natural infection (26/44) and HPV vaccination (18/44) is discussed. Many studies indicate that HPV-specific antibody detection in CVS is variable but feasible with a variety of collection methods and immunoassays. Most CVS samples were collected by cervicovaginal washing or wicks, and antibody presence was mostly determined by VLP-based ELISAs. The moderate to strong correlation between vaccine-induced antibody levels in serum and in CVS indicates that HPV vaccines generate antibodies that transudate through the cervical mucosal epithelium.

Conclusion

Although HPV-specific antibodies have lower titres in CVS than in serum samples, studies have shown that their detection in CVS is feasible. Nevertheless, the high variability of published observations and the lack of a strictly uniform, well-validated method for the collection, isolation and quantification of antibodies indicates a need for specific methods to improve and standardize the detection of HPV-specific antibodies in CVS.

Immune Response to Human Papillomavirus One Year after Prophylactic Vaccination with AS04-Adjuvanted HPV-16/18 Vaccine: HPV-Specific IgG and IgA Antibodies in the Circulation and the Cervix

Objective:

This study was designed to describe the course of IgG/IgA responses in cervical secretions and in serum one year after the first dose of intramuscular administration of the HPV16/18 AS04-adjuvant vaccine.

Methods:

Blood and cervical mucus samples were collected for immunologic assays, 7 months after the first doses and 1 year following the last boost vaccination (month 7) by enzyme linked immunosorbent assay (ELISA). The detection of IgG and IgA anti-HPV/VLP was developed for this purpose.

Result:

A total of 100% of serum samples were IgG antibody positive at a titer of 1:100 at both time periods and decreased according to the serum dilution. For serum IgA antibody, 95% were positive one month after vaccination and 79% were positive 1 year later. Similar results were observed with the cervical samples positive for both IgG and IgA antibodies at one month and decreasing after 1 year to 33% and 29%. The median absorbance in serum and the cervix for IgG and IgA anti-HPV-VLP antibodies was significantly higher at one month after vaccination when compared to 1 year post-vaccination (P<0.0001).

Conclusion:

Immune responses were significant one year after immunization, however it decreased in cervical and serum samples when compared to levels observed one month after the last dose. This suggests that a vaccine booster may be necessary to increase antibody titers.