Tissue effects and host response. The key to the rational triage of cervical neoplasia

Immunogenicity Assessment of a 14-Valent Human Papillomavirus Vaccine Candidate in Mice

BACKGROUND

Cervical cancer ranks as the fourth most common cancer affecting women globally, with HPV as the primary etiology agent. Prophylactic HPV vaccines have substantially reduced the incidence of cervical cancer.

METHODS

This study assessed the immunogenicity of SCT1000, a 14-valent recombinant virus-like particle (VLP) vaccine developed by Sinocelltech, Ltd. using pseudovirion-based neutralization assays (PBNAs) and total IgG Luminex immunoassays (LIAs). Currently in phase III clinical trials in China, SCT1000 targets the same HPV types as Gardasil 9®, plus five additional high-risk types, thereby covering twelve high-risk HPV types implicated in 96.4% of cervical cancer cases.

RESULTS

In murine models, a dose of 1.85 μg per mouse was identified as optimal for evaluating SCT1000's immunogenicity in a three-dose regimen, as measured by PBNA and total IgG LIA across all 14 HPV types. SCT1000 induced high levels of protective antibodies, which were sustained for at least four months following the third dose. The vaccine also demonstrated stable and consistent immunogenicity in mouse potency assays under both long-term and accelerated conditions. Additionally, our studies revealed a strong correlation between the two serological tests used.

CONCLUSIONS

SCT1000 elicited robust, durable, and consistent humoral immune responses across all 14 HPV types, indicating its potential as a broad-spectrum vaccine candidate against HPV types 6/11/16/18/31/33/35/39/45/51/52/56/58/59. The significant correlations observed between PBNA and total IgG LIA support the use of the Luminex-based total IgG method as a reliable and effective alternative for immunogenicity assessment in preclinical and future clinical vaccine development.

The skin microbiome and immune system: Potential target for chemoprevention?

There has been increasing interest in understanding the role of the human microbiome in skin diseases. Microbiome studies are being utilized in skin cancer research in numerous ways. Commensal bacteria are being studied as a potential tool to judge the biggest environmental risk of skin cancer, ultraviolet (UV) radiation. Owing to the recognized link of skin microbes in the process of inflammation, there have been theories linking commensal bacteria to skin cancer. Viral metagenomics has also provided insight into virus linked forms of skin cancers. Speculations can be drawn for skin microbiome that in a manner similar to gut microbiome, they can be involved in chemoprevention of skin cancer. Nonetheless, there are definitely huge gaps in our knowledge of the relationship of microbiome and skin cancers, especially in relation to chemoprevention. The utilization of microbiome in skin cancer research seems to be a promising field and may help yield novel skin cancer prevention and treatment options. This review focuses on recent utilization of the microbiome in skin cancer research, and it explores the potential of utilizing the microbiome in prevention, earlier diagnosis, and treatment of skin cancers.

Mucosal IgG and IgA responses to human papillomavirus type 16 capsid proteins in HPV16-infected women without visible pathology

Human papillomavirus type 16 (HPV16) may infect the cervical epithelium without producing pathological changes for a long time. To investigate if mucosal antibodies are induced in HPV16-infected women without visible pathology, cervical mucus from HPV16-infected patients with and without evident pathology, along with mucus from uninfected women were analyzed for the presence of mucosal IgG and secretory IgA (sIgA) antibodies to HPV16 capsid proteins by ELISA. sIgA and IgG antibodies were found in a significantly higher proportion of infected patients compared with uninfected women (p < 0.0001). sIgA antibodies were present in 13.1% of infected patients without visible pathology, the proportion of positivity increased to 27.0% in patients with visible pathology (p = 0.001). Mucosal IgG response was observed in 6.5% of patients without and 27.5% of patients with visible pathology (p = 0.00005). The antibody mean signal strength was significantly higher in patients with than in patients without pathological evidence (p < 0.005). In conclusion, both sIgA and IgG are found in patients without pathological signs of infection, however, the response increases significantly in patients with pathological evidence, suggesting that the appearance of these changes might be associated with a more vigorous antibody-mediated mucosal reaction.

Preinvasive diseases of the cervix, vulva, and vagina

OBJECTIVES

To discuss the epidemiology, treatment, and psychosocial implications of preinvasive disease of the lower genital tract.

DATA SOURCES

Review articles, research studies, and government publications.

CONCLUSIONS

Routine cervical cytology has been one of the most successful public health screening programs accomplished over the last 50 years. However, our success has plateaued. The focus now is to address existing barriers to screening and treatment, and to develop an effective triage protocol for the management of abnormal cervical cytology. IMPLICATIONS FOR NURSING CARE: Nurses as patient advocates are best prepared to meet the culturally sensitive, financially, and geographical challenges of addressing barriers to screening and treatment.

Human papillomavirus and skin cancer

Human papillomavirus (HPV) appears to be the most ubiquitous of the human viruses. Over 100 HPV types have been identified. A minority of HPV cause cutaneous warts and mucosal condylomata. The HPV that cause mucosal condylomata put the patient at various degrees of risk for developing cancers, particularly cervical cancer. The majority of HPV infect the skin of normal and immunocompromised individuals. In normal people, most of these HPV appear to establish a latent infection of the skin, most likely as normal flora residing in hair follicles; however, in patients with various systemic and localized depressions of cell-mediated immunity, some HPV infections appear to be involved in the development of nonmelanotic skin cancer and its precursor lesions in skin, usually in sunlight-exposed areas. Circumstantial evidence suggests that these HPV may have a role in promoting proliferative lesions of the skin, although their sites of active infection and mode of transmission to susceptible individuals remain unknown.

Human papillomavirus infection in adolescents

The recent gain in knowledge of the genomic function of HPV has led to a greater understanding of the natural history of HPV infection in women, starting from infection to the development of invasive cancer. LSIL is reflective of a benign process associated with HPV replication, and in the majority of women, HPV is eradicated or put into some type of immunologic control so that it remains undetected. In contrast, in the minority of women who have persistent infection, HSIL and invasive cancer are more likely to occur. These findings can be translated clinically to suggest that LSIL can be followed up for a defined period of time and that HPV testing in older women may be useful to identify persistent HPV infections and subsequent risk for invasive cancers.

The significance of squamous metaplasia in the development of low grade squamous intraepithelial lesions in young women

BACKGROUND

The purpose of this study was to examine, prospectively, the presence and extent of cervical epithelial immaturity as well as the rate of squamous metaplastic activity as a risk for the development of low grade squamous intraepithelial lesions (LSIL).

METHODS

The study was a nested case-control design that used subjects from an ongoing cohort study of human papillomavirus infection. Fifty-four sexually active young women who developed LSIL were matched for age and number of visits with 54 women who had never developed LSIL. The percent of cervical immaturity was interpreted from colpophotography using a computer-generated pixel count of delineated immature and total cervical areas. Activity of squamous metaplasia was interpreted as the percent change in the area of immaturity over a defined time period. Conditional logistic regression analysis examined risks for the development of LSIL.

RESULTS

Baseline area of biologic immaturity was not a predictor of LSIL. However, women with the a high degree of metaplastic activity near the SIL event were more likely to develop LSIL (odds ratio = 3.01 [95% confidence interval, 1.3, 6.8] for every 10% unit change in area of immaturity).

CONCLUSIONS

A rapid rate of metaplastic change within the transformation zone, rather than the initial area of biologic immaturity, is a significant risk factor for the development of LSIL.

Detection and identification of human papilloma viral DNA, types 16, 18, and 33, by a combination of polymerase chain reaction and a colorimetric solid phase capture hybridisation assay

A colorimetric microplate hybridization assay was developed previously to simplify detection procedures of DNA fragments resulting from polymerase chain reactions (PCR). This format has now been adapted for the simultaneous detection and identification of three human papillomavirus (HPV), types 16, 18 and 33, associated frequently with cervical cancer. This post-PCR detection system uses three type-specific capture oligonucleotides linked covalently to a single microplate well and three type-specific multibiotinylated oligonucleotidic probes for detection. It therefore offers a double specificity; the first is conferred by pairs of primers, specific of each type of virus tested, and the second, by the sets of capture and detection probes which are complementary to internal regions of the amplified DNA fragments. The detection format outperformed agarose gel electrophoresis of amplified DNA products in sensitivity and specificity. The rapidity and simplicity of this hybridisation system would justify its use in routine diagnostic examination of cervical specimens (smears and biopsies).