Immunoinformatics applications in the development of therapeutic vaccines against human papillomavirus-related infections and cervical cancer

The human papillomavirus (HPV) represents the most prevalent sexually transmitted infectious agent worldwide. HPV penetrates the epithelium through microlesions and establishes an infectious focus that can lead to the development of cervical cancer. Prophylactic HPV vaccines are available, but do not affect already-established infections. Using in silico prediction tools is a promising strategy for identifying and selecting vaccine candidate T cell epitopes. An advantage of this strategy is that epitopes can be selected according to the degree of conservation within a group of antigenic proteins. This makes achieving comprehensive genotypic coverage possible with a small set of epitopes. Therefore, this paper revises the general characteristics of HPV biology and the current knowledge on developing therapeutic peptide vaccines against HPV-related infections and cervical cancer.

Correlation between human papillomavirus infection and histopathological diagnosis of women in Northeast Brazil

Cervical carcinoma is the fourth leading cause of death among women worldwide. Epidemiological studies claim that human papillomavirus (HPV) infection is a necessary condition for cervical cancer development. Knowledge of the geographic distribution of HPV is important in guiding the introduction of prophylactic vaccines. This study analyzed the prevalence of HPV infection in cervical samples obtained from women with abnormal cervical histopathological diagnosis in Northeast Brazil. The study included an analysis of 211 women whose diagnosis was confirmed for cervical intraepithelial neoplasia type 1 (CIN-1), cervical intraepithelial neoplasia type 2 (CIN-2), cervical intraepithelial neoplasia type 3 (CIN-3), and cancer. The identification of the HPV genotypes was based on the polymerase chain reaction-restriction fragment length polymorphism technique. A total of 42.7% of the samples showed a single HPV infection, while 57.3% showed multiple infections. The most common genotypes detected were HPV-16, HPV-18, and HPV-31. HPV-16, HPV-31, HPV-35, and HPV-18 were the most common types in CIN-1 with a single infection. HPV-16 and HPV-18 were the most often found in CIN-2 with a single infection. HPV-16, HPV-18, and HPV-31 were the most detected in CIN-3 with a single infection. HPV-16 and HPV-31 were the most frequent in cancer with a single infection. Multiple infection with HPV-16 shows a 2.7 times greater risk of CIN-3 (P = .04). Multiple infections for HPV with HPV-16 and excluding the HPV18/31 types, were associated with CIN-3 (P = .01). The results allowed the detection and genotyping of HPV types circulating in the population studied. These findings must be taken into account when devising vaccination strategies against HPV.

Detection and Type-Distribution of Human Papillomavirus in Vulva and Vaginal Abnormal Cytology Lesions and Cancer Tissues from Thai Women

Vulva and Vaginal cancers are rare among all gynecological cancers worldwide, including Thailand, and typically affect women in later life. Persistent high risk human papillomavirus (HR-HPV) infection is one of several important causes of cancer development. In this study, we focused on HPV investigation and specific type distribution from Thai women with abnormality lesions and cancers of the vulva and Vaginal. A total of ninety paraffin-embedded samples of vulva and Vaginal abnormalities and cancer cells with histologically confirmed were collected from Thai women, who were diagnosed in 2003-2012 at the National Cancer Institute, Thailand. HPV DNA was detected and genotyped using polymerase chain reaction and enzyme immunoassay with GP5+/ bio 6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. The human β-globin gene was used as an internal control. Overall results represented that HPV frequency was 16/34 (47.1%) and 8/20 (40.0%) samples of vulva with cancer and abnormal cytology lesions, respectively, while, 3/5 (60%) and 16/33 (51.61%) samples of Vaginal cancer and abnormal cytology lesions, respectively, were HPV DNA positive. Single HPV type and multiple HPV type infection could be observed in both type of cancers and abnormal lesion samples in the different histological categorizes. HPV16 was the most frequent type in all cancers and abnormal cytology lesions, whereas HPV 18 was less frequent and could be detected as co-infection with other high risk HPV types. In addition, low risk types such as HPV 6, 11 and 70 could be detected in Vulva cancer and abnormal cytology lesion samples, whereas, all Vaginal cancer samples exhibited only high risk HPV types; HPV 16 and 31. In conclusion, from our results in this study we suggest that women with persistent high risk HPV type infection are at risk of developing vulva and Vaginal cancers and HPV 16 was observed at the highest frequent both of these, similar to the cervical cancer cases. Although the number of samples in this study was limited and might not represent the overall incidence and prevalence in Thai women, but the baseline data are of interest and suggest further study for primary cancer screening and/or developing the efficiency of prophylactic HPV vaccines in Thailand.

Human papillomavirus genotypes 68 and 58 are the most prevalent genotypes in women from quilombo communities in the state of Maranhão, Brazil

OBJECTIVES

To determine the frequency of human papillomavirus (HPV) types and behavioral characteristics related to cytological abnormalities in women descendants of slaves, who live in isolated communities known as quilombos in the state of Maranhão, Brazil.

METHODS

Cervicovaginal specimens of 353 women were analyzed by conventional cytology and genotyping. HPV detection and genotyping was performed using a linear array HPV genotyping test kit. Behavioral factors and their association with cytological abnormalities were analyzed, as well as the association between cytological abnormalities and HPV infection.

RESULTS

The frequency of HPV infection was 13%, and infection with high-risk HPV types was more frequent than with low-risk types (10.2% vs. 2.8%). The most prevalent genotypes were HPV 68 (3.1%) and HPV 58 (2.6%). HPV-positive women were 6.5 times more likely than HPV-negative women to be diagnosed with cytological abnormalities. There was a significant association between HPV infection and the presence of cytological abnormalities in women 31-40 years of age and in women 51-60 years of age.

CONCLUSIONS

A distinct profile of high-risk HPV genotypes was detected, with predominance of types 68 and 58. It is possible that the results of the present study are due to specific characteristics of the population, which is geographically isolated and maintains conservative sexual habits.

Association Study between Cervical Lesions and Single or Multiple Vaccine-Target and Non-Vaccine Target Human Papillomavirus (HPV) Types in Women from Northeastern Brazil

We performed an association between high-grade squamous intraepithelial lesions (HSIL), low-grade squamous intraepithelial lesions (LSIL) and single or multiple vaccine-target as well as non-vaccine target Human papillomavirus (HPV) types. Using bead-based HPV genotyping, 594 gynecological samples were genotyped. An association between squamous intraepithelial lesion (SIL) and presence of HPV16, 18, 31, 58 and 56 types were calculated. The risk was estimated by using odds ratio (OR) and 95% of confidence intervals (CI). A total of 370 (62.3%) women were HPV positive. Among these, 157 (42.7%) presented a single HPV infection, and 212 (57.3%) were infected by more than one HPV type. HPV31 was the most prevalent genotype, regardless single and multiple HPV infections. Single infection with HPV31 was associated with LSIL (OR=2.32; 95%CI: 1.01 to 5.32; p=0.04); HPV31 was also associated with LSIL (OR=3.28; 95%CI: 1.74 to 6.19; p= 0.0002) and HSIL (OR=3.82; 95%CI: 2.10 to 6.97; p<0.001) in multiple HPV infections. Risk to harbor cervical lesions was observed in multiple HPV infections with regard to the HPV56 (OR=5.39; 95%CI: 2.44 to 11.90; p<0.001for LSIL; OR=5.37; 95%CI: 2.71 to 10.69; p<0.001) and HPV58 (OR=3.29; 95%CI: 1.34 to 8.09; p=0.0091 for LSIL; OR=3.55; 95%CI: 1.56 to 8.11; p=0.0026) genotypes. In addition, women coinfected with HPV16/31/56 types had 6 and 5-fold increased risk of HSIL (OR=6.46; 95%CI: 1.89 to 22.09; p=0.002) and LSIL (OR=5.22; 95%CI: 1.10 to 24.70; p=0.03), respectively. Multiple HPV infections without HPV16/18 has 2-fold increased risk of HSIL (OR=2.57; 95%CI: 1.41 to 4.70; p=0.002) and LSIL OR=2.03; 95%CI: 1.08 to 3.79; p=0.02). The results of this study suggest that single and multiple vaccine target as well as non-vaccine target HPV types are associated with LSIL and HSIL. These finding should be taken into consideration in the design of HPV vaccination strategies.

A cross-sectional study of high-risk human papillomavirus clustering and cervical outcomes in HIV-infected women in Rio de Janeiro, Brazil

Background

In Brazil, the rate of cervical cancer remains high despite the availability of screening programs. With ongoing vaccine development and implementation, information on the prevalence of specific HPV types is needed, particularly among high-risk populations, such as HIV-infected women.

Methods

We performed a study of HIV-infected women in Rio de Janeiro, Brazil, who underwent cervical HPV genotype testing between 2005-2013. We examined the prevalence of high-risk HPV types and the patterns of high-risk HPV type clustering. Using logarithmic binomial regression, we estimated the risk of abnormal cytology by HPV genotype result.

Results

Of the 562 women included, 498 (89 %) had at least one HPV type detected. 364 women (65 %) had at least one high-risk HPV type detected and 181 (32 %) had more than one high-risk type detected. HPV 58 was the most frequent HPV type detected overall (prevalence 19.8 % [95 % confidence interval 16.4–23.1]), followed by HPV 53 (prevalence 15.5 % [12.5–18.5]) and HPV 16 (prevalence 13 % [10.2–15.8]). Women infected with more than one high-risk HPV type were younger, had lower CD4+ lymphocyte counts, and were more likely to be infected with HPV 16 or 18. In adjusted analyses, presence of more than one high-risk HPV type was associated with a two-fold increased risk of abnormal cytology after adjusting for presence of individual high-risk type, age, and CD4+ lymphocyte count (adjusted prevalence ratios 1.88–2.07, all p <0.001). No single high-risk HPV type was statistically associated with abnormal cytology after adjusting for the presence of more than one high-risk HPV type.

Conclusions

In the largest study of cervical HPV genotypes among HIV-infected women in Latin America, infection by high-risk HPV types other than 16 or 18 and infection by more than one high-risk HPV types were common. Infection by more than one high-risk type was more strongly associated with abnormal cervical cytology than any individual high-risk HPV type, highlighting the need for multi-valent HPV vaccines.

Site of infections associated with human papillomavirus

INTRODUCTION

Human papillomavirus (HPV) is the most clinically common sexually transmitted infection due to its carcinogenic power and the high number of lesions that it causes at different sites of the human body.

MATERIAL AND METHODS

Genital tract organs are the most common sites where the virus can be found, but by increasing the sensitivity of diagnostic technique, it is possible to identify viral presence in different regions of the body such as the stomach, the lung, and the urinary tract. These findings break with the traditional HPV skin/genital tropic profile and demonstrate that the virus is capable of infecting a wide variety of cells, tissues, and organs or can, at least, survive in these areas. The widespread presence of the HPV in the human body, often in latent form, led us to consider the hypothesis that HPV latency may be associated with no disease.

CONCLUSION

This observation raises further questions about the possibility of the virus not causing disease in specific sites of the human body, but rather, behaving like a commensal/opportunistic microorganism.

Prevalence of human papillomavirus infection, distribution of viral types and risk factors in cervical samples from human immunodeficiency virus-positive women attending three human immunodeficiency virus-acquired immune deficiency syndrome reference centres in northeastern Brazil

Human immunodeficiency virus (HIV)-positive patients have a greater prevalence of coinfection with human papillomavirus (HPV) is of high oncogenic risk. Indeed, the presence of the virus favours intraepithelial squamous cell lesion progression and may induce cancer. The aim of this study was to evaluate the prevalence of HPV infection, distribution of HPV types and risk factors among HIV-positive patients. Cervical samples from 450 HIV-positive patients were analysed with regard to oncotic cytology, colposcopy and HPV presence and type by means of polymerase chain reaction and sequencing. The results were analysed by comparing demographic data and data relating to HPV and HIV infection. The prevalence of HPV was 47.5%. Among the HPV-positive samples, 59% included viral types of high oncogenic risk. Multivariate analysis showed an association between HPV infection and the presence of cytological alterations (p = 0.003), age greater than or equal to 35 years (p = 0.002), number of partners greater than three (p = 0.002), CD4⁺ lymphocyte count < 200/mm³ (p = 0.041) and alcohol abuse (p = 0.004). Although high-risk HPV was present in the majority of the lesions studied, the low frequency of HPV 16 (3.3%), low occurrence of cervical lesions and preserved immunological state in most of the HIV-positive patients were factors that may explain the low occurrence of precancerous cervical lesions in this population.

Prevalence and genotyping of high risk human papillomavirus in cervical cancer samples from Punjab, Pakistan

Cervical cancer is the third most common cause of cancer-related death in women worldwide. Infection with high-risk human papillomavirus (HPV) is established as the cause of cervical carcinoma, therefore, high risk HPV detection may have prognostic significance for the women who are at increased risk of disease progression. The paucity of data on the incidence of cervical cancer in Pakistan makes it difficult to determine disease burden. Even less information is available regarding the prevalent HPV strains in cervical specimens collected from this region. Cervical cancer is a neglected disease in Pakistan in terms of screening, prevention, and vaccination. Identification and accurate genotyping of the virus burden in cancer specimens is important to inform intervention policies for future management of HPV associated disease and to potentially stratify patients dependent on HPV status. In this study, detection and genotyping of HPV types 16 and 18 from 77 cervical specimens were carried out. Consensus primers GP5+/GP6+, which detect 44 genital HPV types, and type specific primers (TS16 and TS18) were used in conjunction with newly designed type specific primers. Using a combination of these methods of detection, a total of 94.81% (95% CI ±4.95) of cervical lesions were positive for HPV. Single infections of HPV16 were detected in 24.68% (95% CI ±9.63) of total samples and HPV18 was found in 25.97% (95% CI ±9.79) samples. Interestingly, a high proportion of samples (40.26%, 95% CI ±10.95) was positive for both HPV16 and 18, indicating a higher incidence of co-infection than previously reported for similar ethnic regions. The HPV genotype of 3.90% of HPV positive samples remained undetected, although these samples were positive with the GP5+/GP6+ primer set indicating infection with an HPV type other than 16 or 18. These data indicate that the overall incidence of high risk HPV infection in cervical cancer and intraepithelial neoplasia specimens in Punjab, Pakistan is in line with the worldwide prevalence, but that the incidence of HPV16 and 18 co-infections in our cohort is higher than that previously reported.

Preliminary study on human papillomavirus frequency and specific type-distribution in vulva cancer from Thai women

Vulva cancer is rare among all gynecological cancer worldwide, including Thailand, and mainly affects older women. Persistent high risk type infection of human papillomavirus (HPV) is the one important factor for developing cancer. In this study, we focused on HPV DNA investigation and type-specific distribution of HPV in 25 formalin-fixed paraffin-embedded (FFPE) samples collected from Thai women with vulva cancer histologically confirmed by the National Cancer Institute, Thailand, during 2003-2011. HPV DNA detection and genotyping were undertaken with polymerase-chain reaction and enzyme-immunoassay using GP5+/bio6+ consensus specific primers and digoxigenin-labeled specific oligoprobes, respectively. Human β-globin genes was used as the internal control. Our results showed that 44% (11/25) of all vulva cancer samples were HPV-positive. All of them are high risk HPV type infection, detected as single (63.64%, 7/11) and/or double infections (4/11, 36.36%). HPV 16 was the most common type identified in vulva cancer, followed by HPV 35, 33, 18 and 58. In conclusion, this study presented that HPV-16 is observed at the highest frequency in this cancer, similar to cervical cancer, with HPV 18 being less frequent. Although the sample size was small and could not represent overall incidence and prevalence in Thai women, these preliminary data for vulva cancer are of interest since they reinforce the necessity for HPV screening or vaccination in Thailand.