Role of HIV as cofactor in HPV oncogenesis: in vitro evidences of virus interactions

HIV-1 Reverse Transcriptase Expression in HPV16-Infected Epidermoid Carcinoma Cells Alters E6 Expression and Cellular Metabolism, and Induces a Hybrid Epithelial/Mesenchymal Cell Phenotype

The high incidence of epithelial malignancies in HIV-1 infected individuals is associated with co-infection with oncogenic viruses, such as high-risk human papillomaviruses (HR HPVs), mostly HPV16. The molecular mechanisms underlying the HIV-1-associated increase in epithelial malignancies are not fully understood. A collaboration between HIV-1 and HR HPVs in the malignant transformation of epithelial cells has long been anticipated. Here, we delineated the effects of HIV-1 reverse transcriptase on the in vitro and in vivo properties of HPV16-infected cervical cancer cells. A human cervical carcinoma cell line infected with HPV16 (Ca Ski) was made to express HIV-1 reverse transcriptase (RT) by lentiviral transduction. The levels of the mRNA of the E6 isoforms and of the factors characteristic to the epithelial/mesenchymal transition were assessed by real-time RT-PCR. The parameters of glycolysis and mitochondrial respiration were determined using Seahorse technology. RT expressing Ca Ski subclones were assessed for the capacity to form tumors in nude mice. RT expression increased the expression of the E6*I isoform, modulated the expression of E-CADHERIN and VIMENTIN, indicating the presence of a hybrid epithelial/mesenchymal phenotype, enhanced glycolysis, and inhibited mitochondrial respiration. In addition, the expression of RT induced phenotypic alterations impacting cell motility, clonogenic activity, and the capacity of Ca Ski cells to form tumors in nude mice. These findings suggest that HIV-RT, a multifunctional protein, affects HPV16-induced oncogenesis, which is achieved through modulation of the expression of the E6 oncoprotein. These results highlight a complex interplay between HIV antigens and HPV oncoproteins potentiating the malignant transformation of epithelial cells.

Oncogenic Effects of HIV-1 Proteins, Mechanisms Behind

People living with human immunodeficiency virus (HIV-1) are at increased risk of developing cancer, such as Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL), cervical cancer, and other cancers associated with chronic viral infections. Traditionally, this is linked to HIV-1-induced immune suppression with depletion of CD4+ T-helper cells, exhaustion of lymphopoiesis and lymphocyte dysfunction. However, the long-term successful implementation of antiretroviral therapy (ART) with an early start did not preclude the oncological complications, implying that HIV-1 and its antigens are directly involved in carcinogenesis and may exert their effects on the background of restored immune system even when present at extremely low levels. Experimental data indicate that HIV-1 virions and single viral antigens can enter a wide variety of cells, including epithelial. This review is focused on the effects of five viral proteins: envelope protein gp120, accessory protein negative factor Nef, matrix protein p17, transactivator of transcription Tat and reverse transcriptase RT. Gp120, Nef, p17, Tat, and RT cause oxidative stress, can be released from HIV-1-infected cells and are oncogenic. All five are in a position to affect "innocent" bystander cells, specifically, to cause the propagation of (pre)existing malignant and malignant transformation of normal epithelial cells, giving grounds to the direct carcinogenic effects of HIV-1.

Modeling the Mechanisms by Which HIV-Associated Immunosuppression Influences HPV Persistence at the Oral Mucosa

Human immunodeficiency virus (HIV)-infected patients are at an increased risk of co-infection with human papilloma virus (HPV), and subsequent malignancies such as oral cancer. To determine the role of HIV-associated immune suppression on HPV persistence and pathogenesis, and to investigate the mechanisms underlying the modulation of HPV infection and oral cancer by HIV, we developed a mathematical model of HIV/HPV co-infection. Our model captures known immunological and molecular features such as impaired HPV-specific effector T helper 1 (Th1) cell responses, and enhanced HPV infection due to HIV. We used the model to determine HPV prognosis in the presence of HIV infection, and identified conditions under which HIV infection alters HPV persistence in the oral mucosa system. The model predicts that conditions leading to HPV persistence during HIV/HPV co-infection are the permissive immune environment created by HIV and molecular interactions between the two viruses. The model also determines when HPV infection continues to persist in the short run in a co-infected patient undergoing antiretroviral therapy. Lastly, the model predicts that, under efficacious antiretroviral treatment, HPV infections will decrease in the long run due to the restoration of CD4+ T cell numbers and protective immune responses.

Uncommon non-oncogenic HPV genotypes, TP53 and MDM2 genes polymorphisms in HIV-infected women in Southern Brazil

BACKGROUND

It is believed that Human Papillomavirus (HPV) and Human Immunodeficiency Virus coinfection contributes to increase the risk for cervical intraepithelial injuries. Several factors may contribute to cervical cancer (CC) development, including genetic variants such as TP53 and MDM2 gene polymorphisms.

MATERIALS AND METHODS

A hundred HIV-infected women were examined for HPV detection and its genotypes, as well as the frequencies of the SNPs Arg72Pro and SNP309 and their associations with CC risk factors. Nested Polymerase Chain Reaction (nPCR) was used for HPV detection and PCR-RFLP for TP53 and MDM2 SNP309 genotyping.

RESULTS

HPV DNA was detected in 68% of samples. A higher frequency of low-risk HPV genotypes (66.7%) was observed when compared to high-risk genotypes (33.3%). Nine different HPV genotypes were identified, with the highest prevalence of HPV-6, followed by HPV-16 and 31. p53 Arg72Arg and SNP309 TG genotype were the most prevalent. HPV genotyping was performed by sequencing.

CONCLUSION

The data obtained suggest that HIV-infected women are more susceptible to be infected by low-risk HPV (LR-HPV) genotypes than by high-risk (HR-HPV), and Pro72Pro of TP53 gene and TG of MDM2 SNP309 genotypes apparently seem to be protective factors among HIV-infected women for HPV acquisition and HR-HPV infection, respectively, in a sample of Southern Brazilian woman. Future investigations in larger populations are necessary to better understand the potential roles of these SNPs and the behavior of non-oncogenic HPV genotypes in HIV-mediated immunosuppression cases.

Mechanisms of viral infections associated with HIV: workshop 2B

HIV infection is commonly associated with activation and dissemination of several other viral pathogens, including herpes simplex virus 1/2, human cytomegalovirus, human herpesvirus 8, Epstein-Barr virus, Varicella Zoster virus, and human papillomavirus, which behave as opportunistic agents and cause various diseases in immunocompromised hosts. The increased frequency and severity of diseases caused by these viruses in HIV-infected individuals is due mainly to dysfunction of both the adaptive and innate immune responses to viral pathogens. In addition, molecular interactions between HIV and these opportunistic viruses are likely to play critical roles in the progression of disease, including neoplasia. This report reviews the critical aspects of HIV interaction with opportunistic viruses, including Epstein-Barr virus, human cytomegalovirus, herpes simplex virus, Varicella Zoster virus, human herpesvirus 8, and human papillomavirus.

Women with HIV are more commonly infected with non-16 and -18 high-risk HPV types

OBJECTIVE

To review and summarize evidence from clinical, translational and epidemiologic studies which have examined the clinically relevant aspects of HPV type prevalence and cervical dysplasia in HIV-infected women.

METHODS

Relevant studies were identified through a MEDLINE search. References of identified reports were also used to identify additional published articles for review.

RESULTS

HIV-infected women in different geographic regions (such as Zambia, Brazil, Rochester NY) appear to be infected with less prevalent types of HR-HPV as compared to the general population who, across all continents, are more commonly infected with types 16 and 18. Secondly, integration of HPV DNA into the host genome is no longer thought to be a necessary cause of malignant transformation of cervical cells. However, rate of integration appears to differ by the type of HPV. In fact, the types of HPV which appear to be more common in cervical dysplasia of HIV-infected women are the same types which are more likely to require integration for malignant transformation. Finally, HPV types found in HIV-infected women are relatively common and likely to persist. The most common among these types belong to the alpha-9 and -7 species which are the most carcinogenic species.

CONCLUSION

Given that current vaccines target HR-HPV-16/18, the findings from the above mentioned studies may have important implications for the design of HPV vaccines that target the types of HPV associated with disease risk in HIV-infected women. HPV typing and assessment of the physical state (whether it is integrated or episomal) appear to be two valuable parameters for the prognostic evaluation of dysplastic lesions of the uterine cervix. This, however, has not yet been assessed in HIV-infected women. Recent data about the immune response in HPV/HIV co-infection may lead to understanding potential mechanisms for less virulent HPV causing malignant transformation in HIV-infected women.

Interactions between human papillomavirus and other sexually transmitted agents in the etiology of cervical cancer

The interplay between human papillomavirus, notably type 16, and HIV in cervical carcinogenesis leads to persistent infection and cervical neoplasia by destruction of the afferent arm (Langerhans cells) of the host immune system. The joint effect takes place at the early stages of squamous intraepithelial lesions and has severe consequences if left untreated. The recent increase of cervical cancer mortality in young women in developed countries may well be a result of the HIV epidemic. Infection with Chlamydia trachomatis is associated with cervical squamous cell carcinoma but not with cervical adenocarcinoma, and the association remains after adjusting for human papillomavirus 16. Joint effects of C. trachomatis and the human papillomaviruses have not been studied at the population level but indirect evidence from epidemiological studies suggests that the interaction might be different (synergistic versus antagonistic) at different stages (cervical intraepithelial neoplasia versus invasive cervical cancer) of cervical carcino-genesis. Concomitant exposure to human papillomaviruses 6 or 11 and human papillomavirus type 16 has not been shown to result in excess risk of cervical squamous cell carcinoma. This antagonistic joint effect was also discovered between human papillomavirus types 18 and 16, as well as 33 and 16. Herpes simplex virus type 2 antibodies are associated with a modest risk of cervical cancer, which is not surprising since the presence of herpes simplex virus antibodies reflects risk-taking sexual behaviour. However, no excess risk remains after adjustment for human papillomavirus type 16, and no interaction between these two viruses has been found in epidemiological studies. Evidence of interaction between human papillomavirus type 16 and the other members of the herpesvirus family is still at an experimental level and difficult to judge. Little progress has been made in the most promising experimental association between the oncogenic human papillomaviruses and adeno-associated viruses. In addition to the well established interaction between human papillomaviruses and HIV, intriguing interactions are emerging between the human papillomaviruses and C. trachomatis, as well as between the different human papillomavirus types.

Natural History and Possible Reactivation of Human Papillomavirus in Human Immunodeficiency Virus–Positive Women

BACKGROUND

Little is known in human immunodeficiency virus (HIV)-positive women about how the combination of plasma HIV RNA level and CD4+ T-cell count is associated with the natural history of human papillomavirus (HPV) infection or about HPV reactivation--whether it occurs and with what frequency in HIV-positive women.

METHODS

HIV-positive (n = 1848) and -negative (n = 514) women were assessed at semiannual visits (total person-years = 5661) for cervicovaginal HPV with polymerase chain reaction assays and for squamous intraepithelial lesions (SILs) by Pap smear. We studied the prevalent detection of HPV and SILs with generalized estimating equations and the incident detection and persistence of HPV and SILs with multivariable Cox models. All statistical tests were two-sided.

RESULTS

We observed a strong interaction between the associations of CD4+ and plasma HIV RNA strata with both prevalent (P(interaction) = .002) and incident (P(interaction) = .001) detection of HPV. Indeed, the hazard ratio for incident HPV detection peaked between 4.0 and 5.0, with either a CD4+ count of less than 200 cells per mm3 or an HIV RNA level of more than 100,000 copies per mL. Although incident HPV detection in all women was associated with the number of recent sex partners (P(trend)<.001), 22% of sexually inactive HIV-positive women with a CD4+ count of less than 200 cells/mm3 also had at least one incidentally detected HPV type. The association between CD4+/HIV RNA strata and HPV persistence was statistically significantly smaller (P<.001) than for incident HPV detection. SIL prevalence, incident detection, and persistence had similar associations with CD4+/HIV RNA strata as HPV (above).

CONCLUSION

In HIV-positive women, plasma HIV RNA level and CD4+ count in combination appear to have a strong and statistically interactive association with incident detection of HPV, some of which may reflect HPV reactivation (e.g., in sexually inactive women). The more moderate association between HIV coinfection and HPV persistence could partly explain why cervical cancer rates have not reached more epidemic proportions in HIV-positive women.

Specific serum IgG, IgM and IgA antibodies to human papillomavirus types 6, 11, 16, 18 and 31 virus-like particles in human immunodeficiency virus-seropositive women

To evaluate the humoral immune response to human papillomavirus (HPV) in women infected with human immunodeficiency virus (HIV), serum samples of 83 HIV-positive individuals were analysed by ELISA for specific antibodies of the isotypes IgG, IgA and IgM recognizing HPV-6, -11, -16, -18 and -31 L1 virus-like particles (VLPs). Papillomavirus-related lesions were present in 30 of 83 HIV-positive women. Twenty-one women (25%) presented with high-/intermediate-grade anogenital squamous intraepithelial lesions. PCR analysis and sequencing for HPV typing was done from biopsy specimens of 18 women; PCR-positive results were obtained in 90% of cases. In addition, HPV DNA hybrid capture assays were performed from cervical swabs of 58 HIV-positive women, 53% of whom had a positive result for high-risk HPV. Overall, positive IgG reactivity to HPV-6/-11 and HPV-16/-18/-31 was seen in 19%/31% and 49%/30%/24% of HIV-positive women, respectively. HPV-seropositivity was even higher than in 48 HIV-negative cervical intraepithelial neoplasia/cancer patients with percentages as follows: 8%/2% and 31%/15%/15%. This difference was significant for HPV-16 (P=0.046). IgA responses were comparable to IgG. IgM responses were low. The extraordinarily high rate of antibodies to the capsid protein L1 of high-risk HPVs (HPV-16, -18 and/or -31) in 58% of HIV-positive women compared to 19% (P=0.00001) of 102 healthy HIV-negative control women suggests a high lifetime cumulative exposure to HPV and increased expression of capsid proteins due to cellular immunodeficiency in HIV-infected women.

Association of human papillomavirus with HIV and CD4 cell count in women with high or low numbers of sex partners

OBJECTIVE

To explore whether HIV serostatus (HIV-1, HIV-2, and dual (HIV-D) reactivity) and CD4 cell count affect human papillomavirus (HPV) in two groups of women from Côte d'Ivoire.

METHODS

We conducted a cross sectional study of two groups of women. One group had low numbers of lifetime sex partners (maternal women, n = 258) and were enrolled based on HIV serostatus. The other group had high numbers of sex partners (female sex workers, n = 278) and all consenting self identified sex workers were admitted to this study. We collected epidemiological and clinical data, and cervicovaginal lavage for HPV testing.

RESULTS

The groups had different distributions of HIV seroreactivity, but the rates of HPV DNA detection were similar. Most of the HPV DNAs detected in both groups were high risk types. A strong association of high risk HPV DNA and HIV-1 seropositivity was found in both maternal women (adjusted odds ratio (OR) 7.5 (95% CI 3.2-17.4)) and in sex workers (OR 5.0 (2.1-12.0)). The maternal group also showed an association of high risk HPV DNA detection with HIV-2 (OR 3.7 (1.6-8.5)) and HIV-D (OR 12.7 (4.3-37.5)) that was not observed in the sex workers. In addition, the association of high risk HPV DNA with HIV-1 in the maternal group was independent of low CD4 cell count, while in the sex workers the association depended on CD4 cell counts < or = 500 x 10(6)/l.

CONCLUSIONS

We found that an association between HPV and HIV varied depending on the sexual behaviour and CD4 cell count of the population examined.

HIV infection increases the risk of squamous intra-epithelial lesions in women with HPV infection: an analysis of HPV genotypes. DIANAIDS Collaborative Study Group

We assessed the association between different HPV genotypes, HIV infection, and cervical squamous intra-epithelial lesions (SIL) in 236 women with known HIV serostatus enrolled in a longitudinal multicentric study in Italy. Of these women, 135 were HIV-infected, and were not markedly different from HIV-negative women with regard to demographic characteristics, sexual practices, smoking, or intravenous drug use. We obtained 232 cervical smears suitable for cytological examination and HPV-genotype analysis (134 from HIV-positive women and 98 from HIV-negative women). For 86 HIV-positive and 89 HIV-negative women, the smears appeared normal at cytomorphological analysis. Cytological dysplasia of varying degrees was detected in 48 smears from HIV-positive women and in 9 from HIV-negative women. HPV prevalence, assessed using polymerase-chain-reaction analysis, did not significantly differ between HIV-positive and HIV-negative women. The prevalence of HPV-associated SIL was much greater among HIV-infected women. The most frequently detected genotypes in both groups were HPV 16 and HPV 18. The prevalence of HPV 16 among HIV-positive women was similar to that for HIV-negative women; this was also true for HPV 18. However, in the HIV-positive group, most of these genotypes were associated with SIL. HIV-positive women showed a wider spectrum of genotypes, including non-oncogenic and rare types. An association between SIL and HIV infection was confirmed for all HPV genotype classes.

Anorectal diseases

A proper understanding of the disease of the anorectum in the HIV-positive population mandates a familiarity with the ongoing advances in antiviral chemotherapy, mechanisms of oncogenesis, and effect of HIV infection on wound dynamics. As the prognosis for HIV-infected patients improves, therapies must reflect the expected increased survival of these patients.

Intra-epithelial and invasive cervical neoplasia during HIV infection

Patients affected by human immunodeficiency virus (HIV) infection present an elevated risk of developing cancer. In the last 10 years, the relationship between human papilloma virus (HPV) infection and female cervical intra-epithelial neoplasia (CIN) has been established. Several studies have described an increased prevalence of both cervical HPV infection and CIN among HIV-positive women compared to HIV-negative ones. A high recurrence rate of CIN after standard treatment has been noted in HIV-infected women and the severity of these lesions seems to be inversely correlated to immune function. Taking into account these data, the Centers for Disease Control (CDC) since 1993 have included invasive cervical carcinoma among the AIDS-defining conditions. Once cervical cancer develops in HIV-positive women, the disease may be aggressive and less responsive to treatment. A primary means by which HIV infection may influence the pathogenesis of HPV-associated cervical pathology is by molecular interaction between HIV and HPV genes. Although these have not been well defined, an upregulation of HPV E6 and E7 genes expression by HIV proteins (such as tat) has been postulated by some authors. Cervical cytology appears to be adequate as a screening tool for the cervical intra-epithelial neoplasia in HIV-positive women, but the high recurrence rate and multifocality of this disease reinforces the need for careful evaluation and follow-up of the entire anogenital tract in these women. Probably in the next few years, cervical tumours will represent one of the most frequent complications of HIV infection, a part of progression through AIDS. This points to a need for greater interdisciplinary co-operation for a best disease definition and for the development of effective prevention measures.