Serum levels of soluble tumor-necrosis-factor receptors in patients with benign and malignant HPV-associated anogenital lesions

Increased TNF-alpha and sTNFR2 levels are associated with high-grade anal squamous intraepithelial lesions in HIV-positive patients with low CD4 level

Compared with HIV-negative individuals, HIV-positive individuals have a higher prevalence of anogenital human papillomavirus (HPV) infection, the causative agent of anogenital cancer. TNF-alpha is a major proinflammatory cytokine. sTNFR2 is the soluble form of one of its receptors and is strongly expressed on stimulated lymphocytes. To further understand the role of TNF-alpha, sTNFR2 and other cytokines in the pathogenesis in HPV-related neoplasia, the profiles of serum cytokines in high-risk patients were analyzed for association with anal lesion status. Patients were categorized into 4 groups based on HIV status (HIV-negative vs. HIV-positive with a CD4+ level <200/uL) and anal lesion status [no lesion, low-grade anal squamous intraepithelial lesion (LSIL) vs. high-grade squamous intraepithelial lesion (HSIL)] based on high resolution anoscopy-guided biopsy. Following adjustment for multiplicity, HIV-negative men with HSIL had lower levels of sTNFR2 than HIV-positive men with low CD4 level and HSIL (p=0.02). HIV-positive men with HSIL had higher levels of TNF-alpha than HIV-negative men with HSIL (p<0.001), as well as HIV-positive men with no lesion or LSIL (p=0.03). The levels of other factors, including IL-1beta, IL-2, IL-4, IL-8, IFN-gamma, GM-CSF, sTNFR1 and DR5, were not significantly different between groups. Although the sample size was small, these results suggest that systemic activation of TNF-alpha/sTNFR2 in HIV-positive patients with a low CD4 level may promote the development of HSIL and possibly anal cancer.

Human papillomavirus vaccine trials and tribulations: Clinical perspectives

Human papillomavirus (HPV) affects hundreds of millions of people worldwide and is associated with both benign and malignant neoplasms in men and women. It is a double-stranded DNA virus with an icosahedral capsid. Forty HPV types are known to infect mucosal keratinocytes. If not cured by the immune system, the infection can lead to genital warts, mucosal dysplasia, or cancer. The most common oncogenic types are 16 and 18. The vaccine to prevent HPV and its associated morbidity and mortality has existed since 2006. Several variations protect against an increasing number of HPV types. The recommended vaccination age is before sexual exposure; administration of the vaccine to children has been controversial. This continuing medical education review evaluates the current HPV vaccines available to clinicians. Part I focuses on the debate over who should be vaccinated, at what age, and in which populations.

Lack of TNFα mRNA expression in cervical cancer is not associated with loss of heterozygosity at 6p21.3, inactivating mutations or promoter methylation

Infection with oncogenic human papillomavirus (HPV) is considered to be the major etiologic event for cervical cancer. Tumor necrosis factor alpha (TNFalpha), a proinflammatory cytokine, may be involved in orchestrating an antitumor immune response against human papillomavirus expressing cervical cancer cells. Hence, loss of TNFalpha could be advantageous for tumor cells to escape immune clearance. The aim of our study was to investigate TNFalpha gene expression and epigenetic characteristics associated with the loss of TNFalpha expression in cervical cancer. To this end, we examined TNFalpha expression, loss of heterozygosity (LOH) at 6p21.3, the locus of TNFalpha, mutational status of the TNFalpha locus, loss of the TNFalpha promoter variant 2 allele and CpG hypermethylation of the TNFalpha promoter. RNA in situ hybridization showed absence of TNFalpha expression in 45% of 63 tumors. LOH occurred in 57% of the tumors and was not concordant with absence of TNFalpha mRNA. No mutations in the TNFalpha gene were identified in 15 cases deficient in TNFalpha expression exhibiting LOH. Furthermore, lack of TNFalpha expression did not correlate with promoter methylation. In conclusion, TNFalpha mRNA expression is absent in nearly half of the cervical tumors analyzed. Neither promoter methylation nor genetic causes for lack of expression were evident.

A shift to a peripheral Th2-type cytokine pattern during the carcinogenesis of cervical cancer becomes manifest in CIN III lesions

BACKGROUND

A shifted balance between T helper 1 (Th1)-type and Th2-type cytokines has been hypothesised in cervical dysplasia.

AIMS

To evaluate possible deregulation of the cytokine network by estimating the expression of peripheral cytokines in different stages of cervical disease and in relation to the presence or absence of high risk human papillomavirus (HR-HPV).

METHODS

Twenty one HR-HPV positive women with high grade cervical intraepithelial neoplasia (CIN II-III) and 12 patients with invasive cervical carcinoma formed the study groups. Two control groups consisted of 10 HR-HPV positive and 11 HR-HPV negative women without CIN. Differences in leucocyte subgroups were evaluated by a differential leucocyte count. Plasma concentrations of tumour necrosis factor alpha (TNFalpha), TNFalpha receptors TNFRI and TNFRII, interferon gamma (IFNgamma), interleukin 2 (IL-2), IL-12, IL-4, and IL-10 were determined by enzyme linked immunosorbent assays.

RESULTS

Leucocyte counts in patients with CIN III and carcinoma were significantly higher than in controls. Plasma IFNgamma concentrations were significantly lower in patients with CIN III and carcinoma than in women with CIN II or controls. Plasma concentrations of IL-12, IL-2, IL-4, and TNFalpha did not differ significantly between groups, but significantly lower plasma concentrations of TNFRII were found in CIN III and carcinoma compared with CIN II. IL-10 was detected with increased frequency in the plasma of patients with CIN III and carcinoma.

CONCLUSIONS

These results indicate that a shift to a Th2-type cytokine pattern during the carcinogenesis of cervical cancer occurs in women with CIN III lesions.

Association of tumor necrosis factor a-2 and a-8 microsatellite alleles with human papillomavirus and squamous intraepithelial lesions among women in Brazil

Infection with oncogenic human papillomavirus (HPV) is considered to be the major risk factor for cervical cancer. Tumor necrosis factor (TNF) is a pluripotent cytokine that plays an important role in inhibiting the action of microbial agents, and TNF microsatellite polymorphisms have been associated with several diseases, including cancer and viral infections. This study analyzed the associations between TNFa to -e microsatellite polymorphisms and the severity of squamous intraepithelial lesions (SIL), according to the presence of the oncogenic HPV16 and HPV18 types. Samples from 146 HPV-positive women with low-grade SIL (LSIL) and high-grade SIL (HSIL) and samples from 101 healthy women were studied. TNF microsatellite polymorphism typing and HPV detection and typing were performed using PCR-amplified DNA hybridized with sequence-specific primers. Data were analyzed by Fisher's exact test using the GENEPOP software. Significant associations were observed between LSIL and the TNFa-8 allele (4/166; P = 0.04), as well as between TNFa-2 with HPV18 only (16/44; P = 0.002) and TNFa-2 with HPV18 coinfection with HPV16 (16/44; P = 0.001). Patients exhibiting the TNFa-2 allele and harboring HPV18, in the presence or absence of coinfection with HPV16, had an increased risk of HSIL occurrence (13/38; P = 0.04; 5/10; P = 0.04) compared to patients with other HPV types. These results suggest that the TNFa-8 allele is associated with increased susceptibility to the occurrence of LSIL and that despite the presence of a high TNF-alpha production allele, the ability of HPV18 to resist the inhibitory effects of TNF-alpha may contribute to the occurrence of infection and consequently to HSIL in women with cervical HPV18 infection.

Immunity to oncogenic human papillomaviruses

The establishment of human papillomavirus (HPV) infection as a major cause of several human cancer forms, notably cervical cancer, has spurred development of prophylactic and/or therapeutic HPV vaccines for prevention of cervical neoplasia. Knowledge of the immunity to HPV forms the basis for such endeavors.

METHOD

A literature review of humoral and cellular immunity to HPV. The overview on human leukocyte antigen (HLA) and cervical cancer was expanded to a formal metaanalysis, where relevant articles were located by Medline search and citation analysis and graded by preassigned quality criteria on study design.

RESULTS

The antibody response to the HPV particle is dominated by a neutralizing antibody response to a typespecific, conformationally dependent immunodominant epitope. Vaccines based on viral particles lacking the viral genome (virus-like particles, VLPs) have been highly successful in preventing and treating HPV infection in several animal model systems. In humans, the serum antibody response to VLPs is stable over time, also after the HPV infection has been cleared, resulting in HPV serology being used as a marker of cumulative HPV exposure in spite of the fact that a significant proportion of HPV-exposed subjects fail to seroconvert. More than 90% of HPV infections will clear spontaneously. The factors that determine whether an HPV infection is cleared or persists and increases the risk for cancer are not known, but cellular immunity is implicated. Several HLA class II haplotypes are associated with cervical cancer: DQw3 increases and DR13 decreases the risk for cervical cancer in general (odds ratios (OR) and 95% confidence intervals (CI): 1.25(1.15-1.37) and 0.69 (0.56-0.85), respectively); DR15 increases the risk for HPV16-carrying cancer (OR: 1.47; CI: 1.20-1.81); and DR7 may be either protective or increase the risk. Most cervical cancers have downregulated the expression of at least one HLA class I antigen, whereas class II expression is increased in infected epithelium. A Th2 cytokine profile is associated with progression to cervical cancer. HPV-antigen-specific proliferative responses have been detected in many studies, although it is not entirely clear whether these responses are HPV type specific or may be cross-reactive between HPV types. Specific cytotoxic T lymphocyte (CTL) responses were originally reported in only a minority of infected subjects, typically cancer patients, but with advancing technology, specific CTLs can be stimulated from about half of the women with HPV-carrying disease. In animal model systems, CTL responses can mediate clearance.

CONCLUSION

The antibody response to HPV is a mediator of type-specific protective immunity, which forms the basis for prophylactic vaccine candidates. The cellular immunity to HPV is implicated as an important factor in cervical carcinogenesis, but the main targets and types of responses that mediate HPV clearance are not established.

Human papillomaviruses in non-melanoma skin cancer

Recent data suggest that additional factors, other than UV radiation, are involved in the etiology of non-melanoma skin cancer. These include alterations in the tumor suppressor genes, p53, p16$L*I*U$LINK4a$L*I$L/CDKN2A, p21$L*I*U$LWAF1/CIP1$L*I$L and the PTCH gene, as well as cytokines. Papillomavirus infections have been implicated in the etiology of non-melanoma skin cancer. The interaction of tumor suppressor genes and cytokines with the oncoproteins of high-risk mucosal HPV types have been studied in detail, but very little is known about the cutaneous HPV types. We have studied the effect of UV radiation on the URRs of HPV 1, 2, 3, 5, 7, 20, 23, 27, 38, 41, and 77. Neither the CAT-expression and promoter activity of these HPV types, nor presence or absence of wild-type or mutated p53 in the cell lines used, could be related to the DNA sequence homology between the different HPV types or their biological behavior.