Comparison of cervical and blood T-cell responses to human papillomavirus-16 in women with human papillomavirus-associated cervical intraepithelial neoplasia

Human papillomaviruses (HPVs) are obligate epithelial pathogens and typically cause localized mucosal infections. We therefore hypothesized that T-cell responses to HPV antigens would be greater at sites of pathology than in the blood. Focusing on HPV-16 because of its association with cervical cancer, the magnitude of HPV-specific T-cell responses at the cervix was compared with those in the peripheral blood by intracellular cytokine staining following direct ex vivo stimulation with both virus-like particles assembled from the major capsid protein L1, and the major HPV oncoprotein, E7. We show that both CD4(+) and CD8(+) T cells from the cervix responded to the HPV-16 antigens and that interferon-gamma (IFN-gamma) production was HPV type-specific. Comparing HPV-specific T-cell IFN-gamma responses at the cervix with those in the blood, we found that while CD4(+) and CD8(+) T-cell responses to L1 were significantly correlated between compartments (P = 0.02 and P = 0.05, respectively), IFN-gamma responses in both T-cell subsets were significantly greater in magnitude at the cervix than in peripheral blood (P = 0.02 and P = 0.003, respectively). In contrast, both CD4(+) and CD8(+) T-cell IFN-gamma responses to E7 were of similar magnitude in both compartments and CD8(+) responses were significantly correlated between these distinct immunological compartments (P = 0.04). We therefore show that inflammatory T-cell responses against L1 (but not E7) demonstrate clear compartmental bias and the magnitude of these responses do reflect local viral replication but that correlation of HPV-specific responses between compartments indicates their linkage.     

HPV16, HPV18, and HIV infection may influence cervical cytokine intralesional levels

Infection with oncogenic human papillomavirus (HPV) is considered to be the major risk to cervical cancer. This study analyzed the influence of HPV infection on cytokine intralesional levels in cervical lesion in the presence or not of HIV infection. Cervical biopsies from 42 women were studied. HPV detection and typing were performed using amplified DNA hybridized with sequence-specific primers, and cytokine intralesional levels were detected using ELISA. HPV16+ biopsies exhibited increased IFN-gamma and IL-10 when compared to HPV16- (P = 0.03 and 0.04, respectively). HPV18+ biopsies exhibited decreased TNF-alpha (P = 0.009) and IFN- gamma (P = 0.01) when compared to HPV18-. In accordance to HIV status, HIV-/HPV16+ patients exhibited increased IFN-gamma when compared to those presenting HIV-/HPV16- (P = 0.007). HIV-/HPV18+ patients presented decreased IFN-gamma when compared to HIV-/HPV18- (P = 0.02). These results suggest that the presence of HPV16 infection may influence cervical lesion installation, and irrespective of HIV status, HPV18 infection may be more aggressive than HPV-16.     

Induction of human papillomavirus type 16-specific immunologic responses in a normal and an human papillomavirus-infected populations

Human papillomavirus (HPV) infection, especially with the oncogenic genotypes, is the most important risk factor for developing cervical cancer. We focused on generating HPV16 E7-specific cytotoxic CD8(+) T lymphocytes and evaluating HPV16 E7-specific immune responses in HPV16-infected and uninfected populations. Peripheral blood mononuclear cells (PBMCs) were first collected from an uninfected group with an human lymphocyte antigen (HLA) A2 haplotype (four volunteers). Mature monocyte-derived dendritic cells (DCs) were generated from the PBMCs and pulsed with one of two HLA-A2-restricted E7 peptides, aa 11-20 [YMLDLQPETT] and aa 86-93 [TLGIVCPI], as antigen presenting cells. The autologous naive or cultured PBMCs were then cultured with peptide-pulsed DCs to detect the HPV16 E7-specific immune responses by a variety of techniques such as enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunospot (ELISPOT) assay and cytotoxic T lymphocyte assay. Interferon-gamma (IFN-gamma) from E7-specific cytotoxic CD8(+) T lymphocytes stimulated with the respective peptide was detected by ELISA. Using ELISPOT analysis, a marked increase in the number of IFN-gamma-secreting CD8(+) E7-specific lymphocytes was observed following peptide stimulation. Cultured CD8(+) T lymphocytes were highly cytotoxic against the CaSki cells. PBMCs were then collected from an HPV16-infected population of the HLA-A2 haplotype, including four persons of HPV16 infection only, four with cervical intraepithelial neoplasia (CIN) lesions, and four cervical cancer patients. We then compared the immunologic responses to E7 between HPV16-infected and uninfected populations by ELISA and ELISPOT assay. The E7-specific immunologic responses of the HPV16-infected populations were significantly higher than those of the uninfected population. In addition, persons with an HPV16 infection only or those with CIN lesions generated higher E7-specific immunologic responses than cervical cancer patients. Our results demonstrate methods for evaluating E7-specific immunologic responses and reflect the biological responses of HPV16-infected people during different periods of cervical disease.     

Increase of human papillomavirus-16 E7-specific T helper type 1 response in peripheral blood of cervical cancer patients after radiotherapy

It has been suggested that tumour cell lysis by gamma-radiation induces a tumoral antigen release eliciting an immune response. It is not clear how a specific immune response in cervical cancer patients is developed after radiotherapy. This study is an attempt to investigate the role of the human papillomavirus type 16 (HPV-16) E7-specific T helper response before and after radiotherapy. Lymphocytes were isolated from 32 cervical cancer patients before and after radiotherapy and from 16 healthy women. They were stimulated for 12 hr with autologous HPV-16 E7-pulsed monocyte-derived dendritic cells or directly with HPV-16 E7 synthetic peptides: E7(51-70), E7(65-84) and E7(79-98). The cells were stained for CD4, CD69, intracellular interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) cytokines and analysed by flow cytometry. A specific CD4(+) CD69(+) IFN-gamma(+) immune response against HPV-16 E7(79-98) peptide was observed in 10 of 14 patients (71.4%) after treatment, compared with 4 of 14 (28.5%) before radiotherapy (P = 0.039); however, this response was not associated with a successful clinical response. Before treatment, 5 of 31 patients showed a HPV-16 E7(79-98)-specific T helper type 2 (Th2) response. Interestingly, this response was significantly associated with a decrease in disease-free survival (P = 0.027). These results suggest that a Th2-type cellular response could be useful as a predictor of recurrence and poor prognosis. An increase of the HPV-specific immune response was observed after radiotherapy; however, it is not enough to control completely the disease after treatment. Our results support that the E7-specific T-cell IFN-gamma response in cervical cancer patients, rather than reflecting the host's capability of controlling tumour growth, might be an indicator for disease severity.     

Cervicovaginal, oral, and serum IgG and IgA responses to human papillomavirus type 16 in women with cervical intraepithelial neoplasia

Oncogenic human papillomaviruses (HPVs) are obligate mucosal pathogens and typically cause localized infections. The mucosal surface of the genital tract also provides the first line of defense against genital HPV infection. Although local antibody production following HPV-infection has been demonstrated, their role in protection from cervical disease is unclear. This study evaluated oral and cervical HPV infection and the associated linkage between HPV-16 oral, cervical and serum antibody responses in 103 women with varying grades of cervical intraepithelial neoplasia (CIN). We found that HPV-16 was the most prevalent cervical HPV infection (30/103, 29.1%) but was only detected in 1.1% (1/91) of the oral samples. Both the frequency and magnitude of HPV-16-specific cervical IgA was significantly elevated in women with CIN 2/3 compared with women with CIN 1 (P = 0.0073 frequency; P = 0.0045 magnitude). Women with cervical HPV-16 infection had significantly higher magnitude and frequency of cervical HPV-16 IgA responses than women without cervical HPV-16 DNA (P = 0.0002 frequency; P = 0.0052 magnitude). Despite our contention that mucosal HPV-16 antibody responses within distinct mucosal compartments may be linked, the concordance analysis carried out within and between mucosal compartments and serum suggests that no such linkage exists and that these compartments may be functioning independently of one another. An HPV-16 specific antibody response in one mucosal compartment in women with CIN is therefore not predictive of a response at another.     

Depressed type 1 cytokine synthesis by superantigen-activated CD4+ T cells of women with human papillomavirus-related high-grade squamous intraepithelial lesions

Carcinoma of the cervix is causally related to infection with the human papillomavirus (HPV), and T cells play a pivotal role in the immune response of the host to rid itself of HPV infection. Therefore, we assessed the T-cell function of women with HPV-related cervical neoplasia against a superantigen, Staphylococcus enterotoxin B (SEB). Each woman provided a cervical brush specimen for HPV DNA testing and Papanicolaou (Pap) smears for the staging of cervical lesions. They also provided a blood specimen for determination of the ability of CD4(+) T and CD8(+) T cells to synthesize Th1 (interleukin-2 [IL-2], gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) and Th2 (IL-10) cytokines in response to activation with SEB. Compared with control subjects with self-attested negative Pap smears, women with high-grade squamous intraepithelial lesions (HSIL) had significantly lower percentages of activated CD4(+) T cells that produced IL-2 (P = 0.045), IFN-gamma (P = 0.040), and TNF-alpha (P = 0.015) and a significantly lower percentage of activated CD8(+) T cells that produced IL-2 (P < 0.01). These data indicate that women with HPV-related cervical HSIL show a decrease in Th1 cytokine production by activated CD4(+) T cells and suggested that compromised T-helper functions may negatively impact the function of cytotoxic CD8(+) T cells.     

Intracellular staining for TNF and IFN-gamma detects different frequencies of antigen-specific CD8(+) T cells

CD8(+) T lymphocytes are important mediators of adaptive immunity against certain viral, protozoan and bacterial pathogens. Activated CD8(+) T cells are able to induce cytolysis of infected cells (perforin and CD95-CD95L mediated pathways) and also elaborate cytokines, including IFN-gamma and TNF after appropriate MHC class I-peptide recognition. New technologies for the detection of antigen-specific CD8(+) T cells, including tetrameric MHC class I-peptide complexes, intracellular IFN-gamma staining and IFN-gamma ELISPOT analysis have revised our understanding of the magnitude of the CD8(+) T cell response to infection. Here, using intracellular cytokine staining, we compare detection of IFN-gamma and TNF in the analysis of pathogen-specific CD8(+) T cell lines and CD8(+) T cells after primary viral infection (LCMV) or secondary bacterial infection (Listeria monocytogenes). Under multiple conditions and with multiple epitopes, we find that staining for intracellular IFN-gamma consistently detects a higher frequency of antigen-specific CD8(+) T cells than detection of intracellular TNF. However, (a) intracellular staining for TNF can be used to detect antigen-specific CD8(+) T cell responses and (b) intracellular staining for cytokines is a useful approach for in vitro characterization of antigen-specific CD8(+) T cell lines.     

Oral antibodies to human papillomavirus type 16 in women with cervical neoplasia

This study investigated the relationship between human papillomavirus type 16 (HPV-16) antibodies detected in oral fluid from women with cervical neoplasia, their HPV-16 antibody seroprevalence, and their cervical HPV-16 DNA presence. Cervical HPV-16 DNA was detected by polymerase chain reaction in 43.2% (35/81) of these women. The prevalence of IgG and IgA antibodies to HPV-16 virus-like particles (VLP-16) in oral fluid and was investigated by enzyme-linked immunosorbent assay. Anti-VLP-16 IgA antibodies were detected in oral fluid from 54.3% (44/81) of women with cervical neoplasia, compared with 8% (3/36) in controls (P = 0.000002). Anti-VLP-16 IgG was detected in oral fluid from 43.2.9% (25/72) and 13.3% (4/30; P = 0.029), respectively. Women who were HPV-16 DNA positive at their cervical lesion, displayed an oral fluid anti-VLP-16 IgA prevalence of 60.7% (17/28) and HPV-16 DNA negative women an oral fluid anti-VLP-16 IgA prevalence of 50% (20/40; P = 0.38). Oral fluid anti-VLP-16 IgG prevalence in HPV-16 DNA positive women was 28.6% (8/28) compared with 40% (16/40) in oral fluid from HPV-16 DNA negative women (P = 0.3). Amongst HPV-16 DNA positive women, the anti-VLP-16 IgG seroprevalence was 75% (21/28) and IgA seroprevalence 35.7% (10/28) and for the HPV-16 DNA negative women these values were 60% (24/40) and 32.5% (13/40), respectively. Oral IgA antibody testing proved no more sensitive than serum antibody detection for the determination of HPV infection but could be useful as a non-invasive screening method for women with cervical neoplasia and for estimating the mucosal antibody response to HPV vaccines.     

Induction of CD4-independent E7-specific CD8+ memory response by heat shock fusion protein

Infection with human papillomavirus type 16 (HPV16) is strongly associated with a number of disease states, of which cervical and anal cancers represent the most drastic endpoints. Induction of T-cell-mediated immunity, particularly cytotoxic T lymphocytes (CTL), is important in eradication of HPV-induced lesions. Studies have shown that heat shock protein fusion proteins are capable of inducing potent antigen-specific CTL activity in experimental animal models. In addition, E7-expressing tumors in C57BL/6 mice can be eradicated by treatment with HspE7, an Hsp fusion protein composed of Mycobacterium bovis BCG Hsp65 linked to E7 protein of HPV16. More importantly, HspE7 has also displayed significant clinical benefit in phase II clinical trials for the immunotherapy of HPV-related diseases. To delineate the mechanisms underlying the therapeutic effects of HspE7, we investigated the capability of HspE7 to induce antigen-specific protective immunity. Here, we demonstrate that HspE7 primes potent E7-specific CD8(+) T cells with cytolytic and cytokine secretion activities. These CD8(+) T cells can differentiate into memory T cells with effector functions in the absence of CD4(+) T-cell help. The HspE7-induced memory CD8(+) T cells persist for at least 17 weeks and confer protection against E7-positive murine tumor cell challenge. These results indicate that HspE7 is a promising immunotherapeutic agent for treating HPV-related disease. Moreover, the ability of HspE7 to induce memory CD8(+) T cells in the absence of CD4(+) help indicates that HspE7 fusion protein may have activity in individuals with compromised CD4(+) functions, such as those with invasive cancer and/or human immunodeficiency virus infection.     

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.     

Oral immunization with a Salmonella enterica serovar typhi vaccine induces specific circulating mucosa-homing CD4(+) and CD8(+) T cells in humans

The kinetics and homing characteristics of T-cell responses in humans after mucosal immunizations have not been well characterized. Therefore, we have investigated the magnitude and duration of such responses as well as the homing receptor expression of antigen-specific peripheral blood T cells by using an oral model vaccine, i.e., the live, attenuated Salmonella enterica serovar Typhi vaccine (Ty21a). Eight volunteers were each given three doses of the vaccine 2 days apart, and blood samples, from which CD4(+) and CD8(+) T cells were selected by the use of magnetic beads, were collected before vaccination and at regular intervals thereafter. To purify the potentially antigen-specific gut-homing T cells, CD45RA(-) integrin beta(7)(+) cells were further sorted by flow cytometry. The sorted cells were then stimulated in vitro with the serovar Typhi vaccine strain, and the proliferation of cells and the cytokine production were measured. Following vaccination, there was a large increase in both the proliferation of and the gamma interferon (IFN-gamma) production by blood T cells stimulated with the vaccine strain. The responses were seen among both CD4(+) and CD8(+) T cells, although the CD8(+) cells produced the largest amounts of IFN-gamma. Peak responses were seen 7 to 14 days after the onset of vaccination. Furthermore, most of the IFN-gamma produced by both CD4(+) and CD8(+) cells emanated from cells with the potential to home to mucosal tissues, as the integrin beta(7)-expressing memory T cells produced around 10-fold more IFN-gamma than the remaining populations. In conclusion, we demonstrate that oral vaccination with a live oral bacterial vaccine induces antigen-specific CD4(+) and CD8(+) memory T cells, almost all of which express the gut-homing integrin beta(7).     

Frequencies and role of regulatory T cells in patients with (pre)malignant cervical neoplasia

Oncogenic human papillomavirus (HPV)-infection is crucial for developing cervical cancer and its precursor lesions [cervical intraepithelial neoplasia (CIN)]. Regulatory T cells (T(regs)) might be involved in the failure of the immune system to control the development of HPV-induced cancer. We investigated frequencies, phenotype and activity of T(regs) in patients with cervical neoplasia. CIN and cervical cancer patients showed increased CD4(+)/CD25(high) T cell frequencies in peripheral blood and CD4(+) T cell fraction. These CD4(+)/CD25(high) T cells represent T(regs) as demonstrated by their low proliferation rate, low interferon (IFN)-gamma/interleukin (IL)-10 ratio, high expression of CD45RO, GITR, CTLA-4, forkhead box P3 (FoxP3) and low CD45RA expression. Moreover, in HPV16(+) cervical cancer patients, in-vitro depletion of CD25(+) T cells resulted in increased IFN-gamma T cell responses against HPV16 E6- and E7 peptides. Thus, increased frequencies of T(regs) in cervical cancer patients may indeed suppress HPV-specific immunity. Longitudinal analysis of CD4(+)/CD25(high) T cell frequencies in patients showed a modest decline 1 year after curative surgery or chemoradiation. This study demonstrates increased frequencies and suppressive activity of T(regs) in cervical cancer. These results imply that T(regs) may suppress the immune control of cervical neoplasia and furthermore that suppression of immunity by T(regs) will be another hurdle to overcome in therapeutic immunization strategies against cervical neoplasia.     

T-cell proliferative response to human papillomavirus type 16 peptides: relationship to cervical intraepithelial neoplasia.

The incidence of human papillomavirus (HPV)-related cervical intraepithelial neoplasia (CIN) and cervical cancer is increased with immunodeficiency, but the role of immune response, including cell-mediated immunity, in disease prevention is not well understood. In this study, T-cell proliferative responses to six synthetic peptides with predicted immunogenic determinants from the HPV-16 E4, E6, E7, and L1 open reading frames were analyzed in 22 sexually active women with new-onset CIN and 65 sexually active women without cervical disease, characterized by cytology, colposcopy, and HPV testing. T-cell proliferative responses were demonstrated to all six HPV-16 peptides. Although not statistically significant, rates of reactivity to E6 (24-45) were higher among sexually active women without disease (26%) than among women with current CIN (7%), as was the overall number of peptides stimulating a response. Women with CIN may not respond to selected HPV antigens as well as women without disease do.     

Therapeutic human papillomavirus DNA vaccination strategies to control cervical cancer

A persistent human papillomavirus (HPV) infection is considered causal and necessary for the continued growth of cervical cancer. Thus, vaccination against HPV represents a plausible approach to prevent and treat cervical cancer. A report in the current issue of the European Journal of Immunology describes a therapeutic HPV DNA vaccination strategy using the HPV-16 E7 antigen fused to the invariant chain to enhance the E7-specific CD8+ and CD4+ T cell immune responses, resulting in a potent anti-tumor effect against E7-expressing tumors. Continued exploration of HPV therapeutic DNA vaccines may lead to eventual clinical application.     

CD4+ T cell immunity against the human papillomavirus-18 E6 transforming protein in healthy donors: identification of promiscuous naturally processed epitopes

Infection by 'high-risk' human papillomaviruses (HPV) is associated with the development of neoplastic lesions. HPV-18 is responsible for a very aggressive form of cancer and poor survival. As for other HPV types, immune surveillance has probably a role in the control of the infection. However, very little is known on HPV-18 immunogenicity. CD4(+) T cells from 16 healthy donors were tested ex vivo for reactivity to synthetic peptides corresponding to 3 sequences on the HPV-18 E6 transforming protein predicted by bioinformatics as promiscuous HLA-DR ligands, and to the recombinant E6 protein. We found 3 donors with CD4(+) T cells that specifically proliferated in the presence of HPV-18 E6 antigens and produced IFN-gamma in the presence of the E6 protein. We then propagated CD4(+) T cell lines and clones from the responsive subjects to better characterize the recognized sequences. We show that E6(52-66) and E6(97-111) are indeed promiscuous and, most importantly, they contain naturally processed epitopes. Collectively, our data indicate that healthy donors may develop spontaneous CD4 immunity against HPV-18 E6 epitopes, thus strongly suggesting the potential for this protein to elicit in the host a natural productive immune response.     

Increased expression of programmed death (PD)‐1 and its ligand PD‐L1 correlates with impaired cell‐mediated immunity in high‐risk human papillomavirus‐related cervical intraepithelial neoplasia

Impaired local cellular immunity contributes to the pathogenesis of persistent high-risk human papillomavirus (HR-HPV) infection and related cervical intraepithelial neoplasia (CIN), but the underlying molecular mechanisms remain unclear. Recently, the programmed death 1/programmed death 1 ligand (PD-1/PD-L1; CD279/CD274) pathway was demonstrated to play a critical role in attenuating T-cell responses and promoting T-cell tolerance during chronic viral infections. In this study, we examined the expression of PD-1 and PD-L1 on cervical T cells and dendritic cells (DCs), respectively, from 40 women who were HR-HPV-negative (−) or HR-HPV-positive (+) with CIN grades 0, I and II–III. We also measured interferon-γ, interleukin-12 (IL-12) and IL-10 in cervical exudates. The most common HPV type was HPV 16, followed by HPV 18, 33, 51 and 58. PD-1 and PD-L1 expression on cervical T cells and DCs, respectively, was associated with HR-HPV positivity and increased in parallel with increasing CIN grade. The opposite pattern was observed for CD80 and CD86 expression on DCs, which decreased in HR-HPV(+) patients in parallel with increasing CIN grade. Similarly, reduced levels of the T helper type 1 cytokines interferon-γ and IL-12 and increased levels of the T helper type 2 cytokine IL-10 in cervical exudates correlated with HR-HPV positivity and CIN grade. Our results suggest that up-regulation of the inhibitory PD-1/PD-L1 pathway may negatively regulate cervical cell-mediated immunity to HPV and contribute to the progression of HR-HPV-related CIN. These results may aid in the development of PD-1/PD-L1 pathway-based strategies for immunotherapy of HR-HPV-related CIN.     

Cervical human papillomavirus (HPV) infection and HPV type 16 antibodies in South African women

There is a high incidence of cervical cancer in South African women. No large studies to assess human papillomavirus virus (HPV) infection or HPV type 16 (HPV-16) exposure have occurred in the region, a requirement for policy making with regards to HPV screening and the introduction of vaccines. Control women (n = 1,003) enrolled in a case control study of hormonal contraceptives and cervical cancer were tested for 27 cervical HPV types by reverse line blot analysis. The seroprevalence of HPV-16 immunoglobulin G (IgG) and IgA antibodies was assessed by a virus-like particle-based enzyme-linked immunoassay of 908 and 904 control women, respectively, and of 474 women with cervical cancer. The cervical HPV prevalence was 26.1%. The HPV-16 IgG seroprevalence was 44.4% and the HPV-16 IgA seroprevalence was 28.7% in control women, and these levels were significantly higher (61.8% and 52.7%, respectively) for women with cervical cancer (odds ratio [OR], 2.1 and 2.8, respectively). The cervical HPV prevalence showed an association with cervical disease, and the HPV-16 IgG prevalence decreased while the HPV-16 IgA prevalence increased with increasing age (P < 0.05). The prevalence of oncogenic HPV types (including HPV-16) decreased with age, whereas nononcogenic HPV types showed limited association with age. Multivariate analysis revealed cervical HPV infection to be associated with herpes simplex virus type 2 infection (OR, 1.7) and increasing years of education (OR, 1.9). HPV-16 IgG antibodies were inversely associated with current smoking status (OR, 0.6), and the presence of HPV-16 IgA antibodies was inversely associated with the use of alcohol (OR, 2.1) and inversely associated with the use of oral contraceptives (OR, 0.6). High levels of exposure to HPV, and particularly HPV-16, were evident in this population. The apparent increase of serum HPV-16 IgA with increasing age requires further investigation.     

Patterns of genotype distribution in multiple human papillomavirus infections.

The relationship between severe-grade cervical lesions and clusters of human papillomavirus (HPV) genotypes in a taxonomic classification was surveyed in 232 women with previous abnormal cytology. HPV co-infections were clustered according to phylogenetic criteria. Multiple infections were detected in 22.0% of the entire sample. Clade A10 (represented by HPV-6 and HPV-11) appeared more frequently in multiple infections than clade A9, which was represented by five of the most common high-risk types, including HPV-16. Although HPV-16 was the most frequent genotype, it was not more prevalent in multiple infections. Abortion and two or more sexual partners were risk-factors associated with HPV co-infections. Severe cervical dysplasia was associated with co-infections with oncogenic types from different clades, with the association being significant for the high-risk clades A7 and A9.     

IL-10 and TGF-beta cooperate in the regulatory T cell response to mucosal allergens in normal immunity and specific immunotherapy

The regulation of normal and allergic immune responses to airborne allergens in the mucosa is still poorly understood, and the mechanism of specific immunotherapy (SIT) in normalizing the allergic response to such allergens is currently not clear. Accordingly, we have investigated the immunoregulatory mechanism of both normal and allergic responses to the major house-dust mite (HDM) and birch pollen allergens--Dermatophagoides pteroynyssinus (Der p)1 and Bet v 1, respectively--as well as the immunologic basis of SIT to HDM in rhinitis and asthma patients. In normal immunity to HDM and birch pollen, an allergen-specific peripheral T cell suppression to Der p 1 and Bet v 1 was observed. The deviated immune response was characterized by suppressed proliferative T cell and Th1 (IFN-gamma) and Th2 (IL-5, IL-13) cytokine responses, and increased IL-10 and TGF-beta secretion by allergen-specific T cells. Neutralization of cytokine activity showed that T cell suppression was induced by IL-10 and TGF-beta during SIT and in normal immunity to the mucosal allergens. In addition, SIT induced an antigen-specific suppressive activity in CD4(+) CD25(+) T cells of allergic individuals. Together, these results demonstrate a deviation towards a regulatory/suppressor T cell response during SIT and in normal immunity as a key event for the healthy immune response to mucosal antigens.