Increased alpha-9 human papillomavirus species viral load in human immunodeficiency virus positive women.

BACKGROUND: Persistent high-risk (HR) human papillomavirus (HPV) infection and increased HR-HPV viral load are associated with the development of cancer. This study investigated the effect of human immunodeficiency virus (HIV) co-infection, HIV viral load and CD4 count on the HR-HPV viral load; and also investigated the predictors of cervical abnormalities. METHODS: Participants were 292 HIV-negative and 258 HIV-positive women. HR-HPV viral loads in cervical cells were determined by the real-time polymerase chain reaction. RESULTS: HIV-positive women had a significantly higher viral load for combined alpha-9 HPV species compared to HIV-negative women (median 3.9 copies per cell compared to 0.63 copies per cell, P = 0.022). This was not observed for individual HPV types. HIV-positive women with CD4 counts >350/µl had significantly lower viral loads for alpha-7 HPV species (median 0.12 copies per cell) than HIV-positive women with CD4 ≤350/µl (median 1.52 copies per cell, P = 0.008), but low CD4 count was not significantly associated with increased viral load for other HPV species. High viral loads for alpha-6, alpha-7 and alpha-9 HPV species were significant predictors of abnormal cytology in women. CONCLUSION: HIV co-infection significantly increased the combined alpha-9 HPV viral load in women but not viral loads for individual HPV types. High HR-HPV viral load was associated with cervical abnormal cytology.

Risk factors for oral human papillomavirus in heterosexual couples in an African setting.

OBJECTIVE: Oral human papillomavirus (HPV) prevalence and factors associated with oral HPV infection were investigated. METHODS: Cervical, penile and oral HPV types were determined in 221 heterosexual couples by Roche Linear Array HPV genotyping assay. RESULTS: Oral HPV prevalence was found to be 6.8% in women and 13.5% in men (P = 0.23). The risk of oral infection with a specific HPV type in women was increased when the same type was detected in their genital tract (odd ratio (OR): 3.65, 95% confidence interval (CI): 1.62-8.25, P = 0.002), the genital tract of their male partner (OR: 6.08, 95% CI: 2.90-12.73, P < 0.001) or the mouth of their male partner (OR: 8.30, 95% CI: 1.58-43.50, P = 0.012). In men, the risk of oral infection with a specific HPV type was increased when the same type was detected in the genital tract of their female partner (OR: 7.28, 95% CI: 1.45-36.58, P = 0.016) or the mouth of their female partner (OR: 5.43, 95% CI: 0.79-37.06, P = 0.084) but not when the same type was present in their own genital tract. CONCLUSIONS: These findings suggest that in African settings oral HPV infection is acquired from sexual partners, and that in women may also be the result of self-inoculation.

The impact of human immunodeficiency virus on human papillomavirus transmission in heterosexually active couples.

OBJECTIVES: This study investigated HPV transmission and the factors influencing it in heterosexually active couples in South Africa. METHODS: A total of 486 heterosexual couples were recruited at a health facility and returned at 6-monthly intervals. Cervical and penile HPV types were determined by Roche Linear Array HPV genotyping assay. HPV transmission was defined as the detection of a new HPV type in an individual whose partner was infected with the same type at the date of acquisition. RESULTS: The female-to-male HPV transmission rate was 2.80/100 person-months (95% confidence interval (CI): 2.03-3.86) while the male-to-female HPV transmission rate was 1.17/100 person-months (95% CI: 0.82-1.67). HIV-positive women were found to be at higher risk of HPV infection transmitted from their male partners compared to HIV-negative women (RR (relative risk): 2.31, 95% CI: 1.08-4.92, P = 0.03). HIV-positive men with CD4 counts <350/mL had a higher risk of HPV infection transmitted from their female partners compared to HIV-positive men with CD4 counts ≥350/mL (RR: 3.17, 95% CI: 1.05-9.55, P = 0.04). CONCLUSIONS: HIV infection and low CD4 counts increase the rate of HPV acquisition from sexual partner.

Impact of human immunodeficiency virus on the natural history of human papillomavirus genital infection in South African men and women.

BACKGROUND: This study investigated genital human papillomavirus (HPV) incidence and clearance in 278 human immunodeficiency virus (HIV)-seropositive (HIV-positive) women, 208 HIV-negative women, 161 HIV-positive men, and 325 HIV-negative men, followed at 6-month intervals for up to 24 months. METHODS: HPV types were determined by the Roche Reverse Linear Array HPV genotyping assay. RESULTS: The rate of new HPV detection at the cervix and penis were 33.83 events/1000 person-months (95% confidence interval [CI], 26.39-43.46) and 55.68 events/1000 person-months (95% CI, 43.59-69.19), respectively. HIV infection was associated with increased risk of new HPV detection in women (relative risk [RR], 2.98; 95% CI, 2.07-4.29) and men (RR, 2.00; 95% CI, 1.49-2.69). The risk of new HPV detection increased in women (RR, 5.25; 95% CI, 3.52-7.81) and men (RR, 8.71; 95% CI, 6.19-12.24) when the sexual partner was infected with the same HPV type. The rate of clearing any HPV infection was 95.1 events/1000 person-months (95% CI, 83.3-108.1) in men and 66.9 events/1000 person-months (95% CI, 57.0-78.5) in women. HIV infection reduced the rate of HPV clearance in women (RR, 0.46; 95% CI, .34-.62) and men (RR, 0.71; 95% CI, .55-.93). CONCLUSIONS: HIV infection increases the risk of new HPV detection and decreases the rate of HPV clearance in both women and men.

Influence of human immunodeficiency virus and CD4 count on the prevalence of human papillomavirus in heterosexual couples.

This study investigated the impact of human immunodeficiency virus (HIV) infection on genital human papillomavirus (HPV) in heterosexual couples. More HIV-positive men and women had genital HPV compared with HIV-negative men (77 vs 49%; P<0.001) and women (74 vs 36%; P<0.001). More men and women with partners who were HPV positive had HPV genital infection compared with those with HPV-negative partners (for men, 72% compared with 40%; P<0.001). Men with HIV-positive female partners were at greater risk of high-risk HPV and low-risk HPV (LR HPV) infection compared with men with HIV-negative female partners. This risk increased with decreasing CD4 count { ≥ 350 ml⁻¹: odds ratio [OR ], 2.37 [95% confidence interval (CI), 1.47-3.83]; < 350 ml⁻¹: OR, 3.02 [95 % CI, 1.86-4.9]}. Conversely, the risk of HPV of any type was not found to differ between women with an HIV-positive or HIV-negative male partner. In men, HIV infection and female partner HIV-positive status were both associated with a higher risk of type-specific HPV concordance with their sexual partner, though the associations were not significant for LR HPV. In women, HIV infection and low CD4 count were significantly associated with increased risk of type-specific HPV concordance, but male partner HIV-positive status was not significantly associated with this concordance. In conclusion, male genital HPV prevalence and type-specific sharing were influenced by their own HIV-positive status and that of their female partner. In contrast, female genital HPV prevalence and HPV type-specific sharing were determined by their own HIV-positive status and not by that of their male partner.

Genital human papillomavirus prevalence and human papillomavirus concordance in heterosexual couples are positively associated with human immunodeficiency virus coinfection.

This study examined the concordance of genital human papillomavirus (HPV) infection in 254 heterosexually active couples and the impact of HIV coinfection. Genital HPV detection was significantly more common among HIV-infected women than among HIV-seronegative women (99 [68%] of 145 women vs. 33 [31%] of 107 women; P < .001); similarly, HPV detection was significantly more common among HIV-infected men than among HIV-seronegative men (67 [72%] of 93 and 65 [43%] of 150 men, respectively; P < .001). HIV-seronegative male partners of HIV-infected women had a significantly greater prevalence of HPV infection than did HIV-seronegative male partners of HIV-seronegative women (38 [58%] of 65 men vs. 27 [32%] of 85 men; P = .001), indicating that HIV coinfection in one partner has a significant impact on the prevalence of HPV genital infection in the other partner. HPV concordance between couples was associated with HIV infection status (P < .001, by Pearson's chi2 test) and was significantly higher among HIV-infected couples than among HIV-seronegative couples. Type-specific sharing of HPV was associated with HIV concordance status (P = .024). HIV-seronegative couples were more likely to share 1 HPV type and were unlikely to share >1 type, whereas HIV-infected or HIV-discordant couples were more likely to share >1 HPV type. Women with a high HPV load frequently shared HPV types with their male partners, suggesting that a high HPV load may play a role in HPV transmission between partners. In conclusion, HIV coinfection in one or both sexually active partners increased HPV prevalence and HPV type-specific concordance.

HIV-1 seroconversion promotes rapid changes in cervical human papillomavirus (HPV) prevalence and HPV-16 antibodies in female sex workers.

The extent to which human immunodeficiency virus (HIV-1) infection impacts on the ability to mount an effective immune response to HPV is unknown, but is relevant in planning HPV vaccine strategies for HIV-1 infected individuals. This longitudinal study investigated changes shortly after HIV-1 seroconversion on cervical HPV types and HPV-16 antibody responses in serum and at the cervix of female sex workers. Typing of HPV DNA from cervical cells was done prior to HIV-1 seroconversion and within 1 year and greater than 2 years after HIV-1 seroconversion. Antibody determinations on serum and cervico-vaginal rinse samples were by HPV-16 virus-like particle-based, enzyme-linked immunosorbent assay. Of 104 women tested, 40 (38.4%) became HIV-1 seropositive (HIV-positive) during the course of the study. Shortly after HIV-1 seroconversion a significant increase in multiple (>1) HPV infection (OR 4.0, 95% CI 1.3-11.9) was observed compared with HIV-1 seronegative (HIV-negative) women and certain changes in HPV type infection. HIV-1 seroconversion resulted in a reduced prevalence of serum HPV-16 IgA and cervico-vaginal IgA and IgG but an increased prevalence of serum HPV-16 IgG. All HIV-positive women had been exposed to HPV-16 as all displayed serum HPV-16 IgG. Serum HPV-16 responses were maintained at a high magnitude in the presence of HPV-16 infection irrespective of HIV infection, but decreased in the absence of HPV-16 infection. In conclusion, HIV-1 seroconversion in sex workers rapidly increased cervical HPV infection and caused a reduced ability to produce cervical HPV-16 antibodies but a continued ability to generate serum IgG antibodies.

Cervical and oral human papillomavirus types in HIV-1 positive and negative women with cervical disease in South Africa.

This study tested cervical and oral human papillomavirus (HPV) infection in HIV-1 seropositive (HIV+) and seronegative (HIV-) women to determine any association between infections at both sites and the difference in prevalence of the HPV types infecting these women. Participants were 115 women referred to a colposcopy clinic after diagnosis of abnormal cervical cytology. The women showed low grade cervical intraepithelial neoplasia (CIN1) or high grade disease (CIN2/3) or no CIN based on colposcopy and histology. Typing of HPV in cervical and oral cells was by Roche linear array and included direct sequencing on selected oral samples. Cervical HPV prevalence was 86.5% and 97.1% in HIV- and HIV+ women respectively. With the exception of HPV-45, prominent in HIV+ women, the hierarchy of predominant types were similar in HIV- and HIV+ women. HPV-16 was most prevalent in both HIV+ (41.7%) and HIV- women (38.5%) with CIN2/3. Significantly more HIV+ women had multiple cervical (>1) infections than HIV- women (36.1% vs. 88.2%, P < 0.001) and more oral HPV infections (45.5% and 25% respectively; P = 0.04). The most prevalent oral HPV types were HPV-33, -11, and -72. The majority of women did not have concordant oral and cervical HPV types, reflecting possible independence of infection at the two sites. HIV immune suppression did not impact significantly on the predominant types of cervical HPV infection (except for HPV-45). HIV+ women had more multiple HPV infections and those with severe cervical disease a similar prevalence of HIV-16 but a lower HPV-18 prevalence than HIV- women.

Association of serum and mucosal neutralizing antibodies to human papillomavirus type 16 (HPV-16) with HPV-16 infection and cervical disease.

We investigated neutralizing antibodies to human papillomavirus type 16 (HPV-16) in serum and cervical washes from 84 women with normal cytology or cervical disease. Serum neutralizing antibodies were detected in 78 % of women infected at the cervix with HPV-16, compared with 35 % (P=0.002) of women infected with HPV-16-related types (alpha9 HPV types), 14 % (P<0.0001) of women infected with HPV-16 non-related types and none of HPV-uninfected women. A significant correlation between HPV-16 infection and serum HPV-16-neutralizing antibodies was observed (r(s)=0.97; P=0.032). Cervical neutralizing antibodies were detected in 38 % of women with HPV-16 infection and in 17 % of women infected with the HPV-16-related type HPV-31. Cervical neutralizing antibodies correlated with HPV-16 infection (r(s)=0.95; P=0.08), but not with cervical disease. Serum and cervical HPV-16 antibody responses were not affected significantly by human immunodeficiency virus type 1 infection. In conclusion, serum and cervical HPV-16-neutralizing antibodies were found to correlate with HPV-16 infection, but not with cervical disease.

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.

Cervical human papillomavirus (HPV) infection in South African women: implications for HPV screening and vaccine strategies.

The prevalence of cervical human papillomavirus (HPV) in South African women (n = 1,073) increased from 20.4% (173/848) in women with normal cytology to 41.7% (48/115) in women with atypical squamous cells of undetermined significance, 70.2% (40/57) in women with low-grade squamous intraepithelial lesions, and 83% (44/53) in women with high-grade squamous intraepithelial lesions (HSILs). HPV types 16 and 35 were the dominant types in women with HSILs but not in women in the other categories.

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.

The seroprevalence of IgG antibodies to human papillomavirus (HPV) types HPV-16, HPV-18, and HPV-11 capsid-antigens in mothers and their children.

Human papillomavirus (HPV) types causing anogenital lesions and cancer are accepted as being sexually transmitted. The methods whereby children acquire these anogenital type HPV infections are unclear. The present study determined the prevalence of anti-HPV-16, HPV-11 and HPV-18 IgG antibodies in mothers and their children in an attempt to identify evidence of HPV transmission from mother to child. HPV virus-like particles (VLP) VLP-16, VLP-11 and VLP-18 were used in enzyme-linked immunosorbent assay to identify IgG antibodies in serum from 100 mothers and their 111 children. Antibodies to VLP-16, VLP-11 and VLP-18 were found in serum from 17%, 21% and 16% of mothers, respectively and seroprevalences were 9%, 11.7% and 9.9%, respectively amongst the children. Of the 111 children, 23 (20.7%) showed antibodies to one or more of the three HPV types tested. Seven of these (30.4%) HPV IgG positive children had the same antibodies to one or more HPV types as their mothers. The prevalence of HPV-11 was similar in children of seropositive compared with seronegative mothers (14% and 11%, respectively). The prevalence of HPV-16 and HPV-18 was higher in children of seropositive mothers compared with seronegative mothers (for HPV-16, 18% and 7%, respectively, P = 0.1, for HPV-18, 19% and 8%, respectively, P = 0.2). None of these differences were statistically significant indicating a lack of correlation between antibodies in mothers and children and no evidence to support vertical or horizontal mother to child transmission of HPV infection. Indications were of multiple sources of HPV infection in the children.

The agreement between cervical abnormalities identified by cytology and detection of high-risk types of human papillomavirus.

OBJECTIVES AND DESIGN: Human papillomavirus (HPV) is causally associated with cervical cancer. Using the Digene Hybrid Capture 2 high-risk HPV test (HC2), we investigated the prevalence of high-risk HPV in cervical specimens, and compared results with those of Papanicolaou (Pap) smears taken concurrently. SUBJECTS AND SETTING: Cervical specimens were obtained from women attending hospitals / community health centres in the Western Cape province of South Africa. They were participating in a case-control study of the association of hormonal contraceptives and invasive cervical cancer. RESULTS: Of 1 491 women tested, 254 (17%) were HPV DNA positive. The age-specific prevalence of HPV was 36/97 (37.1%) in those aged < 30 years, 78/369 (21.1%) in those aged 30 - 39 years, 78/603 (12.9%) in those aged 40 - 49 years and 62/422 (14.7%) in those aged 50 - 59 years. In women with normal cytology the prevalence of HPV was 10.9% (138/1 264); in those with abnormal squamous cells of unknown significance (AS-CUS) it was 30.8% (36/117); in those with low-grade squamous intraepithelial lesions (LSIL) it was 63.2% (36/57), and in those with high-grade squamous intraepithelial lesions (HSIL) it was 83% (44/53). The odds ratio between HPV and HSIL in women aged 40 - 59 years was 57.1 (confidence interval 22.4 - 170.7). CONCLUSIONS: HC2 detected a high prevalence of HPV (17%) in this population. Most women with HSIL (83%) were positive, indicating that HPV testing of AS-CUS women may aid in management. When costs decrease, HC2 could be introduced as an adjunct to Pap smears in identifying women at risk for high-grade cervical disease and could be useful in the maintenance of cervical health in those who remain Pap smear negative.

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.

More men than women make mucosal IgA antibodies to Human papillomavirus type 16 (HPV-16) and HPV-18: a study of oral HPV and oral HPV antibodies in a normal healthy population.

BACKGROUND: We have previously shown the high prevalence of oral anti-human papillomavirus type 16 (HPV-16) antibodies in women with HPV-associated cervical neoplasia. It was postulated that the HPV antibodies were initiated after HPV antigenic stimulation at the cervix via the common mucosal immune system. The present study aimed to further evaluate the effectiveness of oral fluid testing for detecting the mucosal humoral response to HPV infection and to advance our limited understanding of the immune response to HPV. METHODS: The prevalence of oral HPV infection and oral antibodies to HPV types 16, 18 and 11 was determined in a normal, healthy population of children, adolescents and adults, both male and female, attending a dental clinic. HPV types in buccal cells were determined by DNA sequencing. Oral fluid was collected from the gingival crevice of the mouth by the OraSure method. HPV-16, HPV-18 and HPV-11 antibodies in oral fluid were detected by virus-like particle-based enzyme-linked immunosorbent assay. As a reference group 44 women with cervical neoplasia were included in the study. RESULTS: Oral HPV infection was highest in children (9/114, 7.9%), followed by adolescents (4/78, 5.1%), and lowest in normal adults (4/116, 3.5%). The predominant HPV type found was HPV-13 (7/22, 31.8%) followed by HPV-32 (5/22, 22.7%). The prevalence of oral antibodies to HPV-16, HPV-18 and HPV-11 was low in children and increased substantially in adolescents and normal adults. Oral HPV-16 IgA was significantly more prevalent in women with cervical neoplasia (30/44, 68.2%) than the women from the dental clinic (18/69, 26.1% P = 0.0001). Significantly more adult men than women displayed oral HPV-16 IgA (30/47 compared with 18/69, OR 5.0, 95% CI 2.09-12.1, P < 0.001) and HPV-18 IgA (17/47 compared with 13/69, OR 2.4, 95% CI 0.97-6.2, P = 0.04). CONCLUSION: The increased prevalence of oral HPV antibodies in adolescent individuals compared with children was attributed to the onset of sexual activity. The increased prevalence of oral anti-HPV IgA in men compared with women was noteworthy considering reportedly fewer men than women make serum antibodies, and warrants further investigation.

Single-cell cytokine analysis allows detection of cervical T-cell responses against human papillomavirus type 16 L1 in women infected with genital HPV.

Specific types of human papillomavirus (HPV) are known to play a causal role in the development of cervical cancer, with human papillomavirus type 16 (HPV-16) identified as the predominant type. Despite this, little is known about cervical immune responses to this pathogen. The aim of this study was to assess the feasibility of cervical cytobrush sampling and single-cell cytokine staining to investigate cervical lymphocyte-specific cytokine responses to HPV-16 antigens. Of eighteen women recruited into the study, five were HPV DNA positive at the cervix (current exposure) and a further five had circulating antibodies to HPV-16 (previous exposure). Cervical lymphocytes, isolated from the five HPV DNA-positive women, two HPV DNA-negative controls, and one woman with circulating HPV-16 antibodies were assessed for HPV-specific responses using intracellular staining for interferon-gamma (IFN-gamma) and interleukin-4 (IL-4). We demonstrate that both CD4(+) and CD8(+) cervical T lymphocytes, harvested from noninfected and infected subjects, produce these cytokines in response to nonspecific stimulation. However, antigen-specific (HPV-16 L1) IFN-gamma production by CD4(+) and CD8(+) cervical T lymphocytes is only detectable in women exposed currently or previously to HPV-16. This is the first time that antigen-specific cytokine responses of mucosal lymphocytes, obtained from a site of HPV infection, have been demonstrated. This finding clearly illustrates the use of intracellular cytokine staining for investigation of low precursor frequency single-cell antigen-specific responses in lymphocytes harvested from mucosal sites with HPV infection.