The characteristics of human papillomavirus DNA in head and neck cancers and papillomas

AIM

To determine the prevalence, type, physical state, and viral load of human papillomavirus (HPV) DNA in cases of head and neck cancer and recurrent respiratory papillomatosis (RRP).

METHODS

The prevalence and type of HPV DNA was determined in 27 fresh frozen tissue specimens from patients with head and neck cancers and 16 specimens from 10 patients with RRP by MY09/MY11 and GP5+/GP6+ nested polymerase chain reaction (PCR) and subsequent restriction enzyme cleavage. The physical state of HPV DNA was analysed by E1, E2, and E1E2 specific PCRs and Southern blot hybridisation (SBH).

RESULTS

HPV DNA was detected in 13 of 27 cancers and 10 of 10 papillomas. Both low risk HPV-6 and HPV-11 and high risk HPV-16 were present in cancers in low copy numbers, whereas papillomas exclusively harboured low risk HPV-6 and HPV-11. E1E2 PCRs failed to determine the physical state of HPV in cancers except one case where HPV-6 DNA was integrated. In contrast to cancers, all papillomas showed the episomal state of HPV DNA and a relatively higher viral load.

CONCLUSIONS

Based on the prevalence, type, physical state, and copy number of HPV DNA, cancers and papillomas tend to show a different HPV DNA profile. The 100% positivity rate of low risk HPV types confirms the role of HPV-6 and HPV-11 in the aetiology of RRP.

Sexual and non-sexual transmission of human papillomavirus

Benign tumors and lesions of the anogenital tract are caused by human papillomaviruses (HPVs). They are also major risk factors for cervical cancer. Introduction of the polymerase chain reaction (PCR) revealed that HPV infections are much more common among young asymptomatic women than it had been previously suspected. The side-specificity of genital HPVs led to the assumption that HPVs were primarily transmitted by sexual contact. However, since HPVs have been detected in virgins, infants/children and juvenile laryngeal papillomatosis was shown to be caused by these viruses, it became acknowledged that HPVs may be transmitted by other--non-sexual--routes as well. The evidence for sexual and different non-sexual routes of transmission of HPVs will be reviewed here.

[Virologic aspects of juvenile laryngeal papillomatosis]

Juvenile laryngeal papillomatosis is the most common benign tumor of the larynx in childhood. The specific etiological factors are non-oncogenic human papillomavirus types 6 and 11. In the present study two cases (a 6-year-old male and a 5 and a half-year-old female) operated five times each and harbouring type 11 DNA in papillomas excised in the first operations are analysed from the following virological aspects: 1. the examination of vertical transmission by general primer-polymerase chain reaction of maternal cervical exfoliation; 2. sites of papilloma predilections in the larynx; 3. histopathology; 4. viral DNA detection from the formalin-fixed and paraffin-embedded archive tissues and from a fresh papilloma tissue in one case by polymerase chain reaction applying type-specific primers. We did not find any signs of maternofoetal transmission in the anamnesis and the maternal cervix proved to be negative for viral DNA. However, the vertical route of transmission can not be excluded due to the special natural history of papillomavirus infections. Papillomas usually localised in normal squamociliary junctions of the larynx. The histopathologic review did not reveal any signs of malignancy. Koilocytosis referring to productive viral infection and the signs of abnormal keratinisation were present in each tissue. All tissues of the patients proved to be positive for the short amplimer deriving from the genome of human papillomavirus type 11.

Detection of human papilloma virus DNA in lymph nodes extirpated at radical surgery for cervical cancer is not predictive of recurrence

In women with recurrent cervical cancer after radical surgery, lymph node metastasis is detectable histologically at the time of surgery in only about 50% of cases. The present study was designed to determine whether the detection of human papilloma virus (HPV) DNA in lymph nodes extirpated at operation, as an indication of micrometastasis, is predictive of recurrence. Using polymerase chain reaction (PCR), a total of 140 lymph nodes from 31 patients with HPV 16 DNA positive primary cervical tumours were tested for the presence of an HPV 16 LCR/E6 gene fragment. HPV 16 DNA was detected in extirpated lymph nodes in 75% (6/8) of patients with recurrence (and who died within 5 years after surgery) and in 70% (16/23) of recurrence-free patients. In only four of the patients with recurrence (three of whom had HPV 16 DNA positive lymph nodes) was metastasis detectable histologically at surgery. HPV DNA positive lymph nodes were found in 91% (10/11) of patients with histologically detectable metastasis at surgery and in 60% (12/20) of patients without metastasis. It is concluded that the presence of HPV DNA in extirpated lymph nodes at cervical cancer operation does not appear to be predictive of tumour recurrence.

Human papilloma viruses in non-melanoma skin cancers. (A short review)

The knowledge in the realms of pathology, epidemiology and molecular biology of human papillomaviruses (HPV) has defined them as etiological agents in benign tumors of the anogenital tract and major carcinogens in cancer of cervix uteri. Non-melanoma skin cancer (NMSC) is the most common human cancer amongst lightly pigmented individuals. The mortality is low, the morbidity is significant in susceptible individuals often developing multiple primary tumors. Several groups now report a high prevalence of HPV DNA in human NMCS of immunosuppressed patients. This provides impetus for researching the role (causal or passenger) of cutaneous HPVs in the genesis of skin cancer.

HPV 16 DNA and mRNA in cervical brush samples quantified by PCR and microwell hybridization

To quantitate HPV 16 DNA and mRNA, biotinylated amplicons from PCR and reverse transcription PCR were captured on streptavidin-coated microtitre plates. The amount of amplicon was determined by colorimetric detection after hybridization with an alkaline phosphatase-labelled probe. Dynamic ranges of between 4 and 6 log10, sufficient to cover the amounts of viral DNA and mRNA prepared from cervical samples were achieved. The reproducibility of the colorimetric detection step was reflected in coefficients of variation (C.V.) below 8%, considerably better than that of chemiluminescence detection. In a series of 89 HPV 16 DNA positive cervical samples, as compared with a CIN I/normal diagnosis subgroup, the number of HPV 16 genome copies per assay was significantly greater in a CIN II subgroup (P = 0.014), and a high-grade neoplasia subgroup (P = 0.040), and the content of HPV 16 mRNA significantly greater in the high-grade neoplasia subgroup (P = 0.0021). The number of mRNA equivalents per copy of viral DNA was higher for E5 than for the other three mRNA species analyzed (P < 0.001), and the concentration of E6*I mRNA was higher than those of the E6 full-length (P < 0.001) and E6*II (P < 0.001) transcripts. Despite these differences, no correlation was found between histological/cytological diagnosis and the amount of viral mRNA relative to the viral load.

[Detection of human papillomavirus gene sequences in laryngeal tumors and premalignant changes by polymerase chain reaction]

Human papillomavirus gene sequences have been detected in a number of malignant and benign tumours. Non-oncogenic types 6 and 11 are etiological factors of benign mucosal tumours. Types 16 and 18 can be detected in malignancies most often but their role in the etiopathogenesis of cancers is still unclear. In our study we examined formalin-fixed and paraffin-embedded archive laryngeal tissues containing squamous cell carcinoma, papilloma and precancerous lesions for the presence of human papillomavirus genes. As a control we also examined tissues harbouring laryngeal nodules which represented the normal larynx in our study. After DNA preparation from the paraffin blocks we performed polymerase chain reaction to detect the DNA of human papillomavirus types 6, 11, 16 and 18. In the squamous cell carcinomas, papillomas and precancerous lesions the presence of human papillomavirus gene sequences was significantly higher than in the control group. To verify the integrity of DNA we also amplified a sequence deriving from the cellular beta-globin gene. Based on the 100% positivity for this gene we declare that the combination of our DNA preparation and polymerase chain reaction is a reliable method for detecting DNA sequences from formalin-fixed and paraffin-embedded tissues.

[Follow-up of high risk, human papillomavirus (HPV)-positive patients with cancer of the uterine cervix]

The study population consisted of 30 cervical cancer patients stage I.a-II.b. (FIGO) stages operated on according to the Wertheim technique. A parallel histological evaluation and HPV status determination were carried out on biopsies from the primary tumors and on the regional lymph nodes. A general primer mediated polymerase chain reaction (PCR) was performed at first and the samples not amplified were examined by type-specific primers. All except one primary tumors contained DNA-sequences characteristic for high risk HPV-types. The lymph nodes of these HPV-positive patients proved to be also HPV-positive with a frequency of 25/30 (83%). The frequency of the HPV-positivity was higher (100%) in the group of patients with HPV-18 positive status, than in the HPV-16 positive group. Two thirds of the evaluated regional lymph nodes were HPV-positive in the HPV-16 group of patients. The same HPV-types were harboured by the primary tumors and by the regional lymph nodes both in the HPV-16 positive and HPV-18 positive groups of patients. In the HPV-16-positive group of patients metastatic lymph nodes occurred with a frequency of 3/16, while the frequency of HPV-16 positivity in the same nodes was 11/15. In the group of patients with HPV-18 positivity the difference was even greater, 1/12 v. 12/12. Early recurrences were detected in a relation of 3 to 1 in the group of patients with histologically tumor-free and metastatic-positive lymph node status. At the same time all of the lymph nodes in this group with early recurrency (4/4) contained DNA-sequences characteristic for the HPV-18 type. These findings raise the hypothesis that the HPV-specific nucleic acids detected in the lymph nodes can be taken as sensitive indicators of metastases. The follow-up results support these hypothesis as patients with HPV-18 positive lymph node status showed early recurrencies and short survival that is poor prognosis not corresponding to the early stage of cervical cancer with histologically negative lymph node status.

HPV- and node status in cervical cancer long-term results

OBJECTIVE

To evaluate prognostic significance of HPV-status in cervical cancer and to compare that with the prognostic significance of lymph-node status.

METHODS

Cervical cancer biopsy specimens from primaries and, in surgical cases, from pelvic lymph-nodes too were analysed for the presence of human papillomavirus type 16 DNA-sequences using PCR technique. The management of surgical cases with two exceptions included Wertheim's hysterectomy predominantly with preoperative local radiotherapy and also with postoperative local and external beam radiotherapy depending on the histology. Non-surgical cases were treated with combined local and external radiotherapy to pelvic fields.

RESULTS

Patients have been followed up for an average of 37 months after treatment ranging between 0 and 102 months. The mean progression-free survival time of surgical and non-surgical cases were 43 and 28 months, respectively. Patients with HPV-16 positive biopsies from the cervical primary had an average progression-free survival of 37 months, the same as those with HPV-16 negative cervical biopsies. Those patients who were found to carry HPV-16 DNA in their surgically removed pelvic lymph-nodes had an average of 27 months progression-free survival. The mean progression-free survival among histologically node-positive and node-negative surgical cases were 23 and 42 months, respectively. The mean progression-free survival time of node-positive cases with HPV-16 positive cervical primary was 7.5 months while that of patients with HPV-16 negative cervical biopsy was 38 months. Among histologically node-negative patients, HPV-16 positive and negative cases had an average progression-free survival time of 38 and 46 months, respectively.

CONCLUSIONS

Among those under investigation the most important factors to predict progression-free survival were surgically amenable disease, histologically negative pelvic lymph-nodes and HPV-16 negative cervical biopsies, though this latter one proved significant only among surgical cases.

Follow-up of human papillomavirus (HPV) DNA and local anti-HPV antibodies in cytologically normal pregnant women

The high level of progesterone during pregnancy may enhance the transcription and replication of genital human papillomaviruses (HPV) through the glucocorticoid/progesterone response element found in the long control region of the viral genome. In this study, cytologically and colposcopically healthy pregnant women were subjected to a follow-up examination. Samples from the uterine cervix were collected during early pregnancy (n = 39), in the third trimester (n = 31), and a few weeks after birth (n = 30). The presence of HPV DNA was detected by polymerase chain reaction (PCR), while local secretory anti-viral IgA antibodies were demonstrated by enzyme-linked immunosorbent assay using synthetic peptide antigens. Follow-up examination by PCR revealed HPV DNA persistence in 5 women. In 5 other cases, HPV positivity changed from negative to positive during the follow-up. There was 1 case which changed from positive to negative and 1 in which the HPV type changed during the study. Altogether, 12 of 39 women (31%) were shown to harbor HPV DNA at some time during follow-up. HPV DNA positivity increased from 18% during early pregnancy to 27% after birth (difference not significant). On the other hand, there was a significant rise in the level of local antibodies against HPV antigens (E2, E7, and L2) between samples collected in early pregnancy and those collected after birth (P < 0.0001). This may indicate the reactivation of genital HPV infections during late pregnancy.

Can a test for E6/E7 transcripts of human papillomavirus type 16 serve as a diagnostic tool for the detection of micrometastasis in cervical cancer?

Tissue from 11 cases of cervical cancer positive for human papillomavirus (HPV) type 16 DNA and 69 pelvic lymph nodes from the same patients were examined for HPV 16 DNA and mRNA from the E6/E7 genes. Five of the tumors were squamous, 3 adeno- and 3 adenosquamous carcinoma. From the primary tumors and the extirpated lymph nodes DNA and RNA or mRNA was subjected to PCR and RT-PCR. Three transcription profiles (only E6*I, E6*I and E6*II or full-length E6-E7 plus both of the spliced transcripts) were found in all of the 11 HPV 16 DNA-positive primary tumors. From the total of 69 lymph nodes analyzed 28 were positive for mRNA. HPV 16 DNA was found in 7 additional samples. Cytokeratin was found in 19 of these lymph nodes, indicating epithelial origin of tumor cells. Only 1 patient had 2 metastases evidenced by histology. These were both positive for HPV DNA and mRNA. The finding of HPV DNA, mRNA and cytokeratin in lymph nodes of patients with cervical cancer should be an indication of lymphogenically driven micrometastases of the tumor. The HPV mRNA assay should offer higher specificity than the DNA test since mRNA can be found in live cells only, while HPV DNA also can originate from dead cell material sequestered in the lymph nodes.

Correlation of human papillomavirus 16 and 18 with prognostic factors in invasive cervical neoplasias

Forty-seven patients with cervical carcinoma were examined in order to correlate human papillomavirus (HPV) types with prognostic factors in invasive cervical neoplasias. Age, clinical stage, histological type, and grade and parity were analysed with respect to HPV status as determined by a general primer mediated polymerase chain reaction (PCR) or a type specific PCR. All but one sample (98%) harboured HPV sequences: HPV 16 was found in 26 cases (55%), HPV 18 in 19 cases (40%), and HPV 31 in 1 case. The presence of HPV 18 DNA was significantly associated with cancers developed below 40 years of age (P = 0.029). HPV 18 detection was associated with poor differentiation malignancy (P = 0.045) and histological types of poor prognosis (adenocarcinoma or nondifferentiated carcinoma; P = 0.006). HPV 18 positivity was also correlated with advanced clinical stages (FIGO II and III; P = 0.032). Parity and HPV status proved to be independent of each other (P approximately 0.99). Eighty-seven percent (27/31) of pelvic lymph nodes from HPV positive patients contained HPV DNA. The virus types found in lymph nodes were identical with those of the primary tumours in all cases. Virological results were compared to those obtained by routine histological examination. Only 6 of 27 patients with HPV positive lymph nodes had any histological evidence of metastasis. Nevertheless, the lack of metastasis as detected by histology does not exclude the possibility of relapses. Follow-up of the clinical prognostic significance of PCR detection of HPV in the possible sites of early metastases.

Human papillomavirus DNA and anti-HPV secretory IgA antibodies in cytologically normal cervical specimens

Cervical specimens collected from 163 cytologically healthy women were screened for the presence of human papillomavirus (HPV) DNA and anti-HPV secretory IgA antibodies. HPV DNA was detected by a general primer mediated polymerase chain reaction (PCR), which amplifies a conserved region from the L1 ORF of genital HPVs. The PCR products were typed by restriction enzyme digestion. A total of 35 samples (21.5%) were positive for HPV DNA (13 samples for HPV 6, 6 for HPV 16, 3 for HPV 18, and 13 for untypeable HPV X). HPV DNA positivity was significantly higher among women under 25 years of age (34.8%) than among the older patients (12.4%) (P < 0.001). An enzyme-linked immunosorbent assay (ELISA) using synthetic peptide antigens was carried out to detect local secretory IgA antibodies against the following HPV specific antigens: HPV 16 E2, HPV 16 E7, HPV 16 L1, HPV 16 L2, and HPV 11 L2. Thirty-four secretions (20.9%) were found to react with at least one of the oligopeptides. Anti-HPV IgA positivity was the highest among women aged 25-32 years, and it was significantly lower in both the younger and the older age groups (P < 0.05). Correlation between HPV DNA and anti-HPV IgA detection was rather weak: anti-peptide IgA positivity was 34.3% (12 of 35) among HPV DNA positive patients compared to 17.2% (22 of 128) among HPV DNA negative women (P < 0.05). The fluctuating course of latent HPV infections should be considered in evaluating the low level of correlation between HPV DNA and anti-HPV IgA positivity.

Human papillomavirus type 18 E6* mRNA in primary tumors and pelvic lymph nodes of Hungarian patients with squamous cervical cancer

Seven biopsy specimens from squamous-cell carcinomas of the uterine cervix were examined by RT-PCR for human-papilloma-virus(HPV)-specific transcripts. With our HPV18-transcription-specific primer pair (5' nts 127-149; 3' nts 587-607), all 7 were shown to contain one strong viral mRNA signal from the early 6/early 7 open reading frames (E6/E7 ORFs). Sequence analysis of the cloned PCR product proved that the transcript was generated by splicing out an intron in E6 from nucleotides 233 to 416, thereby corresponding to the HPV18 E6* spliced mRNA. Nine out of 9 metastatic and 5 of 7 histologically negative lymph nodes from the same patients were also found to be positive for the same mRNA transcript. However, 4 HPV18 unrelated primary tumors and the connected regional pelvic lymph nodes (3 metastatic, 7 histologically negative) were negative for the HPV18 E6* mRNA. Cytokeratin signals indicating tumor cells of epithelial origin were detected in 7 out of the 9 transcript-positive lymph nodes with histological signs of metastasis and in 2 out of the 5 transcript-positive histologically negative lymph nodes. This suggests that the dispersion of the epithelial monoclonal tumor cells was lymphogenic in origin.

Relation between the presence of human papillomavirus type 16 deoxyribonucleic acid in cervicovaginal cells and general health condition

Cervicovaginal cell samples were analyzed for the presence of human papillomavirus type 16 deoxyribonucleic acid. All 99 women included in the study had normal Papanicolaou smear results, normal findings on wet smear, and no clinical signs of genital papillomavirus or any other genital infection. Deoxyribonucleic acid polymerase chain reaction was performed with three different human papillomavirus type 16-specific primer pairs from the early 6, early 7, and upstream regulatory regions. Human papillomavirus type 16 was detected in 21% of the 99 women. Seven of 69 women (10%) who were not taking any medication except for cyclic estrogen or progestin replacement therapy were carriers of human papillomavirus type 16. Seven of 19 women (37%) who used hormonal contraceptives or who sought early pregnancy termination were carriers of human papillomavirus type 16. All 7 women with diseases that required frequent hospital care were carriers of human papillomavirus type 16. The 4 women who had never had sexual intercourse were not carriers of human papillomavirus type 16. Our results indicate that the human papillomavirus type 16 prevalence in women may reflect to some extent the general health conditions of the patients.

Oral contraceptive use and human papillomavirus infection in women without abnormal cytological results

Both experimental and epidemiological data support the idea that oral contraceptive (OC) use may have a stimulating effect to a certain point on cervical carcinogenesis. The current investigation tries to answer the question whether OC use might have an influence on early human papillomavirus (HPV) infections. A total of 425 women without abnormal cytological results were examined colposcopically, and filter in situ hybridisation (FISH) was used to determine the presence of human papillomavirus (HPV) types 6, 11, 16 and 18. Eighty-one cervical specimens (19.1%) were found to be positive for one or more of the HPV types in FISH. HPV positivity was found to correlate with age and parity, being the highest among women under 25 and with less than two births. The use of OCs was inversely correlated with the presence of ectopy or dysplasia in this group of women. On the other hand, HPV positivity was not significantly higher among OC users than among non-users in any colposcopic group. Neither the type of pill used, nor the duration of use had any significant effect on HPV positivity. Further investigations are needed to evaluate the effects of OC use on more severe HPV-induced cervical lesions.

High-risk human papillomavirus types in cytologically normal cervical scrapes from Kenya

Seventy-seven women with normal cervical cytology on routine visit to a family planning clinic in Nairobi, Kenya, were analysed for genital human papillomavirus (HPV) types by polymerase chain reaction (PCR). We applied a general primer pair (GP60/GP124) recognising sequences conserved among HPV types 6, 11, 16, 18, 31 and 33. Of the 77 specimens tested 15 (19.5%) proved to be positive for genital HPV. Amplification products were examined for the presence of high-risk HPV types by Slot-blot hybridization. Out of the 15 PCR-positive samples, 4 were positive for HPV 16.3 for HPV 18, while 1 contained both HPV 16 and 33. HPV DNA prevalence in this group of women from a "high-risk" area is similar to that in "low-risk" Swedish women but much lower than in cervical cancer samples from the same region.

Amplification of human papillomavirus type 16 transforming genes from cervical cancer biopsies and lymph nodes of Hungarian patients

We have used a polymerase chain reaction (PCR) to examine cervical cancer biopsy specimens and pelvic lymph nodes for the presence of human papillomavirus type 16 (HPV 16) DNA. Of the 75 cervical specimens tested, 36 (48%) were positive for HPV 16 in the PCR. A total of 65 pelvic lymph nodes removed during radical surgery on 35 women were also analyzed. Lymph nodes originating from 19 patients whose cervical biopsy specimens were negative for HPV 16 seemed to lack HPV 16 sequences. For 16 women with positive PCR results for cervical biopsy specimens, 9 of 10 lymph node metastases were positive in the PCR, while 11 of their 36 histologically negative lymph nodes were also shown to contain HPV 16 DNA.

Analysis of transforming gene regions of human papillomavirus type 16 in normal cervical smears

Exfoliated cells from the uterine cervix of 102 Hungarian women with no cytological abnormality were screened using the polymerase chain reaction (PCR) for human papillomavirus (HPV) type 16 infection. Twenty-nine patients with histologically confirmed cervical intraepithelial neoplasia (CIN) served as reference cases. PCR was performed with 2 different HPV 16 specific oligonucleotide primer pairs flanking a 300 and a 200 base-pair fragment from the early 6 (E6) and early 7 (E7) genes, position 215-514 and 605-805. The specimens exhibited the same proportions of type 16 sequences specific for the tested regions. 8.8% (9/102) of normal samples showed amplification for HPV type 16 E6 and E7 regions, while 48.3% (14/29) of CIN biopsies were positive for the same gene sequences.

Detection of transforming gene regions of human papillomavirus type 16 in cervical dysplasias by the polymerase chain reaction

In a study of 29 cases of histologically confirmed, characterized colposcopically and cytologically, cervical intraepithelial neoplasias 48.3% (14/29) of biopsies were positive for human papillomavirus (HPV) type 16 DNA by polymerase chain reaction. We used two oligonucleotide primer pairs (position 215-514 and 606-805) flanking a 300 and a 199 base pair fragment from the early 6 (E6) and early 7 (E7) genes. The results were concordant both with the E6 and with the E7 regions. Of the amplified products 85.7% (12/14) could be confirmed; these carried 16 specific sequences by Southern blot hybridization. HPV 16 DNA was present in 6.7% (2/30) of the colposcopically directed cytologically normal matched control samples using the same methods.

Detection of human papillomavirus deoxyribonucleic acid by filter in situ hybridization during pregnancy

Samples taken from 101 healthy pregnant women (49 over and 52 under the 20-week gestational period) and 108 healthy nonpregnant women were tested for human papillomavirus (HPV) types. Using 6, 11, 16, and 18 HPV DNA probes, 3-5 x 10(5) exfoliated cells scraped from the cervix were tested by filter in situ hybridization (FISH). Thirty-five of the pregnant women (34.6%) had evidence of the presence of HPV DNA: with 11.8% (12/101) HPV 6; 7.9% (8/101) HPV 11; 8.9% (9/101) HPV 16; and 5.9% (6/101) HPV 18 positivity. HPV DNA was detected in 20.4% (22/108) of the non-pregnant women. Compared with the healthy, nonpregnant group, the higher level of asymptomatic cervical HPV infection was mainly due to the accumulation of HPV 16 and 18 nucleic acids during the gestational period: with detection of HPV 16 in 8/49 cases (16.3%) and of HPV 18 DNA sequences in 4/49 (7.6%) cases. Screening 6-8 weeks after delivery indicated a decline of HPV positivity. Of the 4/12 HPV type 16 positive mothers, only one retained the presence of HPV 16 DNA, whereas neither of the 2/12 type 18 positive women reacted after birth with the type 18 radioactive probe.

Human papillomavirus in cervical smears taken from women wearing an intrauterine contraceptive device

Cervical cells were screened for human papillomavirus (HPV) infections by in situ filter hybridization in 108 patients wearing intrauterine contraceptive devices. The cells were tested for the presence of HPV 6, 11, 16, 18 DNA. In 86 cases (79.6%) no reactions were obtained with 32P-labeled HPV DNA probes. 22 smears (20.3%) were positive for HPV: type 6 and 11 sequences were demonstrated in 17 cases (3 of them carried both). 4 smears hybridized with the probe for oncogenic HPV 16 and one with that for oncogenic type 18. All these five patients had normal smears and no abnormality on colposcopy.

Detection of human papillomavirus deoxyribonucleic acid in the female genital tract

A total of 336 biopsies, scrapes and exfoliated cells from the cervix and from the lower genital tract were screened for human papilloma (HP) viral sequences of types 6, 11, 16 and 18 by Southern blot, dot blot and filter in situ (FISH) hybridizations with cloned 32P-radiolabeled HPV DNA probes. The specimens included cervical intraepithelial neoplasias (CIN I-III), carcinoma in situ and invasive carcinoma of the cervix and vagina, adenocarcinomas, vulvar and vaginal condylomata acuminata and healthy epithelial samples. The oncogenic HPV 16 was found in 46% of the cervical carcinomas. Most of the type 16 occurrences (75%) represented the third stage of inoperable cases. Similarly, HPV 18 was also most frequently present in this stage as well as in carcinoma in situ and in CIN III (25%, 18%). At the same time, in condylomata acuminata, types 6 and 11 were detectable in 88.7% of cares. In all, 13.5% of the normal samples harboured HPV DNA.

Human antibody response to human cytomegalovirus-specific DNA-binding proteins

Human antibody responses to human cytomegalovirus (HCMV) specific DNA-binding proteins were studied in serum samples by the Western blot technique. The molecular weights of six DNA-binding proteins found in HCMV-infected cells, ranged from 52kD to 18kD. The sera obtained from patients with acute HCMV infections reacted well with the six HCMV specific DNA-binding proteins. The strongest reactivity was observed with the 52kD and 35kD proteins. The sera from healthy HCMV seropositive donors reacted only with the 52kD DNA-binding protein as visualized in Western blots, but 2 out of 8 sera failed to react with any HCMV specific DNA-binding proteins.

Antibodies to the second Epstein-Barr virus nuclear antigen in non-Hodgkin lymphomas

Human antibodies against the first and second Epstein-Barr virus encoded nuclear antigens (EBNA-1 and EBNA-2) were analysed by modified ELISA reaction on immunoblots: 5 out of 20 EBNA-1 positive, healthy donor sera reacted with the EBNA-2. Healthy EBV seronegatives contained no antibodies against EBNA-2. The antibodies against this EBNA-2 developed several months after acute EBV infections. Four out of 8 infectious mononucleosis sera failed to react EBNA-2 in the late stage. In the group of EBV seropositive patients with non-Hodgkin lymphoma, 14 out of 18 sera contained EBNA-2 antibodies.

Detection of human cytomegalovirus-induced DNA-binding proteins on Western blots

DNA-binding proteins have been isolated from human embryonic fibroblast cells infected with human cytomegalovirus strain AD169 by native and denatured DNA-cellulose affinity chromatography and Polymin P precipitation. The DNA-binding proteins separated by polyacrylamide gel electrophoresis and electrophoretically transferred to a nitrocellulose sheet were identified by a modified ELISA reaction. Six DNA-binding proteins were found in infected cells, their molecular weights range from 52K to 18K.

Anti-human cytomegalovirus nuclear antigen antibodies of different immunoglobulin classes

IgG, IgM and IgA immunoglobulin classes of antibodies to human cytomegalovirus nuclear antigens (CMNA) were studied by the acid-fixed nuclear binding technique (AFNB) and combined anti-complement immunofluorescence (combined ACIF). In acute cases of infectious mononucleosis (IM) of human cytomegalovirus (HCMV) origin and in the so-called double virus infections (HCMV + Epstein-Barr virus), anti-CMNA IgM antibodies were detected. They were absent from both anti-HCMV positive sera of healthy donors and sera of patients suffering of IM caused by EBV used as controls. The presence of anti-CMNA IgM may thus serve as an additional evidence of acute HCMV infection. Non-complement-fixing IgA classes of the anti-CMNA antibodies were not found in some of the sera gathered during the acute phase of IM of EBV origin: in one fourth of the HCMV seropositive donors and in a number of late serum samples. But non-complement-fixing and complement-fixing anti-CMNA components of the IgG class were detected.

Early nuclear antigen as DNA-binding protein in cytomegalovirus-infected cells

Early nuclear complement-fixing antigen in cytomegalovirus (CMV) (strain Ad 169)-infected human embryonic fibroblasts is described. The nuclear antigen was solubilized from CMV-infected cells by high salt treatment. DNA-binding properties were studied by DNA-cellulose chromatography. The purified antigen, eluted from double-stranded DNA-cellulose columns, was added to acid-fixed nuclear preparations from human embryonic fibroblasts and then exposed to human sera containing antibodies to CMV. Positive staining was obtained by anti-complement immunofluorescence. These data identify the CMV-determined nuclear antigen as a DNA-binding protein. In this respect, it is similar to the Epstein-Barr virus nuclear antigen.