The Correlations Between HPV L1-Specific Immunologic Responses in Cervical Cancer and CIN Patients and Their Prognosis
Cervical cancer is the most frequent neoplasm of the women in Taiwan and in the world.
Cervical cancer affects half a million women each year and results in about 200,000
worldwide and it also influences about 2,700 women and about 1,000 women dying of cervical
cancer each year and in Taiwan. There is strong evidence suggesting that this cancer is 100%
attributable to infection with certain types of human papillomavirus (HPV); in fact, the
World Health Organization (WHO) has very recently recognized that this cancer is caused by
HPV. There are around 100 different HPV-types, of which around 40 types infecting the
anogenital tract and causing cervical lesions and cervical cancer have been called High Risk
HPV (i.e., HR-HPV-16, -18, -31, -33, and -58). From recent years, there is compelling
evidence that infection with human papillomavirus (HPV) is a major etiologic factor in the
development of cervical intraepithelial neoplasia (CIN) and cervical carcinoma.
As in most virus induced diseases, an adequate immune response is likely to play a key role
in clearance of HPV infections and HPV-related lesions. This assumption is born out by both
epidemiological studies and animal models. Immune compromised patients such as HIV infected
women, organ transplant recipients, and patients suffering other forms of malignancies, are
at higher risk of developing CIN lesions and invasive cervical cancer. Moreover, several
studies establish the existence of natural HPV-specific immunity in humans. Immune responses
of the host are indeed critical in the virus-related infectious diseases. The immune
response against HPV antigens is Human leukocyte antigen restricted. Consequently, the HLA
class I and II phenotype may be correlated with an effective immune response against HPV
associated cervical lesions. Differences in the recognition of foreign antigen, such as
those contributed by alleles at the HLA class I or II loci, might be proposed to affect the
risk of developing cervical cancer. Studies by different groups on associations between
certain HLA alleles and susceptibility to, or protection against CIN lesions and cervical
carcinoma, reveal varying conclusions and warrant further research.
Most potentially oncogenic, persistent, long-term HPV infections induce an antibody response
against virus proteins which can be detected by ELISA test and can be a good indicator of
past as well as current infections and chronic active infection, associated with the
presence of cervical lesions and the high risk of acquiring cervical cancer. In fact, it has
been reported that women who are seropositive for HPV-16 present a higher risk of developing
cervical carcinoma than seronegative women. L1-viral capsid proteins are one of the targets
for antibodies induced by persistent HPV genital infection.
The L1 protein represents more than 90% of the total protein on the surface of the virus.
This protein is able to assemble itself, forming virus-like particles (VLPs). VLPs, mainly
type 16, have been broadly used for studying the antibody response induced by genital
HPVinfection. The VLP-antibody presence is stable in time, correlated with the number of
sexual partners, and associated with persistent infection, viral load, and development of
neoplasic lesions; this is rarely found in patients suffering from transitory infections.
Seropositivity occurs more frequently in patients who have progressed to CIN III and
invasive cancer than in those suffering from CIN I or CIN II and the antibody response is
significantly higher in women having a higher viral load than those with lower viral load.
Prospective studies have shown that 70-90% of HPV-16 infected women are seroconverted
between 6 and 18 months after HPV DNA has been detected and that this rarely occurs in
patients detected as having transient HPV DNA.
However, other serological studies have shown that 20-50% of women suffering from
HPV-associated lesions, with HPV DNA presence, do not present detectable levels of anti-VLP
antibodies; this is in part due to the lack of an optimized test and the fact that these
antibodies reactivity is type-specific for the virus. An optimized VLP-based ELISA test has
been recently reported showing 93% sensitivity and 98.5% specificity for discriminating
between positive and negative control sera. However, there was no report to evaluate the
antibody response in patients with HPV-infected cervical lesions and with the prognosis of
So in the present proposal, we would like to examine the anti-L1 antibodies of various HPV
types among Taiwanese women with HPV-related CIN or cervical cancer. The purposes of this
proposal are 1) to address the immunologic responses to HPV between CIN and cervical cancer
patients. , 2) to elucidate the correlation between immunologic responses to HPV and disease
severity of cervical cancer., 3) to evaluate the correlation between immunologic responses
to HPV and the prognosis of cervical cancer patients.
The samples of patients' sera were collected on the day of surgery. 2. The sera samples were
freezedon -200C until analyzed. 3. The sera samples will be shipped to the Lab. of Merck
company in US. 4. HPV Serologic Assay A competitive radioimmunoassay developed by Merck
Research Laboratories will be was used and perform to quantitate serum HPV- 6, 11, 16, 18,
31, 33, 45, 51, 52, 58, 59, or 68 antibodies in Merck Research Laboratories (12). Results
will be read from a standard curve, corrected for dilution, and reported in arbitrary units
(milli-Merck Units, or mMU per milliliter). A fixed cutoff of 5.9 mMU per milliliter
(derived by repeatedly testing a panel of positive and negative samples against the standard
curve) will be used to determine the HPV-6, 11, 16, 18, 31, 33, 45, 51, 52, 58, 59, or 68
serologic status of the women.
Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science
from CS operation to close
Chi-An Chen, MD
National Taiwan University Hospital
Taiwan: Department of Health