IFN-γ Produced by Human Papilloma Virus-18 E6-Specific CD4+ T Cells Predicts the Clinical Outcome after Surgery in Patients with High-Grade Cervical Lesions

Abstract

Cervical neoplastic lesions are associated with infection by high-risk human papilloma viruses (HPVs). HPV-16 and HPV-18 are the most common genotypes. It has been proposed that development of HPV-16-positive cervical lesions is associated with impaired CD4+ T cell immunity against early Ags. The aim of the study was to evaluate whether this impairment also applies to HPV-18. We investigated the presence and the quality of anti-HPV-18 E6 CD4+ T cell responses in the blood of 37 consecutive patients with high-grade cervical lesions, 25 normal donors, and 20 cord bloods. The immune infiltrate in the cervical lesions was also evaluated. The characteristics of the responses were correlated to the clinical outcome. We found that one or more HPV-18 E6 peptides, containing naturally processed epitopes, were able to induce a response in 40–50% of the patients, depending on the effector function tested. Importantly, these percentages rose to 80–100% when HPV-18-positive patients were considered. HPV-18 E6-specific CD4+ T cells produced mixed Th1/Th2 responses and statistical analysis of the cytokines produced revealed that the amount of IFN-γ released could predict infection persistence and/or disease relapse after surgery. Finally, we found that a higher number of infiltrating CD4+ and T-bet+ T cells in the lesions correlated with a favorable clinical outcome. Our results strongly suggest a relevant role for CD4+ T cells in the control of the HPV-18 compared with HPV-16 infections in patients with high-grade cervical lesions and identify an immunologic parameter potentially useful for patients’ stratification.

Disruption of the E2 Gene Is a Common and Early Event in the Natural History of Cervical Human Papillomavirus Infection: A Longitudinal Cohort Study

“…For example, in vitro studies suggest that loss of episomal E2 with the emergence of integrated forms is associated with the endogenous activation of anti-viral genes, and therefore, the type-specific differences we have observed may be consistent with a recent report suggesting that HPV18 is more immunogenic than HPV16 (52,53).…”

Carcinoembryonic Antigen-Specific but Not Antiviral CD4+ T Cell Immunity Is Impaired in Pancreatic Carcinoma Patients

“…The experiments were performed as described previously (31,44). Briefly, CD4 ϩ T cells were purified from total PBMC by using magnetic beads (Miltenyi Biotec) and cultured in 96-well plates at 3 ϫ 10 4 /well in five replicates for each condition in 200 l/well X-VIVO 15 (BioWhittaker) supplemented with penicillin (100 U/ml; BioWhittaker), streptomycin (50 mg/ml; BioWhittaker), and 3% heat-inactivated pooled human serum (tissue culture medium; BioWhittaker) in the presence of irradiated CD4 ϩ depleted PBMC as APC, at a CD4 ϩ :APC ratio of 1:3.…”

“…Normal donors and patients were tested for the presence of CD4 ϩ T cells against CEA sequences described to contain promiscuous and naturally processed epitopes (35, 37-39) using an ex vivo restimulation assay, which we previously demonstrated not to favor in vitro priming (44). CD4 ϩ T cells were cultured in several replicates in the presence or the absence of single CEA peptides or PHA as a positive control.…”

“…GM-CSF was tested to detect unpolarized cells. IL-4 was not tested because of potential consumption by CD4 ϩ T cells in culture in the assay used (44). IL-10 and IL-13 were tested in a limited number of subjects to confirm production of Th2 cytokines.…”

Cytokines and Markers of Immune Response to HPV Infection

“…They observed that increasing levels of IL-4 and IL-10 levels were significantly associated with HPV infection and that decreasing levels of IL-2 and IFNwere associated with HPV status. Seresini et al (Seresini, Origoni et al 2007) measured lymphoproliferative responses and IL-2, IFN-g, IL-4, and IL-10 levels in PBMCs stimulated not with HPV16 peptides, but rather with HPV18-specific E6 peptides. Their analyses revealed that one or more HPV18 E6 peptides were able to induce a response in 40-50% of the women evaluated.…”