Introduction: Given that the cervical intraepithelial neoplasia (CIN) develops in the cervical mucosa followed by human papillomavirus (HPV) infection, the mucosal cytotoxic (type1) immunity against HPV is necessary for control of CIN. The aim of this study was to establish a method for measuring mucosal anti-HPV cellular immune response and to examine the relationship between the mucosal immunity and the CIN course. In this study, we focused on mucosal type1 immune responses to HPV16 E7 oncoprotein.

Patients and Methods: Cervical lymphocytes (105-6 cells) were obtained from cervix of 27 patients with CIN lesions by Cytobrash under written informed consent. Among them, 17 patients with CIN 2-3 were positive for HPV16, and 10 patients with CIN 1/2 were positive for other HPV ("Other HPV group"). Seventeen patients with CIN 2-3 were grouped according to their course; 8 patients who received conization after sampling due to progression were classified into "Cone group", and 9 who dispensed with conization after sampling due to stable diseases or regression to CIN1 into "Treatment-free (TF) group". Cervical lymphocytes were examined for ELISPOT assay to detect HPV16 E7-specific IFN-gamma producing cells. Numbers of E7-specific IFN-gamma producing cells (anti-E7 type1 immune cells) were compared between the three groups.

Result: FACS analysis revealed that 3.7-20% (median=6.0%) of the cervical lymphocytes expressed CD3 (CD4:CD8=6:4) whereas 0.1-0.5% expressed CD19. Number of anti-E7 type1 immune cells of TF, Cone and Other HPV groups was 63-126 (average=98.6), 0-70 (average= 36.0), and 0-71 (average=42.7) /104 cells, respectively. The cell number of TF group was significantly higher when compared to either Cone or Other HPV group (t test; p<0.005).

Conclusion: Patients who induced mucosal E7-specific type1 immune responses can control CIN2-3 lesions spontaneously. The number of anti-E7 type1 immune cells in the cervical mucosa was a promising-biomarker to determine a fate of CIN2-3 lesions.