T-cell Alteration in Cervical Neoplasia

Lim, S C; choi, S J

Abstract

The host immune response is commonly cited as a determining factor in the development or clearance of various neoplasia, but the immunobiology of neoplastic progression is poorly understood. The cervix has the largest concentration of lymphocytes found in the female genital tract as a component of the common mucosal immune system, but cervical immunocytes have not been well characterized in the neoplasia itself. The objective of this study was to characterize the subpopulations of lymphocytes that infiltrate various grades of cervical neoplasia. To establish the characteristics we examined 60 cases of uterine cervix which were divided 4 categories according to the Bethesda classification system: normal cervix (15), low grade squamous intraepithelial lesions (LSILs) (15), high grade squamous intraepithelial lesions (HSILs) (15), and invasive squamous cell carcinomas (15 cases). The degrees and subpopulations of infiltrating lymphocytes were assessed quantitativ-ely and qualitatively by immunohistochemical stain and electron microscopy. There were significant increasing the numbers and the proportions of T-cells in the invasive cancers compared with those in the preinvasive lesions. The ratios of CD4 (+)/CD8 (+) cells between the preinvasive groups and the invasive group were reversed by profound increment of CD8 (+) cells and relative decrement of CD4 (+) cells in the invasive group. On ultrastructural observations, there were many of apoptosis of the tumor infiltrating lymphocytes and cancer cells in the invasive cancer group, and there were a few of apoptosis of the only neoplastic cells in the preinvasive groups. In conclusion, the UCHL1-positive T cells infiltrate far exceeded in the invasive, but not in the preinvasive lesions, a finding that suggests that T cells, especially CD8 (+) cells are recruited preferentially to cervical lesions with progression to invasion. It is suggested that the T cell recruitment is related to inactivation, autosuppression or apoptosis of the T cells, especially CD8 (+) cells, and the profound decrement of helper T cells have the essen-tial role in tumor invasion.