Background: The onset and persistence of cutaneous lichen sclerosus et atrophicus (LSA) are linked to the presence of an inflammatory infiltrate of CD3+ T cells that includes CD4+ and CD8+ cells. The functional relevance of the presence of these cells is unknown. Objective: The study intended to quantify resting and activated cytotoxic T cells in LSA lesions. Methods: Twenty patients with active LSA were studied. Skin-infiltrating T cells were immunohistologically characterized with antibodies against CD3, CD8, T-cell-restricted intracellular antigen (TIA-1) and granzyme B (GrB). TIA-1 labels cytotoxic granules of resting and activated T cells, whereas GrB designates activated cytotoxic T lymphocytes (CTL). Results: In all cases, numerous T cells were consistently found expressing cytotoxic granules. The results indicated a high number of infiltrating CD8+ TIA+ T cells. Furthermore, a notable number of GrB+ activated CTL associated with hydropic degeneration of the basal cell layer were found within the dermal infiltrate and at the dermoepidermal interface. Conclusion: This study shows that a high proportion of skin-infiltrating T cells in LSA has a potential cytotoxic function. The results indicate that hydropic degeneration of basal keratinocytes may at least partially be mediated by CTL-dependent mechanisms. Our data also indicate that a cell-mediated immune response may play an important role in the pathogenesis of the disease.

Purpose: The goal of this study was to investigate the therapeutic potential of a novel immunotherapy strategy resulting in immunity to localized or metastatic human papillomavirus 16-transformed murine tumors. Experimental Design: Animals bearing E7-expressing tumors were coimmunized by lymph node injection with E7 49-57 antigen and TLR3-ligand (synthetic dsRNA). Immune responses were measured by flow cytometry and antitumor efficacy was evaluated by tumor size and survival. In situ cytotoxicity assays and identification of tumorinfiltrating lymphocytes and T regulatory cells were used to assess the mechanisms of treatment resistance in bulky disease. Chemotherapy with cyclophosphamide was explored to augment immunotherapy in late-stage disease. Results: In therapeutic and prophylactic settings, immunization resulted in a considerable expansion of E7 49-57 antigen-specific T lymphocytes in the range of 1/10 CD8 + T cells. The resulting immunity was effective in suppressing disease progression and mortality in a pulmonary metastatic disease model. Therapeutic immunization resulted in control of isolated tumors up to a certain volume, and correlated with antitumor immune responses measured in blood. In situ analysis showed that within bulky tumors, T-cell function was affected by negative regulatory mechanisms linked to an increase in T regulatory cells and could be overcome by cyclophosphamide treatment in conjunction with immunization. Conclusions: This study highlights a novel cancer immunotherapy platform with potential for translatability to the clinic and suggests its potential usefulness for controlling metastatic disease, solid tumors of limited size, or larger tumors when combined with cytotoxic agents that reduce the number of tumor-infiltrating T regulatory cells. (Clin Cancer Res 2009;15(19):6167-76) Human papillomavirus (HPV)-associated tumors remain a significant health care problem worldwide, as the second leading cause of cancer mortality in women (1, 2), and the number one cause of cancer-related death in women in developing countries (3, 4). Although effective prophylactic HPV vaccines have recently been developed targeting the late (L1 and L2) genes (5), they are ineffective at eliminating preexisting infection or HPV-related tumors whose cellular transformation and progression depend upon expression of the E6 and E7 early proteins (2). Therefore, a therapeutic vaccine triggering T-cell immunity specific to the E6 and E7 early proteins of HPV 16 and 18 strains-those responsible for the pathogenesis of the majority of cervical cancers (6)-could offer a promising option to prevent the progression of HPV infection to cervical cancer, or the progression of early stage tumors to invasive disease (2, 7).Recent advances in lymph node-targeted active immunotherapy, in our hands and others, have resulted in greatly improved CD8 + T-cell responses against a variety of tumor antigens (8-10). Using a novel intralymphatic immunization approach consisting of the administration of a HPV 16 tumor-...