Viewing Study NCT00155792



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Study NCT ID: NCT00155792
Status: UNKNOWN
Last Update Posted: 2005-12-20
First Post: 2005-09-09

Brief Title: The Development of Human Papillomavirus Type 16 E7-Specific Human Immunologic Assays in Non-HLA2 Type Human Being
Sponsor: National Taiwan University Hospital
Organization: National Taiwan University Hospital

Study Overview

Official Title: None
Status: UNKNOWN
Status Verified Date: 2001-12
Last Known Status: RECRUITING
Delayed Posting: No
If Stopped, Why?: Not Stopped
Has Expanded Access: False
If Expanded Access, NCT#: N/A
Has Expanded Access, NCT# Status: N/A
Acronym: None
Brief Summary: Cervical cancer the most frequent neoplasm and the third mortality rate of malignancies of the women in the world It results in about 200000 women dying of cervical cancer each year worldwide The available forms of treatment-surgery radiation therapy and chemotherapy are all cytoreductive treatment modalities so in addition to killing cancerous cells healthy cells are also destroyed in the process Indeed there is a need to decrease the incidence of cervical cancer and develop better forms of its treatment

Human papilloma viruses HPV have been consistently implicated in causing cervical cancer especially those high-risk types HPV 16183145 have been strongly associated with cervical cancer HPV 16 was found in more than 50 of cervical cancer tissues So the host immune response plays an important role in determining the regression of cervical abnormality or persistence and progression to malignancy via targeting HPV

The ideal cancer treatment should be able to eradicate systemic tumors at multiple sites in the body while having the specificity to discriminate between neoplastic and nonneoplastic cells In this regard antigen-specific cancer immunotherapy represent an attractive approach for cancer treatment It is now clear that major histocompatibility complex MHC class I restricted CD8 T cytotoxic cells are critical to the generation of antitumor immunity Cell-mediated responses are critical in anti-tumor immunity

By cooperating with Dr TC Wu in Johns Hopkins Medical Institutes we have recently developed some E7-specific cancer vaccines of different strategies such as DNA or replication-defective SINrep5 virus We found that these E7-chimeric DNA vaccines are capable of preventing and treating the growth of murine model tumors expressing E7 These positive results from the preclinical murine models have encouraged us to focus on the development of cancer vaccine and immunotherapy and apply these vaccines to human subjects However it is very important to set up various E7-specific immunologic assays of human being to evaluate the effect of cancer vaccine or immunotherapy in the future clinical trials So we would like to provide this proposal to address on the development of HPV 16 E7-specific immunologic assays in human being
Detailed Description: HPV and Cervical Cancers Human papillomaviruses HPV are small nonenveloped DNA viruses which induce epithelial tumors of skin or mucosa The majority of tumors are benign show limited growth and usually regress spontaneously However a number of human papillomaviruses induce tumors that may eventually progress to carcinomas The genital HPV types 16 and 18 and less frequently types 31 33 35 45 51 and 56 have been implicated in the etiology of cervical and other anogenital cancers Approximately 500000 women worldwide develop cervical cancer yearly and it is the second leading cause of death from cancer in women 1 In developed countries cancer of the cervix ranks behind cancers of the breast lung uterus and ovaries and accounts for 7 of all female cancers In the United States there are about 4800 deaths annually from cervical cancer 2 The evidence linking HPVs to anogenital cancer comes from epidemiologic and laboratory studies More than 90 of cervical cancers and their precursors so-called cervical intraepithelial neoplasia CIN contain human papillomavirus HPV DNA sequences 3 The HPV types found in cancer cells have transforming activity in in vitro studies 4 and the viral transforming proteins E6 and E7 are consistently expressed in cervical cancer cell lines 5 and in HPV-associated cancers of patients 6 In HPV-associated malignant transformation viral DNA may be integrated into the cellular DNA and integration often results in deletion of large sectors of the viral genome Late genes L1 and L2 and some early genes E1 and E2 are usually lost leaving E6 and E7 as the only open reading frames frequently found in carcinomas Expression of E6 and E7 is likely to overcome the regulation of cell proliferation normally mediated by proteins like p53 and Rb allowing uncontrolled growth and providing the potential for malignant transformation 7

HPV Oncogenic Proteins E6 and E7 as Ideal Targets for the Development of Antigen-Specific Immunotherapies or Vaccines for HPV-Associated Cervical Malignancies E6 and E7 represent ideal targets for the development of antigen-specific immunotherapies or vaccines for HPV-associated malignancies First more than 90 of cervical cancers have been associated with HPVs particularly type 16 and E6 and E7 are consistently expressed in most cervical cancers Second while most tumor specific antigens are derived from normal proteins or mutated protein E6 and E7 are completely foreign viral proteins and potentially may harbor more antigenic peptidesepitopes than a mutant protein ie p53 or a reactivated embryonic protein ie MAGE-1 Third since E6 and E7 are required for the induction and maintenance of malignant phenotype of cancer cells 8 cells of cervical cancer cannot evade an immune response through antigen loss Without functional E6 and E7 these cells would cease to be tumorigenic Therefore E6 and E7 proteins represent ideal targets for developing antigen-specific immunotherapies or vaccines for cervical cancer

Various forms of vaccines such as vector-based vaccines tumor-based vaccines DNA based vaccines and proteinpeptide-based vaccines have been described in experimental systems targeting HPV-16 E6 andor E7 proteins 9 10 For example Meneguzzi et al reported that inoculation of rats with vaccinia recombinants expressing HPV-16 E6 or E7 retarded or prevented tumor development in 25-47 of rats challenged with a tumorigenic rat cell line co-transfected with HPV-16 and activated ras 9 In addition Chen et al demonstrated that immunization of mice with syngeneic non-tumorigenic cells transfected with the HPV-16 E7 gene confers protection against transplanted HPV-16 E7 positive syngeneic tumor cells 11 Feltkamp et al identified a CTL epitope in HPV-16 E7 using H-2Kb and H-2Db MHC class I-peptide-binding studies Immunization with this peptide rendered mice resistant to a challenge with HPV-16 transformed tumor cells 12 Furthermore chimeric papillomavirus-like particles CVLPs consist of HPV-16 L1-E7 Nieland et al personal communication or HPV-16 L1L2-E7 Greenstone et al personal communication chimeric proteins has been used as therapeutic vaccines against HPV-16 E7 expressing tumors in murine models More recently a phase III clinical trial were performed in eight patients with late stage cervical cancer using a live recombinant vaccinia virus expressing the E6 and E7 proteins of HPV 16 and 18 TA-HPV 13 In that study no significant clinical side-effects or environmental contamination by live TA-HPV were observed 13

Importance of Cell Mediated Immune Responses in Controlling both HPV Infections and HPV-Associated Neoplasms Several lines of evidence suggest that cell mediated immune responses are important in controlling both HPV infections and HPV-associated neoplasms for review see 14 First the prevalence of HPV-related diseases infections and neoplasms is increased in transplant recipients 15 and human immunodeficiency virus HIV infected patients 16 both of whom are known to have impaired cell mediated immunity Second animal studies have demonstrated that immunized animals are protected from papillomavirus infection and from the development of neoplasia Immunization also facilitates the regression of existing lesions 17-19 Third infiltrating CD4 T helper cells and CD8 cytotoxic suppressor T cells T cells have been observed in spontaneously regressing warts 20 and fourth warts in patients who are on immunosuppressive therapy often disappear when this treatment is discontinued for review see 21

Cellular Immune Responses to HPV The understanding of T-cell mediated immunity to HPV infections was facilitated by identification of MHC class I and class II epitopes of HPV proteins Several groups have attempted to map murine 22-24 and human 25 26 T helper Th cell epitopes on HPV proteins Several groups have also tried to map murine 12 27-30 as well as human 31-34 cytotoxic T-lymphocyte CTL epitopes on HPV proteins Kast et al have identified several high affinity binding peptides of HPV-16 E6 and E7 proteins for human HLA-A alleles 32 Furthermore HPV-specific CTLs recognizing HPV E6 and E7 proteins have been demonstrated in peripheral blood of cervical cancer patients 13 35 in healthy donors 33 36 and in patients with CIN lesions 34 37 38 Furthermore infiltration of cervical cancer tissue with HPV-specific CTLs has been recently described39

Cell-mediated immune responses in HPV-infected lesions can be demonstrated by in vivo skin tests 40 41 in vitro CTL assays 35 37 39 and in vitro lymphoproliferative response 25 26 42-48 For instance Hopfl et al have used bacterially-expressed HPV-16 proteins for skin tests in patients with CIN lesions and have found specific skin responses to the virion protein L1 and not the E4 protein 40 In patients with CIN lesions HPV-specific CTLs have been identified in PBMC 35 37 and in cervical tissues 39 The in vitro lymphoproliferative responses in patients with CIN lesions has been actively investigated For example de Gruijl et al reported that T cell proliferative responses against HPV-16 E7 oncogenic protein were most prominent in CIN patients with a persistent HPV infection 45 However Kadish et al reported that lymphoproliferative responses to specific HPV-16 E6 and E7 peptides appeared to be associated with the clearance of HPV infection and the regression of CIN lesions 46

Importance of Helper T Cell Functions in Generating Effective Antitumor Responses Increasing evidence has suggested that inadequate antitumor responses can result from a failure of the helper arm of the immune response The events leading to the activation of CTL are tightly regulated in order to protect against the development of inappropriate immune responses to self antigens or exaggerated responses to foreign antigens This regulation is mediated by lymphokines produced by CD4 T helper cells CD4 T helper cells are critical to the generation of potent antitumor immune responses CD4 T cells have been shown to be instrumental in generating immune responses against several solid malignancies in murine 49 50 and in human 51 52 Several mouse tumors that are transfected with syngeneic MHC class II genes become very effective vaccines against subsequent challenge with wild type class II negative tumors 53 54 In addition as crucial memory cells in the T cell arm of the immune system CD4 cells may be able to provide long term immunity against specific antigens 55 56

Role of Cytokines in Cell-Mediated Immunity Cell mediated immunity is regulated by cytokines which are secreted by T helper cells In general T helper cells can be classified as Th1 andor Th2 cells based on the different types of cytokines they secrete Th1 cells secrete interleukin IL 2 and interferon gamma IFN- Th2 cells produce IL-4 IL-5 IL-10 and IL-13 The Th1 lymphocytes are the most important effector cells in inflammatory reactions associated with vigorous delay-type hypersensitivity but low antibody production as occurs in contact dermatitis and in viral or intracellular bacterial infections for review see 57 58 The functional phenotype of most Th2 cells may account for both the persistent production of certain antibody isotypes particularly IgG1 and IgE and the eosinophilia observed in human helminthic infections and allergic disorders Lymphocyte mediated protection from viral infections as well as control of tumors is thought to be mediated by Th1 cytokine responses and impaired by Th2 cytokine responses The IL-2 and IFN- producing Th1 response is likely to be the major component that contributes to the development of cell mediated immunity against HPV infections and HPV-associated neoplasms

Chimeric E7-specific vaccines can control the HPV16 E7-expressing tumor model With cooperating with Prof TC Wu in Johns Hopkins Medical Institutes we have successfully developed several chimeric DNA RNA and virus-vector vaccines to prevent and treat HPV16 E7-expressing tumor in the animal model 59-61 We found that these E7-chimeric DNA vaccines are capable of preventing and treating the growth of murine model tumors expressing E7 These positive results from the preclinical murine models have encouraged us to focus on the development of cancer vaccine and immunotherapy and apply these vaccines to human subjects

However it is very important to set up various E7-specific immunologic assays of human being to evaluate the effect of cancer vaccine or immunotherapy in the future clinical trials So we would like to provide this proposal to address on the development of HPV 16 E7-specific immunologic assays in human being There are several aims in this project 1 to develop and utilize assays to measure CTLs to HPV 16 E7 proteins 2 to develop and utilize assays to measure T helper Th responses to HPV 16 E7 antigens

Study Oversight

Has Oversight DMC: None
Is a FDA Regulated Drug?: None
Is a FDA Regulated Device?: None
Is an Unapproved Device?: None
Is a PPSD?: None
Is a US Export?: None
Is an FDA AA801 Violation?: None