Identification of HLA-A11-restricted CTL epitopes derived from HPV type 18 using DNA immunization

Abstract

Identification of the cytotoxic T lymphocyte (CTL) epitopes of tumor antigens is important for effective immunotherapy. We report that a combination of epitope prediction, enzyme-linked immunosorbent assay (ELISA)-based epitope-HLA complex formation, and DNA immunization methods can improve the efficiency and accuracy of CTL epitope studies. In this study, two HLA-A11-restricted epitopes derived from human papillomavirus (HPV)18 E6 oncoprotein were identified. HLA-A11-transgenic mice immunized with these epitopes could specifically induce interferon-gamma (IFNgamma) production, cytotoxicity and peptide/HLA-A11 tetramer binding in CD8(+) T-cells. To study intracellular processing of CTL epitopes, we constructed a DNA plasmid containing an endoplasmic reticulum (ER) targeting sequence as well as the HPV18 E6 and E7 genes (pEK/HPV18E6E7). CTL responses against peptide-pulsed T2/A11 cells could be detected after immunizing HLA-A11-transgenic mice with pEK/HPV18E6E7. Furthermore, the identified peptides could stimulate T-cells to secrete IFNgamma from HPV18-infected patients. Our results demonstrate that the antigenic E6 peptides derived from HPV18 are potential candidates for the treatment of HPV 18-associated tumors in HLA-A11(+) populations.

Cancer-Targeted BikDD Gene Therapy Elicits Protective Antitumor Immunity against Lung Cancer

“…Cytolytic activity was measured by standard 4-hour chromium release assay as previously described (15). In brief, every 2 weeks after the last treatment, erythrocytedepleted splenocytes (1 Â 10 6 cells/mL) were cultured in vitro with irradiated TC-1 (30 Gy; 1 Â 10 5 ) and 10 U/mL of recombinant human IL-2 in 24-well plates for 5 days as effector cells.…”

“…The mouse IFN-g ELISpot assay was done as previously described (15). In brief, 2 Â 10 5 splenocytes were incubated with 1 Â 10 5 of irradiated (30 Gy) TC-1 cells or synthetic HPV16 E7 peptide (49-57, RAHYNIVTF; ref.…”

Clinical features and major histocompatibility complex genes as potential susceptibility factors in pediatric immune thrombocytopenia

“…23 KIRs downregulate cytotoxic T-lymphocyte and NK-cell responses by binding to MHC class I molecules, thereby preventing lysis of target cells. Several epitopes recognized by cytotoxic T lymphocytes are HLA-A11 restricted, including peptides derived from human papillomavirus, 24 hepatitis C virus, 25,26 human immunodeficiency virus, 27e29 and Epstein-Barr virus. 30e32 HLA-DQ5 is associated with a number of autoimmune disorders, such as myasthenia gravis, 33 juvenile rheumatoid arthritis, 34e36 and other diseases.…”

Depletion of tumor-associated macrophages enhances the anti-tumor immunity induced by a Toll-like receptor agonist-conjugated peptide

“…In our previous studies, we have identified the HLA-A11-restricted CTL epitopes of HPV 18, 52 and 58. [45][46][47] These long peptides could be synthesized with TLR2 agonist. The synthetic di-acyl lipopeptides are easy to manufacture for clinical used.…”