Pharmaceutical compositions comprising dengue virus-specific multiple HLA-binding T cell epitopes

Inventors

Philip, Ramila

Assignees

Emergex Vaccines Holding Ltd

Abstract

Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF) are significant global public health problems and understanding the overall immune response to infection will contribute to appropriate management of the disease and its potentially severe complications. Live attenuated and subunit vaccine candidates, which are under clinical evaluation, induce primarily an antibody response to the virus and minimal cross-reactive T cell responses. Currently, there are no available tools to assess protective T cell responses during infection or post vaccination. Herein, we report novel, naturally processed and presented MHC class I restricted epitopes, a subset of which binds to and activates T cells in both an HLA-A2 and HLA-A24 restricted manner. We show that epitope specific T cells can be activated in vivo in transgenic mice and in vitro in seropositive and seronegative individuals and that these T cells are functional, recognizing peptide pulsed and dengue virus infected cells in a pro-inflammatory and cytotoxic manner. These epitopes have potential as new informational and diagnostic tools to characterize T cell immunity in Dengue virus (DV) infection, and may serve as a universal vaccine candidate complementary to current vaccines in trial.

Core Innovation

The disclosed subject matter relates to dengue virus immunogenicity at the level of naturally processed MHC class I epitopes and identifies HLA-A2 and/or HLA-A24 restricted CD8 T cell epitopes. An immunoproteomic workflow is used to isolate MHC class I peptides from infected cells and to identify epitopes by LC-MS/MS. The identified epitopes are presented as epitopic peptide sequences.

The disclosure reports functional immunogenicity of identified epitopes using cytotoxic T lymphocyte activation. Dual-binding and/or promiscuous epitopes are described as capable of activating CTLs in vitro. Immune responses are discussed in seropositive and seronegative individuals, and robust CTL responses are described in HLA-A2 transgenic mice against peptide-pulsed and DENV-infected targets.

The disclosure further describes immunogens and pharmaceutical compositions that incorporate DV epitopic peptides corresponding to SEQ ID NOs 1 to 16. These compositions include peptide/carrier conjugates linked directly or through a spacer or linker, and are described in connection with broader vaccine and diagnostic or screening use, including CTL-based screening or diagnostic tools and tetramer or pentamer approaches.

Claims Coverage

The provided material includes one independent claim. The claim covers one composition framework defined by an 8 to 50 amino acid residue peptide containing a selected epitopic peptide sequence from specified SEQ ID NOs, linked to an immunogenic carrier either directly or through a spacer or linker. Inventive features are therefore centered on peptide length, restriction to selected epitopic sequences, and carrier or spacer linkage.

Across the independent claim, the core coverage is a pharmaceutical composition containing a defined-length peptide that includes an epitopic peptide sequence selected from specified SEQ ID NOs and that is configured as a conjugate with an immunogenic carrier via direct attachment or a spacer or linker.

Stated Advantages

Documented Applications