Induction of a Strong HIV-Specific CD8⁺T Cell Response in Mice Using a Fowlpox Virus Vector Expressing an HIV-1 Multi-CTL-Epitope Polypeptide

Abstract

Recombinant avipoxvirus vectors are attractive candidates for use in vaccination strategies for infections such as human immunodeficiency virus type 1 (HIV-1), where induction of a CD8+ T cell response is thought to be an important component of protective immunity. Here, we report the expression of a multiepitope polypeptide (TAB9) composed of the central 15 amino acids of the V3 loop from six different isolates of HIV-1 in a fowlpox virus (FWPV) vector, and the use of this vector (FPTAB9LZ) to induce strong HIV-specific CD8+ T cell responses in mice. In animals immunized twice intravenously with FPTAB9LZ, almost 2% of the CD8+ T cells in the spleen were shown to produce IFN-gamma in response to stimulation with HIV-1 peptides 1 week after the second immunization. The most dominant response was to the HIV-1 IIIB peptide. A strong HIV-specific response was also induced by intraperitoneal immunization of mice with FPTAB9LZ, whilst subcutaneous immunization elicited a weaker response. Intraperitoneal immunization with FPTAB9LZ was also shown to provide protection against challenge with a recombinant vaccinia virus expressing antigens, including those in TAB9. These results confirm the potential of FWPV vectors for use in HIV vaccination strategies.

Recombinant Leishmania Tarentolae Encoding the HPV Type 16 E7 gene in Tumor Mice Model

“…In one recent study, mucosal co-administration of live Lactococcus lactis expressing E7 and IL-12 showed full antitumor protection and prolonged immunity [54]. Moreover, in a number of related studies, the intraperitoneal immunization of different live vaccines has also demonstrated strong protection against HPV-associated or other infections [33,56,57]. As demonstrated in several studies, sc.…”

Reduced Virus Load in Lungs of Pigs Challenged with Porcine Reproductive and Respiratory Syndrome Virus after Vaccination with Virus Replicon Particles Encoding Conserved PRRSV Cytotoxic T-Cell Epitopes

“…Several examples already exist for other viruses where replicon-or viral vector-based vaccines expressing transgenic single epitopes or polyepitopes were capable of inducing a CTL response. In many cases, protective immunity upon challenge has even been successfully established [46][47][48][49]. The CSF-VRP, like the virus they are derived from, have a tropism for dendritic cells (DC) and both conventional DCs (cDC) and plasmacytoid DCs (pDC) are early targets for the virus [29].…”