Functional Aspects of Intrahepatic Hepatitis B Virus-specific T Cells Induced by Therapeutic DNA Vaccination

Abstract

Current therapies for the hepatitis B virus (HBV), a major cause of severe liver disease, suppress viral replication but replication rebounds if therapy is withdrawn. It is widely accepted that immune activation is needed to control replication off-therapy. To specifically activate T cells crossreactive between the hepatitis B core and e antigens (HBcAg/HBeAg) in chronically infected patients, we developed a therapeutic vaccine candidate. The vaccine encompass codon-optimized HBcAg and IL-12 expressing plasmids delivered using targeted high-pressure injection combined with in vivo electroporation. One dose of the vaccine primed a B-cell-independent polyfunctional T-cell response, in wild-type, and in HBeAg-transgenic mice with an impaired ability to respond to HBc/eAg. The response peaked at 2 weeks and contracted at week 6 after vaccination. Coadministration of IL-12 improved antibody levels, and T-cell expansion and functionality. The vaccine primed T cells that, 2 weeks after a single dose, cleared hepatocytes transiently expressing HBcAg in vaccinated wild-type and HBeAg-transgenic mice. However, 4 weeks later, these functional responses were lost. Booster doses after 8–12 weeks effectively restored function and expansion of the rapidly contracting T cells. Thus, this vaccine strategy primes functional HBcAg-specific T cells in a host with dysfunctional response to HBV.

Blocking Entry of Hepatitis B and D Viruses to Hepatocytes as a Novel Immunotherapy for Treating Chronic Infections

“…To evaluate the immunogenicity of the constructs in vivo, mice and rabbits were immunized essentially as described [ 25 , 30–32 ], boosted at monthly intervals, and sacrificed 2 weeks later for spleens and blood collection. In brief, female C57BL/6 mice (5 per group) were immunized intramuscularly in the tibialis cranialis anterior muscle with 50 μg plasmid DNA in a volume of 50 μL in sterile phosphate-buffered saline (PBS) by regular needle (27G) injection followed by in vivo electroporation using a Cliniporator 2 device (IGEA).…”

A targeted controlled force injection of genetic material in vivo

“…We have previously shown that in vivo ET greatly improves transfection efficacy and immunogenicity of DNA vaccines. 11–13 We first evaluated whether different pulse pattern for the in vivo ET had an impact on the transfection efficacy and immune activation. A high–low pulse combination pattern induced a high transfection rate, influx of CD3+ cells, and a strong T-cell response.…”

“…in the tibialis cranialis muscle once with doses of 50, 20, or 5 μg plasmid DNA ( e.g. , coNS3/4A-pVAX1 or C2.2-pVAX1-pVAX1) alone or in combination with 5 μg mIL-12-pORF1 12 in a volume of 30 μl using the IVIN or regular needle injection. Immediately following administration of the plasmid DNA, tibialis cranialis muscles were subsequently electrotransferred using the Cliniporator 2 device (IGEA) with two 60 ms 246 V/cm pulses or 1 ms 600 V/cm pulse followed by a 400 ms 60 V/cm pulse pattern.…”

Functional differences in hepatitis C virus nonstructural (NS) 3/4A- and 5A-specific T cell responses

“…Groups of mice were immunized by the intramuscular (i.m.) route using a regular needle or using the in vivo intracellular injection device (IVIN) 45 . All immunizations were performed in the left tibialis cranialis muscle.…”