Genetically Modified Mouse Mesenchymal Stem Cells Expressing Non-Structural Proteins of Hepatitis C Virus Induce Effective Immune Response

Abstract

Hepatitis C virus (HCV) is one of the major causes of chronic liver disease and leads to cirrhosis and hepatocarcinoma. Despite extensive research, there is still no vaccine against HCV. In order to induce an immune response in DBA/2J mice against HCV, we obtained modified mouse mesenchymal stem cells (mMSCs) simultaneously expressing five nonstructural HCV proteins (NS3-NS5B). The innate immune response to mMSCs was higher than to DNA immunization, with plasmid encoding the same proteins, and to naïve unmodified MSCs. mMSCs triggered strong phagocytic activity, enhanced lymphocyte proliferation, and production of type I and II interferons. The adaptive immune response to mMSCs was also more pronounced than in the case of DNA immunization, as exemplified by a fourfold stronger stimulation of lymphocyte proliferation in response to HCV, a 2.6-fold higher rate of biosynthesis, and a 30-fold higher rate of secretion of IFN-γ, as well as by a 40-fold stronger production of IgG2a antibodies to viral proteins. The immunostimulatory effect of mMSCs was associated with pronounced IL-6 secretion and reduction in the population of myeloid derived suppressor cells (MDSCs). Thus, this is the first example that suggests the feasibility of using mMSCs for the development of an effective anti-HCV vaccine.

Review of the potential of mesenchymal stem cells for the treatment of infectious diseases

“…In a pre-clinical model, Liu et al [ 117 ] reported that transplantation of MSCs expressing short hairpin RNA against hepatitis viral proteins (HBV S and HBV X) significantly reduced HBV antigens in the liver and serum. Masalova et al [ 179 ] tested the efficacy of utilizing MSCs as an immunization agent against HCV and found that murine BM-MSCs expressing five non-structural HCV proteins induced significantly higher proliferation of lymphocytes, IFN-γ secretion, and IgG2a levels compared to naked DNA immunizations suggesting the feasibility of utilizing modified MSCs as vaccine agents. Hypoxic pre-conditioning also improves the migration, survival, and anti-inflammatory properties of MSCs[ 174 , 180 , 181 ].…”

Recent Trends in Multipotent Human Mesenchymal Stem/Stromal Cells: Learning from History and Advancing Clinical Applications

“…Some studies have shown that MSC-secreted factors can have anti-bacterial and anti-viral activities [193,194]. Indeed, several cytokines including IL-6, IL-10 and TNF-α have been shown to fluctuate during bacterial infection [195][196][197][198][199]. Meisel and colleagues demonstrated that MSCs stimulated by inflammatory cytokines display antimicrobial activities against several bacteria, protozoal parasites and viruses [193].…”

Difluoromethylornithine (DFMO), an Inhibitor of Polyamine Biosynthesis, and Antioxidant N-Acetylcysteine Potentiate Immune Response in Mice to the Recombinant Hepatitis C Virus NS5B Protein

“…Analysis of lymphocyte proliferation during treatment of the compounds was carried out as described previously [65]. Splenocytes were isolated from the mice, washed with the RPMI-1640 medium (Paneco, Moscow, Russia), and seeded onto 96-well plates at a density of 5 × 10 6 per well in the RPMI-1640 medium supplemented with 20% fetal calf serum (Invitrogen, Waltham, MA, USA), 2 mM glutamine, 4.5 mg/mL glucose, 50 µg/mL gentamycin, and 0.2 U/mL insulin.…”