Influenza antigen-sparing by immune stimulation with Gram-positive enhancer matrix (GEM) particles.

Abstract

Gram-positive enhancer matrix (GEM) particles, produced from non-genetically modified Lactococcus lactis bacteria have an inherent immunostimulatory activity. It was investigated whether co-administration of GEM particles can reduce the amount of influenza subunit vaccine (HA) necessary to protect mice from viral infection. Decreasing HA amounts of 5, 1, 0.2 and 0.04μg admixed with GEM particles were tested in intramuscular immunizations. Combinations of GEM and seasonal HA (A/Wisconsin/67/2005 [H3N2]) induced significantly higher systemic and better Th1/Th2-type balanced immune responses than HA alone. Addition of GEM to 0.04μg HA resulted in similar HI titers as 1-5μg non-adjuvanted HA. To test the protective efficacy of the adjuvanted combination, mice were immunized with influenza subunit vaccine A/PR/8/34 (H1N1) and then challenged with live virus (A/PR/8/34). Mice immunized with 1μg HA+GEM showed undetectable virus titers in the lungs 5 days after challenge, whereas mice immunized with 1μg HA alone showed detectable levels of virus in the lungs. Interestingly, mice vaccinated with the 0.04μg HA+GEM vaccine demonstrated reduced lung virus titers and a reduction in weight that was similar as that in mice vaccinated with 1μg non-adjuvanted HA. These results indicate that the use of GEM as immunostimulant allows for a strong reduction in the antigen dose as compared to the benchmark vaccine by using GEM particles. Thus, addition of GEM can strongly potentiate immunogenicity of influenza subunit vaccine both quantitatively and qualitatively.

• Authors: V Saluja, M R Visser, W Ter Veer, M L van Roosmalen, K Leenhouts, W L J Hinrichs, A Huckriede, H W Frijlink
• Journal: Vaccine (Vaccine) Vol. 28 Issue 50 Pg. 7963-9 (Nov 23 2010) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 20946860 (Publication Type: Journal Article)
• Copyright: Copyright © 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Adjuvants, Immunologic
• Antibodies, Viral
• Hemagglutinin Glycoproteins, Influenza Virus
• Influenza Vaccines
• Vaccines, Subunit

Topics

• Adjuvants, Immunologic (chemistry)
• Animals
• Antibodies, Viral (blood)
• Dose-Response Relationship, Immunologic
• Hemagglutination Tests
• Hemagglutinin Glycoproteins, Influenza Virus (immunology)
• Immunization
• Influenza A Virus, H1N1 Subtype (immunology)
• Influenza A Virus, H3N2 Subtype (immunology)
• Influenza Vaccines (administration & dosage, immunology)
• Injections, Intramuscular
• Lactococcus lactis (chemistry)
• Lung (virology)
• Mice
• Mice, Inbred BALB C
• Orthomyxoviridae Infections (immunology, prevention & control)
• Vaccines, Subunit (administration & dosage, immunology)
• Viral Load