A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine

Abstract

Please cite this paper as: Svindland et al. (2012) A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine. Influenza and Other Respiratory Viruses 10.1111/irv.12056000(000), 000–000. Background Highly pathogenic avian influenza A/H5N1 virus remains a potential pandemic threat, and it is essential to continue vaccine development against this subtype. A local mucosal immune response in the upper respiratory tract may stop influenza transmission. It is therefore important to develop effective intranasal pandemic influenza vaccines that induce mucosal immunity at the site of viral entry. Objectives We evaluated the humoral and cellular immune responses of two promising mucosal adjuvants (Chitosan and c‐di‐GMP) for intranasal influenza H5N1 vaccine in a murine model. Furthermore, we evaluated the concept of co‐adjuvanting an experimental adjuvant (c‐di‐GMP) with chitosan. Methods BALB/c mice were intranasally immunised with two doses of subunit NIBRG‐14 (H5N1) vaccine (7·5, 1·5 or 0·3 μg haemagglutinin (HA) adjuvanted with chitosan (CSN), c‐di‐GMP or both adjuvants. Results All adjuvant formulations improved the serum and local antibody responses, with the highest responses observed in the 7·5 μg HA CSN and c‐di‐GMP‐adjuvanted groups. The c‐di‐GMP provided dose sparing with protective single radial haemolysis (SRH), and haemagglutination inhibition (HI) antibody responses found in the 0·3 μg HA group. CSN elicited a Th2 response, whereas c‐di‐GMP induced higher frequencies of virus‐specific CD4+ T cells producing one or more Th1 cytokines (IFN‐γ+, IL‐2+, TNF‐α+). A combination of the two adjuvants demonstrated effectiveness at 7·5 μg HA and triggered a more balanced Th cytokine profile. Conclusion These data show that combining adjuvants can modulate the Th response and in combination with ongoing studies of adjuvanted intranasal vaccines will dictate the way forward for optimal mucosal influenza vaccines.

Induction of Local Secretory IgA and Multifunctional CD4+ T‐helper Cells Following Intranasal Immunization with a H5N1 Whole Inactivated Influenza Virus Vaccine in BALB/c Mice

“…This was verified further by the detection of (IL‐2 and TNF‐ α ) double‐producing multifunctional Th1 CD4 + cells that were significantly higher in the intranasal group, while (IFN‐ γ , IL‐2 and TNF‐ α ) multifunctional Th1 CD4 + cells were present in comparable amounts in both the intranasal and intramuscular group. This is consistent with our previous reports, where multifunctional Th1 CD4 + cells were detected in response to a c‐di‐GMP‐adjuvanted H5N1 influenza vaccine administered intranasally, intramuscularly and sublingually . Moreover, we have also shown that a virosomal H5N1 influenza vaccine induces a balanced Th1/Th2 profile both in mice and in humans, when adjuvanted with Matrix‐M .…”

In Vivo Synthesis of Cyclic-di-GMP Using a Recombinant Adenovirus Preferentially Improves Adaptive Immune Responses against Extracellular Antigens

“…These results parallel recent studies evaluating the beneficial effects of direct administration of c-di-GMP as an adjuvant during vaccination with OVA (49, 50), and 4-Hydroxy-3-nitrophenylacetyl-Chicken Gamma Globulin, NP-CGG, in which c-di-GMP was shown to have the capacity to enhance germinal center (GC) development (67). Additionally, the presence of c-di-GMP in an adjuvant formulation containing chitosan (CSN) improved adaptive immune responses to H5N1 antigens (16), and (along with a conventional aluminum salt-based adjuvant) improved adaptive immune responses specific to the hepatitis B surface antigen (HBsAg) (67). Recently, it was demonstrated that nasal administration of c-di-GMP significantly increases the MYPS-mediated uptake of OVA antigen via endocytosis and pinocytosis in vivo .…”

“…The direct administration of c-di-GMP has been shown to induce innate immune responses that can enhance protection of mice against challenges with Klebsiella pneumoniae (10), Staphylococcus aureus (11), methicillin-resistant S. aureus (MRSA) (12), Bordetella pertussis (13), Streptococcus pneumoniae (14), and avian influenza A/H5N1 (15, 16). Specifically, following intranasal challenge with B. pertussis in BALB/c mice, c-di-GMP induced production of cytokines such as IFN-γ, TNF-α, IL-6, and the chemokine MCP-1 in lung tissue (13).…”

Chitosan Nanoparticle Encapsulated Hemagglutinin-Split Influenza Virus Mucosal Vaccine

“…It served as an immunopotentiating agent to augment vaccine immunogenicity and effectiveness (23). Besides, annotated data have demonstrated that the CS nanoparticles induced both mucosal and systemic immune responses to the entrapped antigen after intranasal administration (24,25). In this study, a split influenza vaccine containing hemagglutinin of H1N1 virus formulated with CS nanoparticles was administered intranasally.…”