5th Asia-Pacific Summit on Cancer Therapy
University of Queensland, Australia
Title: Using layered double hydroxides nanoparticle conjugated with CpG to polarise immune responses from Th2 to Th1 bias
Biography: Zhi Ping Xu
Vaccine is one of the promising treatments in cancer therapy. Modulation of immune response is very important in the induction of humoral or cellular immunity, which will affect vaccine efficiency. Here we have tailored an anionic clay nanomaterial to specifically load the model antigen obalbumin (OVA) and the toll-like receptor ligand CpG in combination to modulate the immune response from Th2 bias towards the preferred polarity Th1 for anti-cancer purpose. Alum is a vaccine adjuvant approved for human use by FDA, while it has a severe inflammatory response and cannot modulate the immune response. The anionic clay, MgAl-layered double hydroxide (LDH) nanomaterial, has a similar chemical composition to Alum, but distinct properties. For example, MgAl-LDH nanoparticles can strongly interact with and carry proteins and gene materials for cellular delivery. In this research, using MgAl-LDH to carry OVA induced a comparable antibody response to Alum. In sharp contrast, combination of CpG to LDH-OVA resulted in much higher IgG2a:IgG1 ratio than that in the case of Alum, demonstrating polarisation of the immune response from Th2 towards Th1. Moreover, CpG-OVA-loaded LDH retarded tumour growth in vivo, further confirming LDH-CpG adjuvant activity. Therefore, MgAl-LDH nanomaterial has the great potency to be a vaccine adjuvant for switching Th2 to Th1 dominant immune responses.