Influenza Inactive Virus Vaccine with the Fusion Peptide (rTα1- BP5) Enhances Protection Against Influenza Through Humoral and Cell-Mediated Immunity

Abstract

Thymosin α1 (Tα1) and Bursopentin (BP5) are both immunopotentiators. To explore whether the thymosin α1-Bursopentin (rTα1-BP5) is an adjuvant or not, we cloned the gene of Tα1-BP5 and provided evidence that the gene of Tα1-BP5 in a recombinant prokaryotic expression plasmid was successfully expressed in Escherichia coli BL21. To evaluate the immune adjuvant properties of rTα1-BP5, chickens were immunized with rTα1-BP5 combined with H9N2 avian influenza whole-inactivated virus (WIV). The titers of HI antibody, antigen-specific antibodies, Avian influenza virus (AIV)-neutralizing antibodies, levels of Th1-type cytokines (gamma interferon (IFN-γ)) and Th2-type cytokines (interleukin 4 (IL-4)), and lymphocyte proliferation responses were determined. We found that rTα1-BP5 enhanced HI antibody and antigen-specific immunoglobulin G (IgG) antibodies titers, increased the level of AIV-neutralizing antibodies, induced the secretion of Th1-and Th2-type cytokines, and promoted the proliferation of T and B lymphocyte. Furthermore, virus challenge experiments confirmed that rTα1-BP5 contributed to the inhibition replication of the virus (H9N2 AIV (A/chicken/ Jiangsu/NJ07/05) from chicken lungs. Altogether, these findings suggest that rTα1-BP5 is a novel adjuvant suitable for H9N2 avian influenza vaccine.

COVID-19 Therapeutic Options Under Investigation

“…It has an antineoplastic activity and is used as an anticancer treatment (Billich, 2002;Maio et al, 2010). It was used as an adjuvant with influenza (H1N1pdm09 and H9N2) vaccines to boost the immune response and the vaccine efficacy (Carraro et al, 2012;Wang C. et al, 2016). It is also approved in some countries for the treatment of chronic viral infections such as hepatitis B and C (Andreone et al, 2001;Kullavanuaya et al, 2001;Iino et al, 2005).…”