Polymeric Caffeic Acid Acts as a Nasal Vaccine Formulation against Streptococcus pneumoniae Infections in Mice

Abstract

Infectious diseases are the second leading cause of death worldwide, highlighting the importance of the development of a novel and improved strategy for fighting pathogenic microbes. Streptococcus pneumoniae is a highly pathogenic bacteria that causes pneumonia with high mortality rates, especially in children and elderly individuals. To solve these issues, a mucosal vaccine system would be the best solution for the prevention and treatment of these diseases. We have recently reported that enzymatically polymerized caffeic acid (pCA) acts as a mucosal adjuvant when co-administered with antigenic proteins via the nasal route. Moreover, the sources of caffeic acid and horseradish peroxidase are ingredients found commonly in coffee beans and horseradish, respectively. In this study, we aimed to develop a pneumococcal nasal vaccine comprising pneumococcal surface protein A (PspA) and pCA as the mucosal adjuvant. Intranasal immunization with PspA and pCA induced the production of PspA-specific antibody responses in the mucosal and systemic compartments. Furthermore, the protective effects were tested in a murine model of S. pneumoniae infection. Intranasal vaccination conferred antigen-dependent protective immunity against a lethal infection of S. pneumoniae. In conclusion, pCA is useful as a serotype-independent universal nasal pneumococcal vaccine formulation.

Role of Interleukin-6 in the Antigen-Specific Mucosal Immunoglobulin A Responses Induced by CpG Oligodeoxynucleotide-Loaded Cationic Liposomes

“…Subsequently, the obtained samples were incubated for 1 h at 4 • C, and the serum samples were collected after centrifugation at 1200× g for 30 min. To monitor the induction of OVA-specific IgA in nasal washes, nasal wash samples (250 µL of cold PBS) were collected [18,19]. The samples were stored at -80 • C until further analysis.…”

Role of interleukin-6 in antigen-specific mucosal immunoglobulin A induction by cationic liposomes

“…The obtained samples were incubated for 1 h at 4 • C, and serum samples were collected after centrifugation at 1200 × g for 30 min. To monitor the induction of OVA-specific immunoglobulin A (IgA) in nasal washes, nasal wash samples (250 µL of cold PBS) were collected [20][21][22]. The samples were stored at − 80 • C until further analysis.…”

Polymeric Caffeic Acid Acts as an Antigen Delivery Carrier for Mucosal Vaccine Formulation by Forming a Complex with an Antigenic Protein

“…Recently, it was discovered that intranasal immunization with an antigenic protein and enzymatically polymerized caffeic acid (pCA) induced specific antibody responses in both systemic and mucosal compartments in mice. This makes pCA a promising mucosal adjuvant for nasal vaccines against infectious diseases [32][33][34]. However, the molecular mechanisms underlying pCA's mucosal adjuvant properties are still unclear.…”