Nanoparticle composed adjuvant employed in a vaccine against Bovine Respiratory Disease improves humoral immune response in a murine model

DÍAZ AM; ALMOZNI B; SÁNCHEZ-VALECILLO MF; MARÍN C; PALMA S; MALETTO B; CASTRO MS

Mar del Plata

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Inmunología; 2018

Sociedad Argentina de Inmunología

Bovine Respiratory Disease (BRD) is a multi-factorial disease that causes high morbidity and mortality in cattle. Pasteurella multocida (Pm) and Mannheimia haemolytica (Mh) are, among others, pneumonia-causing bacterial agents. Although BRD vaccines are worldwide employed, they do not always provide an adequate control of the pneumonic form of the disease. Consequently, it is recommendable the improvement of antigens and adjuvants to enhance their immunogenicity. Coagel is a liquid crystal nanostructure formed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16) that has been shown to promote high antigen-specific immune response. This work aimed to evaluate the action of Coagel as adjuvant in an experimental BRD vaccine, studying the humoral and cellular immune response specific for Pm and Mh.To this end, BALB/c mice (n:5/group) were immunized with heat-killed Pm-Coagel, heat-killed Mh-Coagel or a commercial BRD vaccine. Immunizations were performed on days 0, 15 and 27 by subcutaneous injection. Control group received PBS and Coagel. Blood samples were obtained on days 0, 10, 27 and day 38 when animals were sacrificed. Specific Pm and Mh antibody levels (IgG, IgG1, and IgG2a) were measured in sera, and cytokines (IL-2, IL-12) in spleen supernatants (ELISA).All immunized mice generated specific antibodies. Coagel immunized mice presented higher IgG levels for both bacteria compared with commercial vaccine immunized mice (p