Protective Effect against Neosporosis Induced by Intranasal Immunization with Neospora caninum Membrane Antigens Plus Carbomer-Based Adjuvant

Abstract

Neospora caninum is an obligate intracellular protozoan responsible for abortion and stillbirths in cattle. We previously developed a mucosal vaccination approach using N. caninum membrane proteins and CpG adjuvant that conferred long-term protection against neosporosis in mice. Here, we have extended this approach by alternatively using the carbomer-based adjuvant Carbigen™ in the immunizing preparation. Immunized mice presented higher proportions and numbers of memory CD4+ and CD8+ T cells. Stimulation of spleen, lungs and liver leukocytes with parasite antigens induced a marked production of IFN-γ and IL-17A and, less markedly, IL-4. This balanced response was also evident in that both parasite-specific IgG1 and IgG2c were raised by immunization, together with specific intestinal IgA. Upon intraperitoneal infection with N. caninum, immunized mice presented lower parasitic burdens than sham-immunized controls. In the infected immunized mice, memory CD4+ T cells predominantly expressed T-bet and RORγt, and CD8+ T cells expressing T-bet were found increased. While spleen, lungs and liver leukocytes of both immunized and sham-immunized infected animals produced high amounts of IFN-γ, only the cells from immunized mice responded with high IL-17A production. Since in cattle both IFN-γ and IL-17A have been associated with protective mechanisms against N. caninum infection, the elicited cytokine profile obtained using CarbigenTM as adjuvant indicates that it could be worth exploring for bovine neosporosis vaccination.

Protective efficacy of intranasal inactivated pseudorabies vaccine is improved by combination adjuvant in mice

“…These effects were found to be successful in opening epithelial tight junctions and establishing paracellular transport. Not only PAA but also its commercial derivatives (Carbopol ® and Carbomer ® ) exhibit strong mucoadhesion and absorption-promotion ( Gasper et al, 2016 ; Chen et al, 2019 ; Correia et al, 2022 ). MONTANIDE™ Gel 01 is a hydrogel polymer of sodium polyacrylate, which is also a commercial derivative of PAA.…”

“…Gel 01 is based on a dispersion of highly stable gel particles of sodium polyacrylate in water. Polyacrylic acid and commercial derivatives (Carbopol ® and Carbomer ® ) have been reported and used as effective mucoadhesive and absorption-promoting agents ( Gasper et al, 2016 ; Chen et al, 2019 ; Correia et al, 2022 ). The adjuvant CVCVA5 (VA5), which holds a Chinese patent license with the registered number 201210235427.0, improved the efficacy of both the serum and mucosal antibody response and the cell-mediated immune response of inactivated vaccine ( Tang et al, 2014 ; Lu et al, 2016 ; Wu et al, 2017 ).…”