Comparative efficacy and toxicity of two vaccine candidates against Sporothrix schenckii using either Montanide™ Pet Gel A or aluminum hydroxide adjuvants in mice

Abstract

Sporotrichosis is an important zoonosis in Brazil and the most frequent subcutaneous mycosis in Latin America, caused by different Sporothrix species. Currently, there is no effective vaccine available to prevent this disease. In this study, the efficacy and toxicity of the adjuvant Montanide™ Pet Gel A (PGA) formulated with S. schenckii cell wall proteins (ssCWP) was evaluated and compared with that of aluminum hydroxide (AH). Balb/c mice received two subcutaneous doses (1st and 14th days) of either the unadjuvanted or adjuvanted vaccine candidates. On the 21st day, anti-ssCWP antibody levels (ELISA), the phagocytic index, as well as the ex vivo release of IFN-γ, IL-4, and IL-17 by splenocytes and IL-12 by peritoneal macrophages were assessed. Cytotoxicity of the vaccine formulations was evaluated in vitro and by histopathological analysis of the inoculation site. Both adjuvanted vaccine formulations increased anti-ssCWP IgG, IgG1, IgG2a, and IgG3 levels, although IgG2a levels were higher in response to PGA+CWP100, probably contributing to the increase in S. schenckii yeast phagocytosis by macrophages in the opsonophagocytosis assay when using serum from PGA+CWP100-immunized mice. Immunization with AH+CWP100 led to a mixed Th1/Th2/Th17 ex vivo cytokine release profile, while PGA+CWP100 stimulated a preferential Th1/Th2 profile. Moreover, PGA+CWP100 was less cytotoxic in vitro, caused less local toxicity and led to a similar reduction in fungal load in the liver and spleen of S. schenckii- or S. brasiliensis-challenged mice as compared with AH+CWP100. These results suggest that PGA may be an effective and safe adjuvant for a future sporotrichosis vaccine.

Immunization with recombinant enolase ofSporothrixspp (rSsEno) confers effective protection against sporotrichosis in mice

“…However, the higher virulence of S. brasiliensis caused a long-lasting infection associated with severe tissue lesions that stimulated a regulatoryT cell (Tregs) response with deleterious effects on the Th1 and Th1/Th17 response, although a compensatory Th17 response was induced 50 . We also demonstrated in an immunoprophylaxis study in BALB/c mice that either aluminum hydroxide adjuvant or PGA, both formulated with the Ss16345-WCP containing the immunoreactive enolase, induced a Th1, Th2 and Th17 profile, in addition to high stimulation of specific antibodies that conferred protection in these animals after challenge with Ss16345 or Ss250 20 .…”

“…Several studies have shown that the IgG antibody response 44,45 and especially IgG1 46,47 , IgG2a and IgG3 isotypes 19,20 against the S. schenckii and S. brasiliensis cell wall proteins is associated with protection against progressive infection. Our results showed that rSsEno100 and PGA+rSsEno100 stimulated a Th2 (IgG1 and IgG3) and Th1/Th2 (IgG1, IgG2a and IgG3) immune response, respectively.…”

Protective efficacy of inactivated reverse genetics based equine influenza vaccine candidate adjuvanted with Montanide^TM Pet Gel in murine model

“…The MPG adjuvant has been shown to influence the increase in antibody response of inactivated Rhodococcus equi vaccine in horses without any adverse effect [7]. Recent studies investigating a vaccine against Sporothrix schenckii observed significantly higher antibody production in mice immunized with MPG adjuvanted cell wall protein or recombinant enolase protein [22,29]. Cytokine profiling showed a surge in IFN- , IL-2, IL-4, IL-6, IL-10…”

“…Switching from conventional adjuvants such as alum to novel adjuvants can aid in long lasting cell mediated immunity (CMI) [22] as well as humoral immune response [4,7]. The Montanide TM Pet Gel (MPG) (SEPPIC, Paris, France) is a highly stable microspherical polymer [7] which provides depot effect to the antigen and has been used in many vaccine formulations, including vaccines against influenza viruses [6].…”

Caracterização e avaliação da capacidade protetora dos peptí­deos imunogênicos de <i>Sporothrix brasiliensis</i>

“…A resposta Th1 é caracterizada pela produção de IFN-, que aumenta a atividade microbicida de macrófagos, sendo a citocina mais importante na proteção contra a esporotricose (UENOTSUCHI et al, 2006). As células Th17 estão envolvidas no recrutamento de neutrófilos e são importante contra infecções fúngicas (ROMANI, 2011;MARCOS et al, 2016 PORTUONDO et al, 2017). Na blastomicose, um tetrâmero foi utilizado como adjuvante em um modelo de vacina protetor na doença (WÜTHRICH et al, 2015).…”