Sporotrichosis is a cosmopolitan mycosis caused by pathogenic species of Sporothrix genus, that in Brazil is often acquired by zoonotic transmission involved infected cats with S. brasiliensis. Previous studies showed that the Sporothrix spp. recombinant
enolase (rSsEno), a multifunctional
protein with immunogenic properties, could be a promising target for vaccination against
sporotrichosis in cats. Nevertheless, the considerable sequence identity (62%) of SsEno with its feline counterpart is a great concern. Here, we report the identification in silico, chemical synthesis and biological validation of six
peptides of SsEno with low sequence identity to its cat orthologue. All synthesized
peptides exhibit
B-cell epitopes on the molecular surface of SsEno and proved to be highly reactive with the serum of infected mice with S. brasiliensis and sera of cats with
sporotrichosis. Interestingly, our study revealed that anti-
peptide sera did not react with the recombinant
enolase from Felis catus (cats, rFcEno), thus, may not trigger autoimmune response in these felines if used as a
vaccine antigen. The immunization with
peptide mixture (PeptMix) formulated with
Freund adjuvant (FA), induced high levels of
antigen-specific
IgG,
IgG1 and
IgG2b antibodies that conferred protection upon passive transference in infected BALB/c mice with S. brasiliensis. We also observed, that the FA+PeptMix formulation induced a Th1/Th2/Th17
cytokine profile ex vivo, associated with protecting effect against the experimental
sporotrichosis. Our results suggest that the six SsEno-derived
peptides here evaluated, could be used as safe
antigens for the development of
vaccine strategies against feline
sporotrichosis, whether prophylactic or therapeutic.