Identification and characterization of peptides mimicking the epitopes of metalloprotease of Schistosoma japonicum.
In an attempt to isolate and characterize peptides mimicking epitopes of metalloprotease and explore their immunological protection against Schistosoma japonicum (S. japonicum), polyclonal anti-metalloprotease sera was prepared to screen a 12-mer random peptide library to isolate phages binding specially to antisera IgG. Then, phage ELISA, animal immunization, DNA sequencing, Western blotting and enzymatic activity neutralizing analysis were used to characterize the selected phage clones. All of ten randomly picked clones were shown to be positive. Five peptides of different amino acid sequences deduced from DNA sequences were obtained and two of them (peptides 2 and 3) could induce significant reduction (31.0% and 31.8%, respectively) in worm burden and high reduction (52.6% and 54.9%, respectively) in liver eggs per gram (LEPG), while, unexpectedly, others (peptides 1, 4 and 5) could not elicit enough protection against infection of S. japonicum. Peptides 2 and 3 could be recognized by S. japonicum infected mouse sera (IMS) and could elicit neutralizing Abs. The results show that peptides 2 and 3 are antigenic and immunogenic. They are true mimics of epitopes of metalloprotease and useful as novel vaccine candidates against S. japonicum.
Tang
Lianfei
L
Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha 410008, China.
Chen
Yuxiao
Y
Wang
Linqian
L
Zhang
Shunke
S
Zeng
Xianfang
X
Yi
Xinyuan
X
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D005780:Gelatin / Q000378:metabolism; D015151:Immunoblotting; D045726:Metalloproteases / Q000737:chemistry* / Q000276:immunology*; D051379:Mice; D018716:Molecular Mimicry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000276:immunology*; D012549:Schistosoma japonicum / Q000201:enzymology* / Q000276:immunology; D012554:Schistosomiasis japonica / Q000276:immunology / Q000517:prevention & control; D013379:Substrate Specificity; D014611:Vaccination
D000939:Epitopes; D010455:Peptides; D005780:Gelatin; D045726:Metalloproteases