TY - JOUR
T1 - Identification and partial characterization of a gut Rhipicephalus appendiculatus cystatin
AU - Imamura, Saiki
AU - Konnai, Satoru
AU - Yamada, Shinji
AU - Parizi, Luís F.
AU - Githaka, Naftaly
AU - Vaz, Itabajara da S.
AU - Murata, Shiro
AU - Ohashi, Kazuhiko
N1 - Funding Information:
This work was supported by grants from the Ministry of Science, Culture and Education and JSPS (Japan).
PY - 2013/2
Y1 - 2013/2
N2 - Vaccines are among the alternative tick control methods expected to replace at least in part the volumes of chemical acaricides currently used worldwide. However, a vaccination approach depends on a host immune response against proteins that are essential to tick physiology. The cystatin family is a protein class recently investigated to compose an effective antigen in a tick vaccine. In this study, a cDNA from Rhipicephalus appendiculatus with high sequence similarity to cystatins type 2 was identified by random sequencing analysis and called R. appendiculatus cystatin 1 (Ra-cyst-1). DNA sequence analysis showed that the cloned Ra-cyst-1 has a 423-bp open reading frame and codified to a 140-amino acid polypeptide. The putative mature protein consists of 115 amino acid residues with a deduced molecular weight of 12.8. kDa. The highly conserved G (P-I), QxVxG (P-II), and PW (P-III) type 2 cystatins motifs are present in Ra-cyst-1 cDNA. RT-PCR analysis showed that the Ra-cyst-1 gene is expressed in nymph, male, and female midgut following blood feeding, but not in the salivary glands of fed females. In addition, Western blot revealed that recombinant Ra-cyst-1 was not recognized by sera derived from rabbits infested with ticks, suggesting that this cystatin is not secreted into the host during infestation. We hypothesize that Ra-cyst-1 may play a role in the tick feeding process and could be a concealed antigen candidate in further anti-tick vaccination trials.
AB - Vaccines are among the alternative tick control methods expected to replace at least in part the volumes of chemical acaricides currently used worldwide. However, a vaccination approach depends on a host immune response against proteins that are essential to tick physiology. The cystatin family is a protein class recently investigated to compose an effective antigen in a tick vaccine. In this study, a cDNA from Rhipicephalus appendiculatus with high sequence similarity to cystatins type 2 was identified by random sequencing analysis and called R. appendiculatus cystatin 1 (Ra-cyst-1). DNA sequence analysis showed that the cloned Ra-cyst-1 has a 423-bp open reading frame and codified to a 140-amino acid polypeptide. The putative mature protein consists of 115 amino acid residues with a deduced molecular weight of 12.8. kDa. The highly conserved G (P-I), QxVxG (P-II), and PW (P-III) type 2 cystatins motifs are present in Ra-cyst-1 cDNA. RT-PCR analysis showed that the Ra-cyst-1 gene is expressed in nymph, male, and female midgut following blood feeding, but not in the salivary glands of fed females. In addition, Western blot revealed that recombinant Ra-cyst-1 was not recognized by sera derived from rabbits infested with ticks, suggesting that this cystatin is not secreted into the host during infestation. We hypothesize that Ra-cyst-1 may play a role in the tick feeding process and could be a concealed antigen candidate in further anti-tick vaccination trials.
KW - Anti-tick vaccine
KW - Cystatin
KW - Rhipicephalus appendiculatus
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U2 - 10.1016/j.ttbdis.2012.11.001
DO - 10.1016/j.ttbdis.2012.11.001
M3 - Article
C2 - 23265949
AN - SCOPUS:84872607524
VL - 4
SP - 138
EP - 144
JO - Ticks and Tick-borne Diseases
JF - Ticks and Tick-borne Diseases
SN - 1877-959X
IS - 1-2
ER -
