Rmcystatin3, a cysteine protease inhibitor from Rhipicephalus microplus hemocytes involved in immune response.
Biochimie
; 106: 17-23, 2014 Nov.
Article
in En
| MEDLINE
| ID: mdl-25064361
ABSTRACT
The Rhipicephalus microplus tick is responsible for losses in the livestock production estimated in 2 billions USD. Despite its economical importance the knowledge in tick's physiology is sparse. In order to contribute to this scenario we describe the characterization of a cysteine proteinase inhibitor named Rmcystatin-3. Purified recombinant Rmcystatin-3 was able to inhibit cathepsin L (Ki = 2.5 nM), BmCl1 (Ki = 1.8 nM) and cathepsin B (Ki = 136 nM). Western blot and quantitative PCR analysis revealed the presence of Rmcystatin-3 in fat body, salivary gland but mainly in hemocytes. The mRNA levels of Rmcystatin-3 during bacterial challenge are drastically down-regulated. In order to define the Rmcystatin-3 possible role in tick immunity, the cystatin gene was knockdown by RNA interference with and without Escherichia coli infection. Our results showed that the Rmcystatin-3 silenced group was more immune competent to control bacterial infection than the group injected with non-related dsRNA. Taking together, our data strongly suggested an important role of Rmcystatin-3 in tick immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cysteine Proteinase Inhibitors
/
Rhipicephalus
/
Disease Resistance
/
Hemocytes
Limits:
Animals
Language:
En
Journal:
Biochimie
Year:
2014
Document type:
Article
Affiliation country:
Brazil