Tick saliva contains a number of effector molecules that inhibit host immunity and facilitate pathogen transmission. How tick proteins regulate immune signaling, however, is incompletely understood. Here, we describe that loop 2 of sialostatin L2, an anti-inflammatory tick protein, binds to annexin A2 and impairs the formation of the NLRC4 inflammasome during infection with the rickettsial agent Anaplasma phagocytophilum Macrophages deficient in annexin A2 secreted significantly smaller amounts of interleukin-1β (IL-1β) and IL-18 and had a defect in NLRC4 inflammasome oligomerization and caspase-1 activation. Accordingly, Annexin a2-deficient mice were more susceptible to A. phagocytophilum infection and showed splenomegaly, thrombocytopenia, and monocytopenia. Providing translational support to our findings, better binding of annexin A2 to sialostatin L2 in sera from 21 out of 23 infected patients than in sera from control individuals was also demonstrated. Overall, we establish a unique mode of inflammasome evasion by a pathogen, centered on a blood-feeding arthropod.
- MeSH
- Anaplasma phagocytophilum genetika imunologie MeSH
- annexin A2 chemie genetika imunologie MeSH
- arachnida jako vektory chemie genetika imunologie MeSH
- cystatiny chemie genetika imunologie MeSH
- ehrlichióza imunologie mikrobiologie patologie MeSH
- Escherichia coli genetika metabolismus MeSH
- imunitní únik * MeSH
- inflamasomy genetika imunologie MeSH
- interleukin-18 genetika imunologie MeSH
- interleukin-1beta genetika imunologie MeSH
- kaspasa 1 genetika imunologie MeSH
- kaspasy genetika imunologie MeSH
- klíště chemie genetika imunologie MeSH
- lidé MeSH
- makrofágy imunologie mikrobiologie MeSH
- molekulární modely MeSH
- myši MeSH
- protein - isoformy chemie genetika imunologie MeSH
- proteiny regulující apoptózu chemie genetika imunologie MeSH
- proteiny vázající vápník chemie genetika imunologie MeSH
- regulace genové exprese MeSH
- rekombinantní proteiny chemie genetika imunologie MeSH
- sekvence aminokyselin MeSH
- signální transdukce MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
