Ixodes ricinus tick salivary gland extract inhibits IL-10 secretion and CD69 expression by mitogen-stimulated murine splenocytes and induces hyporesponsiveness in B lymphocytes

Sigrid Hannier, Janet Mary Liversidge, Jeremy M Sternberg, Alan Stuart Bowman (Corresponding Author)

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

Tick saliva contains immunosuppressive factors allowing this blood-feeding ectoparasite to remain on hosts and enhancing pathogen transmission. In this study, we examined the modulation of mitogen-induced activation of naive murine splenocytes by the saliva and salivary gland extract (SGE) of I. ricinus ticks. We found that saliva-specific factors reduced IL-10 production by both concanavalin A (ConA) and lipopolysaccharide (LPS) stimulated splenocytes. The LPS-induced IL-10 production is 10 times more sensitive to SGE than the ConA-induced IL-10 production. Flow cytometric analysis determined that SGE particularly inhibited B (B220 (+) ) cell IL-10 production in mitogen-stimulated splenocyte preparations. Moreover, SGE reduced the early activation marker CD69 expression on ConA-activated T cells and also on B cells in presence of ConA or LPS. Annexin V and Via-probe staining demonstrated that SGE did not increase cell death in activated splenocytes and slightly decreased apoptosis in B lymphocytes. By employing assays with isolated B cells, we further showed that SGE had a direct effect on B cells and inhibited LPS-induced B cell proliferation. Taken together, our results indicate that salivary immunomodulators induce hyporesponsiveness to mitogen in both T and B cells, and that a direct B-cell inhibitory activity is present in tick saliva.

Original languageEnglish
Pages (from-to)27-37
Number of pages10
JournalParasite Immunology
Volume25
Issue number1
DOIs
Publication statusPublished - Jan 2003

Keywords

  • B lymphocytes
  • IL-10
  • immunosuppression
  • Ixodes ricinus
  • salivary glands
  • tick
  • LYME-DISEASE VECTOR
  • BORRELIA-BURGDORFERI
  • IN-VITRO
  • IFN-GAMMA
  • CYTOKINE PRODUCTION
  • CELL ACTIVATION
  • IMMUNE-RESPONSE
  • BALB/C MICE
  • SCAPULARIS
  • PROTEIN

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