Coinfection with Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis suppresses IL-2 and IFN gamma production and promotes an IL-4 response in C3H/HeJ mice

Parasite Immunol. 2000 Nov;22(11):581-8. doi: 10.1046/j.1365-3024.2000.00339.x.


Previously we demonstrated that Borrelia burgdorferi transmission by Ixodes scapularis suppressed IL-2 and IFN gamma production and promoted IL-4 production in mice. The present studies were conducted to determine whether coinfection with the human granulocytic ehrlichiosis (HE) agent would promote a Th2 cytokine response in mice. Transmission to the spleen of the agent of human granulocytic ehrlichiosis (aoHGE) and B. burgdorferi occurred 4 and 7 days, respectively, after tick infestation. Coinfection synergized to suppress splenic IL-2 production 7-14 days after tick infestion. Transmission of B. burgdorferi or aoHGE alone significantly decreased splenic IFN gamma 4-7 days after tick infestation, while coinfection suppressed IFN gamma production 7-14 days after tick infestation. Splenic IL-4 production was significantly increased 4 days after coinfection, and by day 10, aoHGE plus B. burgdorferi induced greater splenic IL-4 (57.2 pg/ml, 348% of control values) than either organism transmitted alone (aoHGE, 22.7 pg/ml, B. burgdorferi, 25.1 pg/ml). Coinfection enhanced expansion of splenic T cells, CD4+ lymphocytes and B cells while decreasing CD8+ T cells. These data demonstrate that aoHGE and B. burgdorferi, when cotransmitted, suppress a systemic IL-2 and IFN gamma response, while strongly promoting systemic IL-4 production in the susceptible host. The antigen(s) responsible for this polarization are unknown and will be the subject of future studies.

MeSH terms

  • Animals
  • Borrelia burgdorferi Group / genetics
  • Borrelia burgdorferi Group / immunology*
  • Cytokines / biosynthesis*
  • Cytokines / immunology
  • Cytokines / metabolism
  • Ehrlichia / genetics
  • Ehrlichia / immunology*
  • Ehrlichiosis / complications
  • Ehrlichiosis / immunology*
  • Ehrlichiosis / transmission
  • Flow Cytometry
  • Humans
  • Interferon-gamma / biosynthesis
  • Interleukin-2 / biosynthesis
  • Interleukin-4 / biosynthesis
  • Ixodes / microbiology
  • Lyme Disease / complications
  • Lyme Disease / immunology*
  • Lyme Disease / transmission
  • Mice
  • Mice, Inbred C3H
  • Polymerase Chain Reaction
  • Spleen / cytology
  • Spleen / immunology
  • Spleen / microbiology
  • Th2 Cells / immunology*


  • Cytokines
  • Interleukin-2
  • Interleukin-4
  • Interferon-gamma