Figure 7.
XIAP restricts Anaplasma phagocytophilum colonization of Ixodes scapularis. A–E, I. scapularis nymphs were body injected with 9.2 ηL containing 1 × 1013 molecules/µL of xiap siRNA (si619) or scrambled siRNA (sicontrol) and allowed to feed for 72 h on A. phagocytophilum infected C57BL/6 mice. A, Average weight of ticks (n = 30) treated with sicontrol and si619 is shown. Xiap is silenced in (B) salivary glands (SG) and (C) midguts (MG). D and E, A. phagocytophilum load was measured in the (D) SG and (E) MG by qRT-PCR using the ΔΔCt method for the 16S gene relative to tick β-actin expression. Each dot indicates individual or pools of 2 ticks (n = 15 per group). Experiments were repeated twice. Error bars in (A) represent standard error of the mean. Statistical analysis was performed using the Student t test (P≤ .05). Abbreviations: qRT-PCR, quantitave reverse transcription polymerase chain reaction; XIAP, x-linked inhibitor of apoptosis protein.