IgM mediates the mitigation of liver gene transfer by a HDA vector.

<p>A) Rag1KO mice were passively <i>i.v.</i> transferred with serum of non-immunized WT mice or similar serum samples reduced by β-mercaptoethanol. Level of gene transfer of WT mice is provided as a control. Liver gene transfer of luciferase by HDA vector (dose of 5×10¹⁰ viral particles/mouse) was assessed by bioluminescence as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0085432#pone-0085432-g001" target="_blank">Figure 1</a>. B) Experiments as in A but passively transferring 2 doses of 130 μg of IgG and IgM (both purified by affinity chromatography from serum) or 400 μl of serum from WT mice. C) B6.µMT-KO mice were passively transferred <i>i.v.</i> with 2 doses of 130 μg of serum IgM purified by affinity chromatography and analyzed for liver gene transduction as in A. Wild-type, WT; Rag1KO, BALB/C Rag1^−/− (C.129S7(B6)-Rag1^tm1Mom/J; B6.µMT, (B6.129S2-Ighm^tm1Cgn/J; B6.Rag1KO, pIgG, polyclonal immunoglobulin G; pIgM, polyclonal immunoglobulin M; HDA-<i>luc</i>, helper-dependent adenoviral vectors encoding luciferase. Experiments were performed twice.