TLR7 and B cell-intrinsic Myd88 are required for a neutralizing antibody response.

<p>Serum from infected wild-type (WT) or TLR7-deficient mice (<i>Tlr7</i> KO) (<b>A</b>), as well as mice with Myd88 deleted in B cells (CD19-Cre/Myd88^flox/−) (<b>B</b>), was diluted over a wide range and incubated with a defined quantity of infectious FV. The effect of the serum on the infectivity of the sample was then measured by focus-forming assay. The neutralizing antibody (NAb) titer was defined as the maximum serum dilution that reduced the infectivity of the virus sample by at least 50%. Each dot represents an individual mouse.