KSHV lytic reactivation induces the double strand break response, and the formation of DNA breaks.

<p>(<b>A</b>), TREx BCBL Rta cells remained unreactivated or were reactivated for 24 hours and fixed for immunofluorescence. Cells were then stained using a monoclonal antibody to ORF57 to show reactivation and a monoclonal antibody to γH2A.x to show sites of DNA damage. (<b>B</b>) A time-course of protein expression in reactivated TREx BCBL Rta cells over 0, 8, 16 and 24 hours post induction. A monoclonal antibody to GAPDH was used to show equal loading, and monoclonal antibodies to Myc for Rta and to ORF57 were used to show KSHV reactivation. To demonstrate DNA damage, a polyclonal antibody was used to show total levels of H2A.x and a monoclonal antibody for the phosphorylated form, γH2A.x. (<b>C</b>) For comet assays, TREx BCBL Rta cells were reactivated for 24 hours and reactivation assessed by western blot using monoclonal antibodies to Myc for Rta and to ORF57. A monoclonal antibody to GAPDH was also used to show equal loading. (<b>D</b>). Comet assays were performed and scored using CometScore and tail moments calculated (<b>E</b>); n- and <i>P</i>-values are represented in the figure and error bars show the standard error from the mean.