A43 secreted from OMCMV infected cells blocks NK cell cytotoxicity.

(A) Same as in Fig 9A, except that YT or NK-92 cells were pre-incubated for 30 min with 50 μL of supernatants from OMK cells mock infected or infected with OMCMV diluted 1/2, with 10 μg/mL of α-2B4 mAb, or left untreated (CTL). (B) Flow cytometry analysis of YT or NK-92 cells exposed to different volumes of supernatants derived from OMK cells either mock infected or infected with OMCMV (moi of 2 for 6 days), followed by biotinylated human CD48-Fc. One representative experiment of each assay is shown. Percentages of blockade of hCD48-Fc cell binding were calculated from the MFIs obtained. (C) Same as in A at a 20/1 E/T ratio, except that YT cells were pre-incubated for 30 min with 50 μL of supernatants from OMK cells mock infected or infected with OMCMV diluted 1/2, or with these supernatants pre-absorbed (pa.) with the anti-A43 polyclonal antibody. The asterisks indicate that the difference between both points is statistically significant. ** p <0.01, *** p <0.001.