Engineered CAR Spacer Mutations

Example 3

The overall data from the above Examples suggested that the Fc spacer performs best overall. However the Fc domain in vivo may lead to non-specific activation from cells which express Fc receptors. To abrogate this effect, mutations were introduced into the Fc region as shown in FIG. 5(a). These mutations had no deleterious effects on CAR expression, as shown in FIG. 5(b).

In addition, it was shown that these mutations had no effect on CAR killing function (FIG. 5(c)). Finally, it was shown that these mutations had the desired effect in terms of non-specific killing of FcR expressing targets (a monocytoid line called THP1), and IL-1Beta release by these monocytes (FIG. 5e).