RT1-Un (RT1-CE16) is a ligand for the Ly49s4/-i4/-s3/-i3 group of
receptors. (A) Ly49s4/-i4/-s3/-i3 reporter cells were co-incubated
with YB2/0 stimulator cells stably transfected with different MHC class Ia
(A1n, A2n) or class Ib (CE1–CE16) molecules
from the n haplotype. As negative and positive controls are
shown stimulation with YB2/0 wild-type cells (YB) and Ionomycin (io.),
respectively. (B) Blocking of the specific response induced by the
RT1-CE16/Un transfectant by addition of 1 μg of mAb AAS6
(anti-CE16/RT1-U). As isotype control (Ctr.) was added purified mAb LOV8 (anti-
CDw93). (C) Testing of a reciprocal RT1-Un reporter cell
against 293T stimulator cells stably transfected with Ly49i3,-s3,-i4 or-s4. The
response could be blocked with mAb DAR13 binding these four Ly49 receptors. As
isotype control (Ctr.) was used mAb FLY5. (D) Comparison of
wild-type (BWZ.s3) and point-mutated Ly49s3 reporter (Ser85Cys in the stem
region; BWZ.s3-S85C) against YB2/0.RT1-Un (YB.Un)
stimulator cells. (E) Comparison of a reciprocal RT1-Un
reporter cell against 293T stimulator cells transfected with wild-type Ly49s3
(s3) and the point-mutated variant (Ser85Cys in the stem region; s3-S85C). Data
are representative of at least 3 independent experiments,
*p<0.01.