D^b plus peptide protective motifs prevent rejection of D^8P2+ but not D^d+ bone marrow cells(BMC) by B6 host natural killer(NK) cells

Crosses between wild type spretus and BIO H2^b mice produced congenic B10.SP2 and intra-H2 recombinant 9347 and R40 mice. 9347 and R40 mice are KIS^b/DM3^sp2 (breakpoints between Bat2-Tnf segments of S/D interval). Bone marrow cells of B 10.SP2, 9347 and R40 mice were rejected by B6 H2^b host NK cells as if B6 NK cells recognize codominantly inherited D^sp2 on donor BMC. 9347 × B6 F1 but not R40 X B6 BMC were accepted by B6 hosts, suggesting that D^b plus a Bat2-Tnf^b peptide from 9347 but not of R40 form a protective motif to prevent rejection by B6 host. Therefore 9347 and R40 mice were crossed to DBA.D^b(H2^dD^b) transgenic mice to produce K^b/dD^sp2/dL^d, D^b F1 mice; their BMC cells were rejected by B6 but were accepted by D8(H2^bD^d) hosts as if D^d was the target BMC from F2 donors that were H2⁹³⁴⁷⁺(or even H2^R40+), H2^d-, D^b+ grew in B6 hosts; BMC from D^b- donors were rejected. D^b plus peptides from non-H2^d DBA genes may generate protective motifs for D^sp2 but not for D^d targets. Thus specific peptides and class I molecules are apparently required to create negative signaling motifs for NK cells to prevent rejection of BMC. BMC Donor 5-Day 125IUdR Uptake in Spleens Strain K D L Hosts: B6 D8: H2^b, D^d R40 or 9347 b sp2 B6 × R40 b b/sp2 - NT B6 × 9347 b Wsp2 + NT 9347 × DBA.D^b F1 b/d Sp2/d,b d - + 9347 × DBA.D^b F2 b sp2, b+ + NT 9347 × DBA.D^b F2 b sp2, b- - NT.