Appeal 2007-1161
Application 09/954,166
chain/MHC complexed with immunoglobulin light chain (Dal Porto, p. 6675
(Discussion); Findings of Fact 8-13). The Examiner contends that Dal
Porto’s success with soluble MHC would have prompted the skilled worker
to apply its system to soluble TCR heterodimers in order to increase their
binding affinity (Answer 7-8), which were known to have been difficult to
study because of their relatively low binding affinity (Matsui, p. 12862, cols.
1-2; Findings of Fact 3-6; Answer 6-7).
Chang is relied upon by the Examiner for teaching that assembly of
the TCR subunits into a heterodimer is facilitated by attaching each subunit
to peptide segments which “selectively associate” to form stable dimers
(Chang, p. 11408; Findings of Fact 14-17; Answer 5). Thus, the Examiner
contends that that Chang provides “a strong suggestion . . . to modify Dal
Porto . . . by fusing both TCR α and β extracellular segments . . . to the N-
terminus of the antibody heavy and light chains . . . to facilitate heterodimer
formation” (Answer 11).
Harris is cited for teaching methods of producing complexes of two
fusion proteins which having binding activity (Findings of Fact 18-20;
Answer 6) and that “binding domains can be fused via a linker to the N-
terminus of the variable regions of immunoglobulin . . . chains without
altering the binding function of the fusion proteins” (Answer 7).
Appellants contend that a person of ordinary skill in the art would not
have been motivated to have combined the references as asserted by the
Examiner. They argue that Masui teaches a method to directly measure the
interaction between the soluble forms of TCR and MHC; thus, Matsui
solved the problem (Br. 14). They also assert that Chang “teaches no other
method of associating proteins other than by using leucine zipper
10
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: September 9, 2013