Interference No. 105,188
Short v. Punnonnen
genetic vaccine vector and having altered activity through CTLA4
or CD28 as compared to a predecessor B7-2 molecule, e.g., wild-
type B7-2. However, the reference also teaches that optimization
may be achieved by recursive activity whereby (Exh. 2040,
5 pp. 19-20, III. Transfection of Host Cells and Screening for
Novel B Lymphocyte Activation Antigens) a prepared cDNA library
is used to clone the B7-2 gene of interest, plasmid DNA is
introduced into a simian COS cell line by known methods of
transfection and allowed to replicate and express the cDNA
10 inserts, transfectants expressing human B7-2 antigen are selected
by reacting the transfectants with the fusion proteins CTLA4Ig,
CD28Ig and other cross-reactive proteins and panning, episomal
DNA is recovered from the panned cells and transformed into
E. coli, plasmid DNA is reintroduced into COS cells and the
15 expression and panning cycle is repeated at least two times, and
the COS cells of the final repeat are analyzed for expression of
novel B lymphocyte antigens using CTLA4Ig and CD28Ig.
Moreover, we find explicit teaching in the Freeman PCT that
optimization may be achieved by homologous recombination of DNA
20 comprising a library of DNA including endogenous and altered B7-2
DNA (Exh. 2040, p. 22, l. 17, to p. 23, l. 17). Accordingly,
while our previous finding that Short failed to establish that
the Freeman PCT explicitly describes recursive sequence
-15-
Page: Previous 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Next
Last modified: November 3, 2007