Ex Parte Tissot-Lecuelle et al

Patent Trial and Appeal Board

Mar 21, 2017

11992113 (P.T.A.B. Mar. 21, 2017)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
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APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/992,113 08/07/2008 Ghislaine Tissot-Lecuelle 037759.00006 4245
4372 7590 03/23.
ARENT FOX LLP
1717 K Street, NW
WASHINGTON, DC 20006-5344
EXAMINER
KUBELIK, ANNE R
ART UNIT PAPER NUMBER
1662
NOTIFICATION DATE DELIVERY MODE
03/23/2017 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
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PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte GHISLAINE TISSOT-LECUELLE, HELENE CANARD, and
MANUEL DUBALD1
Appeal 2016-001216
Application 11/992,113
Technology Center 1600
Before DEMETRA J. MILLS, TAWEN CHANG, and
RACHEL H. TOWNSEND, Administrative Patent Judges.
TOWNSEND, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a
chimeric gene, which have been rejected as obvious. We have jurisdiction
under 35 U.S.C. § 6(b).
We affirm.
STATEMENT OF THE CASE
“In general, plant cells contain 500-10,000 copies of a small 120-160
kilo base circular plastid genome.” (Spec. 1.) Plastids “are responsible for
the production of important compounds such as amino acids, complex
1 Appellants identify the Real Party in Interest as Bayer CropScience AG.
(Br. 2.)
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Application 11/992,113
carbohydrates, fatty acids and pigments.” (Id.) Plant plastids include
chloroplasts. (Id.) Transgenic chloroplast lines are known in the art. (Id. )
“[N]o gene silencing has been reported in chloroplast transgenic lines
despite the accumulation of transcripts at a level 169 times higher than
nuclear transgenic plants.” (Id. )
Chloroplasts are bound by a double-membrane envelope and
“compris[e] three distinct soluble phases.” (Id.) The major soluble phase is
the stroma, which[, among other things,] is the site of. . . amino acids
synthesis.” (Id.) “The dominant membrane is the . . . thylakoid membrane[,
which] encloses the third soluble phase, the thylakoid lumen.” (Id.)
Most chloroplast proteins “are encoded in the nucleus, synthesized as
precursors in the cytosol, and post-translationally imported into one of the
chloroplast subcompartments.” (Id.) “Proteins imported into the [thylakoid]
lumen ... are processed by a thylakoid processing protease that removes the
carboxyl-proximal portion of the transit peptide,” which is responsible for
importing the peptide through the thylakoid membrane. (Id. at 1—2.)
The claimed invention relates to constructs and methods for the
expression of recombinant proteins in the thylakoid lumen of transplastomic
plant cells. (Id. at 1.) According to the Specification,
The present invention provides . . . nucleic acid
sequences useful in targeting a recombinant protein encoded by
a transgene integrated into the chloroplast genome to the
thylakoid lumen of chloroplast, using lumen targeting signal
sequence from nuclear-encoded proteins.
(Id. at 2.)
Claims 1—13 are on appeal. Claim 1 is representative and reads as
follows:
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Application 11/992,113
1. A chimeric gene comprising, linked to one another in a
functional fashion in the direction of transcription:
a) a promoter functional in a plant plastid,
b) a nucleic acid sequence encoding a methionine N-
terminus lumen targeting signal peptide from a nuclear-encoded
protein translationally fused with,
c) a heterologous nucleic acid sequence encoding a peptide,
and
d) optionally a terminator which is active in the plastids of
plant cells,
wherein said chimeric gene does not comprise a nucleic acid
sequence encoding a stromal targeting signal peptide from said
nuclear-encoded protein.
(Appeal Br. 16 (App’x A).)
The following ground of rejection by the Examiner is before us on
review:
Claims 1—13 under 35 U.S.C. § 103(a) as unpatentable over
Hajdukiewicz,2 Henry,3 and Hageman.4
DISCUSSION
The Examiner finds that Hajdukiewicz teaches a chimeric gene that
includes the claimed elements except that it does not teach a thylakoid
2 Peter Hajdukiewicz, WO 01/04327 Al, published Jan. 18, 2001.
3 R. Henry et al., Differences between Lumen Targeting Domains of
Chloroplast Transit Peptides Determine Pathway Specificity for Thylakoid
Transport, 269 (14) J. Biol. Chem., 10189—92 (1994).
4 J. Hageman et al., Protein Import into and Sorting inside the Chloroplast
Are Independent Processes, 2 The Plant Cell, 479—94 (1990).
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Application 11/992,113
lumen targeting signal sequence as the transit peptide. (Final Action 3.) The
Examiner finds, however, that “Hajdukiewicz suggests targeting peptides to
the thylakoid lumen.” (Id.)
The Examiner further finds that Henry teaches transit peptides that
target proteins solely to the thylakoid lumen and that Hageman teaches “the
thylakoid lumen targeting sequence does not require the stromal targeting
sequence to function and that the thylakoid lumen targeting signal sequence,
when present in the stroma, contains all the information necessary for
routing to the thylakoid lumen.” (Id.)
In light of the foregoing, the Examiner concludes that it would have
been obvious to one of ordinary skill in the art using routing molecular
biological methods to substitute “one of the thylakoid lumen targeting
sequences described in Henry et al or the one described in Hageman et al”
for the signal peptide taught by Hajdukiewicz with a reasonable expectation
of success. (Final Action; Ans. 4.)
We agree with the Examiner’s factual findings and conclusion that it
would have been obvious to one of ordinary skill in the art to substitute into
the chimeric gene of Hajdukiewicz the lumen targeting signal peptide
disclosed in Hageman without including the stromal targeting signal peptide.
In particular, Hageman determined that a specific portion of the N-terminal
extension, C2, of the precursor plastocyanin protein “is essential for the
targeting to and translocation across the thylakoid membrane” of
plastocyanin. (Hageman 489.) As the Examiner found, Hageman clearly
teaches that the two portions of the extension that are responsible for transit
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Application 11/992,113
of the plastocyanin into the chloroplast and then the thylakoid lumen,
namely Cl and C2, “function independently.” (Id.)
Appellants argue that the Examiner’s rejection is in error because it
“assumes that expression in plastids would need only the lumen targeting
portion of the N-terminal extension of plastocyanin,” but “[tjhere is no
disclosure or suggestion in Hageman et al. of plastid expression of
transgenes, much less plastid expression of a nucleic acid sequence encoding
a thylakoid lumen targeting signal peptide from a nuclear-encoded protein
translationally fused with a heterologous nucleic acid sequence encoding a
peptide.” (Br. 12—13.) We do not find this argument persuasive.
Hageman reports the results of proteases involved in the transport
pathway of plastocyanin, a “native nuclear-encoded chloroplast thylakoid
lumen protein that is synthesized in the cytoplasm” (Hageman abs.) and does
not discuss transport of transgenes. However, this fact is not decisive or on
point. The Examiner’s obviousness rejection is based on a combination of
references. Hageman is important to the rejection because it teaches that
thylakoid lumen targeting sequences contain all the information necessary
for routing protein to the thylakoid lumen from the stroma and that these
sequences do not require the stromal targeting sequence to function in that
capacity. (See, e.g., Hageman 488—89 (in particular noting that experiments
showing that the N terminus of C2 can be variable and the “intermediates are
routed correctly to the thylakoid lumen”).)
Hajdukiewicz teaches chimeric gene constructs for expression of
heterologous protein in plastids of plant cells (see, e.g., Hajdukiewicz abs.)
and suggests employing “sequences to target the expressed protein to a
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Application 11/992,113
particular suborganellar region, for example, the thylakoid lumen of the
chloroplast” (Hajdukiewicz 17:13—15). Hageman teaches such sequences
are known as does Henry (Henry 10189 (referencing “proteins of the oxygen
evolving complex (OE17, OE23, and OE33) and plastocyanin”). In light of
the foregoing teachings and the high level of skill in the art (Ans. 4 (noting
“[o]ne of ordinary skill in this art has a Ph.D. or is working towards one and
thus has a high level of skill”), we agree with the Examiner that one of
ordinary skill in the art would have had a reasonable expectation of success
in the substitution of the thylakoid lumen targeting sequences described in
Henry or Hageman for the signal peptide taught by Hajdukiewicz.
“Obviousness does not require absolute predictability of success. ... all that
is required is a reasonable expectation of success.” In re O ’Farrell, 853
F.2d 894, 903—04 (Fed. Cir. 1988). All that claim 1 requires is a chimeric
gene construct. For the foregoing reasons, Appellants do not persuade us
that the Examiner erred in maintaining the obviousness rejection of claim 1.
Claim 9, unlike claim 1, requires transforming a plastid with the
chimeric gene of claim 1 and obtaining expression of the chimeric gene at
least at 0.1% of the total soluble protein. Appellants argue that the
Examiner’s speculation based on Hageman that expression in plastids would
need only the lumen targeting sequence is not supported and is based on
hindsight. (Br. 13.) We disagree. We find the Examiner’s position that one
of ordinary skill in the art would have a reasonable expectation of success in
achieving those requirements based on the prior art teachings to be well-
founded.
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As the Examiner noted, “Henry and Hageman both showed that both
parts [of the signal peptide targeting the stroma and the thylakoid lumen]
were required to obtain translocation of a protein in the lumen only when the
protein started outside the chloroplast.” (Ans. 8. (emphasis added).) We
find that the Specification teaches that it was known in the art to transform
the plastid genome with particle bombardment, which permits the DNA to
“cross the cell wall, the plasma membrane and the double membrane of the
organelle before reaching the stroma.” (Spec. 11.) As discussed above,
Hageman teaches that once in the stroma, C2 is capable of translocating
protein across the thylakoid membrane to the lumen. (Hageman 489—90:
“the PC processing intermediate[, referring to the FD transit-C2 intermediate
fusion described at 480], when present in the stroma, contains all the
information necessary for subsequent routing into the thylakoid lumen.”)
As discussed above, a finding of obviousness only requires a
reasonable expectation of success, not absolute predictability. In re
O ’Farrell, 853 F.2d at 903—04. In light of the high level of skill of one of
ordinary skill in this art, and the fact that it was known in the prior art how
to move genes into the plastid stroma, we agree with the Examiner that it
would have been obvious from the teaching of Hageman regarding C2 “to
only put the thylakoid lumen targeting portion[, i.e., C2,] in Hajdukiewicz’s
vector” (Ans. 6) with a reasonable expectation that transformation would
occur.
As the Examiner explained, the foregoing does not rely on hindsight:
One of ordinary skill in the art, seeing Hajdukiewicz’s
suggestion to target peptides to the thylakoid lumen, would
look to the prior art to see what was known about peptides that
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Application 11/992,113
target to the thylakoid lumen, see that the thylakoid lumen
targeting portion, when present in the stroma, contains all the
information necessary for routing to the thylakoid lumen, and
just use routine molecular biological methods to modify
Hajdukiewicz’s plastid transformation vectors to replace the
nucleic acid encoding the thylakoid membrane targeting peptide
with one encoding a thylakoid lumen targeting peptide.
Using Henry and Hagemann to add one element is not
using the claimed invention as a template to piece together the
teachings of the prior art.
(Ans. 7.)
Appellants point out that they have shown that targeting to the
thylakoid lumen of chloroplasts (plastids) results in expression of at least 0.1
% of the total soluble protein (Br. 14). It does not appear that Appellants
argue that this is an unexpected result. And in any event, “it is well settled
that unexpected results must be established by factual evidence. Mere
argument or conclusory statements in the specification does not suffice.” In
re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984); see also In re Wood, 582
F.2d 638, 642 (CCPA 1978) (“Mere lawyer’s arguments and conclusory
statements in the specification, unsupported by objective evidence, are
insufficient to establish unexpected results.”).
Moreover, as the Examiner noted, “Hajdukiewicz achieved levels of
expression of 0.2%—'7 .0% total soluble protein with plastid expression
(Table 9).” (Ans. 9.) Appellants do not provide sufficient evidence that
would lead one of ordinary skill in the art not to expect similar results using
only a lumen targeting signal peptide without the stromal targeting signal
peptide when the chimeric gene is provided to the stroma by particle
bombardment.
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For the reasons discussed, Appellants do not persuade us that the
Examiner erred in maintaining the obviousness rejection of claim 9.
Claims 2—8 and 10—13 have not been argued separately and therefore
fall with claims 1 and 9. 37 C.F.R. § 41.37(c)(l)(iv).
SUMMARY
We affirm the rejection of claims 1—13 under 35 U.S.C. § 103(a) as
unpatentable over Hajdukiewicz, Henry, and Hageman.
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
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