DETAILED CORRESPONDENCE
Status of the Application
The examiner of your application in the USPTO has changed. To aid in correlating any papers for this application, all further correspondence regarding this application should be directed to David Steadman in Art Unit 1656.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-3, 5-7, 9, 10, 13-15, 17-19, 21, 22, 24, 25, 34, 36, 37, and 39 are pending in the application.
Applicant’s preliminary amendment to the claims, filed July 17, 2025 is acknowledged. This listing of the claims replaces all prior versions and listings of the claims.
Restriction/Election
Applicant’s election without traverse of Group II, claims 13-15, 17-19, 21, 22, and 39, drawn to the technical feature of a method for covalently modifying a red blood cell, in the reply filed July 17, 2025 is acknowledged.
Claims 1-3, 5-7, 9, 10, 24, 25, 34, 36, and 37 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected inventions, there being no allowable generic or linking claim.
Priority
This application is filed under 35 U.S.C. 371 as a national stage of international application PCT/CN2021/081838, filed March 19, 2021, which claims foreign priority under 35 U.S.C. 119(a)-(d) to Chinese application PCT/CN2020/080476, filed March 20, 2020. A certified copy of the foreign priority document has been filed in this application on September 15, 2022.
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on January 6, 2023 and July 17, 2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the IDSs have been considered by the examiner.
The listing of references in the specification at p. 58 is not a proper information disclosure statement. 37 CFR 1.98(b) requires a list of all patents, publications, or other information submitted for consideration by the Office, and MPEP § 609.04(a) states, "the list may not be incorporated into the specification but must be submitted in a separate paper." Therefore, unless the references have been cited by the examiner on form PTO-892, they have not been considered.
Specification/Informalities
The use of trade names or marks used in commerce, have been noted in this application, e.g., “CytoFLEX” at paragraph [0149] of the specification. All instances of trade names or marks should be accompanied by the generic terminology and capitalized wherever they appear or, where appropriate, include a proper symbol indicating use in commerce such as ™, SM , or ® following the term.
Although the use of trade names and marks used in commerce (i.e., trademarks, service marks, certification marks, and collective marks) are permissible in patent applications, the proprietary nature of the marks should be respected and every effort made to prevent their use in any manner which might adversely affect their validity as commercial marks.
Sequence Compliance
The sequence listing incorporation statement in the specification amendment filed September 15, 2022 is objected to because the size of the ASCII text file in the sequence incorporation statement must be listed in bytes (not kilobytes). See MPEP 2422.03.I.
This application contains sequence disclosures that are encompassed by the definitions for nucleotide and/or amino acid sequences set forth in 37 CFR 1.821(a)(1) and (a)(2), yet fails to comply with the requirements of 37 CFR 1.821 through 1.825; applicants’ attention is directed to the final rulemaking notice published at 55 FR 18230 (May 1, 1990), and 1114 OG 29 (May 15, 1990). See claim 19, paragraphs [0004], [0011], [0020], [0028], [0079], [0087], [0088], and [0112] of the specification, and the column identified as “Sequence” in Table 2 beginning at p. 36 of the specification. To be in compliance, applicants should identify nucleotide sequences of at least 10 nucleotides and amino acid sequences of at least 4 amino acids in the claims and specification by a proper sequence identifier, i.e., “SEQ ID NO:” (see MPEP 2422.01). If these sequences have not been listed in the computer readable form and paper copy of the sequence listing, applicant must provide an initial computer readable form (CRF) copy of the “Sequence Listing”, an initial paper copy of the “Sequence Listing”, as well as an amendment directing its entry into the specification, and a statement that the content of the paper and CRF copies are the same and, where applicable, include no new matter as required by 37 C.F.R. 1.821(e) or 1.821(f) or 1.821(g) or 1.821(b) or 1.825(d).
Claim Interpretation
Claim 13 is drawn to a method for covalently modifying the glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of at least one endogenous, non-engineered membrane protein of a red blood cell (RBC), comprising contacting the RBC with a sortase substrate that comprises a sortase recognition motif and an agent, in the presence of a sortase under conditions suitable for the sortase to conjugate the sortase substrate to the glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of the at least one endogenous, non-engineered membrane protein of the RBC by a sortase-mediated reaction, wherein the sortase-mediated reaction comprises a sortase-mediated glycine conjugation and/or a sortase-mediated lysine side chain ε-amino group conjugation, wherein the sortase is a Staphylococcus aureus transpeptidase A variant (mgSrtA) comprising the mutations of P94R/S, D124G, D160N, D165A, Y187L, E189R, K190E K196T, and F200L and optionally E105K and/or E108E/Q, wherein the numbering of the mutations is according to the numbering of SEQ ID NO: 1.
Given a broadest reasonable interpretation, the recitation of “at internal sites of the extracellular domain” in the phrase “the glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain” in claim 13 is interpreted as referring to both glycine(n) and/or lysine ε-amino group or, in the alternative, as referring only to “lysine ε-amino group” and not “glycine(n).”
The recitation of “non-engineered membrane protein” is interpreted as meaning a naturally-occurring membrane protein that has not been modified by the hand of man, e.g., by genetic engineering or chemical modification(s).
Claim 14 is drawn to the method of claim 13, wherein the sortase-mediated glycine conjugation and/or the sortase-mediated lysine side chain ε-amino group conjugation occur at least on glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of the at least one endogenous, non-engineered membrane protein, optionally n being 1 or 2, wherein the at least one endogenous, non-engineered membrane protein include a native RBC membrane protein with UniProt ID selected from the following: CASR , CD3G , DSCL1 , TRPC2 , C209B , ITCH, AKA12, ITIH4 , ATP4A , P2RX1 , RYR3 , C163A , AMER1 , MRCKB , ELMO1 , DESP , CD40L , S12A2 , ADCY6 , CY24B , MNAR1 and PLXC1.
Given a broadest reasonable interpretation, the phrase “wherein the at least one endogenous, non-engineered membrane protein include a native RBC membrane protein with UniProt ID…” in claim 14 is considered to be optional since it follows the recitation of “optionally n being 1 or 2.”
Claim Objections
Claim 17 is objected to in the recitation of “60% identity” and in the interest of improving claim form, it is suggested that the noted phrase be amended to recite “60% sequence identity.”
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 13-15, 17-19, 21, 22, and 39 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 13 (claims 14, 15, 17-19, 21, 22, and 39 dependent therefrom) recites the limitation “the glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of at least one endogenous, non-engineered membrane protein of a red blood cell” in lines 1-3. There is insufficient antecedent basis for this limitation in the claim.
Claim 13 (claims 14, 15, 17-19, 21, 22, and 39 dependent therefrom) is confusing in the recitation of “the extracellular domain of at least one endogenous, non-engineered membrane protein of a red blood cell.” The art-recognized meaning of the term “extracellular” in the context of the phrase “extracellular domain of at least one endogenous, non-engineered membrane protein of a red blood cell” is a domain of a membrane protein that is outside of a red blood cell, and the art-recognized meaning of the term “endogenous” in the context of the phrase “endogenous, non-engineered membrane protein of a red blood cell” as a non-engineered membrane protein inside of a red blood cell. In this case, it is unclear as to how a membrane protein that is inside the cell simultaneously has a domain that is outside of the cell. It is suggested that applicant clarify the meaning of the noted phrase.
Claims 13 (claims 15, 17-19, 21, and 39 dependent therefrom) and 14 are indefinite in the recitation of “glycine(n)” because it is unclear as to what “(n)” represents in the noted term. It is suggested that the applicant recite the intended meaning of “(n)” in claims 13 and 14. In the interest of clarity, it is noted that claim 14 recites “optionally n being 1 or 2,” however, this description of “(n)” is optional and non-limiting.
Claim 14 contains the trademark/trade name “UniProt.” Where a trademark or trade name is used in a claim as a limitation to identify or describe a particular material or product, the claim does not comply with the requirements of 35 U.S.C. 112(b). See MPEP 2173.05(u). The claim scope is uncertain since the trademark or trade name cannot be used properly to identify any particular material or product. A trademark or trade name is used to identify a source of goods, and not the goods themselves. Thus, a trademark or trade name does not identify or describe the goods associated with the trademark or trade name. In the present case, the trademark/trade name is used to identify/describe a membrane protein and, accordingly, the identification/description is indefinite.
Claim 14 is indefinite in the recitation of various UniProt Accession Numbers because it is unclear as to the scope of proteins that are intended as being encompassed by the recited UniProt Accession Numbers. For example, there is no specific protein or proteins that has/have the UniProt Accession Number “CASR.” It is suggested that the applicant clarify the scope of proteins that are intended as being encompassed by the recited UniProt Accession Numbers.
Claim 15 is indefinite in the recitation of “the RBC is a natural RBC a natural human RBC” because it is unclear as to the recited RBC is intended to “a natural RBC” or “a natural human RBC.” It is suggested that applicant clarify the meaning of the claim.
Claim 17 (claim 18 dependent therefrom) is indefinite in the recitation of “the sortase is a Staphylococcus aureus transpeptidase A variant (mgSrtA)” because it is unclear as to whether the limitation recited in parentheses is intended to be limiting or merely exemplary. If applicant intends for the limitation recited in parentheses to be an example of a Staphylococcus aureus transpeptidase A variant, it is noted that description of examples is properly set forth in the specification rather than the claims. See MPEP § 2173.05(d).
Claim 22 is indefinite in the recitation of “on the surface of the RBC” in line 2. Claim 13 does not require the endogenous, non-engineered membrane protein of a RBC to be on the surface of the RBC. It is suggested that applicant clarify the meaning of claim 22.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 13-15, 17-19, 21, 22, and 39 are rejected under 35 U.S.C. 103 as being unpatentable over Swee et al. (WO 2014/183066 A2; cited on the IDS filed January 6, 2023; hereafter “Swee”) in view of Chen et al. (CN 109797194 A; cited on the IDS filed January 6, 2023; hereafter “Chen”). Reference is made to applicant’s machine translation of Chen (hereafter “Translation”).
Regarding instant claims 13 and 14, claim 1 of Swee recites a method of conjugating an agent to an animal cell, the method comprising: contacting an animal cell with a sortase substrate that comprises a sortase recognition sequence and an agent in the presence of a sortase under conditions suitable for the sortase to conjugate the sortase substrate to an endogenous, non-engineered polypeptide expressed by the animal cell; and
claim 2 of Swee recites the method of claim 1, wherein the sortase substrate is conjugated to an extracellular portion of an endogenous, non-engineered polypeptide expressed by the cell.
Swee teaches sortase can be used for modification of eukaryotic cell surfaces without requiring that the cells be engineered to express polypeptides comprising a sortase recognition sequence or nucleophilic acceptor sequence, noting that such polypeptides may comprise a sequence of one or more glycines exposed at the cell surface, e.g., in an N-terminal domain, available to act as a nucleophile in a reaction in which sortase is used to conjugate a sortase substrate to the polypeptide (p. 56, paragraph [0066]). Swee teaches the polypeptide modified by the sortase is an integral membrane protein or a peripheral membrane protein (p. 63, paragraph [0088]).
Swee teaches the cells include red blood cells (p. 98, paragraph [0169]) and teaches examples of sortase-mediated conjugation of red blood cells with various agents modified to comprise a sortase recognition sequence (Examples 28-32 beginning at p. 259).
Swee teaches a variant of a naturally occurring sortase may be used (p. 75, paragraph [00118]) and teaches a variant of a wild-type S. aureus sortase comprising P94R/S, D160N, D165A, K190E, and K196T mutations (p. 76, paragraph [00119]).
The difference between Swee and claims 13 and 14 is that Swee does not teach or suggest a Staphylococcus aureus transpeptidase A variant (mgSrtA) comprising the mutations of P94S/R, D124G, D160N, D165A, Y187L, E189R, K190E K196T, and F200L and optionally E105K and/or E108E/Q.
Chen teaches S. aureus sortase mutant 1 comprising the mutations P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L (Translation at p. 3, middle) and referred to as “mgSrtA” (Translation at p. 4, fifth full paragraph). Chen teaches mgSrtA can bind a molecule comprising a LPXTG sequence to the cell membrane surface (Translation at p. 4, first paragraph). Chen teaches the surface of the cell membrane has few oligo glycines and mgSrtA exhibits greatly improved efficiency at single glycine residues on the surface of the cell membrane (Translation at p. 5, second paragraph).
In view of the combined teachings of Swee and Chen, it would have been obvious to one of ordinary skill in the art before the effective filing date to use mgSrtA of Chen in the method of Swee. One would have been motivated and would have expected success to do this because Swee taught the use of a variant sortase comprising the mutations P94R/S, D160N, D165A, K190E, and K196T mutations to conjugate the sortase substrate to a glycine exposed at the cell surface, Chen taught mgSrtA comprising the mutations P94R/S, D160N, D165A, K190E, and K196T, and Chen taught the surface of the cell membrane has few oligo glycines and mgSrtA exhibits greatly improved efficiency at single glycine residues on the surface of the cell membrane.
Regarding instant claim 15, Swee teaches the cell surfaces can be modified without requiring that the cells be engineered to express polypeptides comprising a sortase recognition sequence or nucleophilic acceptor sequence (p. 56, paragraph [0066]).
Regarding instant claims 17 and 18, Chen teaches mgSrtA mutant 1 comprises the mutations P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L (Translation at p. 3, middle) and has the amino acid sequence of SEQ ID NO: 1 (Translation, beginning at p. 7). SEQ ID NO: 1 of Chen is identical to instant SEQ ID NO: 3 (see Appendix for sequence alignment).
Regarding instant claim 19, Swee teaches sortase substrates include a sortase recognition motif at their C-terminus and teaches the exemplary sortase recognition motifs LPXTGG and LPETGG (p. 44, paragraph [0053]).
Regarding instant claim 21, Swee teaches a wide variety of agents may be conjugated (p. 2, paragraph [0007]) and claim 20 of Swee recites the agent comprises an amino acid, a peptide, a protein, a polynucleotide, a carbohydrate, a tag, a metal atom, a chelating agent, a contrast agent, a catalyst, a polymer, a recognition element, a small molecule, a lipid, a label, an epitope, an antigen, a therapeutic agent, a cross-linker, a toxin, a radioisotope, an antibody, an antibody domain, a click chemistry handle, a virus, a cell, or a particle, and Chen teaches a labeling molecule including a small molecule or a biological macromolecule such as biotin, fluorescent dye, enhanced and green fluorescent protein (eGFP) (Translation at p. 4, first full paragraph).
Regarding instant claim 22, Swee teaches the exemplary sortase recognition motifs LPXTGG and LPETGG (p. 44, paragraph [0053]) and shows a representation of a sortase-modified cell (pp. 60-61, paragraph [0080]), which is encompassed by claim 22.
Regarding instant claim 39, Swee teaches the average circulation time or plasma half-life may be increased (pp. 65-66, paragraph [0093]).
Therefore, the invention of claims 13-15, 17-19, 21, 22, and 39 would have been obvious to one of ordinary skill in the art before the effective filing date.
Claim Rejections - Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 13-15, 17-19, 21, 22, and 39 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 5, 7, 10-12, and 18 of co-pending application 18/251,030 (reference application).
Regarding instant claims 13, 14, and 17-19, claim 1 of the reference application recites a method for covalently modifying at least one membrane protein of a red blood cell (RBC), comprising contacting the RBC with a sortase substrate that comprises a sortase recognition motif and an agent, in the presence of a sortase under conditions suitable for the sortase to conjugate the sortase substrate to the at least one membrane protein of the RBC by a sortase-mediated reaction,
wherein the sortase substrate comprises a structure of A1-Sp-M, in which
A1 represents the agent, Sp represents one or more optional spacers, and M represents the sortase recognition motif comprising an unnatural amino acid located at position 5 from the direction of N-terminal to C-terminal of the sortase recognition motif, wherein the unnatural amino acid is an optionally substituted hydroxyl carboxylic acid having a formulae of CH2OH-(CH2)n-COOH, n being an integer from 0 to 3, preferably n=0;
claim 5 of the reference application recites the method of claim 1, the wherein the at least one membrane protein is at least one endogenous, non-engineered membrane protein and the sortase substrate is conjugated to the at least one endogenous, non-engineered membrane protein of the RBC by a sortase-mediated glycine conjugation and/or a sortase-mediated lysine side chain ε-amino group conjugation, wherein the sortase-mediated glycine conjugation and/or the sortase-mediated lysine side chain ε-amino group conjugation occur at least on glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of the at least one endogenous, non-engineered membrane protein, optionally n being 1 or 2; and
claim 10 of the reference application recites the method of claim 9, wherein the sortase is a mgSrtA, and wherein the mgSrtA comprises an amino acid sequence having the amino acid sequence as set forth in SEQ ID NO: 3 (SEQ ID NO: 3 of the reference application is identical to instant SEQ ID NO: 3 and comprises the mutations P94R/S, D124G, D160N, D165A, Y187L, E189R, K190E K196T, and F200L relative to instant SEQ ID NO: 1).
Regarding instant claim 15, claim 7 of the reference application recites the method of claim 5, wherein the RBC has not been genetically engineered to express a protein comprising a sortase recognition motif or a nucleophilic acceptor sequence, and preferably the RBC is a natural RBC such as a natural human RBC.
Regarding instant claim 21, claim 11 of the reference application recites the method of claim 1, wherein the agent comprises a binding agent, a therapeutic agent, or a detection agent.
Regarding instant claim 22, claim 12 of the reference application recites the method of claim 1, wherein the covalently modified at least one membrane protein on the surface of the BRC comprises a structure of A1-L1-P1, in which L1 is linked to a glycine(n) in P1, and/or a structure of A1-L1-P2 in which L1 is linked to the side chain ε-amino group of lysine in P2, wherein n is 1 or 2; A1 represents the agent; L1 is selected from the group consisting of LPXT, LPXA, LPXS, LPXL, LPXV, LGXT, LAXT, LSXT, NPXT, MPXT, IPXT, SPXT, VPXT, and YPXR; P1 and P2 independently represent the at least one membrane protein; and X represents any amino acid.
Regarding instant claim 39, claim 18 of the reference application recites the method of claim 1, wherein the method is for increasing the circulation time or plasma half-life of the agent in a subject, comprising providing the sortase substrate that comprises the sortase recognition motif and the agent, and conjugating the sortase substrate in the presence of a sortase under conditions suitable for the sortase to conjugate the sortase substrate to at least one membrane protein of the red blood cell by a sortase-mediated reaction.
Therefore, claims 13-15, 17-19, 21, 22, and 39 of this application are unpatentable over claims 1, 5, 7, 10-12, and 18 of the reference application. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Claims 13-15, 17-19, 21, 22, and 39 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 18 of co-pending application 18/264,098 (reference application) in view of Swee and Chen.
Regarding instant claims 13 and 14, claim 18 of the reference application recites a method for preparing the red blood cell of claim 1, comprising contacting a red blood cell (RBC) with a sortase substrate that comprises a sortase recognition motif and an agent, in the presence of a sortase under conditions suitable for the sortase to conjugate the sortase substrate to the at least one endogenous, non-engineered membrane protein of the RBC by a sortase-mediated reaction, optionally by a sortase-mediated glycine conjugation and/or a sortase-mediated lysine side chain ε-amino group conjugation, wherein the agent comprises a uric acid degrading polypeptide,
wherein the sortase substrate comprises a structure of (A1-Sp)m-M, in which A1 represents an agent, Sp represents the optional spacer, and M represents a sortase recognition motif; m being an integer greater than or equal to 1, optionally m=1 to 3,
wherein the sortase recognition motif comprises or consists essentially of or consists of an amino acid sequence selecting from a group consisting of LPXTG, LPXAG, LPXSG, LPXLG, LPXVG, LGXTG, LAXTG, LSXTG, NPXTG, MPXTG, IPXTG, SPXTG, VPXTG, YPXRG, LPXTS and LPXTA, wherein X is any amino acid,
optionally wherein the sortase recognition motif comprises an unnatural amino acid located at position 5 from the direction of N-terminal to C-terminal of the sortase recognition motif, wherein the unnatural amino acid is an optionally substituted hydroxyl carboxylic acid having a formulae of CH2OH-(CH2)-COOH, n being an integer from 0 to 3, optionally n=0,
optionally wherein M comprises or consists essentially of or consists of an amino acid sequence selecting from a group consisting of LPXT*Y, LPXA*Y, LPXS*Y, LPXL*Y, LPXV*Y, LGXT*Y, LAXT*Y, LSXT*Y, NPXT*Y, MPXT*Y, IPXT*Y, SPXT*Y, VPXT*Y and YPXR*Y, wherein * represents the optionally substituted hydroxyl carboxylic acid; and X and Y independently represent any amino acid,
optionally wherein M comprises or consists essentially of or consists of an amino acid sequence selecting from a group consisting of LPXT*G, LPXA*G, LPXS*G, LPXL*G, LPXV*G, LGXT*G, LAXT*G, LSXT*G, NPXT*G, MPXT*G, IPXT*G, SPXT*G, VPXT*G, YPXR*G, LPXT*S and LPXT*A, optionally M is LPET*G with * being 2-hydroxyacetic acid.
The differences between claim 18 of the reference application and claims 13 and 14 of this application are:
claim 18 does not recite modifying the glycine(n) and/or lysine ε-amino group at internal sites of the extracellular domain of at least one endogenous, non-engineered membrane protein; and
claim 18 does not recite the sortase is a Staphylococcus aureus transpeptidase A variant (mgSrtA) comprising the mutations of P94R/S, D124G, D160N, D165A, Y187L, E189R, K190E K196T, and F200L and optionally E105K and/or E108E/Q, wherein the numbering of the mutations is according to the numbering of SEQ ID NO: 1.
Regarding difference 1), Swee teaches sortase can be used for modification of eukaryotic cell surfaces without requiring that the cells be engineered to express polypeptides comprising a sortase recognition sequence or nucleophilic acceptor sequence, noting that such polypeptides may comprise a sequence of one or more glycines exposed at the cell surface, e.g., in an N-terminal domain, available to act as a nucleophile in a reaction in which sortase is used to conjugate a sortase substrate to the polypeptide (p. 56, paragraph [0066]). Swee teaches the polypeptide modified by the sortase is an integral membrane protein or a peripheral membrane protein (p. 63, paragraph [0088]). Swee teaches the cells include red blood cells (p. 98, paragraph [0169]) and teaches examples of sortase-mediated conjugation of red blood cells with various agents modified to comprise a sortase recognition sequence (Examples 28-32 beginning at p. 259).
In view of the teachings of Swee, it would have been obvious to one of ordinary skill in the art for the at least one endogenous, non-engineered membrane protein of the RBC to comprise a sequence of one or more glycines exposed at the cell surface. One would have been motivated and would have expected the at least one endogenous, non-engineered membrane protein of the RBC to comprise a sequence of one or more glycines exposed at the cell surface because Swee taught polypeptides modified by sortase may comprise a sequence of one or more glycines exposed at the cell surface.
Regarding difference 2), Chen teaches S. aureus sortase mutant 1 comprising the mutations P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L (Translation at p. 3, middle) and referred to as “mgSrtA” (Translation at p. 4, fifth full paragraph). Chen teaches mgSrtA can bind a molecule comprising a LPXTG sequence to the cell membrane surface (Translation at p. 4, first paragraph). Chen teaches the surface of the cell membrane has few oligo glycines and mgSrtA exhibits greatly improved efficiency at single glycine residues on the surface of the cell membrane (Translation at p. 5, second paragraph).
In view of the teachings of Chen, it would have been obvious to one of ordinary skill in the art before the effective filing date to use mgSrtA of Chen in the method of claim 18 of the reference application. One would have been motivated and would have expected success to use mgSrtA of Chen in the method of claim 18 of the reference application because the method of claim 18 of the reference application includes a sortase-mediated glycine conjugation, and Chen taught mgSrtA comprising the mutations P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L with greatly improved efficiency at single glycine residues on the surface of the cell membrane.
Regarding instant claim 15, Swee teaches the cell surfaces can be modified without requiring that the cells be engineered to express polypeptides comprising a sortase recognition sequence or nucleophilic acceptor sequence (p. 56, paragraph [0066]).
Regarding instant claims 17 and 18, Chen teaches mgSrtA mutant 1 comprises the mutations P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L (Translation at p. 3, middle) and has the amino acid sequence of SEQ ID NO: 1 (Translation, beginning at p. 7). SEQ ID NO: 1 of Chen is identical to instant SEQ ID NO: 3 (see Appendix for sequence alignment).
Regarding instant claim 19, Swee teaches sortase substrates include a sortase recognition motif at their C-terminus and teaches the exemplary sortase recognition motifs LPXTGG and LPETGG (p. 44, paragraph [0053]).
Regarding instant claim 21, Swee teaches a wide variety of agents may be conjugated (p. 2, paragraph [0007]) and claim 20 of Swee recites the agent comprises an amino acid, a peptide, a protein, a polynucleotide, a carbohydrate, a tag, a metal atom, a chelating agent, a contrast agent, a catalyst, a polymer, a recognition element, a small molecule, a lipid, a label, an epitope, an antigen, a therapeutic agent, a cross-linker, a toxin, a radioisotope, an antibody, an antibody domain, a click chemistry handle, a virus, a cell, or a particle, and Chen teaches a labeling molecule including a small molecule or a biological macromolecule such as biotin, fluorescent dye, enhanced and green fluorescent protein (eGFP) (Translation at p. 4, first full paragraph).
Regarding instant claim 22, Swee teaches the exemplary sortase recognition motifs LPXTGG and LPETGG (p. 44, paragraph [0053]) and shows a representation of a sortase-modified cell (pp. 60-61, paragraph [0080]), which is encompassed by claim 22.
Regarding instant claim 39, Swee teaches the average circulation time or plasma half-life may be increased (pp. 65-66, paragraph [0093]).
Therefore, claims 13-15, 17-19, 21, 22, and 39 of this application are unpatentable over claim 18 of the reference application in view of Swee and Chen. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Conclusion
Status of the claims:
Claims 1-3, 5-7, 9, 10, 13-15, 17-19, 21, 22, 24, 25, 34, 36, 37, and 39 are pending.
Claims 1-3, 5-7, 9, 10, 24, 25, 34, 36, and 37 are withdrawn from consideration.
Claims 13-15, 17-19, 21, 22, and 39 are rejected.
No claim is in condition for allowance.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID J STEADMAN whose telephone number is (571)272-0942. The examiner can normally be reached Monday to Friday, 7:30 AM to 4:00 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, MANJUNATH N RAO can be reached on 571-272-0939. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/David Steadman/Primary Examiner, Art Unit 1656
APPENDIX
BGJ38537
ID BGJ38537 standard; protein; 181 AA.
XX
AC BGJ38537;
XX
DT 22-AUG-2019 (first entry)
XX
DE Staphylococcus aureus SrtA mutant, SEQ ID 1.
XX
KW Sorting enzyme A; SrtA protein; mutein; protein labeling.
XX
OS Staphylococcus aureus.
OS Synthetic.
XX
CC PN CN109797194-A.
XX
CC PD 24-MAY-2019.
XX
CC PF 24-JAN-2019; 2019CN-10067616.
XX
PR 24-JAN-2019; 2019CN-10067616.
XX
CC PA (UYPK ) UNIV PEKING.
XX
CC PI Chen P, Chen L, Ge Y, Liu S;
XX
DR WPI; 2019-47417N/60.
DR N-PSDB; BGJ38543.
XX
CC PT Labeling cell membrane surface comprises carrying LPXTG sequence is
CC PT linked to a cell membrane surface using Staphylococcus aureus sortase A
CC PT mutant.
XX
CC PS Claim 3; SEQ ID NO 1; 18pp; Chinese.
XX
CC The present invention relates to a novel method for labeling a cell
CC membrane surface. The method comprises: ligating a marker comprising a
CC LPXTG peptide to the cell membrane surface using a Staphylococcus aureus
CC sorting enzyme A (SrtA) (BA000018) mutant selected from SEQ ID NO: 1-6
CC (see BGJ38537-BGJ38542). The invention further claims a method for
CC detecting cell-cell interaction displaying the Staphylococcus aureus SrtA
CC mutant. The method of the present invention is useful for labeling a cell
CC membrane surface and for detecting cell-cell interaction. The present
CC sequence represents a Staphylococcus aureus SrtA mutant
CC (P94R/D124G/D160N/D165A/Y187L/E189R/K190E/K196T/F200L) which is
CC specifically claimed and can be used in the method of the present
CC invention for labeling a cell membrane surface.
XX
SQ Sequence 181 AA;
Query Match 100.0%; Score 944; Length 181;
Best Local Similarity 100.0%;
Matches 181; Conservative 0; Mismatches 0; Indels 0; Gaps 0;
Qy 1 KPHIDNYLHDKDKDEKIEQYDKNVKEQASKDKKQQAKPQIPKDKSKVAGYIEIPDADIKE 60
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Db 1 KPHIDNYLHDKDKDEKIEQYDKNVKEQASKDKKQQAKPQIPKDKSKVAGYIEIPDADIKE 60
Qy 61 PVYPGPATREQLNRGVSFAEENESLDDQNISIAGHTFIGRPNYQFTNLKAAKKGSMVYFK 120
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Db 61 PVYPGPATREQLNRGVSFAEENESLDDQNISIAGHTFIGRPNYQFTNLKAAKKGSMVYFK 120
Qy 121 VGNETRKYKMTSIRNVKPTAVGVLDEQKGKDKQLTLITCDDLNRETGVWETRKILVATEV 180
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Db 121 VGNETRKYKMTSIRNVKPTAVGVLDEQKGKDKQLTLITCDDLNRETGVWETRKILVATEV 180
Qy 181 K 181
|
Db 181 K 181