Antigen tolerance induction through use of flt3l variants

Patent metadata

Field	Value
Publication number	US-2025340607-A1
Application number	US-202318871076-A
Country	US
Kind code	A1
Filing date	Jun 2, 2023
Priority date	Jun 3, 2022
Publication date	Nov 6, 2025
Grant date	—

Abstract

The current disclosure describes compositions and methods that may be administered to prevent immune responses against therapeutic molecules. The disclosure provides for a composition comprising a polypeptide comprising an engineered Fms Related Receptor Tyrosine Kinase 3 Ligand (Flt3L) protein. Also described is a method of treatment comprising: administering to a subject in need thereof, an effective amount of an engineered Flt3L protein of the disclosure. Methods also relate to a method for inducing immunotolerance in a subject in need thereof comprising, the method comprising administering to the subject an engineered Flt3L protein of the disclosure.

First claim

1 . A composition comprising a polypeptide comprising an engineered Fms Related Receptor Tyrosine Kinase 3 Ligand (Flt3L) protein.

2 . The composition of claim 1 , wherein the polypeptide comprises an albumin protein.

3 . The composition of claim 2 , wherein the engineered Flt3L protein is connected to the albumin protein.

4 . The composition of claim 3 , wherein the polypeptide is a fusion of the engineered Flt3L protein and the albumin.

5 . The composition of claim 3 , wherein the engineered Flt3L protein is conjugated to the albumin protein.

6 . The composition of any of claims 2-5 , wherein the albumin protein is a Mouse Serum Albumin (MSA) protein.

7 . The composition of claim 6 , wherein the Flt3L-MSA fusion protein comprises an amino acid sequence that is at least 90% identical to SEQ ID NOs: 58 and 60.

8 . The composition of any of claims 2-5 , wherein the albumin protein is a Human Serum Albumin (HSA) protein.

9 . The composition of claim 8 , wherein the Flt3L-HSA fusion protein comprises an amino acid sequence that is at least 90% identical to SEQ ID NOs: 59 and 61.

10 . The composition of claim 1 , wherein the Flt3L protein is fused to a Fc domain of an IgG1 (Flt3L-Fc).

11 . The composition of claim 10 , wherein the Fc protein is a mouse Fc protein.

12 . The composition of claim 11 , wherein the Flt3L-Fc fusion protein comprises an amino acid sequence that is at least 90% identical to SEQ ID NOs: 58 and 62.

13 . The composition of claim 10 , wherein the Fc protein is a human Fc protein.

14 . The composition of claim 13 , wherein the Flt3L-Fc fusion protein comprises an amino acid sequence that is at least 90% identical to SEQ ID NOs: 59 and 63.

15 . The composition of any one of claims 1-14 , wherein the Flt3L protein is a mouse Flt3L protein.

16 . The composition of any one of claims 1-14 , wherein the Flt3L protein is a human Flt3L protein.

17 . The composition of any one of claims 1-16 , wherein the composition does not comprise rapamycin.

18 . The composition of any one of claims 1-17 , wherein the composition further comprises an immunogenic biomolecule and/or immunogenic cell therapy.

19 . The composition of claim 18 , wherein the immunogenic biomolecule is a nucleic acid, protein, or virus, or a combination thereof.

20 . The composition of claim 19 , wherein the nucleic acid is DNA, RNA, or a combination thereof.

21 . The composition of claim 19 , wherein the nucleic acid is an siRNA, miRNA, gRNA, mRNA, lincRNA, cDNA, gene or gene fragment, expression construct, or plasmid, or a combination thereof.

22 . The composition of claim 19 , wherein the virus is adenovirus, adeno-associated virus, lentivirus, or retrovirus, or a combination thereof.

23 . The composition of claim 19 , wherein the protein is an enzyme, an antigen binding protein, an antibody or antibody fragment, a cytokine, a chemokine, a ligand, a receptor, or binding protein, or a combination thereof.

24 . The composition of claim 19 , wherein the cell therapy comprises T-cells, B-cells, dendritic cells, NK or iNK cells, other hematopoietic cells, epithelial cells, neuronal or nerve cells, stem cells, pluripotent cells, cardiac cells, skeletal cells, smooth muscle cells, skin cells, endothelial cells, fat cells, pancreatic cells, or bone cells, or a combination thereof.

25 . The composition of any one of claims 1-24 , wherein the composition comprises or consists essentially of one or more of the Flt3L protein, Flt3L fusion protein, an immunogenic biomolecule, and an immunogenic cell therapy.

26 . The composition of any one of claims 1-25 , wherein the composition consists of the Flt3L protein and/or Flt3L fusion protein.

27 . A method of treatment comprising: administering to a subject in need thereof an effective amount of an engineered Flt3L protein of any one of claims 1-26 .

28 . A method for inducing immunotolerance in a subject in need thereof comprising, the method comprising administering to the subject an engineered Flt3L protein of any one of claims 1-26 .

29 . The method of claim 27 or 28 , wherein the FLT3L polypeptide comprises a fusion protein comprising: a FLT3L polypeptide linked to a serum protein.

30 . The method of claim 29 , wherein the serum protein comprises albumin.

31 . The method of claim 30 , wherein the albumin comprises human serum albumin or mouse serum albumin.

32 . The method of any one of claims 29-31 , wherein the serum protein comprises the amino acid sequence of SEQ ID NO:60 or 61, or an amino acid sequence having at least 80% sequence identity to SEQ ID NO:60 or 61.

33 . The method of any one of claims 27-32 , wherein the FLT3L polypeptide comprises the amino acid sequence of one of SEQ ID NOs: 40-50, 58 or 59 or an amino acid sequence having at least 80% sequence identity to one of SEQ ID NOs: 40-50, 58 or 59.

34 . The method of any one of claims 27-33 , wherein the FLT3L polypeptide comprises a fusion protein comprising: a FLT3L extracellular domain operably linked to an immunoglobulin fragment crystallizable region (Fc region).

35 . The method of claim 34 , wherein at least 5 amino acids are truncated from the C-terminus of the FLT3L extracellular domain; and/or the Fc region does not comprise a hinge region.

36 . The method of claim 34 or 35 , wherein the FLT3L extracellular domain is a human FLT3L extracellular domain or derived from a human FLT3L extracellular domain.

37 . The method of any one of claims 34-36 , wherein the fusion protein is capable of binding to human FLT3.

38 . The method of any one of claims 34-37 , wherein the FLT3L extracellular domain is from FLT3L isoform 1.

39 . The method of any one of claims 34-37 , wherein the FLT3L extracellular domain is from FLT3L isoform 2.

40 . The method of any one of claims 34-39 , wherein the FLT3L extracellular domain does not comprise the amino acid sequence PTAPQ.

41 . The method of any one of claims 34-40 , wherein at least 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 amino acids are truncated from the C-terminus of the FLT3L extracellular domain.

42 . The method of any one of claims 34-41 , wherein the FLT3L extracellular domain does not comprise the amino acid sequence APTAPQ (SEQ ID NO:29), TAPTAPQ (SEQ ID NO: 30), ATAPTAPQ (SEQ ID NO:31), EATAPTAPQ (SEQ ID NO:32), or LEATAPTAPQ (SEQ ID NO:33).

43 . The method of any one of claims 34-42 , wherein the FLT3L extracellular domain does not comprise the amino acid sequence PTAPQPP (SEQ ID NO:34), APTAPQPP (SEQ ID NO: 35), TAPTAPQPP (SEQ ID NO:36), ATAPTAPQPP (SEQ ID NO:37), EATAPTAPQPP (SEQ ID NO:38), or LEATAPTAPQPP (SEQ ID NO:39).

44 . The method of any one of claims 34-43 , wherein the FLT3L extracellular domain comprises an N-terminal signal peptide.

45 . The method of any one of claims 34-44 , wherein the FLT3L extracellular domain comprises amino acid substitutions at one or more of the following amino acid positions: H8Y, K84E, N100, S102, N123 and S125, wherein the amino acid residue positions are with reference to SEQ ID NOs: 1-18,

Assignees

• Univ Chicago

Inventors

• Hubbell Jeffrey A
• Alpar Aaron
• Wallace Rachel P
• Refvik Kirsten C

Classifications

• C07K14/765

  Serum albumin, e.g. HSA · CPC title

• A61K45/06

  Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca · CPC title

• A61K38/18

  Growth factors; Growth regulators · CPC title

• A61P37/04

  Immunostimulants · CPC title

• A61K47/68 Primary

  the modifying agent being an antibody, an immunoglobulin or a fragment thereof, e.g. an Fc-fragment · CPC title