# US 12,215,339 B2 · Lentivirus packaging system comprising a synthetic positive feedback loop

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- Number: US 12,215,339 B2
- Document ID: US12215339B2
- Status: Granted
- Kind: B2
- Application number: 17/532,075
- Filed: 2021-11-22
- Published: 2022-05-19
- Granted: 2025-02-04
- Earliest claimed: 2016-01-12
- Assignees: University of Cincinnati
- Applicants: University of Cincinnati
- Inventors: Toru Matsuura; Christian I. Hong; Kaoru Matsuura
- Web page: https://patentgrep.com/patent/US12215339B2

## CPC

- C12N 15/86: Viral vectors
- A61K 48/005: {characterised by an aspect of the 'active' part of the composition delivered, i.e. the nucleic acid delivered}
- C07K 14/005: from viruses
- C12N 2740/15042: virus or viral particle as vehicle, e.g. encapsulating small organic molecule
- C12N 2740/15052: relating to complementing cells and packaging systems for producing virus or viral particles
- C12N 2740/16022: New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
- C12N 2740/16043: viral genome or elements thereof as genetic vector
- C12N 2740/16052: relating to complementing cells and packaging systems for producing virus or viral particles
- C12N 2830/003: tet inducible
- C12N: MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA (microbiological testing media C12Q1/00)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)

## Abstract

Novel lentivirus packaging systems engineered with a synthetic gene network having a positive feedback loop to amplify the expression of virus genes are provided. When co-transfected into a host cell with a transfer plasmid and envelope vector, extremely high viral titers are achieved when compared to transfection of a host cell with conventional third generation packaging systems. Methods for enhancing production of lentivirus, compositions comprising high titer lentivirus, and therapeutic methods based on delivery of lentiviral nucleic acid to target cells are also provided.

## Claims

### Claim 1

A lentivirus packaging system comprising:
(a) a helper plasmid comprising tetracycline transactivator (tTA) under the control of tetracycline responsive element (TRE) (TRE-tTA);
(b) a CMV promotor-controlled tTA (CMV-tTA) helper plasmid;
(c) a CMV-VSV-G envelope plasmid; and
(d) at least one plasmid comprising a TRE promotor controlling a subset of HIV-1 genes, selected from the group consisting of:
a TRE-ΔR8.2-Δvpr plasmid, and
a TRE-ΔR8.2-Δvpr, rev, nef plasmid and a TRE-rev plasmid.

### Claim 2 (depends on 1)

The packaging system according to claim 1, wherein the subset of HIV genes excludes LTRs, vpr and env.