Virus-like particle conjugates for diagnosis and treatment of tumors
Inventors
de los Pinos, Elisabet • Schiller, John Todd • Kines, Rhonda C. • MacDougall, John
Assignees
Aura Biosciences Inc • US Department of Health and Human Services
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Publication Number
US-10588984-B2
Publication Date
2020-03-17
Expiration Date
2034-09-18
Abstract
The present disclosure is directed to methods and compositions for the diagnosis and/or treatment of tumors, such as ocular tumors, using virus-like particles conjugated to photosensitive molecules.
Core Innovation
The invention provides methods and compositions for the diagnosis and/or treatment of tumors, such as ocular tumors, using virus-like particles conjugated to photosensitive molecules. These photosensitive viral-like nanoparticles can be selectively delivered to tumor cells and activated by light exposure to cause cellular toxicity without damaging healthy cells. The virus-like nanoparticles are assembled from papilloma virus capsid proteins (L1 or L1/L2), with photosensitive molecules covalently conjugated to surface-exposed peptides of these capsid proteins.
A key aspect of the innovation is that conjugation of photosensitive molecules to the viral-like particles does not interfere with their specificity and binding to tumor cells via heparan sulphate proteoglycans. The viral-like particles can carry a substantially higher number of photosensitive molecules per particle (e.g., about 50 to 1000 molecules), enabling the selective killing of tumor cells upon photoactivation with extremely small drug amounts. The photosensitive molecules include infrared dyes such as IR700, porphyrins like verteporfin, and chlorophyll molecules, which become cytotoxic upon light activation.
The problem being addressed is the limitation and side effects of current cancer treatments, especially for ocular cancers such as ocular melanoma. Existing treatments are highly invasive or cause severe complications, and antibody-based photodynamic therapies are limited by low delivery capacity and off-target effects. The invention overcomes these issues by providing viral-like particles that can target tumor cells with high specificity and deliver large payloads of photosensitive molecules for effective photodynamic therapy with minimized off-target damage.
Claims Coverage
The patent presents 17 inventive features based on a method for producing tumor-targeting bioconjugates using virus-like particles conjugated with photosensitive near infrared phthalocyanine dyes.
Method of producing tumor-targeting bioconjugates
Describes transfecting cells in vitro with DNA encoding papilloma virus capsid proteins that assemble into proto-capsids, maturing the proto-capsids into virus-like particles, and conjugating near infrared phthalocyanine dye molecules to the capsid proteins, producing bioconjugates containing about 50 to 1000 dye molecules that become toxic upon light activation.
Elimination of host cell DNA
Involves treating the capsid proteins with benzonase to remove host cell DNA during the production process.
Use of human papilloma virus capsid proteins
Specifies that the papilloma virus capsid proteins can be human HPV capsid proteins.
Inclusion of HPV L1 and L2 capsid proteins
Employs HPV L1 capsid proteins or a combination of HPV L1 and L2 capsid proteins in forming the virus-like particles.
Variant HPV16/31 L1 capsid proteins
Uses HPV L1 capsid proteins comprising an amino acid sequence encoded by the nucleotide sequence SEQ ID NO: 1.
Use of non-human papilloma virus capsid proteins
Allows for using non-human papilloma virus capsid proteins in producing the virus-like particles.
Use of bovine papilloma virus capsid proteins
Specifically utilizes bovine papilloma virus (BPV) capsid proteins as non-human papilloma virus capsid proteins.
Inclusion of BPV L1 and L2 capsid proteins
Employs BPV L1 capsid proteins or a combination of BPV L1 and L2 capsid proteins in the virus-like particles.
BPV L1 capsid protein sequence
Uses BPV L1 capsid proteins comprising an amino acid sequence encoded by the nucleotide sequence SEQ ID NO: 2.
Covalent conjugation of dye molecules
The near infrared phthalocyanine dye molecules are covalently conjugated to papilloma virus capsid proteins.
Amide bond conjugation
Specifies that the dye molecules are conjugated to capsid proteins through covalent amide bonds.
Conjugation to lysine residues
The dye molecules are covalently attached specifically to lysine residues of the capsid proteins.
Photosensitizer properties of dye molecules
The near infrared phthalocyanine dye molecules act as photosensitizers that upon light absorption produce singlet oxygen causing cytotoxicity.
Use of IR700 dye molecules
Specifies that IR700 dye molecules comprise the near infrared phthalocyanine dye molecules used for conjugation.
Bioconjugate composition with 50 to 500 dye molecules
Each bioconjugate comprises about 50 to about 500 near infrared phthalocyanine dye molecules.
Bioconjugate composition with about 200 dye molecules
Each bioconjugate comprises about 200 dye molecules.
Bioconjugate composition with about 300 or 400 dye molecules
Each bioconjugate comprises about 300 or about 400 near infrared phthalocyanine dye molecules.
The claims cover a method of producing virus-like particle bioconjugates with papilloma virus capsid proteins conjugated covalently to near infrared photosensitive phthalocyanine dyes, especially IR700, with detailed capsid protein types and dye conjugation chemistry. The invention emphasizes tumor-targeting bioconjugates containing about 50 to 1000 dye molecules that confer photoactivated cytotoxic properties.
Stated Advantages
High delivery capacity of photosensitive molecules per virus-like particle, enabling effective tumor targeting and cell killing.
Selective targeting of tumor cells without damaging healthy cells, reducing undesirable side effects associated with conventional therapies.
Preserves the natural tissue and tumor tropism of virus-like particles even after conjugation with photosensitive molecules.
Capability of treating tumors that lack identified tumor receptor molecules and are untreatable by antibody-based therapies.
Efficacy in treating distant metastases and early malignant or pre-cancerous lesions.
Documented Applications
Diagnosis and treatment of ocular tumors including ocular melanoma and retinoblastoma.
Treatment of tumors located in lung, pleura, liver, pancreas, stomach, esophagus, colon, breast, ovary, prostate, brain, meninges, testis, gastrointestinal tract, kidneys, bladder, head, neck, cervix, larynx or skin.
Selective killing of cancerous tumor cells while sparing non-cancerous cells via photodynamic therapy using photosensitive virus-like particles.
Use of photosensitive virus-like particles for imaging and localization of tumors through light activation and fluorescence.
Treatment of metastatic tumors and rare or orphan diseases involving tumors.
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