Using Synthetic DNA Fragments to Block HIV Replication
A 1987 patent describing a specific synthetic DNA molecule designed to stop the HIV virus from replicating by blocking a key part of its genetic code.
Original patent title: “Oligonucleotide phosphonates and method of inhibiting a human immunodeficiency virus in vitro utilizing said oligonucleotide phosphonates”
A 1987 patent describing a specific synthetic DNA molecule designed to stop the HIV virus from replicating by blocking a key part of its genetic code. Granted to City of Hope in 1992 with 8 claims and 26 forward citations.
Key facts
Coverage
What does this patent actually cover?
The patent describes an oligodeoxyribonucleoside methylphosphonate, a synthetic molecule that mimics DNA but is chemically modified to be more stable. This molecule is designed to bind specifically to the first splice acceptor site of the HIV tat III gene. By binding to this site, the molecule prevents the virus from producing the proteins it needs to replicate and form syncytial giant cells, which are clusters of infected cells. The patent claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → both the specific sequence 3' TCTTAACC 5' and the method of using such sequences to inhibit HIV in laboratory cell cultures.
The gap
What does this patent NOT cover?
- Does not cover naturally occurring DNA or RNA sequences.
- Does not cover therapeutic methods for treating human patients, as the claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → are limited to in vitro applications.
- Does not cover other chemical modifications to DNA backbones beyond methylphosphonates.
- Does not cover sequences that do not target the specific tat III splice acceptor site.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The inventors used a methylphosphonate backbone to replace the standard phosphate backbone of DNA, making the molecule resistant to degradation by cellular enzymes that would otherwise destroy it before it could reach its target.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Antisense oligonucleotide research
Experimental HIV gene therapy models
Why it matters
The bigger picture
This patent represents an early attempt to use antisense technology to treat viral infections. By targeting the genetic instructions of the virus rather than the proteins it produces, the inventors sought a more precise way to halt the HIV life cycle. It is a foundational example of using synthetic nucleic acids for therapeutic intervention.
Filed
July 14, 1987
Granted
May 5, 1992
Market context
Who's building on this
Companies in this space
Modern biotech companies like Ionis Pharmaceuticals and Alnylam Pharmaceuticals have advanced the field of antisense and RNA interference therapies, building on the fundamental concept of using synthetic oligonucleotides to regulate gene expression.
Market impact
This work helped validate the potential of antisense technology as a therapeutic tool. While this specific sequence did not become a standard HIV treatment, it contributed to the broader development of nucleic acid-based drugs that are now used to treat rare genetic diseases and other conditions.
Claim 1 — Plain English
What this patent covers
The patent describes an oligodeoxyribonucleoside methylphosphonate, a synthetic molecule that mimics DNA but is chemically modified to be more stable. This molecule is designed to bind specifically to the first splice acceptor site of the HIV tat III gene. By binding to this site, the molecule prevents the virus from producing the proteins it needs to replicate and form syncytial giant cells, which are clusters of infected cells. The patent claims both the specific sequence 3' TCTTAACC 5' and the method of using such sequences to inhibit HIV in laboratory cell cultures.
The clever bit
The inventors used a methylphosphonate backbone to replace the standard phosphate backbone of DNA, making the molecule resistant to degradation by cellular enzymes that would otherwise destroy it before it could reach its target.
What it does not cover
- Does not cover naturally occurring DNA or RNA sequences.
- Does not cover therapeutic methods for treating human patients, as the claims are limited to in vitro applications.
- Does not cover other chemical modifications to DNA backbones beyond methylphosphonates.
- Does not cover sequences that do not target the specific tat III splice acceptor site.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Early stage
Citation count
29/40
Moderately cited
Claim breadth
5/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$34K – $108K
Midpoint $68K · expired or expiring · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
8 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Wallace, R. B., Cantin, E. M., Rossi, J. J., & Zaia, J. A. (1992). Using Synthetic DNA Fragments to Block HIV Replication (U.S. Patent No. 5,110,802). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/5110802/crixivan-indinavir
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US5110802"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4965188 · 1990
How to Make Many Copies of a DNA Piece with Heat
This patent describes the Polymerase Chain Reaction (PCR) method, a technique to make millions of copies of a specific DNA segment using a heat-resistant enzyme and repeated temperature changes.
Cetus Corp
US 4235871 · 1980
How to Encapsulate Active Materials in Lipid Bubbles Efficiently
This patent describes a method for trapping biologically active substances inside tiny, multi-layered fat bubbles called liposomes, using a specific water-in-oil emulsion and gel-forming process to improve how much material gets captured.
Individual
More to explore
More in Biotech & Medicine
US 4683195 · 1987 · Cetus Corp
How to Make Billions of Copies of a DNA Segment
US 8697359 · 2014 · Massachusetts Institute of Technology
How to Edit Genes in Human Cells Using an Engineered CRISPR System
US 4733665 · 1988 · Expandable Grafts Partnership
How Doctors Implant a Permanent Stent Using a Balloon
US 4965188 · 1990 · Cetus Corp
How to Make Many Copies of a DNA Piece with Heat
New to patents?
Common Questions
Frequently Asked Questions
What does Using Synthetic DNA Fragments to Block HIV Replication cover?
A 1987 patent describing a specific synthetic DNA molecule designed to stop the HIV virus from replicating by blocking a key part of its genetic code.
Who owns patent US 5110802?
City of Hope owns this patent, granted in 1992.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 5110802 cited by?
This patent has been cited by 26 later patents that build on its ideas.
What problem does this patent solve?
This patent represents an early attempt to use antisense technology to treat viral infections. By targeting the genetic instructions of the virus rather than the proteins it produces, the inventors sought a more precise way to halt the HIV life cycle. It is a foundational example of using synthetic nucleic acids for therapeutic intervention.
What does this patent NOT cover?
Does not cover naturally occurring DNA or RNA sequences.
Patent monitoring