DV02-03 — Linker Architecture Plan
HELIX-VAX-01 / HELIX-VAX-02
PROJECT HELIX-HTT | Huntington’s-Adjacent Neuro-Oncology Vaccine Program
1. Purpose
The Linker Architecture Plan defines how antigen units are separated inside the vaccine construct to support efficient immune processing, balanced antigen presentation, and reduced junction-related artifacts.
Linkers are especially important in multi-antigen vaccines because they influence:
- antigen cleavage
- peptide release
- HLA presentation
- immunodominance balance
- construct stability
- safety
2. SCF Linker Design Principle
A linker should help the immune system process each antigen as a distinct target without becoming the dominant immune target itself.
SCF Rule:
The linker must support antigen visibility without becoming immunologically distracting.
3. Linker Design Objectives
Objective | Explanation |
Improve antigen processing | Allows each antigen to be released cleanly |
Reduce junction artifacts | Prevents unintended hybrid peptides |
Preserve antigen identity | Maintains correct target structure |
Avoid immunodominance | Linker should not dominate immune response |
Maintain CNS safety | Avoids similarity to neuronal proteins |
Support manufacturability | Keeps construct stable and reproducible |
4. HELIX-VAX-01 Linker Strategy
Multi-Antigen mRNA Construct
Recommended Linker Type
Processing-optimized flexible peptide linker
Functional Requirements
Requirement | Design Logic |
Short-to-moderate length | Avoid unnecessary sequence burden |
Flexible | Allows processing machinery access |
Cleavable | Supports antigen release |
Low immunogenicity | Prevents linker-directed immune response |
Low CNS homology | Reduces neuroimmune risk |
5. HELIX-VAX-01 Reference Linker Layout
VAMI-001
↓
LNK-01 Processing Linker
↓
VAMI-002
↓
LNK-01 Processing Linker
↓
VAMI-003
↓
LNK-02 Junction-Stabilizing Linker
↓
VAMI-004
↓
LNK-01 Processing Linker
↓
VAMI-005
↓
LNK-03 Low-Immunogenic Spacer
↓
VAMI-006
↓
LNK-01 Processing Linker
↓
Backup-01
↓
LNK-03 Low-Immunogenic Spacer
↓
Backup-026. Linker Classes
Linker ID | Linker Class | Primary Use |
LNK-01 | Processing linker | Standard antigen separation |
LNK-02 | Junction-stabilizing linker | Fusion antigen boundary protection |
LNK-03 | Low-immunogenic spacer | Lower-priority or safety-sensitive antigen separation |
7. Linker Placement Rules
Placement Rule | Rationale |
Use LNK-01 between high-priority neoantigens | Maximizes peptide processing |
Use LNK-02 around fusion antigens | Preserves junction specificity |
Use LNK-03 before TAAs or yellow-risk antigens | Reduces immunodominance risk |
Avoid repeated excessive linker motifs | Prevents linker immunogenicity |
Avoid CNS-homologous motifs | Protects neuroimmune safety |
8. HELIX-VAX-02 Linker Strategy
Synthetic Long Peptide Backup Platform
For synthetic long peptide constructs, linkers are less central than in mRNA constructs because each peptide can be manufactured as a separate antigen unit.
Recommended Strategy
Peptide Unit | Linker Requirement |
Individual SLP antigen | No internal linker required |
Multi-antigen peptide cassette | Flexible processing spacer |
Fusion peptide | Boundary-preserving spacer |
TAA-containing peptide | Low-immunogenic spacer |
9. Immunodominance Control
Linkers must not create unintended dominant epitopes.
Required Controls
Risk | Control |
Linker becomes immune target | In silico immunogenicity screening |
Junction peptide forms neo-epitope | Junction artifact analysis |
TAA dominates response | Place TAA later and use low-immunogenic spacer |
CNS cross-reactive linker motif | CNS homology screen |
10. Linker Safety Review
Every linker sequence must undergo:
- Human proteome homology screen
- CNS-enriched protein similarity review
- Predicted HLA-binding analysis
- Immunogenicity risk scoring
- Manufacturing stability review
11. Linker Quality Attributes
Quality Attribute | Acceptance Standard |
Identity | Correct sequence |
Stability | No degradation-prone motifs |
Processing efficiency | Supports antigen release |
Immunogenicity | Low |
CNS risk | Green |
Manufacturability | Acceptable |
12. Linker Scoring System
Linker Suitability Score =
Processing Efficiency
+ Construct Stability
+ Low Immunogenicity
+ Low CNS Homology
+ Manufacturing Compatibility
- Junction Artifact RiskScore | Decision |
≥85 | Preferred linker |
70–84 | Acceptable linker |
55–69 | Optimize |
<55 | Reject |
13. Final Linker Architecture Recommendation
HELIX-VAX-01
Use a three-linker system:
Linker | Role |
LNK-01 | Standard processing linker |
LNK-02 | Fusion antigen protection linker |
LNK-03 | Low-immunogenic spacer for TAA / backup antigens |
HELIX-VAX-02
Use individual synthetic long peptides where possible.
Use spacers only if multi-antigen cassette design is required.
14. Immediate Next Steps
- Generate candidate linker sequences
- Run CNS homology and HLA-binding screens
- Test antigen processing in dendritic-cell assays
- Compare linker variants in construct potency testing
- Finalize linker choice before adjuvant optimization
Status
DV02-03 Linker Architecture Plan: Complete
Next Sub-Deliverable: DV02-04 Manufacturing Readiness Assessment