Skip to content

Latest commit

 

History

History
 
 

README.md

Antibody Engineering & Optimization

Comprehensive antibody optimization skill for therapeutic development. From mouse antibody to clinical candidate in one workflow.

Quick Start

Basic Usage

from tooluniverse import ToolUniverse

tu = ToolUniverse()
tu.load_tools()

# Example 1: Humanize a mouse antibody
result = tu.chat("""
Humanize this mouse anti-PD-L1 antibody:

VH: EVQLVESGGGLVQPGGSLRLSCAASGYTFTSYYMHWVRQAPGKGLEWVSGIIPIFGTANYAQKFQGRVTISADTSKNTAYLQMNSLRAEDTAVYYCARDDGSYSPFDYWGQGTLVTVSS

VL: DIQMTQSPSSLSASVGDRVTITCRASQSISSYLNWYQQKPGKAPKLLIYAASSLQSGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQSYSTPLTFGQGTKVEIK

Target: PD-L1 (Q9NZQ7)
""")

Output: Humanized sequences with 85-90% human framework, CDR preservation, developability assessment, and recommendations.


What This Skill Does

Core Capabilities

  1. Humanization (Example 1)

    • Identify germline genes (IMGT)
    • Design CDR grafting strategy
    • Identify backmutations for CDR support
    • Predict affinity retention
  2. Affinity Maturation (Example 2)

    • Analyze binding interface
    • Design affinity-improving mutations
    • In silico screening for optimal variants
    • Balance affinity vs. developability
  3. Developability Assessment (Example 3)

    • Identify aggregation-prone regions
    • Detect PTM liability sites
    • Predict stability and expression
    • Calculate comprehensive developability score (0-100)
  4. Immunogenicity Prediction (Example 6)

    • Predict T-cell epitopes (IEDB)
    • Calculate immunogenicity risk score
    • Design deimmunization strategy
    • Compare to clinical precedents
  5. Manufacturing Assessment (Example 7)

    • Expression optimization (CHO cells)
    • Purification strategy design
    • Formulation recommendations
    • CMC timeline and cost estimates
  6. Advanced Engineering

    • Bispecific antibodies (Example 4)
    • pH-dependent binding (Example 5)
    • Aggregation mitigation (Example 3)
    • CDR optimization strategies

Key Features

Report-First Approach

Creates antibody_optimization_report.md with progressive updates throughout analysis.

Comprehensive Scoring

  • Humanization Score: % framework identity to human germline
  • Developability Score: 0-100 combining aggregation, PTM, stability, expression
  • Immunogenicity Risk: Low/Medium/High based on T-cell epitopes
  • Evidence Grading: T1-T4 tiers for variant ranking

Evidence-Based Design

  • Uses IMGT germline database for humanization
  • Benchmarks against approved antibodies (TheraSAbDab)
  • Validates with clinical precedents
  • Structural modeling (AlphaFold)

Input Requirements

Minimum Input

- Antibody sequence (VH and/or VL)
- Target antigen (UniProt ID or name)
- Optimization goal (humanization, affinity, developability)

Optional Input

- Current affinity (KD)
- Known issues (aggregation, immunogenicity)
- Species (if not mouse)
- Epitope information
- Clinical development stage

Output Files

1. Main Report

File: antibody_optimization_report.md

Contains:

  • Input characterization
  • Humanization strategy (if applicable)
  • Structure modeling & analysis
  • Affinity optimization (if requested)
  • Developability assessment
  • Immunogenicity prediction
  • Manufacturing feasibility
  • Final recommendations

2. Sequence Files

File: optimized_sequences.fasta

All designed variants in FASTA format with annotations:

>VH_Humanized_v2 | 85% human | KD=2.1nM | Dev=79/100
EVQLVQSGAEVKKPGASVKVSCKASGYAFTSYYMHWVRQAPGQGLEWMV...

3. Comparison Tables

File: humanization_comparison.csv or developability_assessment.csv

Detailed metrics for all variants.


Common Use Cases

Use Case 1: Mouse to Human (Humanization)

Query: "Humanize this mouse antibody"

Process:

  1. CDR annotation (IMGT numbering)
  2. Germline gene search (IMGT)
  3. Framework selection (identity + clinical use)
  4. CDR grafting design
  5. Backmutation analysis
  6. Structure validation (AlphaFold)
  7. Developability scoring

Output: 2-3 humanized variants (85-90% human) with recommendations

Timeline: ~30 minutes for full analysis


Use Case 2: Affinity Improvement

Query: "Improve affinity from 15 nM to <5 nM"

Process:

  1. Interface analysis
  2. Hotspot identification
  3. In silico mutation screening
  4. Combination variant design
  5. Developability impact assessment
  6. Testing strategy

Output: 5-10 affinity variants ranked by predicted improvement

Timeline: ~20 minutes for full analysis


Use Case 3: Aggregation Reduction

Query: "This antibody aggregates at >50 mg/mL. Fix it."

Process:

  1. Aggregation-prone region (APR) identification
  2. Hydrophobic patch analysis
  3. Charge distribution assessment
  4. Mutation design (disrupt APRs)
  5. Formulation recommendations
  6. Validation plan

Output: 3-5 aggregation-mitigated variants with predicted max concentration

Timeline: ~25 minutes for full analysis


Use Case 4: Complete Optimization Pipeline

Query: "Take this mouse antibody to clinical candidate"

Process (all phases):

  1. Humanization (Phase 2)
  2. Structure modeling (Phase 3)
  3. Affinity optimization (Phase 4)
  4. Developability assessment (Phase 5)
  5. Immunogenicity prediction (Phase 6)
  6. Manufacturing assessment (Phase 7)

Output: Comprehensive 1000+ line report with top candidate recommendation

Timeline: ~45-60 minutes for full pipeline


Tool Dependencies

Required Tools

Tool Category Tools Used Purpose
Immunogenetics IMGT_search_genes, IMGT_get_sequence Germline identification
Antibody Databases SAbDab, TheraSAbDab Structural & clinical precedents
Structure AlphaFold_get_prediction Structure modeling
Immunogenicity iedb_search_epitopes, iedb_search_bcell Epitope prediction
Target Info UniProt_get_protein_by_accession Target characterization
Literature PubMed_search Clinical precedents

Optional Tools

  • STRING (for bispecifics - protein interaction networks)
  • EMDB (if target has cryo-EM structures)
  • PDB (for experimental structures)

Validation & Quality Control

Automatic Checks

  1. CDR Preservation: Warns if humanization changes CDR sequences
  2. Vernier Zone: Identifies residues affecting CDR conformation
  3. PTM Sites: Flags deamidation (NG, NS), isomerization (DG, DS), oxidation (M, W)
  4. Aggregation: TANGO scores, hydrophobic patches
  5. pI Range: Checks for extreme values (<4 or >10)
  6. Canonical Classes: Validates CDR conformations

Evidence Grading

Tier Criteria Recommendation
T1 Humanness >85%, Dev score >75, Low immunogenicity Advance to development
T2 Humanness 70-85%, Dev score 60-75, Medium immunogenicity Acceptable, monitoring needed
T3 Humanness <70%, Dev score <60, or High immunogenicity Requires optimization
T4 Failed validation or major liabilities Do not advance

Best Practices

1. Start with Complete Information

Provide as much context as possible:

  • Current affinity (if known)
  • Known issues (aggregation, immunogenicity, stability)
  • Development stage (discovery, preclinical, clinical)
  • Target indication and therapeutic modality

2. Review Recommendations Carefully

The skill provides computational predictions. Always:

  • Validate top candidates experimentally
  • Test multiple variants (don't rely on single prediction)
  • Consider backup options
  • Monitor for unexpected issues

3. Iterative Optimization

Use results to guide next steps:

  • If humanization reduces affinity → Test backmutations
  • If aggregation persists → Try alternative formulations
  • If immunogenicity high → Apply deimmunization strategy

4. Balance Metrics

Optimal candidate balances multiple factors:

  • Affinity (target: <10 nM for most applications)
  • Humanization (target: >85% for low immunogenicity)
  • Developability (target: >75 for clinical success)
  • Manufacturing (target: Expression >1 g/L, formulation >100 mg/mL)

Limitations

1. Computational Predictions

  • Affinity predictions: ±2-3x accuracy
  • Structure predictions: CDR-H3 may have lower confidence
  • Aggregation: In silico scores are estimates (require validation)

2. Experimental Validation Required

Always validate computationally designed variants:

  • Binding affinity (SPR, BLI)
  • Expression and stability
  • Functional activity
  • In vivo PK (for final candidate)

3. Species Considerations

  • Primarily optimized for human therapeutics
  • Mouse → Human humanization most common
  • Other species may require custom germline databases

4. Complex Formats

  • Bispecifics require additional manufacturing development
  • Non-IgG formats (scFv, Fab) have different considerations
  • Antibody-drug conjugates (ADCs) need separate conjugation site engineering

Troubleshooting

Issue 1: Low Humanization Score (<80%)

Solutions:

  • Try alternative germline frameworks
  • Accept lower score if affinity critical (clinical monitoring)
  • Consider fully human antibody (phage display, transgenic mice)

Issue 2: Affinity Loss After Humanization

Solutions:

  • Introduce backmutations at Vernier zone positions
  • Test multiple humanization versions
  • Combine humanization with affinity maturation

Issue 3: High Aggregation Risk

Solutions:

  • Apply aggregation mitigation mutations (disrupt APRs)
  • Optimize formulation (pH, excipients, concentration)
  • Consider alternative framework (lower pI)

Issue 4: Immunogenicity Concerns

Solutions:

  • Apply deimmunization (remove T-cell epitopes)
  • Increase humanization level
  • Consider fully human framework

References & Resources

Key Databases

Recommended Reading

  • Antibody humanization: Almagro & Fransson, Front. Biosci. 2008
  • CDR grafting: Queen et al., PNAS 1989
  • Developability: Jain et al., mAbs 2017
  • pH-dependent binding: Igawa et al., Nat. Biotechnol. 2010

Clinical Precedents

  • Use TheraSAbDab to search approved antibodies
  • 100 approved therapeutic antibodies as of 2026

  • Most use IGHV1-69, IGHV3-23, IGKV1-39 germlines

Example Queries

Simple Queries

"Humanize this mouse anti-PD-L1 antibody"

"Improve affinity of this antibody to <5 nM"

"Assess developability of this sequence"

"Reduce aggregation in this antibody"

"Predict immunogenicity risk"

Advanced Queries

"Humanize this mouse antibody, optimize affinity, and assess developability"

"Design a bispecific antibody targeting PD-L1 and TIM-3"

"Engineer pH-dependent binding into this anti-HER2 antibody for improved PK"

"Take this mouse antibody through complete optimization to clinical candidate"

Specific Goals

"Humanize to >85% while maintaining affinity within 2x"

"Reduce aggregation to enable >150 mg/mL formulation"

"Improve affinity from 15 nM to <5 nM without compromising developability"

"Deimmunize this humanized antibody to reduce T-cell epitopes"

Support

For issues, questions, or feature requests:

  1. Check EXAMPLES.md for detailed use cases
  2. Review SKILL.md for complete workflow documentation
  3. Consult ToolUniverse documentation for tool-specific questions

Version History

  • v1.0 (2026-02-09): Initial release
    • Humanization pipeline
    • Affinity maturation
    • Developability assessment
    • Immunogenicity prediction
    • Manufacturing assessment
    • Bispecific antibody design
    • pH-dependent binding engineering

License

This skill is part of the ToolUniverse project. See main repository for license information.