Home » Biologics Discovery » Antibody Lead Optimization » Fc Engineering Service

Silence Fc Effector Function

  • ProBio is partnered with mAbsolve to offer STR silencing technology. Customers benefit directly from STR Fc silencing technology licensed by ProBio.

The highlight of STR silencing technology:

  • STR silencing technology comprises 3 mutations in the CH2 domain of the Fc.
  • STR silencing technology truly abolish Fc domain effector function whereas other Fc silencing technologies, such as LALA or glycosylation only reduce but do not abolish Fc receptor binding.
  • STR silencing technology can be applied to any IgG based antibody or other Fc-fusion protein.
Milestone Service Description TAT Deliverable
1-1 Gene synthesis and antibody production STR mutant gene synthesis and antibody production 2 weeks
  • 0.5mg STR mutant
  • Antibody sequences
  • SEC-HPLC and SPR report
  • Cell-based assay report
1-2 Affinity measurement Detect affinity of STR mutant to CD16a by SPR
1-3 Antibody SEC-HPLC analysis SEC-HPLC analysis of STR mutant 1 weeks
2-1 Cell-based functional assay(optional) ADCC assay(dose response study) 2-3 weeks
CDC assay(dose response study)
ADCP assay(dose response study) 4-6 weeks

ProBio offers mAbsolve's licensed STR technology and free-to-operate Fc silencing technologies according to customers' needs. Click "Contact Us" for more details.

Enhance Fc Effector Function

  • Fc domain binding to Fc receptors mediates the different antibody effects, such as ADCC and ADCP effects by FcγRs, CDC effects by C1q, and FcRn is associated with the half-life of proteins.

    The enhancement of Fc region-mediated effector functions, for instance, ADCC or ADCP effects enhanced by the affinity of the Fc domain to the FcγRIII(CD16), improves antibody efficacy.

ProBio provides multiple Fc engineering solutions for ADCC, CDC, and ADCP enhancement.

Milestone Service Description Timeline Deliverable
1-1 Gene synthesis and antibody production One Fc function enhanced mutant gene synthesis and antibody production 2 weeks
  • 0.5mg Fc function enhanced mutant
  • Mutant antibody sequences
  • SEC-HPLC and SPR report
  • Cell-based assay report
1-2 Affinity measurement Detect affinity of mutants to one antigen by SPR
1-3 Antibody SEC-HPLC analysis SEC-HPLC analysis of mutant 1 weeks
2-1 Cell-based functional assay(optional) ADCC assay(dose response study) 2-3weeks
CDC assay(dose response study)
ADCP assay(dose response study) 4-6 weeks

Click “Contact Us” , get Fc function enhancement solutions

Two mutated Fc constructs were evaluated for their potency of ADCC and CDC against PA-1 target cells. As claimed, the published Fc mutation sequences showed enhanced ADCC and CDC activities on PA-1 cells.

Extend Serum Half-life

  • IgG recycling begins with IgG binding to the FcRn with IgG uptake into an endothelial cell via an acidified endosome. It ultimately ends up with the release of IgG back into the blood. Enhancement of the binding between IgG & FcRn will promote a higher ratio of IgG recycling and improve the antibody serum half-life.

    ProBio provides two strategies to elongate antibody serum half-life: FTO mutants, Library screening for novel Fc mutation.

FTO Fc engineering service

Milestone Service Description Timeline Deliverable
1-1 Gene synthesis and antibody production One Fc domain mutant gene synthesis and antibody production 2 weeks
  • 0.5mg Fc domain mutant
  • Mutant antibody sequences
  • SEC-HPLC and SPR report
  • PK study report
1-2 Affinity measurement Detect affinity of mutants to one antigen by SPR
1-3 Antibody SEC-HPLC analysis SEC-HPLC analysis of mutant 1 weeks
2-1 In vivo pharmacology study Pharmacokinetics Study 2-4 weeks

Library Screening Service

Milestone Description Timeline Deliverable
1-1 FC production and binding confirmation 3 weeks
  • All the optimized sequences
  • 3 Purified antibodies with the best affinity, 0.5mg/antibody
  • Guarantee at least 1 sequence has 10 fold of affinity improvement
1-2 PML library construction & FASEBA screening against target 1 by SPR 6 weeks
1-3 Construction of combinatorial library & screening against 1 antigen 3 weeks
1-4 Production and characterization of affinity-matured Fc(Up to three) 3 weeks
2 Pharmacokinetics Study 2-4 weeks

Fc Engineering Modification(including human/canine/feline)

We are keen to benchmark our unique integrated strategy, in particular, the combination of PML and HTP FASEBA affinity screening platforms, applied in Fc engineering strategies to discover variants with higher affinity towards FcRn. In this case, the result showed that the best variant was improved by 33 fold compared to WT, and 3.3 fold comparing the YTE combo.

Ligand Analyte Chi² (RU²) ka (1/Ms) kd(1/s) KD (M) Rmax (RU)
WT FcRn 1..14E-01 NA NA 1.43E-06 146.6
YTE-positive control FcRn 6.92E-02 1.63E+05 2.30E-02 1.41E-07 74.1
Variant1 FcRn 1.35E-02 1.02E+05 4.45E-03 4.38E-08 5.2
Variant2 FcRn 4.84E-01 1.81E+05 1.05E-02 5.81E-08 48.7
Variant3 FcRn 1.46E-01 2.43E+05 1.61E-02 6.62E-08 52.4

References

Raghavan, M., Bonagura, V.R., Morrison, S.L., and Bjorkman, P.J. (1995). Analysis of the pH dependence of the neonatal Fc receptor/immunoglobulin G interaction using antibody and receptor variants. Biochemistry 34, 14649–14657.

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