The V158F polymorphism in human FcγRIIIa/CD16a defines opposing receptor responses when interacting with soluble...

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• The V158F polymorphism in Fc receptor CD16a (FcγRIIIa) influences autoimmune disorders and IgG-based therapies.
• CD16a V158F affects IgG affinity and CD16a receptor triggering on immune cells.
• Mechanisms of CD16a interaction with soluble IgG immune complexes (ICs) are poorly understood.

Purpose of the Study:

• To clarify the functional impact of the CD16a-V158F polymorphism in IC-mediated diseases.
• To investigate the differential responsiveness of CD16a V158F variants to soluble IgG ICs.

Main Methods:

• Generation of BW5147 reporter cells for human CD16a V158F variants.
• Assessment of functional responses to synthetic and disease-associated soluble IgG ICs.
• Validation of findings using primary human NK cells.

Main Results:

• Both CD16a reporter cell variants bound ICs.
• CD16aV reporter cells, but not CD16aF, exhibited functional responses to soluble ICs.
• This functional difference was confirmed in primary human NK cells.

Conclusions:

• An intrinsic difference exists in CD16a V158F variant responsiveness to soluble ICs, beyond binding affinity.
• Findings suggest genotype-dependent differences in IC-mediated diseases.
• Potential for individualized treatment strategies in autoimmune disorders.