FAQ: What is the Normal Role of CD64 in Innate and Adaptive Immunity?

In this educational rheumatology video, physician assistant Lindsay Tom, PA-C, from the Northern Virginia Center for Arthritis, provides a clear and clinically relevant overview of CD64, also known as FC gamma receptor I, and its role in immune system function. The discussion explores how CD64 is expressed on myeloid lineage cells such as monocytes, macrophages, and dendritic cells, and how it contributes to innate immunity by binding IgG antibodies and triggering phagocytosis and pro-inflammatory cytokine release, including TNF-α. The video also explains CD64’s role in adaptive immunity through antigen processing and presentation to T cells, leading to immune activation and immunologic memory. Importantly, this overview highlights how dysregulated or excessive CD64 activation may contribute to chronic inflammation, tissue damage, and antibody-mediated autoimmune diseases—making it a key concept for clinicians managing inflammatory and rheumatic conditions. This video is part of ongoing educational content designed for advanced practice providers seeking a deeper understanding of immunologic pathways relevant to rheumatology care.