FcGRI (CD64) Lentivirus

FcGRI (CD64) Lentivirus are replication incompetent, HIV based, VSV-G pseudotyped lentiviral particles that are ready to transduce almost all types of mammalian cells, including primary and non-dividing cells. These particles contain the FcgammaRI (Fc-gamma receptor 1), also known as CD64, under the control of an EF1a promoter. The lentiviruses also transduce a hygromycin selection marker (Figure 1). Figure 1. Schematic of the lenti-vector used to generate the FcGRI (CD64) Lentivirus. Antibody-dependent cell-mediated phagocytosis (ADCP) is an important mechanism to consider during antibody drug development. C (Fc gamma receptor 1), also known as CD64, is found in macrophages and monocytes, and its expression can be induced in polymorphonuclear leukocytes by IFNgamma (interferon gamma) and GCSF (granulocyte colony-stimulating factor). Multivalent IgG immune complexes (ICs) promote receptor clustering and activation of intracellular signaling through phosphorylation of ITAMs (immunoreceptor tyrosine-based activation motifs), leading to phagocytosis via Rac-GEFs (guanine exchange factors). This mechanism of action has contributed to the success of rituximab (anti-CD20 antibody) in the treatment of chronic lymphocytic leukemia (CCL). However, an overactivation of FcgammaRI can result in chronic inflammation and autoimmune disorders, such as SLE (systemic lupus erythematosus), ITP (immune thrombocytopenia) and RA (rheumatoid arthritis). Leveraging FcgammaRI properties can improve cancer therapy, while blocking its activation is a promising therapeutic approach for autoimmune disorders.