The Fc receptors
of IgG (a link between humoral and cellular immunological responses), are highly interested in the etiology and pathogenesis of autoimmune diseases and Fc gamma receptors are encoded in the long arm of chromosome 1 (4, 5).
TTI-622 consists of the same CD47-binding domain of human SIRPa as TTI-621 but linked to an IgG4 Fc region, which has a more restricted ability to engage activating Fc receptors
. It is expected to have a different pharmacologic profile than TTI-621 and is being developed primarily for combination therapy.
Ravetch, "Inhibitory Fc receptors
modulate in vivo cytoxicity against tumor targets," Nature Medicine, vol.
M230, a selective immunomodulator of Fc receptors
and the multiple Fc domains of ICs aggregate Fc?
Hellman, "Fc receptors
for immunoglobulins and their appearance during vertebrate evolution," PLoS One, vol.
The best characterized and maybe most important opsonic phagocytic receptors are the Fc receptors
(FcR) and the complement receptors (CR).
Nonneutralizing antibodies do not directly interfere with TNF binding but may compromise therapeutic efficacy by contributing to enhanced clearance of the drug from the circulation through immune complex formation and binding to Fc receptors
on phagocytic cells (14).
The new mouse model incorporated the human versions of both the CD40 protein and Fc receptors
, a group of proteins expressed on immune cells.
The effects of intravenous immunoglobulin include complex mechanisms, but it exerts its essential action by eliminating the non-specific Fc receptors
found in the mononuclear phagocytic system or by inhibiting binding of immune complexes to Fc receptors
in the cells.
Additional functional variation exists as a result of the differential affinities and cellular expression that occurs within the family of Fc receptors
and their variants.
Unlike IgG, IgY antibodies do not bind to bacterial Fc receptors
, such as staphylococcal protein A or streptococcal protein G (JENSENIUS et al., 1981).