Editing CD32 (section)

=== ''CD32A'' ===
CD32A is an activating subtype of CD32 that can be found on a variety of immune cells - notably, CD32A is found on [[platelet]]s, [[neutrophil]]s, [[macrophage]]s, and [[dendritic cell]]s (DCs). On platelets, it is known to aid in the internalization of IgG-[[Opsonin|opsonized]] ''[[Escherichia coli]]'', and it is more generally implicated in mediating bacterial-activated platelet responses.<ref name=":3" /> CD32A also plays an important role in platelet activation, adhesion, and aggregation in response to injured blood vessels.<ref name=":1" /> When bound to an IgG immune complex, the cytosolic ITAM can promote [[Phagocytosis|phagocytic activity]] and [[Cytokine|cytokine secretion]] in neutrophils and macrophages.<ref name=":0" /> CD32A is known to aid in the activation of [[Clathrin|clathrin coat]]-mediated endocytosis on various cell types. On DCs, CD32A plays an important role in maturation and the upregulation of [[B7 (protein)|costimulatory molecules]] on the cell surface, strengthening the DC's ability to [[Antigen presentation|present antigen]] to T cells. CD32A activation is necessary and sufficient to produce T cell anti-tumor cellular immunity. CD32A is also linked to [[autoimmunity]]; for example, the production of antibodies against [[platelet factor 4]] (PF4) bound to CD32A is linked to the development of [[heparin-induced thrombocytopenia]].<ref name=":3" />

CD32A is also found on [[Langerhans cell|Langerhans]] cells, [[mast cell]]s, [[basophil]]s, [[eosinophil]]s, [[monocyte]]s, [[megakaryocyte]]s, and a subpopulation of activated [[T helper cell|CD4+ T cells]]. CD32A is unique to primates.<ref name=":1" />