CARD9 (E4N1E) Rabbit mAb #77568

CARD9 is a caspase recruitment domain (CARD)-containing adaptor protein expressed by myeloid cells (1,2). It is required for antifungal immunity downstream of pathogen detection by C-type lectin receptors (CLRs) such as Dectin-1 (3,4). Recognition of carbohydrates on fungal cell walls by CLRs leads to activation of the tyrosine kinase Syk, followed by activation of PKCδ (5,6). PKCδ phosphorylates CARD9, enabling the assembly of a complex containing CARD9 and Bcl10 (6). This complex activates NF-κB, resulting in upregulation of inflammatory cytokines important for initiation of adaptive immunity (3,4,6,7). CARD9 was also shown to be important for the induction of IL-1β, downstream of the viral nucleic acid sensor RIG-I, as well as for the generation of reactive oxygen species important for bacterial killing by macrophages (2,8).