capsulated bacteria Referring to bacteria surrounded by a polysaccharide shell that resists actions of phagocytes, resulting in pus formation at the site of infection. Also called pyogenic (pus-forming) bacteria.
carboxypeptidase N (CPN) A metalloproteinase that inactivates C3a and C5a. CPN deficiency causes a condition of recurrent angioedema.
cardiolipin A lipid found in many bacteria and in the inner mitochondrial membrane that is a ligand recognized by some human γ:δ T cells.
caspase 8 An initiator caspase activated by various receptors that activates the process of apoptosis.
caspase 11 This caspase is homologous to human capsase 4 and 5. Its expression is induced by TLR signaling. Intracellular LPS can directly activate it, leading to pyroptosis.
caspase recruitment domain (CARD) A protein domain present in some receptor tails that can dimerize with other CARD-domain-containing proteins, including caspases, thus recruiting them into signaling pathways.
caspases A family of cysteine proteases that cleave proteins at aspartic acid residues. They have important roles in apoptosis and in the processing of cytokine pro-polypeptides.
cathelicidins Family of antimicrobial peptides that in humans has one member.
cathelin A cathepsin L inhibitor.
cathepsins A family of proteases using cysteine at their active site that frequently function in processing antigens taken into the vesicular pathway.
CC chemokines   One of the two main classes of chemokines, distinguished by two adjacent cysteines (C) near the amino terminus. They have names CCL1, CCL2, etc. See Appendix IV for a list of individual chemokines.
CCL9 (MIP-1γ) Chemokine made by follicle-associated epithelial cells and binds CCR6, recruiting activated T and B cells, NK cells, and dendritic cells into GALT.
CCL19   Chemokine made by dendritic cells and stromal cells in T-cell zones of lymph nodes that binds CCR7 and functions to attract naive T cells.
CCL20 Chemokine made by follicle-associated epithelial cells and binds CCR6, recruiting activated T and B cells, NK cells, and dendritic cells into GALT.
CCL21   Chemokine made by dendritic cells and stromal cells in T cell zones of lymph nodes that binds CCR7 and functions to attract naive T cells.
CCL25 (TECK) Chemokine made by small-intestinal epithelial cells that binds CCR9 to recruit gut-homing T and B cells.
CCL28 (MEC, mucosal epithelial chemokine) Chemokine made by colonic intestinal cells, salivary gland, and lactating mammary gland cells that binds CCR10 to recruit B lymphocytes producing IgA into these tissues.
CCR1   Chemokine receptor expressed by neutrophils, monocytes, B cells, and dendritic cells, that binds several chemokines, including CCL6 and CCL9.
CCR6 Chemokine receptor expressed by follicular and marginal zone B cells and dendritic cells that binds CCL20.
CCR7   Chemokine receptor expressed by all naive T and B cells, and some memory T and B cells, such as central memory T cells, that binds CCL19 and CCL21 made by dendritic cells and stromal cells in lymphoid tissues.
CCR9   Chemokine receptor expressed by dendritic cells, T cells, and thymocytes, and some γ:δT cells, that binds CCL25 that mediates recruitment of gut-homing cells.