The actions of chemokine molecules is important for a wide range of normal and pathophysiological processes such as allergic responses, infectious and autoimmune diseases, angiogenesis, inflammation, tumor growth and metastasis, and hematopoietic development. Chemokines are a large superfamily of mostly small, secreted chemotactic cytokines that function in leukocyte trafficking, recruitment and activation.
They are particularly relevant to allergy during the late phase response. The secretion of chemokines serves to chemoattract basophils and eosinophils. The actions of chemokines stimulate these cells to secrete proinflammatory substances such as Macrophage Chemotactic Proteins (MCPs), RANTES, and Macrophage Inflammatory Protein-1 alpha (MIP-1 alpha). This response can also be enhanced by the actions of cytokines IL-3, IL-5 and GM-CSF. Chemokines may also affect T helper type 2 cell (Th2) mucosal infiltration since Th2 restricted chemokine receptors CCR4 and CCR8 are upregulated in the asthmatic lung in response to allergen stimulation.