Description
CCL4, also known as macrophage inflammatory protein 1 beta (MIP-1 beta ), is a 12 kDa beta chemokine that is secreted at sites of inflammation by activated leukocytes, lymphocytes, vascular endothelial cells, and pulmonary smooth muscle cells. CCL4 attracts a variety of immune cells to sites of microbial infection as well as to other pathologic inflammation such as allergic asthma and ischemic myocardium . A CCL4 deficiency in mice promotes the development of autoantibodies, possibly as a result of compromised regulatory T cell recruitment . CCL4 is secreted from activated monocytes as a heterodimer with CCL3/MIP-1 alpha . The first two N-terminal amino acids can be cleaved from human CCL4 by CD26/DPPIV . Both the full length and truncated forms exert biological activity through CCR5, Both forms of CCL4 block HIV-1 infection of T cells by inducing the downregulation of CCR5.