Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic

Chemotaxis

Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...

 cytokine

Cytokine

Cytokines are small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system and are a category of signaling molecules used extensively in intercellular communication...

s known as chemokine

Chemokine

Chemokines are a family of small cytokines, or proteins secreted by cells. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells; they are chemotactic cytokines...

s. Macrophage inflammatory protein-1 (MIP-1), MIP-1 (CCL3) and MIP-1(CCL4) are chemokines crucial for immune responses towards infection and inflammation. In humans, there are two major forms, MIP-1α and MIP-1β that are now officially named CCL3

CCL3

Chemokine ligand 3 is a protein that in humans is encoded by the CCL3 gene.-Further reading:...

 and CCL4

CCL4

Chemokine ligand 4, also known as CCL4, is a protein which in humans is encoded by the CCL4 gene.- Function :CCL4, also known as Macrophage inflammatory protein-1β is a CC chemokine with specificity for CCR5 receptors...

 respectively. Both are major factors produced by macrophage

Macrophage

Macrophages are cells produced by the differentiation of monocytes in tissues. Human macrophages are about in diameter. Monocytes and macrophages are phagocytes. Macrophages function in both non-specific defense as well as help initiate specific defense mechanisms of vertebrate animals...

s after they are stimulated with bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

l endotoxin

Endotoxin

Endotoxins are toxins associated with some Gram-negative bacteria. An "endotoxin" is a toxin that is a structural molecule of the bacteria that is recognized by the immune system.-Gram negative:...

s. They activate human granulocyte

Granulocyte

Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the varying shapes of the nucleus, which is usually lobed into three segments...

s (neutrophils, eosinophils and basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6

Interleukin 6

Interleukin-6 is a protein that in humans is encoded by the IL6 gene.IL-6 is an interleukin that acts as both a pro-inflammatory and anti-inflammatory cytokine. It is secreted by T cells and macrophages to stimulate immune response, e.g. during infection and after trauma, especially burns or other...

 and TNF-α from fibroblast

Fibroblast

A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen, the structural framework for animal tissues, and plays a critical role in wound healing...

s and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

They are produced by many cells, particularly macrophages, dendritic cells, and lymphocytes. MIP-1 are best known for their chemotactic and proinflammatory effects but can also promote homoeostasis. Biophysical analyses and mathematical modelling has shown that MIP-1 reversibly forms a polydisperse distribution of rod-shaped polymers in solution. Polymerization buries receptor-binding sites of MIP-1, thus depolymerization mutations enhance MIP-1 to arrest monocytes onto activated human endothelium.