Difference between revisions of "Part:BBa K1993003"

Revision as of 13:50, 16 October 2016

CXCR4

Chemokine receptors are receptors found on the surface of certain cells that interact with chemokines. They have a 7-transmembrane (7-TM) structure and couple to G-protein for signal transduction within a cell. [1] (Figure 1) Following interaction with their specific chemokine ligands, chemokine receptors trigger a flux intracellular calcium (Ca2+) ions, initiate chemotaxis and guide the cell to a desired location. (Figure 2)

Figure 1. typical structure of a chemokine receptor.

Figure 2. the mechanism of interaction between chemokine and chemokine receptor.

Under the circumstances of inflammation, various kinds of cytokines, including chemokines, are released by the lesions. Guided by the chemokines, cells expressing chemokine receptors move towards the lesions where they can function better.[2] What’s more, different diseases would release different pools of chemokines, which would recruit different effector cells. See our disease table-chemokine

Based on the chemotaxis theory, in order to enhance the homing ability of our marvelous mesenchymal stem cells (MSCs) due to lack of enough chemokine receptors on their cell surface, we, SYSU-MEDICINE, had constructed a series of chemokine receptors that corresponding to different inflammatory diseases as far as possible. Among which, CXCL12 is a significant chemokine (CXCR4 is its chemokine receptor) in Inflammatory Bowel Disease(IBD) and Experimental Allergic Encephalomyelitis(EAE). See our disease table-chemokine

We acquired this gene from peripheral mononuclear blood cells (PMBCs) and purified it. (Figure 3) Then we constructed it under the control of EF-1α by Gateway technology. (Figure 4)

Figure 3 purification of gene CXCR4

Figure 4 Construction of expression vector of CXCR4

We introduced that plasmid into MSCs and tested the expression of CXCR4 in MSCs on the protein level (Figure 5)

Figure 5. Western Blot Of CXCR4.

Then, we tested the chemotaxis of engineered MSCs by conducting Transwell assay against CXCL12. To our excitement, our engineered MSCs had improved their homing ability with chemokine receptor CXCR4(Figure 6).

Figure 6. transwell assay of CXCR4.

References

[1]Allen, Samantha J.; Crown, Susan E.; Handel, Tracy M. (2007-01-01). "Chemokine: receptor structure, interactions, and antagonism". Annual Review of Immunology. 25: 787–820.

[2] Griffith J W, Sokol C L, Luster A D. Chemokines and chemokine receptors: positioning cells for host defense and immunity.[J]. Annual Review of Immunology, 2014, 32(1):659-702. Sequence and Features