Which of the following BEST describes chemokines?

A. Membrane receptors that detect the presence of soluble messengers in the environment

B. Soluble proteins that recruit specific cells to an area

C. Chemical messengers that induce cell differentiation

D. Transcription factors that induce the expression of genes involved in cell adhesion

E. Adhesion molecules that bind to the inside of blood vessels.

B. Soluble proteins that recruit specific cells to an area

Explanation:

Chemokines are chemotactic cytokines. These are the structurally similar proteins that serve in migration and activation of specific types of white blood cells. These proteins respond to chemical signals and serve to trigger the arrival of white blood cells at the site of infection. For example, some of the chemokines serve to direct the inflammatory immune cells to the airways. Some other chemokines serve to recruit the leucocytes towards the site of inflammation.