CCL28 chemokine: An anchoring point bridging innate and adaptive immunity

- Chemokines play a vital role in cell migration in response to a chemical gradient by a process known as chemotaxis.
- CCL28 is a β- or CC chemokine that is involved in host immunity through the interactions with its chemokine receptors, CCR10 and CCR3.
- CCL28 is constitutively expressed in a wide variety of tissues including exocrine glands and is inducible through inflammation and infections.
- CCL28 has been shown to exhibit broad spectrum antimicrobial activity against gram-positive bacteria, gram-negative bacteria, and some fungi.
- CCL28 displays strong homing capabilities for B and T cells and orchestrates the trafficking and functioning of lymphocytes.
- In this review, we emphasize the antimicrobial and immunomodulatory feature of CCL28 and its role as bridge between innate and adaptive immunity.

Chemokines are an extensive family of small proteins which, in conjunction with their receptors, guide the chemotactic activity of various immune cells throughout the body. CCL28, β- or CC chemokine, is involved in the host immunity at various epithelial and mucosal linings. The unique roles of CCL28 in several facets of immune responses have attracted considerable attention and may represent a promising approach to combat various infections. CCL28 displays a broad spectrum of antimicrobial activity against gram-negative and gram-positive bacteria, as well as fungi. Here, we will summarize various research findings regarding the antimicrobial activity of CCL28 and the relevant mechanisms behind it. We will explore how the structure of CCL28 is involved with this activity and how this function may have evolved. CCL28 displays strong homing capabilities for B and T cells at several mucosal and epithelial sites, and orchestrates the trafficking and functioning of lymphocytes. The chemotactic and immunomodulatory features of CCL28 through the interactions with its chemokine receptors, CCR10 and CCR3, will also be discussed in detail. Thus, in this review, we emphasize the dual properties of CCL28 and suggest its role as an anchoring point bridging the innate and adaptive immunity.