Chemokine-like factor 1 (CLFK1) is over-expressed in patients with atopic dermatitis

Abstract

Background: Human chemokine-like factor 1 (CKLF1), a recently discovered chemokine, has a broad spectrum of biological functions in immune-mediated diseases. It is highly expressed on Th2 lymphocytes and is a functional ligand for human CCR4. CKLF1 has a major role in the recruitment and activation of leucocytes, which plays an important role in the pathogenesis of allergic diseases. The present study was designed to determine the expression of CKLF1 in skin and serum in patients with atopic dermatitis (AD).

Methods: The CKLF1 protein expression in skin lesion was analyzed by immunohistochemistry and ELISA. The mRNA expression of CKLF1 in skin lesion was detected by Real-time PCR. The serum levels of CKLF1, IgE, eotaxin, IL-4, IL-5, and IL-13 were measured by ELISA.

Results: Histopathological changes in the skin of AD patients showed local inflammation with epidermal thickening and significant inflammatory cellular infiltration. Immunohistochemistry results demonstrated that CKLF1-staining positive cells were located in the epidermal and dermis, and that the CKLF1 expression in AD patients was significantly higher than that in normal control. The CKLF1 mRNA expression in AD patients was significantly higher than that in healthy controls. Serum CKLF1 and IgE levels were significantly increased in AD patients, as were the serum levels of IL-4, IL-5, IL-13 and eotaxin.

Conclusions: Both CKLF1 protien and mRNA levels are overexpressed in the skin lesion of AD patients, along with an increase in serum CKLF1 level, indicating that CKLF1 may play an important role in the development of atopic dermatitis.

Keywords: atopic dermatitis (AD); chemokine-like factor 1 (CKLF1)..

Fig 1

Expression of CKLF1 in AD patients. (A): The CKLF1 protein levels in sera and skin of AD patients were significantly higher than that in the controls. (*P<0.05) (B): The CKLF1 mRNA levels were significantly higher in AD patients than that in the control group. (*P<0.05).

Fig 1

Expression of CKLF1 in AD patients. (A): The CKLF1 protein levels in sera and skin of AD patients were significantly higher than that in the controls. (*P<0.05) (B): The CKLF1 mRNA levels were significantly higher in AD patients than that in the control group. (*P<0.05).

Fig 2

The serum levels of eotaxin-1, IL-4, IL-5, and IL-13 in AD patients were significantly higher than that in the controls (A) (*P<0.05). The serum level of IgE in AD patients was significantly higher than that in the control group (B) (*P<0.05).

Fig 2

The serum levels of eotaxin-1, IL-4, IL-5, and IL-13 in AD patients were significantly higher than that in the controls (A) (*P<0.05). The serum level of IgE in AD patients was significantly higher than that in the control group (B) (*P<0.05).

Fig 3

Histopathological and immunohistochemical analysis of AD skin lesions and controls. Top panel (Normal 1, AD1) as HE staining and the rest as CKLF1 IHC, the CKLF1 staining positive cells could be found in normal skin (Normal 2, Normal 3, Normal 4) and in skin lesion (AD2, AD3, AD4) of AD patients. However, the skin lesions in AD patients showed much more CKLF1-positive cells with higher intensity in the epidermal and dermis than that in normal skins.