Relationship Between Prolactin/Prolactin Receptor Pathway And CD154 Expression And Its Influence On Th1/Th2 Cytokine Balance

Objective In order to investigate the role of the PRL/PRLr pathway in human immune regulation,we investigated the relationship between the PRL/PRLr pathway and the synergic stimulating signal correlated to the activation of the immune cell ,and the influence of the PRL/PRLr pathway on the Th1/Th2 cytokine balance.Methods 1.Human T cell leukemia cell line named JurkatD1.1 cell line which expresses both PRLr and CD154 was randomly divided into 4 groups.After stimulated with Phytohemagglutinin (PHA) and recombinant human prolactin(rhPRL) with or without anti-PRLr Abs,the cells were collected and were immunofluorescence stained with PE-conjugated mouse anti-human CD154 monoclonal antibody IgG1.Flow cytometry was used to estimate the expression of CD154 on the cells. The level of CD154 on the JurkatD1.1 cells were measured. Immunohistochemistry was used as another way to detect it.2. Human T cell leukemia cell line named JurkatD1.1 cell line was cultured for 24 hours with different concentration of rhPRL plus PHA,with or without anti-PRLr Abs. Cell culture supernatants were collected and stored at -20°C until measurement of the IL-4,IFN-γconcentration by enzyme linked immunosorbent assay (ELISA).3. The paraffin sections of skin lesions from SSc patients and normal skin were stained with antibodies to PRL,PRLr and to the cytokines IFN-γand IL-4 which are associated with Th1 and Th2 responses,respectively.Correlations between the cytokines were investigated.Results 1. JurkatD1.1 cells cultured in the presence of rhPRL and PHA had been found optimal reponse,with (20.8±7.0)% of cells expressing CD154. However,addition of anti-PRLr antibodies resulted in a reduction of CD154 expression of around 100%.2. PRL has no important influnce on the expression of IL-4.The expression of IFN-γdepends partially on the PRL,this is supported by the finding that the secretion of IFN-γwas markedly reduced by blocking the PRLr. 3. PRL,PRLr were distributed in keratinocytes,endothelial cells and the superficial layer of the sudoriferous duct,vascular endothelial cells,but only increased PRL-immunoreactivity was found in SSc patients compared with normal subjects(P<0.001).IFN-γand IL-4 were distributed in keratinocytes,vascular endothelial cells and infiltrating mononuclear cells,but only increased IL-4-immunocreactivity was found in SSc patients compared with normal subjects(P<0.001).A positive correlation was found between the immunoreactivity of PRL and that of IL-4 in SSc patients((rs=0.893,P<0.001).Conclusion 1.PRL participates in the immune response through the CD154 expression and Th1/Th2 cytokine balance,which is partially PRL/PRLr mediated.2.PRL and PRLr are expressed in skin lesions from SSc patients.Inflammatory skin from SSc patients appears to be a largely Th2 phenomenon.PRL is positively correlative with Th2 cytokine IL-4.