Intestinal intraepithelial lymphocytes have a promiscuous interleukin-8 receptor.
BACKGROUND
Human intraepithelial lymphocytes (IELs), predominantly T cells of the CD8+CD45RO+ phenotype that are situated between epithelial cells, have a chemotactic response to the alpha-chemokines, IL-8 and GRO, and the beta-chemokine, and the protein termed regulated on activation, normal T cell expressed and secreted (RANTES).


OBJECTIVE
To evaluate the specificity of the IL-8 receptor on IELs.


METHODS
Specificity was determined by the degree of desensitisation of the IL-8 response caused by each chemokine and the degree of inhibition of IL-8 binding to the cell.


RESULTS
IELs migrated towards two additional beta chemokines, macrophage inflammatory protein-1 and monocyte chemotactic protein (MCP). All chemokines inhibited IL-8 induced chemotaxis and calcium ion mobilisation by IELs, with IL-8 having the greatest effect and MCP the least. In addition, specific binding of radiolabelled IL-8 to IELs was reduced by each of the five chemokines in cold competition experiments, whereas only GRO and IL-8 itself displaced 125I-IL-8 from receptors on peripheral blood mononuclear cells.


CONCLUSIONS
The IL-8 responsiveness of IELs is desensitised by chemokines of both the alpha and beta families, and this is likely to occur by the binding of the chemokines to common receptors.
Roberts
A I
AI
Department of Medicine, UMDNJ-Robert Wood Johnson Medical School, New Brunswick 08903, USA.
Bilenker
M
M
Ebert
E C
EC
D015703:Antigens, CD / Q000378:metabolism*; D018932:Chemokine CCL2 / Q000378:metabolism; D054407:Chemokine CCL4; D018925:Chemokines / Q000378:metabolism*; D002634:Chemotaxis, Leukocyte; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D019402:Macrophage Inflammatory Proteins / Q000378:metabolism; D011485:Protein Binding; D018123:Receptors, Interleukin / Q000378:metabolism*; D023062:Receptors, Interleukin-8A
D015703:Antigens, CD; D018932:Chemokine CCL2; D054407:Chemokine CCL4; D018925:Chemokines; D016209:Interleukin-8; D019402:Macrophage Inflammatory Proteins; D018123:Receptors, Interleukin; D023062:Receptors, Interleukin-8A