title: Association of increased levels of heavy-chain ferritin with increased CD4+ CD25+ regulatory T-cell levels in patients with melanoma.
abstract: We have shown previously that melanoma cells in culture release heavy-chain ferritin (H-Ferritin) into supernatants and that this is responsible for the suppression of responses of peripheral blood lymphocytes stimulated by anti-CD3. These effects were mediated by activation of regulatory T cells to produce interleukin (IL)-10. In the present study, we examined whether a similar relation might exist between levels of H-Ferritin and activation of regulatory T cells in patients with melanoma. Ferritin levels were evaluated by ELISA and regulatory T-cell numbers were assessed by three-color flow cytometry to identify CD4(+) CD25(+) CD69(-) T cells. CD69 positive cells were excluded to avoid inclusion of normal activated CD4, CD25 expressing T cells. Measurements of H- and light-chain (L)-Ferritin by ELISA revealed that H- but not L-Ferritin was elevated in the circulation of melanoma patients. In addition, these studies revealed a marked increase in the number of CD4(+) CD25(+) CD69(-) T cells in such patients, compared with age-matched controls. The ratio of H-Ferritin:L-Ferritin correlated with the levels of regulatory T cells consistent with a causal relation between unbound H-Ferritin levels and the activation of regulatory T cells. H-Ferritin or regulatory T cells did not, however, correlate with the stage of the melanoma. These results provide evidence for the importance of H-Ferritin in the induction of regulatory T cells in patients with melanoma and provide additional insight into the suppression of immune responses in such patients.
authors.affiliation: Deparment of Oncology and Immunology, Newcastle Mater Hospital, Newcastle, New South Wales, 2300 Australia.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Gray
authors.forename: Paolo
authors.initials: P
authors.lastname: Arosio
authors.forename: Peter
authors.initials: P
authors.lastname: Hersey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D017252:CD3 Complex / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D002455:Cell Division; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005293:Ferritins / Q000096:biosynthesis*; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D037181:Lectins, C-Type; D008297:Male; D008545:Melanoma / Q000097:blood* / Q000378:metabolism*; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D013997:Time Factors; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D005293:Ferritins; D007371:Interferon-gamma; D016753:Interleukin-10; D037181:Lectins, C-Type; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D000099192:CD69 Antigens