Expression of different immunological markers by cultured human melanocytes

Abstract

The expression of different immunological markers by cultured human melanocytes (MC) in relation to immune phenomena, were investigated on ten different MC cell lines from early (1st) to late (22nd) passage. Four melanocyte lines (MC-a) which had undergone changes in growth behaviour during prolonged culture were included in the study, together with two melanoma lines. Cytospin preparations of the cells were stained for the presence of a set of different immunological markers and a melanoma-associated antigen (MAA). All MC lines, including the MC-a and the melanoma lines, showed expression of MHC class I, IL-1, IL-2, ICAM-1 and the MAA, NKI-Beteb, during all passages tested. Interestingly, four of the MC lines showed staining for the Fc receptor. A tendency towards a stronger expression of ICAM-1 on a higher percentage of cells was observed on MC with increasing passage number, the MC-a and the melanoma lines. Expression of the MAA was strongly reduced for the MC-a lines in comparison with the MC and the M14 melanoma lines. Positive staining for the HLA class II molecules was obtained on MC of intermediate and late passages, and on the MC-a and the melanoma lines in the decreasing order HLA-DR, DP and DQ. Additionally, we carried out a preliminary study showing that cultured MC also produce IL-1 and IL-6. However, we were not able to show the production of biologically active IL-2 testing several cultured MC lines. Nevertheless, the overall results taken together suggest that MC are immunologically important cells that are susceptible to changes during long-term culture.

Melanocytes and Skin Immunity

“…Some melanocyte cell lines also express major histocompatibility complex class II molecules (Smit et al, 1993). Intercellular adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1) and CD40 have also been shown to be expressed by melanocytes (Yohn et al, 1990;Lu et al, 2002).…”

Viewpoint 2

“…After all, melanocytes produce cytokines that draw attention to themselves (5,6). They can phagocytize, and can process and present antigens in the context of MHC class II as one would normally expect a professional antigen-presenting cell to do (7,8).…”

“…Metabolic damage, characterized by increased susceptibility to chemical ⁄ physical stress, high H 2 O 2 intracellular level, low catalase activity, faulty activity of the mitochondrial respiratory chain and defective assembly ⁄ activity of TRP1, all have been demonstrated (6)(7)(8)(9)(10)(11). The increased cellular death cannot be a simple effect of the in vitro manipulation, but mirror the in vivo experience of the Koëbner phenomenon.…”

Autoimmune Melanocyte Destruction in Vitiligo

“…Melanocytes can express major histocompatibility complex (MHC)-class I and II molecules and adhesion molecules, such as intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 (al Badri et al, 1993;Le Poole et al, 1993a;Smit et al, 1993). In addition, they can produce several cytokines, such as interleukin (IL)-1, IL-6 (Smit et al, 1993), IL-8 (Zachariae et al, 1991), and transforming growth factor-␤1 (TGF-␤1) (Le Poole and Boyce, 1999). Furthermore, melanocytes are not only capable of phagocytosis (Le Poole et al, 1993c), but can also process antigen and present antigenic peptides to T cells (Le Poole et al, 1993a).…”