Interleukin‐6 and tumour necrosis factor alpha are expressed by keratinocytes but not by Langerhans cells

Abstract

The presence of human cytokines was examined in parallel skin biopsies and epidermal single cell preparations obtained from normal individuals. Using biotin‐avidin‐peroxidase and immunofluorescence techniques and antibodies against recombinant cytokines, a granular intercellular/membrane‐associated staining for interleukin‐6 (IL‐6) and tumour necrosis factor alpha (TNF alpha), but not IL‐1 alpha or beta, was observed. An epidermal cytoplasmic staining pattern was also detected, which was most pronounced using the anti‐rIL‐6 antiserum. In the epidermal single cell preprations, membrane‐associated staining was detected for both IL‐6 and TNF alpha. Double staining revealed that CD1‐positive Langerhans cells (LC) failed to express any of the examined cytokines. In vitro binding of rIL‐6 or rTNF alpha to skin sections and epidermal single cell preparations indicated that the cell surface‐associated IL‐6 and TNF alpha originally demonstrated on keratinocytes were truly membrane‐bound. Finally, co‐cultivation of epidermal cells with an IL‐6 responsive cell line, B9, and testing of epidermal cell supernatants in this assay, indicated that the in vivo membrane‐bound IL‐6 had biological activity.

Immunohistochemical double-staining of renal allograft tissue: critical assessment of three different protocols

“…This technique has been employed in several studies in combination with immunohistochemistry [6,18] or immunofluorescence [4,14]. Our results clearly underline that this is the most reliable protocol for quantification of two different cellular antigens on frozen sections of renal allograft tissue.…”

Ultraviolet‐B induction of interstitial collagenase and stromelyin‐1 occurs in human dermal fibroblasts via an autocrine interleukin‐6‐dependent loop

“…Taken together, these data contribute to a novel facet of the previously published concept which postulates that UVB irradiation of the skin leads to a keratinocyte-dependent release of growth factors and cytokines IL-1, IL-6 and TNFK which, via paracrine mechanisms, modulate the connective tissue metabolism of ¢broblasts [17,41,42]. Here, we add an independent autocrine mechanism.…”

Rabbit Pigmented Ciliary Epithelium Produces Interleukin-6 in Response to Inflammatory Cytokines

“…Since it is unlikely that this brief exposure to IL-1β induced IL-6 production, IL-1β could have stimulated release of a small pool of preexisting IL-6 into the CCM. Indeed, a membranebound form of IL-6 has been described (Decandia et al, 1995 ;Oxholm et al, 1991). Apparently the presence of IL-1β is required for release of IL-6 to occur since IL-6 was never present in zero time point controls to which serum-free medium without IL-1β was added and immediately removed (data not shown).…”