CD40 ligand (CD40L) is a member of the tumor necrosis factor ligand superfamily. It may play an intricate role in the immune response by functional interaction with CD40 antigen expressed on the surface of B- cells, T-cells, monocytes, macrophages, antigen-presenting cells, endothelial cells and some epithelial cells. A possible role of CD40L in the pathogenesis of non-Hodgkin's lymphoma (NHL) has been recently hypothesized; in fact, CD40L antigen can be constitutively expressed by the neoplastic CD4sup + T-cell of nodal NHL, thus possibly having a physiological role in these neoplasms. We studied the immunophenotypic and genotypic expression of CD40L antigen in different phases of mycosis fungoides - the prototype of cutaneous T-cell lymphoma - in order to investigate the possible significance and role of this molecule in its pathomechanism. On frozen sections, CD40Lsup + T-cells were present in 9/10 specimens from patch/plaque stage mycosis fungoides. Their percentage (10-25%) and location (junctional and basal epidermal) were very similar to those of CD25sup + and Ki67sup + (proliferating) cells. In 5/5 specimens from tumor stage mycosis fungoides, no CD40L immunostaining was found. All patch/plaque stage mycosis fungoides (6/6 specimens) contained the mRNA transcript for CD40L. It was never detected in tumor stage mycosis fungoides (4/4 specimens). These findings suggest that in early mycosis fungoides, CD40Lsup + T-cells home into the skin by interaction with CD40sup + endothelial cells and into the epidermis by interaction with CD40sup + basal epidermal cells. The interaction between CD40Lsup + T-cells and CD40sup + Langerhans cells and the CD40/CD40L autocrine stimulus possibly triggers activation, growth and neoplastic enhancement of T-cells; up to the blastic transformation occurring at the tumor stage, when neoplastic T-cells loose their antigenic and functional features of mature T-cells and proliferate without any significant control.
CD40 ligand expression in mycosis fungoides is restricted to the patch/plaque (epidermotropic) stages
BIANCHI, Benedetta;
1997-01-01
Abstract
CD40 ligand (CD40L) is a member of the tumor necrosis factor ligand superfamily. It may play an intricate role in the immune response by functional interaction with CD40 antigen expressed on the surface of B- cells, T-cells, monocytes, macrophages, antigen-presenting cells, endothelial cells and some epithelial cells. A possible role of CD40L in the pathogenesis of non-Hodgkin's lymphoma (NHL) has been recently hypothesized; in fact, CD40L antigen can be constitutively expressed by the neoplastic CD4sup + T-cell of nodal NHL, thus possibly having a physiological role in these neoplasms. We studied the immunophenotypic and genotypic expression of CD40L antigen in different phases of mycosis fungoides - the prototype of cutaneous T-cell lymphoma - in order to investigate the possible significance and role of this molecule in its pathomechanism. On frozen sections, CD40Lsup + T-cells were present in 9/10 specimens from patch/plaque stage mycosis fungoides. Their percentage (10-25%) and location (junctional and basal epidermal) were very similar to those of CD25sup + and Ki67sup + (proliferating) cells. In 5/5 specimens from tumor stage mycosis fungoides, no CD40L immunostaining was found. All patch/plaque stage mycosis fungoides (6/6 specimens) contained the mRNA transcript for CD40L. It was never detected in tumor stage mycosis fungoides (4/4 specimens). These findings suggest that in early mycosis fungoides, CD40Lsup + T-cells home into the skin by interaction with CD40sup + endothelial cells and into the epidermis by interaction with CD40sup + basal epidermal cells. The interaction between CD40Lsup + T-cells and CD40sup + Langerhans cells and the CD40/CD40L autocrine stimulus possibly triggers activation, growth and neoplastic enhancement of T-cells; up to the blastic transformation occurring at the tumor stage, when neoplastic T-cells loose their antigenic and functional features of mature T-cells and proliferate without any significant control.
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