Expression of co-inhibitory receptors in inflammatory skin disease
Immune responses provide humans with protection from threats of infections and tumors. By contrast, deregulation of immune responses is likely to cause inflammatory and autoimmune diseases and even generation of tumors. We have found molecules (termed DC-HIL and syndecan-4) expressed on leukocytes can negatively regulate skin immune responses using a mouse model and human leukocytes. We will examine aberrant expression of these molecules in skin and leukocytes of patients with inflammatory diseases (for example, atopic dermatitis and psoriasis) and cutaneous t-cell lymphoma.
Histology: Paraffin-embedded slides (from dermatopathology laboratory) or frozen skin biopsies from cutaneous T cell lymphoma and other diseases will be histochemically or immunofluorescent stained with antibodies against DC-HIL, syndecan-4, or other T cell markers. Stained samples will be examined under visual or confocal microscope.
Flow-cytometry: Leukocytes isolated from peripheral blood will be immune-fluorescently stained with aforementioned antibodies. Expression of DC-HIL, syndecan-4 and other T cell markers will be evaluated by flow-cytometry.
RT-PCR: RNA will be extracted from paraffin-embedded slides, frozen biopsies, or leukocytes from patients and subjected to RT-PCR analysis to examine expression levels of mRNA.
Immunoblotting: Protein will be extracted from clinical samples (referred above) Leukocytes isolated from peripheral blood will be immune-fluorescently stained with aforementioned antibodies. Expression of DC-HIL, syndecan-4 and other T cell markers will be evaluated by flow-cytometry.
T cell activation assay in vitro: T cells from patients will be co-cultured with keratinocytes or antigen-presenting cells from peripheral leukocytes for 5 days. Activation of T cells will be measured by IL-2 production by ELISA. The activation will be inhibited by antibodies or recombinant proteins of DC-HIL or sydnecan-4.
Up to 50 normal control subjects will be enrolled for comparison purposes. Moreover, our studies will allow us to evaluate the potential of these molecules as a pharmacological target to treat these skin diseases.
200 male and female subjects 18 years of age or older with inflammatory skin disease (atopic dermatitis, contact dermatitis, allergic diseases, autoimmune disorders, alopecia areata, psoriasis, pityrisis rosea, pityrisis lichenoides, skin lymphomas [cutaneous T-cell lymphoma including Sez[?]ry syndrome] melanomas, head and neck cancers, breast cancer, hepatoma, renal cancer, lung cancer, adenocarcinoma, lymphoma, leukemia and other skin cancers. Up to 50 normal control subjects will be enrolled for comparison purposes.