Paul A. Bleicher

Production of latent transforming growth factor-beta and other inhibitory factors by cultured murine iris and ciliary body cells

Aqueous humor contains transforming growth factor-beta (TGF-beta) and other inhibitory factors for cellular proliferation. In the present study we investigated the possibility that these factors are produced locally by cells found within the iris and ciliary body. Iris and ciliary body (I/CB) cells or whole tissue explants from C57BL/6 mice produced soluble factors which inhibited both murine thymocyte and mink lung epithelial cell proliferation. Indomethacin partially blocked inhibition of thymocyte proliferation, but did not affect inhibition of Mv1 Lu proliferation. The inhibitory activity of culture supernatants was not blocked by neutralizing antibodies to TGF-beta 1 or TGF-beta 2. However, following acid activation of culture supernatants from both I/CB and corneal tissue, increased inhibitory activity consistent with activation of latent TGB-beta was detected. Antibody neutralization experiments demonstrated that this increase in activity was due primarily to TGF-beta 2 for I/CB tissue. Polymerase chain reaction (PCR) analysis of cDNA generated from I/CB tissue mRNA showed prominent fragments representing both TGF-beta 1 and TGF-beta 2 mRNA. Corneal tissue, however, showed a prominent fragment for TGF-beta 1 mRNA, but either no band or a barely detectable fragment for TGF-beta 2 mRNA. Therefore, it remains uncertain whether TGF-beta 2 mRNA is produced by the cornea in this strain. Overall, these results demonstrated that three distinct categories of substances inhibitory to proliferation may be locally produced by resident iris and ciliary body cells: 1) indomethacin sensitive products, 2) TGF-beta 2 in latent form, and 3) factors not blocked by indomethacin or anti-TGF-beta neutralizing antibodies. Products generated by these tissues may have important regulatory properties in the development of immune responses to antigens introduced into the anterior chamber.

CD1 gene expression in human skin

In human epidermis, expression of CD1a is confined to Langerhans cells (LC), whereas CD1c expression has been observed in dendritic cells of the dermis, as well as the epidermis. In transfected fibroblasts, expression of CD1c at the cell surface appears to exclude expression of either CD1b or CD1a, despite continued transcription of the latter genes. In order to determine whether this mechanism might be operative in human skin, we have compared the expression of CD1a and CD1c on the surface of dermal and epidermal dendritic cells to their expression at the level of mRNA using a combination of dual-label immunofluorescence microscopy, northern blot hybridization, and reverse transcriptase-polymerase chain reaction (RT-PCR). By both immunofluorescence and Northern blotting, CD1c expression was observed in both dermal and epidermal cells, whereas expression of CD1a was confined largely to the epidermis. Moreover, as shown by immunomagnetic bead selection and RT-PCR, CD1a and CD1c were both expressed on epidermal LC, but were absent from other epidermal cell types. These results argue against cell surface exclusion as a mechanism for selective expression of CD1c in human dermis.

Lichenoid dermatoses and related disorders. II. Lichen nitidus, lichen sclerosus et atrophicus, benign lichenoid keratoses, lichen aureus, pityriasis lichenoides, and keratosis lichenoides chronica

This article reviews various diseases that are loosely considered lichenoid,either clinically,pathologically,or historically.

Scientific Basis of Dermatology: A Physiological Approach

The past decade has witnessed a dramatic expansion of research in the area of physiology and biochemistry of normal and diseased skin.The Scientific Basis of Dermatologypresents a multiauthor review of these fields in a unique format. Whereas most basic science textbooks in dermatology are organized by anatomic units, the chapters in this book are organized as reviews of the various functions of skin. The first eight chapters review the various normal functions of skin such as sensory functions, immune functions, endocrine function, and ultraviolet protective functions. One unusual topic is that of the skin as an organ of communication. The ten final chapters of the book concentrate on specific diseases, such as psoriasis, acne, and solar radiation-induced disorders. Although the individual chapters are written by different authors, the editors have maintained a crisp and consistent style throughout the book. Each chapter is appropriately illustrated with black-and-white photographs and