Chemokines and inflammatory skin diseases

Novel identified receptors on mast cells

Mast cells (MC) are major participants in the allergic reaction. In addition they possess immunomodulatory roles in the innate and adaptive immune reactions. Their functions are modulated through a number of activating and inhibitory receptors expressed on their surface. This review deals with some of the most recently described receptors, their expression patterns, ligand(s), signal transduction mechanisms, possible cross-talk with other receptors and, last but not least, regulatory functions that the MC can perform based on their receptor expression in health or in disease. Where the receptor role on MC is still not clear, evidences from other hematopoietic cells expressing them is provided as a possible insight for their function on MC. Suggested strategies to modulate these receptors’ activity for the purpose of therapeutic intervention are also discussed.

Overexpression of CXCL16 in lesional psoriatic skin

BACKGROUND

Psoriasis is characterized as an autoimmune disease resulting in an exaggerated innate immune response. The CXC-chemokine ligand 16 (CXCL16) is described to function as an adhesion molecule, a scavenger receptor or as a soluble molecule it acts as a chemoattractant. CXCL16 has been reported to be expressed in a variety of inflammatory diseases. However, no information has been reported in the literature about the expression of CXCL16 in psoriatic skin.

PURPOSE

The present study was designed to analyze the expression and localization of CXCL16 in human psoriatic skin tissues.

RESULTS

In normal skin, cytpoplasmic expression of CXCL16 was increased in keratinocytes of upper epidermal cell layers as compared to the lower epidermal cell layers. In lesional psoriatic skin, CXCL16 immunoreactivity was increased in the cytoplasm of keratinocytes of lower epidermal layer kerartinocytes as compared to the normal epidermis. Cytoplasmic CXCL16 expression was increased in the capillary endothelial cells of psoriatic dermis as compared to capillary endothelial cells of the normal dermis. Notably, almost all inflammatory cells in the dermis were negative for CXCL16.

MATERIALS AND METHODS

Ten paraffinized specimens of human lesional psoriatic skin and five paraffinized specimens of normal skin were studied using an immunohistochemical streptavidinperoxidase technique.

CONCLUSION

We here report for the first time alterations in the immunohistochemical staining pattern of CXCL16 in lesional psoriatic skin compared to the normal skin. These results suggest that CXCL16 may play a role in the pathogenesis of psoriasis.

HIV and the CCR5-Δ32 resistance allele

The combination of molecular biology, epidemiology, virology, evolutionary and population genetics has enabled us to understand the delicate interplay between HIV and the CCR5-Delta32 HIV resistance allele. We here review and collect from the different approaches to show how they can be combined to elucidate the interaction between host and pathogen genetics in this system. We will present an overview of the normal role of CCR5, its involvement in HIV, the molecular biology of the CCR5-Delta32 allele and its probable origins. By focusing on this well-documented and important system we hope to demonstrate the power that such a "holistic" approach might offer in the study of infectious diseases.