Antigen-Presenting Cells and the Eye PDF

Preface

Antigen-presenting cells are indispensable for mediating the induction of a specific immune reaction. Various populations that differ in their location and activation grade have already been described.

This book provides a general evaluation of our understanding of antigenpresenting cells, and assesses their importance for the physiological and pathological condition of the eye. Autoimmune disorders that often lead to severe impairment of the eye's functions, for example, can be invoked by the presentation of self peptides by the antigen-presenting cells to the T-cell receptor complex. An analysis of this cascade may help to identify the initiating autoantigens. Depending on the activation status, dendritic cells can induce a T-cell reaction or, in contrast, even induce tolerance.

Until recently, antigen-presenting cells were thought to play a limited role only in the external segment of the eye, but the use of more refined detection methods has revealed a whole spectrum of different dendritic cells that are localized in the iris and the choroid. As far as the lacrimal gland and the anterior segment are concerned, the research is concentrating on the characterization of factors influencing ocular antigen-presenting cells. In addition, the role of antigen-presenting cells in the mucosa-associated lymphoid tissue in the physiological and pathological state, as found in the dry eye syndrome and infectious disorders, is under investigation. The significance of antigen-presenting cells in corneal disease, especially in the case of transplantation, is also of major importance. In recent years, multiple new subgroups of antigen-presenting cells have been detected in the cornea, but at the present time their respective role still remains unclear.

Antigen-presenting cells of the posterior eye segment are becoming the focus of increased interest because they appear to be strongly involved in two major disorders of the eye: uveitis and age-related maculopathy.