Studies on the immunobiology of Langerhans cells
Langerhans cells (LC) are dendritic antigen-presenting cells that reside in the lower portion of the epidermis that have a key role in immune responses within the skin. Our studies have centered on several aspects of LC function.
The role of Langerhans cells in tumor immune responses. Our laboratory has demonstrated that LC are capable of presenting tumor-associated antigens for induction and elicitation of immune responses. This activity is regulated by cytokines and other regulatory factors.
Regulation of Langerhans cell antigen presentation by cytokines. These studies have demonstrated that the outcome of exposure to a given cytokine is dependent not only on the intrinsic nature of that cytokine signal but also on the status of LC as determined by previous cytokine signals. An understanding of the interactions of cytokines, as well as other modulatory factors, is crucial to understanding the in situ situation.
Regulation of Langerhans cell function by neuropeptides. We found that calcitonin gene-related peptide (CGRP) inhibits the ability of murine LC to present antigen and that, by double immunoflourescence laser confocal scanning microscopy, LC frequently are at or near epidermal nerves. Indeed, some LC were found to have immunoreactive CGRP at or on their cell surfaces. These findings suggest a locus of interaction between the immune system and nerves within the skin. LC were also found to express receptors for other neuropeptides, and furthermore, LC were found to make a factor(s) that induces neural differentiation, suggesting bidirectional signaling.