Recent data from murine models have confirmed that Langerhans cells are not the only population of APCs in the skin involved in initiating immune responses. In healthy human skin, we identify CD1a(+) dermal APCs located close to the lymphatic vessels in the upper layers of the dermis that are unequivocally distinct from migrating Langerhans cells but exhibit both potent allostimulatory capacity...

Langerhans' cells were observed to migrate into chemically injured corneal epithelium of pigmented and albino guinea pigs in substantial numbers. Whereas the migration of Langerhans' cells was a regular occurrence in both pigmented and nonpigmented animals, the migration of melanocytes occurred in only a portion of the pigmented animals and in fewer numbers. These observations may have signific...

On their path to draining lymph nodes, epidermal Langerhans cells traverse collagen-dense connective tissue before reaching lymphatic vessels. The matricellular protein SPARC (secreted protein, acidic and rich in cysteine), which is induced during inflammation and tissue repair, organizes collagen deposition in tissue stroma. We analyzed Langerhans cell and dendritic-cell migration and its impa...

Langerhans cells act as antigen-presenting cells in immune reactions in the skin. What other roles they may play in inflammation is less well defined. We have tested whether these cells can produce TNF-alpha, an important mediator of inflammation. Resting Langerhans cells produce less than 0.1 U TNF-alpha/ml. Langerhans cells stimulated with phorbol myristate acetate (PMA) and lipopolysaccharid...

The differentiation of two types of T-lymphocyte accessory cells, i.e., interdigitating reticulum cells and Langerhans cells, was studied immunocytochemically and ultrastructurally on cutaneous lesions from patients with mycosis fungoides, a neoplasm of mature T-lymphocytes. In such a condition the lymphoid infiltrate creates, adjacent to the epidermis, a microenvironment in the dermis similar ...

The presence of Langerhans cells in the developing mucosal epithelium of mice was investigated by ATPase histochemistry and by electron microscopy. In the stratified squamous epithelium of the tongue and forestomach, a few ATPase-positive Langerhans cells could be recognized at 1 or 2 weeks after birth. They increased in number by 3 weeks of age, but the density was lower than that in the epide...

A causal link between cervical cancer and high-risk human papillomaviruses has been established. The virus infects basal cells of the mucosa, where Langerhans cells are the resident antigen-presenting cells. Langerhans cells and dendritic cells, which are targeted by vaccination, internalize similar amounts of human papillomavirus virus-like particles (VLPs), albeit through different uptake mec...

Langerhans' cell histiocytosis (LCH) is one of the 'histiocytosis disorders', as defined by the Histiocyte Society. LCH is an abnormal proliferation and dissemination of clonal Langerhans' cells in which they accumulate, along with other inflammatory cells, and form tissue granulomas in different organs. It is named after the appearance of the cells, which resemble the normal dendritic cells fo...

Solitary pulmonary Langerhans cell histiocytosis occurs predominantly in young adults, who are frequently heavy smokers. Besides the strong association to smoking, it differs from childhood Langerhans cell histiocytosis as well in that it is a polyclonal disorder, and the lesional Langerhans cells in this form of disease are reported to display mature markers. Thus, in this study we set out to ...

Langerhans cell histiocytosis (LCH) is a rare neoplastic lesion characterized by accumulation of cells having major phenotypic features of skin Langerhans cells. It usually affects young children but rare cases were also reported in adults. The clinical spectrum of LCH includes Letterer–Siwe disease, Hand–Schüller–Christian disease, eosinophilic granuloma, Langerhans cell sarcoma as well as int...