Immunocytochemical and histopathologic characterization of lesions from patients with localized cutaneous leishmaniasis caused by Leishmania panamensis.

Localized cutaneous leishmaniasis (LCL) in Colombia is caused primarily by Leishmania panamensis, a different species from those reported in Brazil, French Guiana, and Venezuela. Because different parasites may elicit disparate immune responses, the present study was undertaken to establish the leukocyte participation in the immune response against L. panamensis.

T cell-mediated terminal maturation of dendritic cells: loss of adhesive and phagocytotic capacities.

Dendritic cells (DC) are a specific subset of APC characterized by the potent ability to activate immunologically naive T cells. We have observed previously that the murine epidermis-derived DC line XS52 undergoes a set of profound changes upon Ag-specific interaction with T cells, including IL-1 beta secretion acquired expression of CD86, and lost expression of CD115 (CSF-1 receptor) and proliferative responsiveness to CSF-1. These changes, which appear to reflect a critical transition during Ag presentation, have been termed T cell-mediated "terminal maturation" of DC, Here we report that XS52 cells also lose their adhesive and phagocytotic capacities during this event.

Abnormal expression of galactosyl(alpha 1-->3) galactose epitopes in squamous cells of the uterine cervix infected by human papillomavirus.

This study describes the presence of alpha-galactosyl epitopes on 12 cervical biopsy samples with features of human papillomavirus infection (HPV) and different stages of cervical intraepithelial neoplasia. An avidin-biotin-peroxidase assay with a monoclonal antibody recognizing gal(alpha 1-->3)gal residues was strongly positive in 5 of 12 cases. None of the controls stained (p = 0.

Hydrogen peroxide mediates UV-induced impairment of antigen presentation in a murine epidermal-derived dendritic cell line.

Ultraviolet-B (290-320 nm) radiation is known to impair the antigen-presenting cell (APC) function of Langerhans cells (LC), skin-specific members of the dendritic cell (DC) family. We sought to address mechanisms of this effect, focusing on the role played by hydrogen peroxide. For this purpose, we used a newly established murine DC line, XS52, which resembles epidermal LC in several respects.

Successive generation of antigen-presenting, dendritic cell lines from murine epidermis.

Dendritic cells are specialized APCs that exhibit an extraordinary capacity to activate naive T cells. Langerhans cells (LC), as epithelial tissue-specific members of this family, play key roles in the induction of T cell-mediated immunity against environmental, infectious, and tumor-associated Ags in skin. A major limitation in studying the biology of dendritic cells or LC has been the absence of stable, long-term cell lines.