Reduced density and morphologic alteration of Ia and ADPase positive Langerhans cells after low-protein diet.

Abstract

This study examined the effects of low-protein diet on the population density, morphology and histochemical characteristics of Langerhans cells. Weaned at 18 days old, BALB/c mice were divided into two groups: one group received a high-protein diet (20% casein) and the other was fed an isocaloric low-protein diet (caesin 4%). After 14 days, the mice were killed and the skin of the ears was removed for investigation. Langerhans cells were visualized using ADPase and anti-Ia immunoperoxidase techniques. In protein malnourished mice, the density of ADPase and Ia-positive Langerhans cells was significantly reduced, while morphometric assessment of their cross-sectional area showed a significant reduction of total cell area, cell body area and degree of arborization. Quantitative cytophotometric analysis revealed a reduction of ADPase ectoenzyme activity and decreased concentration of membrane Ia antigen. We postulate that these changes affect Langerhans cell functions, and in turn influence the immune mechanisms in the skin.