Quantitative analysis of the expression of Ia antigen positive dendritic cells on the squamous epithelia after birth in mice.

Abstract

In this investigation, we immunohistochemically studied the presence of cells bearing Ia antigen in the stratified squamous epithelia of tongue, esophagus and skin in mice. The developmental expression of Ia antigen positive cells were quantitatively analyzed and compared with skin, by using the sheet method, from birth to the adult stage. Additionally, these cells were morphologically studied by immunoelectron microscopy.We observed that in case of skin, the increase in the number of Ia positive dendritic cells (Ia+DC) was rapid and reached adult stage after day 6, whereas in the tongue and esophagus it showed a gradual increase and reached adult stage by day 28 of postnatal life. However, the number of Ia antigen bearing cells were fewer in tongue and esophagus than in skin on the day of birth. During the whole period of our observation, the cell density was found to be heaviest in skin, followed by tongue and esophagus respectively. The Ia antigen positive cells showed clear dendritic features, the ultrastructure of which showed intracytoplasmic Birbeck granules in the tongue, esophagus, and skin in adult mice (day 28 of postnatal life).The Ia+DC of skin were reported to be identical to the Langerhans cells. Our observations of dendritic features and intracytoplasmic Birbeck granules in the Ia+DC of tongue and esophagus suggest that these cells were also Langerhans cells or Langerhans cell-like cells.