Dendritic Cells from Rat Lung Are Potent Accessory Cells

Abstract

Accessory cells are required for the induction of lymphocyte proliferation in response to mitogens or antigens. Rat pulmonary cells were tested for the presence of accessory activity in lymphocyte proliferation induced by sodium periodate. Buffer-perfused lungs were excised, minced, and enzymatically digested. The resulting pulmonary cells (PC) were separated into high density (HD-PC, 32 to 57%) and low density (LD-PC, 9 to 32%) fractions in a discontinuous density gradient of bovine plasma albumin (BPA). Both macrophages and dendritic cells were observed in the LD-PC by light microscopy. HD-PC, LD-PC, adherent LD-PC, nonadherent LD-PC, and a purified preparation of pulmonary dendritic cells (DC-P) were tested for accessory activity in the presence of periodate-treated, lymph-node-derived lymphocytes as responders. Most of the accessory activity was found in the LD-PC. Increasing numbers of LD-PC stimulated proliferation of responder lymphocytes in a linear, dose-dependent manner; higher numbers had a suppressive effect. Nonadherent LD-PC containing dendritic cells also produced a dose-dependent increase in periodate-induced lymphocyte proliferation, whereas adherent LD-PC, morphologically identified as macrophages, were suppressive. Removal of phagocytic macrophages from nonadherent LD-PC resulted in an eightfold increase in both the percent of DC-P present and the amount of accessory activity in the LD-PC. We conclude that pulmonary dendritic cells are potent accessory cells for periodate-induced lymphocyte proliferation.

Ozone exposure enhances antigen-presenting activity of interstitial lung cells in rats

“…This enhancement may be caused by induced in the function and the number of APC in the lung. Previous report show that DC isolated from parenchymal lung tissue exhibits strong AP activity (Holt et al, 1985;Rochester et al, 1988;Sertl et al, 1986). We assessed the AP activity of DC fraction in lung cells.…”

“…Ia is expressed on dendritic cells (DC), macrophages, or B-cells, those play a role of APC in parenchymal lung tissue. DC isolated from parenchymal lung tissue exhibits strong AP activity in vitro (Holt et al, 1985;Rochester et al, 1988;Sertl et al, 1986). Inhalation of bacterial organisms recruits Ia positive DC into the airway epithelium (McWilliam et al, 1994).…”

The Regulation of Pulmonary Immunity

“…Functional assays have included stimulation of periodate-treated lymphocytes, MLRs, and antigen-induced stimulation of either memory T cells or lymphoblasts. All have shown that lung DCs function as well or better than DCs from other sources Rochester et al, 1988;Pollard and Lipscomb, 1990).…”

A Contiguous Network of Dendritic Antigen-Presenting Cells within the Respiratory Epithelium

“…Firstly, studies initially per formed in our laboratory [9] and confirmed by others [10,11] suggest that much of the APC activity detect able in suspensions derived from enzymatically dis rupted lung and airway tissue is attributable to a dendritic cell (DC)-like cell. Secondly, despite their seemingly sparse distribution in transverse sections of airways, significant numbers of la-positive cells can be detected in longitudinal frozen sections which pro vide a wider view of the airway epithelium [12][13][14], However, as is demonstrated below, appropriate sec tioning procedures reveal the presence of a much larger intra-epithelial la-positive cell population.…”