Langerhans cell presentation of sheep red blood cells induces antibody production

Mouse epidermal Langerhans cells (LC) were found to be capable of presenting sheep red blood cells (SRBC) to immune spleen lymphocytes, resulting in antibody production as assessed by a direct plaque cell assay. Spleen lymphocytes, prepared by removal of adherent cells, were unable to respond to SRBC in a 5-day culture; however, when co-cultured with either epidermal cells or splenic adherent cells, a response to SRBC occurred, as demonstrated by an increase in the number of antibody-producing cells. The LC were shown to be the antigen-presenting cells in these cultures, as depletion of LC via their Fc receptors abrogated the response. A similar reduction in the number of epidermal LC added to cultures likewise failed to induce antibody production. These experiments demonstrate that LC are able to present complex cellular antigens to the immune system, resulting in a B lymphocyte response.