I think the question is pretty self-explanatory. Some students of mine need to conduct in vitro experiments on a cell line representing alveolar macrophages.
You did not mention the purpose of cell line. Alveolar macrophages are terminally differentiated cells. If they are benign cells they do not grow. They come from circulation from other Origin (Bone marrow, Spleen, etc.) if you wonder to work with these cells I suggest you collect them after a bronchoalveolar washing. MH-S is the best available option if you really have to take an in vivo cell line approach.