Macrophage inflammatory protein-1 alpha expression in non-neoplastic and neoplastic lung tissue

The chemokines are members of a bipartite superfamily of soluble proteins that have been implicated in a wide range of acute and chronic inflammatory processes, as well as other immunoregulatory functions. Macrophage inflammatory protein-1 alpha (MIP-1alpha) belongs to the C-C subfamily of these chemokines and is primarily a potent chemoattractant and activator of monocytes. MIP-1alpha is also thought to play a role in host defence. We examined the expression of MIP-1-alpha in normal lung, inflammatory lung tissue and lung cancer cells by the immunoperoxidase method using a MIP-1alpha monoclonal antibody. MIP-1alpha protein was found to be expressed not only by alveolar macrophages, but also by bronchial ciliated cells, hyperplastic alveolar type II cells and activated fibroblasts surrounding malignant tissue. Of 33 cases of lung cancer, 23 (70%) expressed MIP-1alpha. These observations suggest that lung cancer cells, non-neoplastic alveolar type II cells and fibroblasts can participate in inflammatory cell recruitment via the production of MIP-1alpha. Tumour derived MIP-alpha may also affect the interaction between lung cancer and host inflammatory cells.