Background: Intercellular interactions through receptor and ligand molecules play an indelible role in regulating communications of cells with each other, especially in multicellular organisms. So far, extensive studies have been done with both experimental and computational approaches in this field. One of the advanced experimental methods is constructing a three-dimensional medium similar to in vivo conditions, but due to the existing limitations, it cannot be investigated on a large scale. Therefore, in order to investigate and analyze the intercellular interactions, use of computational methods such as network reconstruction has attracted the attention of many researchers recently. Methods: The intercellular interaction network was reconstructed using receptor and ligand interaction dataset and gene expression data of the first phase of the immunological genome project. We analyzed the microarray data and reconstructed the network through the identification of cells involved in intercellular communication. Results: In the reconstructed network, there are 9271 communications between 162 cells which were created through 460 receptor-ligand interactions. The results indicate that cells belonging to hematopoietic lineages use fewer communication pathways for interacting with each other and most network communications belong to non-hematopoietic stromal cells followed by macrophages. The investigation of expression specificity of receptors and ligands revealed the high specificity of expression of these genes and interactions between them. Conclusion: Obtained results stressed the importance of the communication of stromal cells with immune cells and also high specificity of genes expression in these cells. The stromal cells have the most autocrine communication, and interactions between the wnt5a with the Ror1/2 and Fzd5a among the stromal lineage cells are abundant.

The First Reconstruction of Intercellular Interaction Network in Mus musculus Immune System