Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 14 1 2022 02 20 125 132 Amin Ebadi Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Navid Momenifar Human and Animal Cell Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Iran Shaghayegh Yazdani Department of Microbiology, Faculty of Advanced Science & Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran Omid Gholizadeh Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran Vahdat Poortahmasebi Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Bacteriology and Virology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Research Center for Clinical Virology, Tehran University of Medical Sciences, Tehran, Iran 2021 11 06 2022 01 16 Background and Objectives: Human T-lymphotropic virus type 1 (HTLV-1) is the cause of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The present study aims to analyze gene expression patterns in ATL and HAM/TSP. Materials and Methods: Microarray gene expression profiling of T-lymphocytes from HTLV-1 associated disease and healthy control were obtained from Gene Expression Omnibus (GEO). Several bioinformatics tools were used to identify differentially expressed genes (DEGs). Among the generated DEGs, we constructed protein-protein interaction (PPI) between HAM/TSM and ATL in comparison to asymptomatic carriers (ACs). Subsequently, gene ontology (GO) and topological analysis were performed. Results: We found that the majority of DEGs in ATL and HAM/TSP were importantly implicated in immune response categories. The nodes and edges number of normal-AC, AC-ATL and ATL-HAM/TSP PPIs were 168 and 145, 116 and 97, and 275 and 327, respectively. Based on the topological analyses of protein-protein interaction networks, APP (Amyloid Beta Precursor Protein) was detected as a critical player in progression of HTLV-1 disease. Conclusion: Dysregulation of immune response associated transcripts play a critical role in HTLV-1 disease progression. Immune response associated genes may be biomarker for prognosis in cancer development and therapeutic targets. https://ijm.tums.ac.ir/index.php/ijm/article/view/3409 https://ijm.tums.ac.ir/index.php/ijm/article/download/3409/1434