AUTHOR=Shim Saerok , Lee Siyoung , Hisham Yasmin , Kim Sinae , Nguyen Tam T. , Taitt Afeisha S. , Hwang Jihyeong , Jhun Hyunjhung , Park Ho-Young , Lee Youngmin , Yeom Su Cheong , Kim Sang-Yeob , Kim Yong-Gil , Kim Soohyun 

TITLE=Comparison of the Seven Interleukin-32 Isoforms’ Biological Activities: IL-32θ Possesses the Most Dominant Biological Activity

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.837588

DOI=10.3389/fimmu.2022.837588

ISSN=1664-3224

ABSTRACT=Cytokines are associated with the homeostasis of immune responses in health and disease. Interleukin-32 (IL-32) is a cytokine originally discovered in natural killer cell transcript 4 (NK4). IL-32 with different disorders has been described in terms of pathogenesis and the progression of diseases. Clinical studies have investigated IL-32 under various conditions such as viral infection, autoimmune diseases, inflammatory diseases, certain types of cancer, vascular disease, and pulmonary diseases. The high expression of IL-32 was identified in different tissue with various diseases and found to have multiple transcripts rising seven isoforms. However, the purification and biological activities of these isoforms have not been investigated yet. It is the first time to clone and purify seven recombinant IL-32 (rIL-32) isoforms (α, β, δ, γ, ε, ζ, and θ) using Escherichia coli expression system. Next, we evaluate the biological activities of these seven rIL-32 isoforms, which were used to treat the different types of cells by assessing the levels of inflammatory cytokine production. The results revealed that rIL-32θ possessed the most dominant biological activity in both immune and non-immune cells.