Expression of SOCS1 and SOCS3 genes in human graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND Suppressor of cytokine signaling genes (SOCS) are regarded as pivotal negative feedback regulators of cytokine signals, including the interferon-gamma (IFN-γ), granulocyte-colony stimulating factor, and interleukin families, released by T cells. A detailed understanding of the involvement of SOCS genes in graft-versus-host disease (GVHD) is critical to effectively manage GVHD, yet their expression patterns among recipients remain largely unexplored. METHODS Expression levels of SOCS1 and SOCS3 were determined by real-time quantitative reverse transcription PCR (qRT-PCR) in patients with acute GVHD (aGVHD) and chronic GVHD (cGVHD), in a severity-dependent manner, after allogeneic hematopoietic stem cell transplantation (HSCT). A total of 71 recipients with AML (N=40), ALL (N=12), myelodysplastic syndromes (MDS; N=10), chronic myelogenous leukemia (CML; N=2), severe aplastic anemia (SAA; N=5), or others (N=2), who received allogeneic HSCT from human leukocyte antigen-identical siblings or unrelated donors between 2009 and 2011, were included in the present study. RESULTS Overall, the expression levels of SOCS1 decreased in recipients with grade II to IV aGVHD and cGVHD when compared to normal donors and non-GVHD recipients. Interestingly, the expressions of SOCS1 decreased significantly more in cGVHD than in aGVHD recipients (P=0.0091). In contrast, SOCS3 expressions were similarly reduced in all the recipients. CONCLUSION This is the first study to show that SOCS1 and SOCS3 are differentially expressed in recipients following allogeneic HSCT, suggesting a prognostic correlation between SOCS genes and the development of GVHD. This result provides a new platform to study GVHD immunobiology and potential diagnostic and therapeutic targets for GVHD.