School of Medicine and Health Sciences Poster Presentations

Title

Survivin Promotes Autoreactive Immune Cells in Myasthenia Gravis: An Animal Model and Human Study

Document Type

Poster

Abstract Category

Immunology/Infectious Diseases

Keywords

Myasthenia gravis, Survivin, B cell, Autoimmune diseases, Flow cytometry

Publication Date

Spring 5-1-2019

Abstract

BACKGROUND: Myasthenia gravis (MG) is a T cell dependent, B cell mediated disorder which targets the neuromuscular junction with autoantibodies directed against the postsynaptic membrane. The majority of patients express antibodies to nicotinic acetylcholine receptor (AChR). We have shown that survivin, a member of the inhibitor of apoptosis family, is expressed in autoreactive lymphocytes from MG patients. Our objectives are to reduce survivin in an experimental autoimmune MG (EAMG) mouse model and to demonstrate survivin as a potential target in human B cells. METHOD: Animal model: MG was induced in C57BL/6J female mice through multiple immunizations of Torpedo AChR. The EAMG mice were stratified into three treatment groups: control PBS, and two groups that received different levels of survivin antibody (20ug and 100ug). Mice were assessed for weakness. Mice splenocytes were obtained and stained for T cell marker (CD3e), B cell marker (CD19) plus intracellular survivin. Splenocytes were analyzed by BD FACSCelesta followed by FlowJo software. ELISAs were used to determine AChR-specific IgGs. Human study: The peripheral blood mononuclear cells (PBMCs) were obtained from MG patients and healthy controls (HCs) by using density gradient media (Ficoll). PBMCs were stained with PBMC marker (CD45), T cell marker (CD4), B cell marker (CD20), plus intracellular survivin. The intracellular survivin expression on human CD20+ or CD4+ lymphocytes were viewed by BD FACSCelesta followed by FlowJo software. RESULTS: The EAMG mouse model demonstrated survivin expression in CD3- CD19+ splenic B cells, but less in CD3+ CD19- splenic T cells. The treatment with anti-survivin effectively reduced survivin in splenic B cells in a dose dependent manner, and corresponded to reduced levels of AChR-Specific IgG subtype production. In the human study, survivin was expressed in CD4- CD20+ human B cells, whereas, CD4-CD20+ survivin+ lymphocytes of MG patients are significantly higher than HCs. CONCLUSION: The animal study demonstrates that survivin does have a pathological role to promote autoreactive B cells and expression of autoantibodies. The expression of the survivin in Human B cells suggest that survivin could be used as a potential therapeutic target.

Open Access

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Presented at Research Days 2019.

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Survivin Promotes Autoreactive Immune Cells in Myasthenia Gravis: An Animal Model and Human Study

BACKGROUND: Myasthenia gravis (MG) is a T cell dependent, B cell mediated disorder which targets the neuromuscular junction with autoantibodies directed against the postsynaptic membrane. The majority of patients express antibodies to nicotinic acetylcholine receptor (AChR). We have shown that survivin, a member of the inhibitor of apoptosis family, is expressed in autoreactive lymphocytes from MG patients. Our objectives are to reduce survivin in an experimental autoimmune MG (EAMG) mouse model and to demonstrate survivin as a potential target in human B cells. METHOD: Animal model: MG was induced in C57BL/6J female mice through multiple immunizations of Torpedo AChR. The EAMG mice were stratified into three treatment groups: control PBS, and two groups that received different levels of survivin antibody (20ug and 100ug). Mice were assessed for weakness. Mice splenocytes were obtained and stained for T cell marker (CD3e), B cell marker (CD19) plus intracellular survivin. Splenocytes were analyzed by BD FACSCelesta followed by FlowJo software. ELISAs were used to determine AChR-specific IgGs. Human study: The peripheral blood mononuclear cells (PBMCs) were obtained from MG patients and healthy controls (HCs) by using density gradient media (Ficoll). PBMCs were stained with PBMC marker (CD45), T cell marker (CD4), B cell marker (CD20), plus intracellular survivin. The intracellular survivin expression on human CD20+ or CD4+ lymphocytes were viewed by BD FACSCelesta followed by FlowJo software. RESULTS: The EAMG mouse model demonstrated survivin expression in CD3- CD19+ splenic B cells, but less in CD3+ CD19- splenic T cells. The treatment with anti-survivin effectively reduced survivin in splenic B cells in a dose dependent manner, and corresponded to reduced levels of AChR-Specific IgG subtype production. In the human study, survivin was expressed in CD4- CD20+ human B cells, whereas, CD4-CD20+ survivin+ lymphocytes of MG patients are significantly higher than HCs. CONCLUSION: The animal study demonstrates that survivin does have a pathological role to promote autoreactive B cells and expression of autoantibodies. The expression of the survivin in Human B cells suggest that survivin could be used as a potential therapeutic target.