Cellular Immune Signatures and Pathways in Autoimmunity
Currently, the Long lab has three interdependent, collaborative projects focused on understanding how tolerance is lost in autoimmunity. Gaining a better understanding of the disease-related causes and consequences of defective cytokine signaling (project 1) may lead to development of more sensitive biomarkers (project 2) and more targeted therapies that promote tolerance (project 3):
How May Altered Cytokine Responses Be Involved In Loss Of Tolerance?
The Long lab is focusing on common gamma chain cytokine signaling pathways in type 1 diabetes (T1D) as compared to other autoimmune diseases including multiple sclerosis, rheumatoid arthritis and systemic lupus erythematosus (SLE). We are using genotype-phenotype and functional studies to discover the underlying molecular mechanisms of defective signaling and the physiological impact of this dysregulation on lymphocytes.
Working with external collaborators, we are involved in understanding how treatments targeting cytokine pathways may promote tolerance in autoimmune patients.
Can Immunological Phenotypes Be Used As A Biomarker Of Autoimmune Disease?
Clinical signs of autoimmune disease often occur long after damage of the organ thereby limiting potential to intervene or reverse disease progression. Thus, it is important to be able to identify deleterious autoimmune responses before the effects of this damage become clinically apparent. In parallel, when treating disease it would be helpful to better understand whether the pathogenic cells are reduced and protective cells are enhanced. With Dr. James and Dr. Cerosaletti the Long lab is discovering and tracking T cell signatures in T1D subjects who have different rates of disease progression. With Dr. Buckner, we are determining when T cell signatures of T1D appear by studying subjects at-risk for developing T1D over time. Lastly, working with the JDRF Core Assay Validation group, we are establishing whether a composite biomarker (multiple assays) will be more effective in defining autoimmune disease progression.
Can We Better Treat Autoimmunity By Understanding The Mechanisms Of Action Of Therapies In The Context Of Each Autoimmune Patient?
Through the HIP Core and work with Dr. Linsley in Systems Immunology, we have discovered unique phenotypes and “signatures” that track with responders, and nonresponders, to therapy. We are using in vitro cultures and extensive cellular immune phenotyping (CyTOF and 18-color flow) paralleled with transcriptional analyses to reveal mechanism of action and associated signatures in each responding patient. With alefacept (LFA-3-Ig) and teplizumab (anti-CD3) in T1D, we have identified a CD4 PD-1+ population and a CD8 population, respectively, that is augmented with therapy and are now asking what these populations are, how do they function and do they have or predict therapeutic benefit.