Edith Janssen, Ph.D.

Cincinnati Children's Hospital Medical Center - Research Foundation, Cincinnati, OH

2015 New Treatments, Target Identification, Biomarkers, Immune System Function

2015 Can Boosting Levels of One Molecule Restore Control?

The Study and What it Means to Patients

Our research has discovered early evidence that immune cells of lupus patients have abnormally low levels of an immune-regulating molecule, known as CD244.  We will explore if this molecule has potential as a biomarker of lupus as well as a target for drug development.

Summary

Our preliminary findings from mouse studies suggest that low levels of one key regulatory molecule known as CD244 may contribute to inflammation and abnormal immune system activity in lupus. Mutations in the genetic code for the CD244 molecule are known risk factors for kidney and mental symptoms of lupus, but how CD244 contributes to autoimmunity is poorly understood. With our LRI Novel Research Grant, we will look at the levels of this molecule in the blood of people with lupus to confirm our initial findings. Next, we will study potential interventions that target CD244 as a way to restore regulation to the immune system. If successful, these interventions will help in the design of new treatment options.

Scientific Abstract: CD244 targeting therapeutics in SLE

Dysregulation of dendritic cells (DCs) contributes to development of Systemic Lupus Erythematosus (SLE) but the mechanisms underpinning this dysregulation are unknown. We recently identified CD244 as immune-regulatory molecule on DCs. CD244 is located in the human SLE susceptibility locus 1q23 and SNPs in CD244 have been identified as risk factors for renal and neuropsychiatric manifestations in SLE. Our preliminary data indicate that SLE patients have decreased CD244 expression on their DCs.

We found that inhibition of CD244 signaling in mouse DCs markedly increased their pro-inflammatory cytokine production and T cell activating capacity. Moreover, reduction of CD244 or its adaptor molecules significantly increased susceptibility to SLE in various spontaneous and inducible mouse models.

Given the homology in mouse and human CD244/adaptor molecule sequences and expression pattern, we hypothesize that altered CD244 signaling in DCs contributes to the proinflammatory environment and the immune-dysregulation observed in SLE and can therefore be used as disease biomarker and exploited for therapeutic targeting.

To test the hypothesis we will assess CD244 and adaptor molecule expression in DCs from SLE patients, and determine the effect of pharmacologic targeting of CD244 and its pathway on human DC function in vitro and SLE development in in vivo mouse models.