Immunotherapy Breakthrough for Autoimmune Diseases: An Exclusive Interview with Professor David Wraith

Scientists in the School of Cellular and Molecular Medicine at the University of Bristol have made an important breakthrough in the fight against debilitating autoimmune diseases such as multiple sclerosis (MS), by revealing how to switch off specific immune cells without compromising the whole immune system. SelectScience spoke to Professor Wraith, who led the research funded by the Wellcome Trust, about the research and the technologies his group used.

Why is it so important to find alternative pathways of therapy for autoimmune diseases?
MS alone affects around 2.5 million people worldwide. Current MS treatments, such as the disease-modifying therapy Natalizumab, tend to non-specifically target immune cells. Unfortunately, these types of disease-modifying therapeutics can have unacceptable side effects such as infections, development of tumors, and disruption of natural regulatory mechanisms. My lab’s research, published in Nature Communications, involved trying to define the different types of cells and has led to the discovery that CD4+ T-cell responses can be converted from being aggressive to actually protecting against disease.

What made you try the ‘antigen-specific immunotherapy’ approach to finding therapies for autoimmune disorders?
Our team discovered that an ‘antigen-specific immunotherapy’ approach, currently used in the treatment of allergic disorders, could be applied to autoimmune diseases. The antigen mechanism for allergic disorders is, however, different to that for autoimmune diseases, with Immunoglobulin E (IgE) being the main culprit causing symptoms in allergy.

Administration of fragments of the proteins that are normally the target for attack leads to correction of the autoimmune response through switching off of specific T-cells. These peptides bind Major Histocompatibility Complex (MHC) proteins, and give tolerance-inducing signals to the specific T-cells via their T-cell receptor.

The therapeutic approach has been controversial, but the research described in our paper helps to define the mechanism by which this desensitization occurs, and how it works through the induction of inflammatory cytokines and ‘bystander suppression’.

We developed a dose escalation strategy for efficient self-antigen-specific tolerance induction, using an experimental autoimmune encephalomyelitis model (EAE) mouse model of multiple sclerosis, and characterized the changes in gene expression in the CD4+ T-cells at each consecutive stage of escalating dose immunotherapy (EDI).

Can you describe the technology used to analyze the effectiveness of the dose escalation?
Cytokine protein analysis: fluorescence intensity of cytokines within CD4+ cells was measured using flow cytometry on a BD Biosciences FACS Calibur flow cytometer. Cytokine secretion was measured with a Molecular Devices SpectraMax 190 microplate reader and cytokine protein concentration was calculated using Microplate Manager software, from Bio-Rad.

Proliferation assays: for in vitro intracellular dye dilution proliferation assays, splenic CD4+ T cells were isolated from untreated mice using a CD4+ T-cell isolation kit by Miltenyi Biotec.

Microarray / Data Analysis: RNA was extracted from CD4+ T cells using RNeasy reagents, including DNase treatment (QIAGEN). RNA quality and quantity was assessed using an Agilent 2100 Bioanalyzer, before biological replicates were pooled and amplified using a Bio-Rad Opticon 2 Real Time Cycler . Fragmentation and labeling was performed using Affymetrix GeneChip WT Terminal Labeling and Hybridization kit before hybridization to GeneChip Mouse Gene 1.0 ST arrays.

What are the next steps in this research?
This pioneering treatment is currently undergoing Phase II clinical development, through the University of Bristol spin-out biotechnology company Apitope.

Professor Wraith told SelectScience: “It is hoped this latest insight will lead to the widespread use of antigen-specific immunotherapy as a treatment for many autoimmune disorders, including multiple sclerosis (MS), type 1 diabetes, Graves' disease and systemic lupus erythematosus (SLE).” He added: ”If we clearly know what the antigen is, we have a target.”