Functional genomics of SLE

Genome-wide associations studies (GWAS) have revealed more than 100 SLE susceptibility loci. In most cases the mechanisms by which these genetic factors elevate the risk of disease is unknown. We are combining both genetic and functional approaches to address these questions. Through genetic studies in multiple ancestries in SLE, we can fine map the association signals and using techniques such as Mendelian randomisation to infer the likely causal functional effects that underpin the genetics. By studying gene expression using single cell RNA sequencing, proteomics and massively parallel sequencing we can gain further insight the functional effects of risk alleles for SLE. This project involves internal collaboration with David L Morris and Deborah Cunninghame Graham

Role of X chromosome in female bias in autoimmunity

Almost all autoimmune diseases show sexual dimorphism with a striking female bias that is most marked in SLE (10:1). The cause of the bias has historically been attributed to ‘hormones’, which undoubtedly can influence immune function. However, several lines of evidence indicate a role for the X chromosome too. Gene expression in females from the X chromosome is usually regulated by random inactivation. This process is subject to perturbation by non-random skewing and loss of full inactivation on a regional bias. We are investigating both these processes in B cells in SLE to determine whether they are dysregulated. We have recently shown that a novel SLE risk gene, CXorf21 (TASL) is upregulated by SLE risk alleles, the gene also escapes X inactivation hence females have a higher dose of this disease risk gene, which acts in a viral sensing pathway that is activated in SLE. This project involves internal collaboration with Deborah Cunninghame Graham

Balance between risk of autoimmunity and infection risk in population

Why autoimmune genetic risk alleles persist in a population has long been subject to speculation. One hypothesis is that such disease risk alleles provide some protection against common infections. This has been difficult to substantiate because genetic studies of infectious disease are highly confounded. The COVID pandemic allows a unique opportunity to study host genetics in the setting of ‘new’ infectious agent. We have compared the genetics of SLE and COVID outcome and found evidence for strong genetic correlation between the two traits: both positive and negative factors were identified. We are actively following this up by using both genetic data from different ancestral populations and by acquiring epidemiological data of common infection frequency in a population cohort to compare infection incidence and severity with polygenic risk scores for common autoimmune diseases. This project involves internal collaboration with David L Morris

13th European SLE Meeting 2022

The Immunogenetics team is organising the 13th European SLE Meeting

• European SLE Meeting