Autoimmunity-associated T cell receptors recognize HLA-B*27-bound peptides

Human leucocyte antigen B*27 (HLA-B*27) is strongly associated with inflammatory diseases of the spine and pelvis (for example, ankylosing spondylitis (AS)) and the eye (that is, acute anterior uveitis (AAU))1. How HLA-B*27 facilitates disease remains unknown, but one possible mechanism could involve presentation of pathogenic peptides to CD8+ T cells. Here we isolated orphan T cell receptors (TCRs) expressing a disease-associated public β-chain variable region–complementary-determining region 3β (BV9–CDR3β) motif2,3,4 from blood and synovial fluid T cells from individuals with AS and from the eye in individuals with AAU. These TCRs showed consistent α-chain variable region (AV21) chain pairing and were clonally expanded in the joint and eye. We used HLA-B*27:05 yeast display peptide libraries to identify shared self-peptides and microbial peptides that activated the AS- and AAU-derived TCRs. Structural analysis revealed that TCR cross-reactivity for peptide–MHC was rooted in a shared binding motif present in both self-antigens and microbial antigens that engages the BV9–CDR3β TCRs. These findings support the hypothesis that microbial antigens and self-antigens could play a pathogenic role in HLA-B*27-associated disease

Seaweed biopolymers as additives for unfired clay bricks

Unfired clay bricks are an environmentally friendly alternative to conventional masonry materials such as fired bricks and concrete blocks but their use is currently limited by their relatively poor mechanical and durability properties. While products like cement and lime are commonly added to earthen materials in an effort to improve their physical performance, these additives can also have a negative influence on the overall environmental impact. The purpose of this research is to investigate the use of alginate, a natural and renewable biopolymer obtained from brown seaweeds, as an admixture for unfired clay blocks. A total of 5 different alginates have been investigated and combined with 3 soil compositions to create prototype specimens which have then been characterised and compared in relation to flexural and compressive strength, microstructure, abrasive strength and hygroscopic behaviour. The results demonstrate that improvements in mechanical strength are dependent on the type of alginate used and the composition of the soil. The greatest increase in compressive strength is achieved using an alginate sourced from the Laminaria Hyperborea seaweed and offers a value more than double that of the equivalent control specimen. Increases in the alginate dosage do not necessarily lead to an increase in strength suggesting that there is an optimum concentration at which strength improvement is most effective