Mansfield, J. | bioRxiv Science

bioRxiv2022

Wheat cells show positional responses to invasive Zymoseptoria tritici

The stomatal complex of grasses consists of two guard cells and two adjacent subsidiary cells that cooperate during stomatal closure. Zymoseptoria tritici, the main causal agent of Septoria tritici blotch in wheat, enters the host via stomata. Here we test the hypothesis that the stomatal complex shows focused sub-cellular responses to invading Z. tritici hyphae. We have combined live-cell transmission light microscopy, immunofluorescence and CRS microscopy to identify cell wall modifications triggered by hyphal invasion. Furthermore, we have used confocal fluorescence microscopy and automated quantitative image analysis to assess whether host cells respond to hyphae through spatial redistribution of organelles. We find that subsidiary cells construct papillae that are accurately aligned with hyphal position even when hyphae are occluded by guard cells. These are distinct from those induced by powdery mildew, with callose restricted to a crust that surrounds content with a high-amplitude Raman signal in the CH-band. Peroxisome populations in subsidiary cells show distributions with modes weakly correlated with hyphal position but do not differ significantly between compatible and incompatible interactions. Our data suggest local changes to cell wall architecture and focal accumulation of organelles in subsidiary cells could play roles in crop defence during host leaf penetration by Z. tritici. Molecular strategies to amplify these responses may provide novel routes for crop protection.

plant biology↗

bioRxiv2018

HLA-DQA1*05 is associated with the development of antibodies to anti-TNF therapy

BackgroundAnti-tumour necrosis factor (anti-TNF) therapies are the most widely used biologic therapies for treating immune-mediated diseases. Their efficacy is significantly reduced by the development of anti-drug antibodies which can lead to treatment failure and adverse reactions. The biological mechanisms underlying antibody development are unknown but the ability to identify subjects at higher risk would have significant clinical benefits.\n\nMethodsThe PANTS cohort consists of Crohns disease patients recruited prior to first administration of anti-TNF, with serial measurements of anti-drug antibody titres. We performed a genome-wide association study across 1240 individuals from this cohort to identify genetic variants associated with anti-drug antibody development.\n\nFindingsThe Human Leukocyte Antigen allele, HLA-DQA1*05, carried by approximately 40% of Europeans, significantly increased the rate of anti-drug antibody development (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.60 to 2.25; P=5.88x10-13). This association was consistent for patients treated with adalimumab (HR, 1.89; 95% CI, 1.32 to 2.70) and infliximab (HR, 1.92; 95% CI, 1.57 to 2.33), and for patients treated with mono-(HR, 1.75; 95% CI, 1.37 to 2.22) or combination therapy with immunomodulators (HR, 2.0; 95% CI, 1.57 to 2.58).\n\nInterpretationHLA-DQA1*05 is significantly associated with an increased rate of anti-drug antibody formation in patients with Crohns disease treated with infliximab and adalimumab. Pre-treatment HLA-DQA1*05 genetic testing may help personalise the choice of anti-TNF therapy and allow the targeted use of immunomodulator therapy to minimise risk and maximise response.

genomics↗