Biology subjects

Muller, W.

Publications and source records attributed to Muller, W..

2 recordsLinked to original sources

bioRxiv2019

The essential role played by B cells in supporting protective immunity against Trichuris muris infection is dependent on host genetic background and is independent of antibody

This study investigates the role of B cells in immunity to Trichuris muris (T. muris) infection in two genetically distinct strains of mouse, using anti-CD20 monoclonal antibody (mAb) (Genentech-clone 5D2) to deplete B cells. Data is presented for the mouse strains: C57BL/6 and BALB/c, which mount mixed Th1/Th2, and highly polarised Th2 immune responses to T. muris, respectively. C57BL/6 mice receiving anti-CD20 treatment prior to and during, or anti-CD20 treatment that commenced two weeks post infection (p.i.), were susceptible to T. muris. Parasite-specific IgG1 antibodies were absent and Th2 type cytokines produced by mesenteric lymph nodes cells from mice receiving -CD20 mAb treatment were significantly lower than produced by cells from isotype control treated mice. T follicular helper cells were also significantly reduced. Importantly, and in complete contrast, BALB/c mice were still able to expel T.muris in the absence of B cells, revealing that the essential role played by B cells in protective immunity was dependent on genetic background. To explore whether the important role played by the B cell in the protective immune response of C57BL/6 mice was in enabling strong Th2 responses in the presence of IFN-{gamma}, IFN-{gamma} was blocked using anti-IFN-{gamma} mAb post B cell depletion. Depleting IFN-{gamma}, in the absence of B cells restored worm expulsion in the absence of parasite-specific IgG1/IgG2c and partially rescued the T. muris specific IL-13 response. Thus, our data suggest an important, antibody independent role for B cells in supporting Th2 type immune responses in mixed IFN-{gamma}-rich Th1/Th2 immune response settings. Author summaryHow B cells contribute to protective immunity against parasitic nematodes remains unclear, with their importance as accessory cells under-explored. This study reveals that, on some genetic backgrounds, B cells are important for the expulsion of T. muris by acting as accessory cells, supporting Th2 immune responses.

immunology↗

bioRxiv2019

Macrophage-specific NF-kappa B activation dynamics can segregate inflammatory bowel disease patients

The heterogeneous nature of inflammatory bowel disease (IBD) presents challenges, particularly when choosing therapy. Activation of the NF-{kappa}B transcription factor is a highly-regulated, dynamic event in IBD pathogenesis. We expressed the human NF-{kappa}B/p65 subunit in blood-derived macrophages, using lentivirus. Confocal imaging of p65 activation revealed that a higher proportion of macrophages from Crohns patients responded to lipid-A compared to controls. In contrast, cells from ulcerative colitis (UC) patients exhibited a shorter duration of p65 nuclear localisation compared to healthy controls and Crohns donors. Using a similar lentivirus approach, NF-{kappa}B-regulated luciferase was expressed in patient macrophages, isolated from frozen peripheral blood mononuclear cell samples. Following activation, samples could be segregated into three clusters based on the NF-{kappa}B-regulated luciferase response. The majority of UC samples appeared in hypo-responsive cluster 1, with Crohns patients representing the majority of hyper-responsive cluster 3. A positive correlation was seen between NF-{kappa}B-induced luciferase activity and cytokine levels released to medium from stimulated macrophages, but not in serum or biopsy. Analysis of macrophage cytokine responses and patient metadata revealed a strong correlation between Crohns patients who smoked and hyper-activation of p65. These in vitro dynamic assays of NF-{kappa}B activation in blood-derived macrophages segregate IBD patients into groups with different phenotypes and therefore may help determine response to therapy. Significance statementThis manuscript describes two dynamic assays of NF-{kappa}B activation in blood-derived macrophages that can segregate IBD patients into groups with different phenotypes. For the first time we introduce the use of dynamic measurements of a transcription factor activation as a method to stratify patients and we are confident that our approach will lead in future to early patient stratification and prediction of treatment outcome.

immunology↗