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Intestinal helminth infection triggers a type 2 immune response that promotes a ‘weep-and sweep’ response characterised by increased mucus secretion and intestinal hypermotility, which function to dislodge the worm from its intestinal habitat. Recent studies have discovered that several other pathogens cause intestinal dysmotility through major alterations to the immune and enteric nervous systems (ENS), and their interactions, within the gastrointestinal tract. However, the involvement of these systems has not been investigated for helminth infections. Eosinophils represent a key cell type recruited by the type 2 immune response and alter intestinal motility under steady-state conditions. Our study aimed to investigate whether altered intestinal motility driven by the murine hookworm, Nippostrongylus brasiliensis , infection involves eosinophils and how the ENS and smooth muscles of the gut are impacted. Eosinophil deficiency did not influence helminth-induced intestinal hypermotility and hypermotility did not involve gross structural or functional changes to the ENS. Hypermotility was instead associated with a dramatic increase in smooth muscle thickness and contractility, an observation that extended to another rodent nematode, Heligmosomoides polygyrus . In summary our data indicate that, in contrast to other pathogens, helminth-induced intestinal hypermotility is driven by largely by myogenic, rather than neurogenic, alterations with such changes occurring independently of eosinophils. (<300 words)

The IκB kinase complex, consisting of IKK1, IKK2 and the regulatory subunit NEMO, is required for NF-κB signalling following the activation of several cell surface receptors, such as members of the Tumour Necrosis Factor Receptor superfamily and the Interleukin-1 Receptor. This is critical for haematopoietic cell proliferation, differentiation, survival and immune responses. To determine the role of IKK in the regulation of haematopoiesis, we used the Rosa26 Cre-ERT2 Cre/lox recombination system to achieve targeted, haematopoietic cell-restricted deletion of the genes for IKK1 or IKK2 in vivo. We found that the IKK complex plays a critical role in haematopoietic cell development and function. Deletion of IKK2, but not loss of IKK1, in haematopoietic cells led to an expansion of CD11b/Gr-1-positive myeloid cells (neutrophilia), severe anaemia and thrombocytosis, with reduced numbers of long-term haematopoietic stem cells (LT-HSCs), short-term haematopoietic stem cells (ST-HSCs) and multipotential progenitor cells (MPPs), increased circulating interleukin-6 (IL-6) and severe gastrointestinal inflammation. These findings identify distinct functions for the two IKK catalytic subunits, IKK1 and IKK2, in the haematopoietic system.

Background There is increasing evidence that the airway microbiome plays a key role in the establishment of respiratory health by interacting with the developing immune system early in life. While it has become clear that bacteria are involved in this process, there is a knowledge gap concerning the role of fungi. Moreover, the inter-kingdom interactions that influence immune development remain unknown. In this prospective exploratory human study, we aimed to determine early post-natal microbial and immunological features of the upper airways in 121 healthy newborns. Results We found that the oropharynx and nasal cavity represent distinct ecological niches for bacteria and fungi. Breastfeeding correlated with changes in microbiota composition of oropharyngeal samples with the greatest impact upon the relative abundance of Streptococcus species and Candida . Host transcriptome profiling revealed that genes with the highest expression variation were immunological in nature. Multi-omics factor analysis of host and microbial data revealed unique co-variation patterns. Conclusion These data provide evidence of a diverse multi-kingdom microbiota linked with local immunological characteristics in the first week of life that could represent distinct trajectories for future respiratory health. Trial registration NHS Health Research Authority, IRAS ID 199053. Registered 5 Oct 2016. https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/breathing-together/ -dqCA8KxpBwUxTCR4xx6Da Video abstract

p53 is critical in the normal response to a variety of cellular stresses including DNA damage and loss of p53 function is a common feature of many cancers. In hematological malignancies, p53 deletion is less common than in solid malignancies but is associated with poor prognosis and resistance to chemotherapy. Compared to their wild-type (WT) counterparts, hematopoietic progenitor cells lacking p53 have a greater propensity to survive cytokine loss, in part, due to the failure to transcribe Puma, a proapoptotic Bcl-2 family member. Using expression arrays, we have further characterized the differences that distinguish p53(-/-) cells from WT myeloid cells in the presence of Interleukin-3 (IL-3) to determine if such differences contribute to the increased clonogenicity and survival responses observed in p53(-/-) cells. We show that p53(-/-) cells have a deregulated intracellular signaling environment and display a more rapid and sustained response to IL-3. This was accompanied by an increase in active ERK1/2 and a dependence on an intact MAP kinase signaling pathway. Contrastingly, we find that p53(-/-) cells are independent on AKT for their survival. Thus, loss of p53 in myeloid cells results in an altered transcriptional and kinase signaling environment that favors enhanced cytokine signaling.

Long-term survival of lung transplant recipients remains limited by chronic lung allograft dysfunction (CLAD). CLAD is only diagnosed following a persistent and substantial decline in lung function, after which irreversible damage to the lungs has occurred, limiting opportunities to effectively intervene at an early stage. There is a critical need for earlier detection prior to its clinical manifestation. The immunological drivers of CLAD remain unclear, limiting the development of predictive biomarkers and new therapies. In this hypothesis-generating, prospective cohort study, we profiled the microbial, metabolic, lipidomic, and gene expression dynamics of longitudinally collected broncho-alveolar lavages (BALs) from 56 CLAD-free lung transplant recipients up to 30 months post-transplant, and compared BALs from 13 CLAD-free patients to BALs from 13 patients who developed CLAD. In CLAD-free patients, the first 6 months post-transplant were hallmarked by diminished microbial diversity and increased abundance of Staphylococcus and Candida, coupled with upregulated innate and adaptive immune responses, and elevated nitric oxide metabolism (FDR < 0.05). This was superseded by homeostatic tissue repair and by the reactivation of T-cell genes such as CD3, GZMA, IL2RB, CD28, CD40LG, and LCK, after tapering of maintenance immunosuppression (FDR < 0.05). In patients who developed CLAD, disease onset was preceded by the increased abundance of sphingolipids and the upregulation of glycocalyx and immune cell recruitment genes such as HAPLN3, HS3ST3B1, SULF2, CHST2, CSGALNACT1, CXCR1, CSF3R, SELL, CXCL2, and CEACAM1 (FDR < 0.05), suggesting increased vascular dysfunction and immune cell graft infiltration prior to CLAD onset. Scoring against a publicly available lung single-cell dataset showed our bulk gene transcriptomics signature to be expressed by monocytes, endothelial, and T cells. In contrast to CLAD-free patients, this signature persisted after 1.5 months post-transplant and increased in intensity upon the start of lung function decline. Multi-omics integration highlighted sphingolipid molecules and genes involved in immune cell recruitment and endothelial function as candidate biomarkers associated with the onset of CLAD. This study is limited by its small sample size. We have identified immunological processes, metabolites, lipids, and genes associated with the onset of CLAD. Our findings are to be considered associative and not aimed at establishing causality. Future studies employing a targeted approach in independent validation cohorts, using, for example, quantitative polymerase chain reaction (PCR) and targeted mass-spectrometry, will be required to confirm these findings.

Soil-transmitted helminth (STH) infections such as Necator americanus infect millions globally, and are a major cause of anemia and developmental stunting in low and middle income countries. Blood-feeding hookworms in particular rely on the digestion of host erythrocytes for nutrition and therefore detoxify heme as a byproduct of their parasitism. This dependency on blood feeding and subsequent detoxification renders this pathway as a vulnerable target for therapeutic intervention, particularly as it is the cause of morbidity in those infected. Here we described the continued development and application of a high-throughput in vitro assay using the so-called rodent hookworm Nippostrongylus brasiliensis, a model that shares key traits with N. americanus including blood feeding and hemozoin-like pigment formation. We optimized a fluorescence-based screening cascade to utilise GelGreen as a cost-effective viability stain and screened 400 compounds from the MMV Pathogen Box. Multiple compounds displayed enhanced activity in the presence of blood, suggesting interference with blood-feeding or blood-feeding-induced development. Five hits were selected for further validation, and as proof-of-principle of this screening cascade, all five were well tolerated in vivo at low doses in a murine model. This study therefore demonstrates this method can be used as a tractable and biologically relevant screening approach to identify compounds active against blood-feeding nematodes. Future work can further develop such compounds into lead drug candidates, and be leveraged for comparative parasitology approaches to identify pan-anthelmintic drugs.

Intestinal helminth infection triggers a type 2 immune response that promotes a ‘weep-and sweep’ response characterised by increased mucus secretion and intestinal hypermotility, which function to dislodge the worm from its intestinal habitat. Recent studies have discovered that several other pathogens cause intestinal dysmotility through major alterations to the immune and enteric nervous systems (ENS), and their interactions, within the gastrointestinal tract. However, the involvement of these systems has not been investigated for helminth infections. Eosinophils represent a key cell type recruited by the type 2 immune response and alter intestinal motility under steady-state conditions. Our study aimed to investigate whether intestinal dysmotility driven by murine hookworm, Nippostrongylus brasiliensis, infection involves eosinophils and how the ENS and smooth muscles of the gut are impacted. Eosinophil deficiency did not influence helminth-induced intestinal hypermotility and hypermotility did not involve gross structural or functional changes to the ENS. Hypermotility was instead associated with a dramatic increase in smooth muscle thickness and contractility. In summary our data indicate that, in contrast to other pathogens, helminth-induced intestinal hypermotility is driven by largely by myogenic, rather than neurogenic, alterations with such changes occurring independently of eosinophils. (<300 words) Intestinal helminth infection is a global threat to those living in poverty without adequate sanitation. Expulsion of intestinal worms is driven by a host type 2 immune response, characterised by increased eosinophils, that results in the intestinal hypermotility and mucus secretion that dislodge the worm from its luminal habitat. Intestinal motility is largely controlled by the local enteric nervous system (ENS) and can be regulated by close interactions between neurons and intestinal immune cells. Utilising Nippostrongylus brasiliensis as a model of murine hookworm infection, we investigated the contribution of the ENS and eosinophils to intestinal hypermotility and worm expulsion. Despite the critical role of the ENS in regulating typical intestinal function, very little alteration to ENS structure or function was observed following N. brasiliensis infection. Instead, infected animals displayed dramatically increased smooth muscle thickness and contractile strength. Neither helminth-induced intestinal hypermotility nor altered smooth muscle morphology required eosinophils. Our findings reveal that, in contrast to other intestinal pathogens, myogenic rather than neurogenic alterations drive small intestinal hypermotility and pathogen expulsion following hookworm infection. (<200 words)