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Biology subjects

Krug, S.

Publications and source records attributed to Krug, S..

2 recordsLinked to original sources

Host regulator PARP1 contributes to sex differences and immune responses in a mouse model of tuberculosis

Tuberculosis (TB) is a devastating infectious disease responsible for nearly 2 million deaths annually that has a poorly understood male bias. Elucidating the basis of this male bias may enable precision medicine interventions for TB treatment and prevention. Here, we identify the master regulator Poly(ADP-ribose) Polymerase 1 (PARP1) as a driver of TB sex differences. We found that infection with M. tuberculosis (M. tb) triggers robust PARP activation in mouse lungs, suggesting that PARP1 activation is a fundamental host response to TB. Remarkably, PARP1 deletion abolished known sex differences in TB cytokine responses and blunted the early induction of TNF, IL-1{beta}, IFN{gamma}, MCP-1, and IL-6, particularly in male mice. In contrast, PARP1 was required for IL-10 induction in male or female mice. PARP1 deletion was protective against TB in female mice, resulting in significantly prolonged survival and reduced bacterial burden, but impaired TB containment in male mice. Our findings indicate that PARP1 contributes to TB sex differences via sexually divergent immune regulation and uniquely enhances early proinflammatory responses in males that prove beneficial for TB containment.

immunology

Dissection of barrier dysfunction in organoid-derived human intestinal epithelia induced by Giardia duodenalis

Background and aimsThe protozoa Giardia duodenalis is a major cause of gastrointestinal illness worldwide, but underlying pathophysiological mechanisms remain obscure, partly due to the absence of adequate cellular models. We aimed to overcome these limitations and to recapitulate the authentic series of events in the primary human duodenal tissue by using the human organoid system. MethodsWe established a compartmentalized cellular transwell system with electrophysiological and barrier properties akin to duodenal mucosa and dissected the events leading to G. duodenalis-induced barrier breakdown by functional analysis of transcriptional, electrophysiological and tight junction components. ResultsOrganoid-derived cell layers of different donors showed a time- and parasite load-dependent leak flux indicated by collapse of epithelial barrier upon G. duodenalis infection. Transcriptomic analysis suggested major expression changes in genes contributing to ion transport and tight junction structure. SLC12A2/NKCC1- and CFTR-dependent chloride secretion was reduced early after infection, while changes in the tight junction composition, localization and structural organization occurred later as revealed by immunofluorescence analysis and freeze fracture electron microscopy. ConclusionData suggest a previously unknown sequence of events culminating in intestinal barrier dysfunction upon G. duodenalis infection ignited by alterations of cellular ion transport followed by breakdown of the tight junctional complex and loss of epithelial integrity. The newly established organoid-derived model to study G. duodenalis infection will help enable further molecular dissection of the disease mechanism and, thus, can help to find new options treating disease and infection, in particular relevant for chronic cases of giardiasis.

microbiology