Membrane nanotubes are ancient machinery for cell-to-cell communication and transport. Their interference with the immune system

Mirani

et al. 2022

Cells

The present study discusses a biofilm-positive P. aeruginosa isolate that survives at pH levels ranging from 4.0 to 9.0. The biofilm consortia were colonized with different phenotypes i.e., planktonic, slow-growing and metabolically inactive small colony variants (SCVs). The lower base of the consortia was occupied by SCVs. These cells were strongly attached to solid surfaces and interconnected through a network of nanotubes. Nanotubes were observed at the stationary phase of biofilm indwellers and were more prominent after applying weight to the consortia. The scanning electron micrographs indicated that the nanotubes are polar appendages with intraspecies connectivity. The micrographs indicated variations in physical dimensions (length, width, and height) and a considerable reduction in volume due to weight pressure. A total of 35 cells were randomly selected. The mean volume of cells before the application of weight was 0.288µm3, which was reduced to 0.144 µm3 after the application of weight. It was observed that a single cell may produce as many as six nanotubes, connected simultaneously to six neighbouring cells in different directions. The in-depth analysis confirmed that these structures were the intra-species connecting tools as no free nanotubes were found. Furthermore, after the application of weight, cells incapable of producing nanotubes were wiped out and the surface was covered by nanotube producers. This suggests that the nanotubes give a selective advantage to the cells to resist harsh environmental conditions and weight pressure. After the removal of weight and proper supply of nutrients, these phenotypes reverted to normal planktonic lifestyles. It is concluded that the nanotubes are not merely the phenomenon of dying cells; rather they are a connectivity tool which helps connected cells to tolerate and resist environmental stress.

Section: Introductionmentioning

confidence: 99%

Nanotubes Formation in P. aeruginosa

Mirani

et al. 2022

Cells

“…To use this route, however, the levels of ROS transported cannot be too high, as the transmitting or receiving cells could be damaged. Cells living within a biofilm, colony, and/or within different plant and animal tissues, are thought to use juxtacrine signalling to mediate cell-to-cell ROS and redox signaling 10,11 . Moreover, it was suggested that ROS can enhance the size of tunneling nanotubes or PDs and facilitate juxtacrine signalling 23,57 .…”

Section: Discussionmentioning

confidence: 99%

“…Cell-tocell communication can occur between cells of the same species or organism (e.g., in a multicellular organism) 5,6 , as well as between cells of different organisms (e.g., during interactions of cells with different bacterial or fungal pathogens) 7,8 . Two of the most conserved cell-to-cell signaling pathways are paracrine, secretion of signals that are perceived by neighboring cells, and juxtacrine, communication between cells connected via tunneling nano tubes, gap junctions, or plasmodesmata [9][10][11] . Examples of these signaling pathways can be found in archaea, bacteria, unicellular eukaryotes, and multicellular organisms 12 .…”

Section: Introductionmentioning

confidence: 99%

ROS are evolutionary conserved cell-to-cell signals

Fichman

Rowland

Oliver

et al. 2022

Preprint

Cell-to-cell communication is fundamental to multicellular organisms, as well as to unicellular organisms living in a microbiome. It is thought to have evolved as a stress- or quorum-sensing mechanism in unicellular organisms. A unique cell-to-cell communication mechanism that uses reactive oxygen species (ROS) as a signal (termed the ROS wave) was recently identified in flowering plants. This process is essential for systemic signaling and plant acclimation to stress and can spread from a small group of cells to the entire plant within minutes. Whether this signaling process is found in other organisms is however unknown. Here we report that a ROS-mediated cell-to-cell signaling process, like the ROS wave, can be found in ferns, mosses, multicellular and unicellular algae, amoeba, and mammalian cells. We further show that this process can be triggered by extracellular H2O2 application and blocked by inhibition of NADPH oxidases, and that at least in unicellular algae growing as a lawn on an agar plate, it communicates important stress-response signals between cells. Taken together, our findings suggest that an active process of cell-to-cell ROS signaling, like the ROS wave, evolved before unicellular and multicellular organisms diverged. This mechanism could have communicated an environmental stress signal between cells and coordinated the acclimation response of cells living in a community. The finding of a signaling process, like the ROS wave, in mammalian cells further contributes to our understanding of different diseases and could impact the development of new drugs that target, for example cancer or heart disease.

“…It also remains to be seen whether yeast-yeast and/or yeast-hypha connections involve the protrusion of microtubules/actin filaments as it appears. Bacteria and higher eukaryotic cells, both, are able to connect through intercellular membrane tunneling nanotubes (TNT; Onfelt et al, 2006 ; Pande et al, 2015 ; Matkó and Tóth, 2021 ). Bacteria and archaebacteria form a network of these filaments which allow a whole community of cells to cross-feed ( Pande et al, 2015 ) and share signaling molecules and other compounds ( Bassler and Losick, 2006 ; Pande et al, 2015 ) or even vesicles ( Onfelt et al, 2006 ; Delage and Zurzolo, 2013 ).…”

Section: Discussionmentioning

confidence: 99%

Moniliophthora perniciosa, the Causal Agent of Cacao Witches’ Broom Disease Is Killed in vitro by Saccharomyces cerevisiae and Wickerhamomyces anomalus Yeasts

et al. 2021

Cacao plantations from South America have been afflicted with the severe fungal disease known as Witches’ Broom Disease (WBD), caused by the basidiomycete Moniliophthora perniciosa. Yeasts are increasingly recognized as good fungal biocides, although their application is still mostly restricted to the postharvest control of plant and fruit decay. Their possible utilization in the field, in a preharvest phase, is nevertheless promising, particularly if the strains are locally adapted and evolved and if they belong to species considered safe for man and the environment. In this work, a group of yeast strains originating from sugarcane-based fermentative processes in Brazil, the cacao-producing country where the disease is most severe, were tested for their ability to antagonize M. perniciosa in vitro. Wickerhamomyces anomalus LBCM1105 and Saccharomyces cerevisiae strains LBCM1112 from spontaneous fermentations used to produce cachaça, and PE2 widely used in Brazil in the industrial production of bioethanol, efficiently antagonized six strains of M. perniciosa, originating from several South American countries. The two fastest growing fungal strains, both originating from Brazil, were further used to assess the mechanisms underlying the yeasts’ antagonism. Yeasts were able to inhibit fungal growth and kill the fungus at three different temperatures, under starvation, at different culture stages, or using an inoculum from old yeast cultures. Moreover, SEM analysis revealed that W. anomalus and S. cerevisiae PE2 cluster and adhere to the hyphae, push their surface, and fuse to them, ultimately draining the cells. This behavior concurs with that classified as necrotrophic parasitism/mycoparasitism. In particular, W. anomalus within the adhered clusters appear to be ligated to each other through roundish groups of fimbriae-like structures filled with bundles of microtubule-sized formations, which appear to close after cells detach, leaving a scar. SEM also revealed the formation of tube-like structures apparently connecting yeast to hypha. This evidence suggests W. anomalus cells form a network of yeast cells connecting with each other and with hyphae, supporting a possible cooperative collective killing and feeding strategy. The present results provide an initial step toward the formulation of a new eco-friendly and effective alternative for controlling cacao WBD using live yeast biocides.