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Cell May 2024FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and...
FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.
Topics: Animals; Female; Humans; Male; Mice; B-Lymphocytes; Bone Marrow; Cell Lineage; Dendritic Cells; Hematopoiesis; Hematopoietic Stem Cells; Killer Cells, Natural; Langerhans Cells; Membrane Proteins; Monocytes; Skin; Mice, Inbred C57BL
PubMed: 38701783
DOI: 10.1016/j.cell.2024.04.009 -
Microbiology Spectrum Jun 2024Lipid droplets (LDs) are dynamic organelles that participate in the regulation of lipid metabolism and cellular homeostasis inside of cells. LD-associated proteins, also...
Lipid droplets (LDs) are dynamic organelles that participate in the regulation of lipid metabolism and cellular homeostasis inside of cells. LD-associated proteins, also known as perilipins (PLINs), are a family of proteins found on the surface of LDs that regulate lipid metabolism, immunity, and other functions. In silkworms, pébrine disease caused by infection by the microsporidian () is a severe threat to the sericultural industry. Although we found that relies on lipids from silkworms to facilitate its proliferation, the relationship between PLINs and proliferation remains unknown. Here, we found infection caused the accumulation of LDs in the fat bodies of silkworm larvae. The characterized perilipin1 gene () promotes the accumulation of intracellular LDs and is involved in proliferation. is similar to in humans and is conserved in all insects. The expression of was mostly enriched in the fat body rather than in other tissues. Knockdown of enhanced proliferation, whereas overexpression of inhibited its proliferation. Furthermore, we confirmed that increased the expression of the and in the JAK-STAT immune pathway and inhibited proliferation. Taken together, our current findings demonstrate that inhibits proliferation by promoting the JAK-STAT pathway through increased expression of and . This study provides new insights into the complicated connections among microsporidia pathogens, LD surface proteins, and insect immunity.IMPORTANCELipid droplets (LDs) are lipid storage sites in cells and are present in almost all animals. Many studies have found that LDs may play a role in host resistance to pathogens and are closely related to innate immunity. The present study found that a surface protein of insect lipid droplets could not only regulate the morphological changes of lipid droplets but also inhibit the proliferation of a microsporidian pathogen () by activating the JAK-STAT signaling pathway. This is the first discovery of the relationship between microsporidian pathogen and insect lipid surface protein perilipin and insect immunity.
Topics: Bombyx; Animals; Nosema; Insect Proteins; Lipid Droplets; Janus Kinases; Signal Transduction; Perilipin-1; STAT Transcription Factors; Fat Body; Larva; Lipid Metabolism
PubMed: 38690912
DOI: 10.1128/spectrum.03671-23 -
PLoS Pathogens Apr 2024The microsporidian Enterocytozoon hepatopenaei (EHP) is a fungi-related, spore-forming parasite. EHP infection causes growth retardation and size variation in shrimp,...
The microsporidian Enterocytozoon hepatopenaei (EHP) is a fungi-related, spore-forming parasite. EHP infection causes growth retardation and size variation in shrimp, resulting in severe economic losses. Studies on shrimp immune response have shown that several antimicrobial peptides (AMPs) were upregulated upon EHP infection. Among those highly upregulated AMPs is c-type lysozyme (LvLyz-c). However, the immune signaling pathway responsible for LvLyz-c production in shrimp as well as its function against the EHP infection are still poorly understood. Here, we characterized major shrimp immune signaling pathways and found that Toll and JAK/STAT pathways were up-regulated upon EHP infection. Knocking down of a Domeless (DOME) receptor in the JAK/STAT pathways resulted in a significant reduction of the LvLyz-c and the elevation of EHP copy number. We further elucidated the function of LvLyz-c by heterologously expressing a recombinant LvLyz-c (rLvLyz-c) in an Escherichia coli. rLvLyz-c exhibited antibacterial activity against several bacteria such as Bacillus subtilis and Vibrio parahaemolyticus. Interestingly, we found an antifungal activity of rLvLyz-c against Candida albican, which led us to further investigate the effects of rLvLyz-c on EHP spores. Incubation of the EHP spores with rLvLyz-c followed by a chitin staining showed that the signals were dramatically decreased in a dose-dependent manner, suggesting that rLvLyz-c possibly digest a chitin coat on the EHP spores. Transmission electron microscopy analysis revealed that an endospore layer, which is composed mainly of chitin, was digested by rLvLyz-c. Lastly, we observed that EHP spores that were treated with rLvLyz-c showed a significant reduction of the spore germination rate. We hypothesize that thinning of the endospore of EHP would result in altered permeability, hence affecting spore germination. This work provides insights into shrimp immune signaling pathways responsible for LvLyz-c production and its anti-EHP property. This knowledge will serve as important foundations for developing EHP control strategies.
Topics: Animals; Penaeidae; Signal Transduction; Muramidase; Enterocytozoon; Microsporidiosis
PubMed: 38683868
DOI: 10.1371/journal.ppat.1012199 -
Mikrobiyoloji Bulteni Apr 2024Microsporidia are obligate intracellular pathogens that can infect many vertebrate and invertebrate hosts. While the Microsporidia phylum was defined as protozoa until...
Microsporidia are obligate intracellular pathogens that can infect many vertebrate and invertebrate hosts. While the Microsporidia phylum was defined as protozoa until the 1990s, it has been associated with fungi in line with the data obtained as a result of phylogenetic and molecular analyzes in recent years. Although approximately 200 genera and 1400 Microsporidia species related to these genera have been reported to date, only 14 species are known to cause infection in humans. Encephalitozoon intestinalis is one of the most frequently detected species in humans and causes serious clinical conditions in immunosuppressed individuals. Little information is available about the immunology of this infection. This study was aimed to investigate the changes in Toll-Like receptor (TLR) gene expressions in Madin-Darby canine kidney (MDCK) cells treated with E.intestinalis spores. Three groups were formed in the study. In the first group, only the medium prepared for E.intestinalis was added to the MDCK cells. In the second group, 108 live spores waiting at +4 °C were added. In the third group, 108 heat-inactivated spores were added. All three groups were incubated at 37ºC with 5% CO2 . RNA isolation and cDNA synthesis were performed from samples taken from these groups at the 1st, 3rd, 6th, 12th and 24th hours. Expression of TLR1-10 genes from the obtained cDNAs was evaluated by real-time polymerase chain reaction (Rt-PCR). GAPDH and ACTB genes were used as housekeeping genes in the study. Target genes were normalized by taking the average of these two genes and statistical analysis was performed by applying the 2-ΔΔCt formula. Genes detected above the threshold value (threshold 1) were considered to have increased expression. Genes detected below the threshold value were considered to have decreased expression. The growth of the live and inactive spores were followed simultaneously with the experimental groups. Approximately two weeks after the start of the culture, it was observed that E.intestinalis grew in the culture with live spore, but did not grow in the culture with inactivated spores. No statistically significant change was observed in gene expressions in the inactivated spore group. In the live spore group, a significant increase was seen in the expression of only two genes. These genes were TLR3 and TLR4. It was observed that there was a significant increase in TLR3 gene expression at the first hour (1.6-fold of control group) but the expression level started to decrease at the third hour (1.4-fold of control group) and returned to the control level at the sixth hour. It was observed that TLR4 gene expression continued parallel to the control until the 24th hour and increased significantly (2.1-fold of control group) at the 24th hour. In conclusion, this study is the f irst report in which the changes in ten different TLR gene expressions were evaluated at different times in MDCK cells stimulated with E.intestinalis and the change in TLR3 gene expression.
Topics: Dogs; Animals; Toll-Like Receptors; Encephalitozoon; Encephalitozoonosis; Madin Darby Canine Kidney Cells; Gene Expression; Spores, Fungal
PubMed: 38676584
DOI: 10.5578/mb.202498201 -
MBio Jun 2024The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered...
UNLABELLED
The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered microsporidian symbiont of , the net impact of which was found to shift from negative to positive based on environmental context. Given this, we hypothesized low baseline virulence of the microsporidian; here, we investigated the impact of infection on hosts in controlled conditions and the absence of other stressors. We also investigated its phylogenetic position, ecology, and host range. The genetic data indicate that the symbiont is , a newly described microsporidian parasite of . We show that infection damages the gut, causing infected epithelial cells to lose microvilli and then rupture. The prevalence of this microsporidian could be high (up to 100% in the lab and 77% of adults in the field). Its overall virulence was low in most cases, but some genotypes suffered reduced survival and/or reproduction. Susceptibility and virulence were strongly host-genotype dependent. We found that North American were able to infect multiple species, including the European species , as well as spp. Given the low, often undetectable virulence of this microsporidian and potentially far-reaching consequences of infections for the host when interacting with other pathogens or food, this symbiosis emerges as a valuable system for studying the mechanisms of context-dependent shifts between mutualism and parasitism, as well as for understanding how symbionts might alter host interactions with resources.
IMPORTANCE
The net outcome of symbiosis depends on the costs and benefits to each partner. Those can be context dependent, driving the potential for an interaction to change between parasitism and mutualism. Understanding the baseline fitness impact in an interaction can help us understand those shifts; for an organism that is generally parasitic, it should be easier for it to become a mutualist if its baseline virulence is relatively low. Recently, a microsporidian was found to become beneficial to its hosts in certain ecological contexts, but little was known about the symbiont (including its species identity). Here, we identify it as the microsporidium . Despite the parasitic nature of microsporidia, we found to be, at most, mildly virulent; this helps explain why it can shift toward mutualism in certain ecological contexts and helps establish is a valuable model for investigating shifts along the mutualism-parasitism continuum.
Topics: Animals; Daphnia; Symbiosis; Host Specificity; Phylogeny; Virulence; Microsporidia; Microsporidia, Unclassified
PubMed: 38651867
DOI: 10.1128/mbio.00582-24 -
Malaria Journal Apr 2024Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking...
BACKGROUND
Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking strategy that may involve mosquito release. A rapid assessment was carried out to develop insight into sociodemographic factors, public health concerns, and malaria awareness, management, and prevention practices with the willingness to accept and participate in Microsporidia MB-based transmission-blocking strategy to develop an informed stakeholder engagement process.
METHODS
The assessment consisted of a survey conducted in two communities in western Kenya that involved administering a questionnaire consisting of structured, semi-structured, and open questions to 8108 household heads.
RESULTS
There was an overall high level of willingness to accept (81%) and participate in the implementation of the strategy (96%). Although the willingness to accept was similar in both communities, Ombeyi community was more willing to participate (OR 22, 95% CI 13-36). Women were less willing to accept (OR 0.8, 95% CI 0.7-0.9) compared to men due to fear of increased mosquito bites near homes. Household heads with incomplete primary education were more willing to accept (OR 1.6, 95% CI 01.2-2.2) compared to those educated to primary level or higher. Perceiving malaria as a moderate or low public health issue was also associated with a lower willingness to accept and participate. Experience of > 3 malaria cases in the family over the last six months and knowledge that malaria is transmitted by only mosquito bites, increased the willingness to accept but reduced the willingness to participate. Awareness of malaria control methods based on mosquitoes that cannot transmit malaria increases the willingness to participate.
CONCLUSION
The study showed a high level of willingness to accept and participate in a Microsporidia MB-based strategy in the community, which is influenced by several factors such as community, disease risk perception, gender, education level, knowledge, and experience of malaria. Further research will need to focus on understanding the concerns of women, educated, and employed community members, and factors that contribute to the lower disease risk perception. This improved understanding will lead to the development of an effective communication strategy.
Topics: Male; Animals; Humans; Female; Kenya; Microsporidia; Insect Bites and Stings; Malaria; Public Health; Mosquito Control; Mosquito Vectors
PubMed: 38643165
DOI: 10.1186/s12936-024-04941-y -
Environmental Microbiology Reports Apr 2024Fungi are present in a wide variety of natural environments, and in the last years, various studies have shown that they are quite abundant in aquatic ecosystems. In...
Fungi are present in a wide variety of natural environments, and in the last years, various studies have shown that they are quite abundant in aquatic ecosystems. In addition, a whole new highly diverse phylum, the Cryptomycota, was discovered. Nevertheless, research on aquatic fungi and a detailed evaluation of their functions and distribution are still sparse. One of the main reasons is a limitation in reliable identification and quantification methods. To bridge part of the research gap, this study aims to implement a quantitative PCR method to detect and quantify the newly discovered phylum. We developed and validated a Cryptomycota-specific qPCR primer pair targeting the 5.8S region that detects the majority of Cryptomycota, but Microsporidia. The resulting amplicon is 102 bp long. We used different environmental samples to evaluate the primer pair, various fungal sequences as negative control and positive control sequences. Obtained amplicons were sequenced using Illumina, and the obtained ASVs were all classified as Cryptomycota. The qPCR method works reliably and specifically for the quantification of Cryptomycota in environmental samples.
Topics: Ecosystem; Fungi; Microsporidia; Environment
PubMed: 38615691
DOI: 10.1111/1758-2229.13257 -
Parasites & Vectors Apr 2024In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing...
BACKGROUND
In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing temperatures. In the present study, we used a mosquito-microsporidian model to determine the impact of environmental factors such as temperature, humidity, wind and rainfall on the occurrence rates of opportunistic obligate microparasites (Microsporidia) in hosts from a family that includes important disease vectors (Culicidae).
METHODS
In our study, 3000 adult mosquitoes collected from the field over 3 years were analysed. Mosquitoes and microsporidia were identified using PCR and sequencing of the hypervariable V5 region of the small subunit ribosomal RNA gene and a shortened fragment of the cytochrome c oxidase subunit I gene, respectively.
RESULTS
DNA metabarcoding was used to identify nine mosquito species, all of which were hosts of 12 microsporidian species. The prevalence of microsporidian DNA across all mosquito samples was 34.6%. Microsporidian prevalence in mosquitoes was more frequent during warm months (> 19 °C; humidity < 65%), as was the co-occurrence of two or three microsporidian species in a single host individual. During warm months, microsporidian occurrence was noted 1.6-fold more often than during the cold periods. Among the microsporidians found in the mosquitoes, five (representing the genera Enterocytospora, Vairimorpha and Microsporidium) were positively correlated with an increase in temperature, whereas one (Hazardia sp.) was significantly correlated with a decrease in temperature. Threefold more microsporidian co-occurrences were recorded in the warm months than in the cold months.
CONCLUSIONS
These results suggest that the susceptibility of mosquitoes to parasite occurrence is primarily determined by environmental conditions, such as, for example, temperatures > 19 °C and humidity not exceeding 62%. Collectively, our data provide a better understanding of the effects of the environment on microsporidian-mosquito interactions.
Topics: Animals; Culicidae; Temperature; Humidity; Mosquito Vectors; Microsporidia; DNA
PubMed: 38605410
DOI: 10.1186/s13071-024-06254-0 -
Journal of Microbiology and... May 2024The increasing economic losses associated with growth retardation caused by (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The...
The Use of the Internal Transcribed Spacer Region for Phylogenetic Analysis of the Microsporidian Parasite Infecting Whiteleg Shrimp () and for the Development of a Nested PCR as Its Diagnostic Tool.
The increasing economic losses associated with growth retardation caused by (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The internal transcribed spacer (ITS)-1 region, the non-coding region of ribosomal clusters between 18S and 5.8S rRNA genes, is widely used in phylogenetic studies due to its high variability. In this study, the ITS-1 region sequence (~600-bp) of EHP was first identified, and primers for a polymerase chain reaction (PCR) assay targeting that sequence were designed. A newly developed nested-PCR method successfully detected the EHP in various shrimp ( and ) and related samples, including water and feces collected from Indonesia, Thailand, South Korea, India, and Malaysia. The primers did not cross-react with other hosts and pathogens, and this PCR assay is more sensitive than existing PCR detection methods targeting the small subunit ribosomal RNA (SSU rRNA) and spore wall protein (SWP) genes. Phylogenetic analysis based on the ITS-1 sequences indicated that the Indonesian strain was distinct (86.2% nucleotide sequence identity) from other strains collected from Thailand and South Korea, and also showed the internal diversity among Thailand ( = 7, divided into four branches) and South Korean ( = 5, divided into two branches) samples. The results revealed the ability of the ITS-1 region to determine the genetic diversity of EHP from different geographical origins.
Topics: Enterocytozoon; Penaeidae; Animals; Phylogeny; DNA, Ribosomal Spacer; Polymerase Chain Reaction; Microsporidiosis; DNA, Fungal; DNA Primers; Feces; Sequence Analysis, DNA; Thailand
PubMed: 38563108
DOI: 10.4014/jmb.2401.01010 -
BMC Genomics Apr 2024Congenital infection caused by vertical transmission of microsporidia N. bombycis can result in severe economic losses in the silkworm-rearing industry....
Congenital infection caused by vertical transmission of microsporidia N. bombycis can result in severe economic losses in the silkworm-rearing industry. Whole-transcriptome analyses have revealed non-coding RNAs and their regulatory networks in N. bombycis infected embryos and larvae. However, transcriptomic changes in the microsporidia proliferation and host responses in congenitally infected embryos and larvae remains unclear. Here, we simultaneously compared the transcriptomes of N. bombycis and its host B. mori embryos of 5-day and larvae of 1-, 5- and 10-day during congenital infection. For the transcriptome of N. bombycis, a comparison of parasite expression patterns between congenital-infected embryos and larva showed most genes related to parasite central carbon metabolism were down-regulated in larvae during infection, whereas the majority of genes involved in parasite proliferation and growth were up-regulated. Interestingly, a large number of distinct or shared differentially expressed genes (DEGs) were revealed by the Venn diagram and heat map, many of them were connected to infection related factors such as Ricin B lectin, spore wall protein, polar tube protein, and polysaccharide deacetylase. For the transcriptome of B. mori infected with N. bombycis, beyond numerous DEGs related to DNA replication and repair, mRNA surveillance pathway, RNA transport, protein biosynthesis, and proteolysis, with the progression of infection, a large number of DEGs related to immune and infection pathways, including phagocytosis, apoptosis, TNF, Toll-like receptor, NF-kappa B, Fc epsilon RI, and some diseases, were successively identified. In contrast, most genes associated with the insulin signaling pathway, 2-oxacarboxylic acid metabolism, amino acid biosynthesis, and lipid metabolisms were up-regulated in larvae compared to those in embryos. Furthermore, dozens of distinct and three shared DEGs that were involved in the epigenetic regulations, such as polycomb, histone-lysine-specific demethylases, and histone-lysine-N-methyltransferases, were identified via the Venn diagram and heat maps. Notably, many DEGs of host and parasite associated with lipid-related metabolisms were verified by RT-qPCR. Taken together, simultaneous transcriptomic analyses of both host and parasite genes lead to a better understanding of changes in the microsporidia proliferation and host responses in embryos and larvae in N. bombycis congenital infection.
Topics: Animals; Transcriptome; Larva; Histones; Lysine; Nosema; Gene Expression Profiling; Cell Proliferation; Lipids; Bombyx
PubMed: 38556880
DOI: 10.1186/s12864-024-10236-y