Exosomes are membranous nanovesicles released by most cell types from multi-vesicular endosomes. They are speculated to transfer molecules to neighboring or distant cells and modulate many ...physiological and pathological procedures. Exosomes released from the gastrointestinal epithelium to the basolateral side have been implicated in antigen presentation. Here, we report that luminal release of exosomes from the biliary and intestinal epithelium is increased following infection by the protozoan parasite Cryptosporidium parvum. Release of exosomes involves activation of TLR4/IKK2 signaling through promoting the SNAP23-associated vesicular exocytotic process. Downregulation of let-7 family miRNAs by activation of TLR4 signaling increases SNAP23 expression, coordinating exosome release in response to C. parvum infection. Intriguingly, exosomes carry antimicrobial peptides of epithelial cell origin, including cathelicidin-37 and beta-defensin 2. Activation of TLR4 signaling enhances exosomal shuttle of epithelial antimicrobial peptides. Exposure of C. parvum sporozoites to released exosomes decreases their viability and infectivity both in vitro and ex vivo. Direct binding to the C. parvum sporozoite surface is required for the anti-C. parvum activity of released exosomes. Biliary epithelial cells also increase exosomal release and display exosome-associated anti-C. parvum activity following LPS stimulation. Our data indicate that TLR4 signaling regulates luminal exosome release and shuttling of antimicrobial peptides from the gastrointestinal epithelium, revealing a new arm of mucosal immunity relevant to antimicrobial defense.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A potential concern with bacteriophage (phage) therapeutics is a host-versus-phage response in which the immune system may neutralize or destroy phage particles and thus impair therapeutic efficacy, ...or a strong inflammatory response to repeated phage exposure might endanger the patient. Current literature is discrepant with regard to the nature and magnitude of innate and adaptive immune response to phages. The purpose of this work was to study the potential effects of
phage K on the activation of human monocyte-derived dendritic cells. Since phage K acquired from ATCC was isolated around 90 years ago, we first tested its activity against a panel of 36 diverse
clinical isolates from military patients and found that it was lytic against 30/36 (83%) of strains. Human monocyte-derived dendritic cells were used to test for an in vitro phage-specific inflammatory response. Repeated experiments demonstrated that phage K had little impact on the expression of pro- and anti-inflammatory cytokines, or on MHC-I/II and CD80/CD86 protein expression. Given that dendritic cells are potent antigen-presenting cells and messengers between the innate and the adaptive immune systems, our results suggest that phage K does not independently affect cellular immunity or has a very limited impact on it.
Correspondence to Dr Amanda Roth, Philosophy, SUNY Geneseo, Geneseo, New York, USA; rothal@geneseo.edu Robinson offers the ‘superior personhood’ approach (SPA) to capture the value of gestation and ...ground justice for women/gestators.1 SPA holds that women/gestators are more than mere persons given the reality of pregnancy and the vital role women/gestators play in reproduction.1 In this commentary, I speak to some background context perhaps relevant to SPA, lay out areas of agreement with Robinson and then raise four worries about the approach. ...as Robinson suggests, container and parthood conceptions of gestation problematically erase the relation between a gestator and fetus (Margaret Little’s work on pregnancy as a form of intimacy is quite relevant here).2 Finally, as Robinson indicates, modern societies are substantially unjust in their treatment of women/gestators; thus, changes such as improved maternity care; revision of surrogacy practices; addressing violence and providing resources to conceive, avoid pregnancy or parent are certainly warranted. ...equality of resources/opportunities is not our only option—egalitarian political theories targeting hierarchies of oppression justify massive restructurings of law, society, family, etc.3 4 Existing strands of feminist theory and activism have also addressed virtually all the changes Robinson recommends.3 In fact, the reproductive justice framework—with its emphasis on intersectionality—potentially recommends an even broader set of justice claims for women/gestators.5 Perhaps SPA can add to the case for justice for women/gestators, but it is not necessary to ground those claims.
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The recent emergence of multidrug-resistant Acinetobacter baumannii strains and the non-efficacy of currently available antibiotics against such infections have led to an urgent need ...for the development of novel antibacterials. In an effort to address this problem, we have identified three novel inhibitors, namely, D5, D12 and D6 using in silico screening with a homology model of the outer membrane protein W2 (OmpW2) from A. baumannii, as the proposed new drug target. OmpW is an eight-stranded β-barrel protein involved in the transport of hydrophobic molecules across the outer membrane and maintenance of homeostasis under cellular stress. The antimicrobial activities of compounds D5, D12 and D6 were evaluated against a panel of clinical isolates of A. baumannii strains. These compounds inhibited the growth of the strains with minimum inhibitory concentration (MIC) ranges of 1–32μg/mL. Time-kill kinetic studies with the highly virulent and multidrug-resistant strain, A. baumannii 5075, indicated that D6 exhibited the highest bactericidal activity asa≥3log10 CFU/mL (99.9%) reduction in colony count from the initial inoculum was observed after 30min incubation. D5 and D12 reduced at least 1log10 CFU/mL (90%) of the initial inoculum after 24h. In conclusion, these three lead inhibitors have provided two distinct chemical scaffolds for further analog design and optimizations, using chemical synthesis, to develop more potent inhibitors of the pathogen.
The unmet demand for effective malaria transmission-blocking agents targeting the transmissible stages of Plasmodium necessitates intensive discovery efforts. In this study, a bioactive ...bisbenzylisoquinoline (BBIQ), isoliensinine, from Cissampelos pariera (Menispermaceae) rhizomes was identified and characterized for its anti-malarial activity.
Malaria SYBR Green I fluorescence assay was performed to evaluate the in vitro antimalarial activity against D6, Dd2, and F32-ART5 clones, and immediate ex vivo (IEV) susceptibility for 10 freshly collected P. falciparum isolates. To determine the speed- and stage-of-action of isoliensinine, an IC
speed assay and morphological analyses were performed using synchronized Dd2 asexuals. Gametocytocidal activity against two culture-adapted gametocyte-producing clinical isolates was determined using microscopy readouts, with possible molecular targets and their binding affinities deduced in silico.
Isoliensinine displayed a potent in vitro gametocytocidal activity at mean IC
values ranging between 0.41 and 0.69 µM for Plasmodium falciparum clinical isolates. The BBIQ compound also inhibited asexual replication at mean IC
of 2.17 µM, 2.22 µM, and 2.39 µM for D6, Dd2 and F32-ART5 respectively, targeting the late-trophozoite to schizont transition. Further characterization demonstrated a considerable immediate ex vivo potency against human clinical isolates at a geometric mean IC
= 1.433 µM (95% CI 0.917-2.242). In silico analyses postulated a probable anti-malarial mechanism of action by high binding affinities for four mitotic division protein kinases; Pfnek1, Pfmap2, Pfclk1, and Pfclk4. Additionally, isoliensinine was predicted to possess an optimal pharmacokinetics profile and drug-likeness properties.
These findings highlight considerable grounds for further exploration of isoliensinine as an amenable scaffold for malaria transmission-blocking chemistry and target validation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The design of information literacy instruction and the building of it are two distinct skillsets and processes; yet all too often everything gets mashed together, creating needless confusion and ...stress. In this book Turnbow, an instructional designer, and Roth, an instructional technologist, suggest a better way to organize the work.
•A total of 28% of infections with positive microscopy for Plasmodium falciparum only harbour non-falciparum.•Non-falciparum infections increased during the follow-up period despite adherence to ...artemisinin-based combination therapies (ACTs).•The “hidden” infections absent on day 0, appeared after clearing P. falciparum.•Half the individuals treated with ACTs tested positive for Plasmodium at least once by day 4.•Cure rates were comparable across each species composition.
This study examined the treatment response of mixed vs single-species Plasmodium falciparum infections to artemisinin-based combination therapies (ACTs).
A total of 1211 blood samples collected on days 0, 7, 14, 21, 28, 35, and 42 from 173 individuals enrolled in two randomized ACT efficacy studies were tested for malaria using 18s ribosomal RNA-based real-time polymerase chain reaction. All recurrent parasitemia were characterized for Plasmodium species composition and time to reinfection during 42-day follow-up compared across ACTs.
Day 0 samples had 71.1% (116/163) single P. falciparum infections and 28.2% (46/163) coinfections. A total of 54.0% (88/163) of individuals tested positive for Plasmodium at least once between days 7-42. A total of 19.3% (17/88) of individuals with recurrent infections were infected with a different Plasmodium species than observed at day 0, with 76.5% (13/17) of these “hidden” infections appearing after clearing P. falciparum present at day 0. Artesunate-mefloquine (16.4 hours) and dihydroartemisinin-piperaquine (17.6 hours) had increased clearance rates over artemether-lumefantrine (21.0 hours). Dihydroartemisinin-piperaquine exhibited the longest duration of reinfection prophylaxis. Cure rates were comparable across each species composition.
No differences in clearance rates were found depending on whether the infection contained species other than P. falciparum. Significantly longer durations of protection were observed for individuals treated with dihydroartemisinin-piperaquine.
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Single nucleotide polymorphisms (SNPs) in the Plasmodium falciparum multi-drug resistance protein 1 (Pfmrp1) gene have previously been reported to confer resistance to Artemisinin-based Combination ...Therapies (ACTs) in Southeast Asia. A total of 300 samples collected from six sites between 2008 and 2019 under an ongoing malaria drug sensitivity patterns in Kenya study were evaluated for the presence of SNPs at Pfmrp1 gene codons: H191Y, S437A, I876V, and F1390I using the Agena MassARRAY® platform. Each isolate was further tested against artemisinin (ART), lumefantrine (LU), amodiaquine (AQ), mefloquine (MQ), quinine (QN), and chloroquine (CQ) using malaria the SYBR Green I-based method to determine their in vitro drug sensitivity. Of the samples genotyped, polymorphism at Pfmrp1 codon I876V was the most frequent, with 59.3% (163/275) mutants, followed by F1390I, 7.2% (20/278), H191Y, 4.0% (6/151), and S437A, 3.3% (9/274). A significant decrease in median 50% inhibition concentrations (IC.sub.50 s) and interquartile range (IQR) was noted; AQ from 2.996 ng/ml IQR = 2.604-4.747, n = 51 in 2008 to 1.495 ng/ml IQR = 0.7134-3.318, n = 40 (P<0.001) in 2019, QN from 59.64 ng/ml IQR = 29.88-80.89, n = 51 in 2008 to 18.10 ng/ml IQR = 11.81-26.92, n = 42 (P<0.001) in 2019, CQ from 35.19 ng/ml IQR = 16.99-71.20, n = 30 in 2008 to 6.699 ng/ml IQR = 4.976-9.875, n = 37 (P<0.001) in 2019, and ART from 2.680 ng/ml IQR = 1.608-4.857, n = 57 in 2008 to 2.105 ng/ml IQR = 1.266-3.267, n = 47 (P = 0.0012) in 2019, implying increasing parasite sensitivity to the drugs over time. However, no significant variations were observed in LU (P = 0.2692) and MQ (P = 0.0939) respectively, suggesting stable parasite responses over time. There was no statistical significance between the mutation at 876 and parasite sensitivity to selected antimalarials tested, suggesting stable sensitivity for the parasites with 876V mutations. These findings show that Kenyan parasite strains are still sensitive to AQ, QN, CQ, ART, LU, and MQ. Despite the presence of Pfmrp1 mutations in parasites among the population.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Dihydroartemisinin-piperaquine (DHA-PPQ) is an alternative first-line antimalarial to artemether-lumefantrine in Kenya. However, recent reports on the emergence of PPQ resistance in ...Southeast Asia threaten its continued use in Kenya and Africa. In line with the policy on continued deployment of DHA-PPQ, it is imperative to monitor the susceptibility of Kenyan parasites to PPQ and other antimalarials. Methods Parasite isolates collected between 2008 and 2021 from individuals with naturally acquired P. falciparum infections presenting with uncomplicated malaria were tested for in vitro susceptibility to piperaquine, dihydroartemisinin, lumefantrine, artemether, and chloroquine using the malaria SYBR Green I method. A subset of the 2019-2021 samples was further tested for ex vivo susceptibility to PPQ using piperaquine survival assay (PSA). Each isolate was also characterized for mutations associated with antimalarial resistance in Pfcrt, Pfmdr1, Pfpm2/3, Pfdhfr, and Pfdhps genes using real-time PCR and Agena MassARRAY platform. Associations between phenotype and genotype were also determined. Results The PPQ median IC.sub.50 interquartile range (IQR) remained stable during the study period, 32.70 nM (IQR 20.2-45.6) in 2008 and 27.30 nM (IQR 6.9-52.8) in 2021 (P=0.1615). The median ex vivo piperaquine survival rate (IQR) was 0% (0-5.27) at 95% CI. Five isolates had a PSA survival rate of greater than or equal to10%, consistent with the range of PPQ-resistant parasites, though they lacked polymorphisms in Pfmdr1 and Plasmepsin genes. Lumefantrine and artemether median IC.sub.50s rose significantly to 62.40 nM (IQR 26.9-100.8) (P = 0.0201); 7.00 nM (IQR 2.4-13.4) (P = 0.0021) in 2021 from 26.30 nM (IQR 5.1-64.3); and 2.70 nM (IQR 1.3-10.4) in 2008, respectively. Conversely, chloroquine median IC.sub.50s decreased significantly to 10.30 nM (IQR 7.2-20.9) in 2021 from 15.30 nM (IQR 7.6-30.4) in 2008, coinciding with a decline in the prevalence of Pfcrt 76T allele over time (P = 0.0357). The proportions of piperaquine-resistant markers including Pfpm2/3 and Pfmdr1 did not vary significantly. A significant association was observed between PPQ IC.sub.50 and Pfcrt K76T allele (P=0.0026). Conclusions Circulating Kenyan parasites have remained sensitive to PPQ and other antimalarials, though the response to artemether (ART) and lumefantrine (LM) is declining. This study forms a baseline for continued surveillance of current antimalarials for timely detection of resistance. Keywords: Artemisinin combined therapy, Antimalarial, Drug resistance, Sensitivity, Genomic, Plasmodium falciparum
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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