Compromised Immune Response Research Articles

Effects of hydroperiod on growth, development, survival and immune defences in a temperate amphibian

Abstract The many and varied effects of human‐induced environmental change have the potential to threaten animal biodiversity and species abundance. Importantly, human land use and global climate change are predicted to reduce water availability, which might have negative consequences for freshwater organisms. In this study, we tested for an effect of a shortened hydroperiod on larval growth and development, and post‐metamorphic survival and immune function in a temperate frog, Rana pipiens. Animals developing under pond drying conditions metamorphosed at a smaller size and had lower survival after metamorphosis. We found sex‐specific differences in larval period in our fastest drying treatment, with males metamorphosing more quickly than females. Individuals that developed under drying conditions also showed reduced skin swelling after phytohaemagglutinin injection, indicating a compromised immune response. We found support for trade‐offs between growth, development and post‐metamorphic immune function across hydroperiod treatments. Whole blood from animals with shorter larval periods had lower bacterial killing ability, and small‐bodied juveniles had lower antibody titres. Overall, our results indicate that a shortened hydroperiod can affect the rate of larval amphibian growth and development, and might negatively impact the condition of species that rely on freshwater for development. Our work improves understanding of the complex impacts that environmental stressors might have on the health of animal populations. A free Plain Language Summary can be found within the Supporting Information of this article.

Signalling of ERK1/2, P38MAPK and P90RSK in HIV-associated pre-eclampsia

Due to their significance in trophoblast differentiation and survival, we evaluated the expression of the cell signalling molecules; Extracellular signal–regulated kinase 1/2 (ERK1/2), Mitogen Activated Protein Kinase 38 (MAPK38) and p90 ribosomal protein S6 kinase (p90 RSK) in buffy coat samples. Eighty pregnant women attending a large hospital in Durban, South Africa were assigned into normotensive and pre-eclamptic groups and further stratified by their HIV status. The degree of phosphorylation of the analytes was determined using the Bio-Plex ProTM Cell Signalling Immunoassay. There was a significantly lower protein concentration of the analytes in the pre-eclamptic versus the normotensive patients, irrespective of HIV status (p < .0001). Also, there was no significant difference in expression of ERK1/2 (p = .4369), p38MAPK (p = .4720) and p90 RSK (p = .0188), according to HIV status. This study demonstrates a down-regulation of ERK1/2, p38MAPK and p90RSK prosurvival markers in pre-eclampsia. This implicates the involvement of the MAPK pathway in the pathogenesis of preeclampsia. Activation of these pathways may prove useful in increasing the body of evidence on prevention of placenta dysfunction and apoptosis. Impact statement What is already known on this subject? Preeclampsia occurring in co-morbidity with HIV is a public health problem among pregnant, black South-African women. There have been conflicting theories regarding the predisposition to the development of preeclampsia as a result of compromised immune response due to HIV infection. In normal pregnancies, the MAPK pathway plays a significant role in molecular processes involved in the cells including survival and differentiation of the placental trophoblast. ERK1/2, p38MAPK and p90RSK are members of the MAPK family, which are pro-apoptotic. Inhibition in the signalling of MAPKs has been found to result in oxidative stress, a process which contributes to the defective trophoblast invasion seen in preeclampsia. What do the results of this study add? The results from this study showed that there is no relationship between HIV infection and an increased predisposition to the development of preeclampsia. In addition, this study highlights a downregulation in the expression of ERK1/2, p38 MAPK and p90RSK in preeclampsia. What are the implications of these findings for clinical practice and/or further research? These findings demonstrate the potential of these analytes as biomarkers for the diagnosis of preeclampsia. Also, this may serve as a framework for further research in the prevention of preeclampsia by elucidating more on the pathway.

Molecular epidemiology of chicken anaemia virus in sick chickens in China from 2014 to 2015.

Chicken anaemia virus (CAV), a member of the genus Gyrovirus, is the etiological agent of chicken infectious anaemia. CAV infects bone marrow-derived cells, resulting in severe anaemia and immunosuppression in young chickens and a compromised immune response in older birds. We investigated the molecular epidemiology of CAV in sick chickens in China from 2014 to 2015 and showed that the CAV-positive rate was 13.30%, in which mixed infection (55.56%) was the main type of infection. We isolated and identified 15 new CAV strains using different methods including indirect immunofluorescence assay and Western Blotting. We used overlapping polymerase chain reaction to map the whole genome of the strains. Phylogenetic analyses of the obtained sequences and related sequences available in GenBank generated four distinct groups (A–D). We built phylogenetic trees using predicted viral protein (VP) sequences. Unlike CAV VP2s and VP3s that were well conserved, the diversity of VP1s indicated that the new strains were virulent. Our epidemiological study provided new insights into the prevalence of CAV in clinical settings in recent years in China.

Leishmania donovani reduces the levels of retinoic acid-synthesizing enzymes in infected macrophages and favoring its own survival.

People suffering from malnutrition become susceptible to the infection like Leishmania sp., as it results in a compromised immune response. Retinoic acid (RA), an important constituent of nutrition, shows an immune-modulatory activity. However, its role in the containment of infection is not yet ascertained, particularly in case of visceral leishmaniasis (VL). VL patients (n = 10) and healthy endemic controls (n = 9) were recruited to measure the serum levels of RA. An in vitro model of Leishmania infection using the murine mφ cell line J774.1 was used to investigate the RA-synthesizing enzymes (RALDH-1 and RALDH-2). Parasite loads among infected mφ were measured by quantitative expression of kDNA in the presence of an inhibitor of the RALDH-2 enzyme. We found a significant decrease in the serum levels of RA in VL cases. Importantly, we observed decreased levels of RALDH-1 and RALDH-2 among L. donovani-infected mφ along with simultaneous decrease as well as increase in the Th-1 and Th-2-associated factors, respectively. Furthermore, the pretreatment of mφ with an RALDH-2 inhibitor improved parasite in vitro infection. Our findings show impaired RA pathway among infected mφ and indicate that an intact RA pathway is critical for anti-Leishmania immune response. Graphical abstract ᅟ.

Kavain Reduces Porphyromonas gingivalis-Induced Adipocyte Inflammation: Role of PGC-1α Signaling.

A link between obesity and periodontitis has been suggested because of compromised immune response and chronic inflammation in obese patients. In this study, we evaluated the anti-inflammatory properties of Kavain, an extract from Piper methysticum, on Porphyromonas gingivalis-induced inflammation in adipocytes with special focus on peroxisome proliferation-activated receptor γ coactivator α (PGC-1α) and related pathways. The 3T3-L1 mouse preadipocytes and primary adipocytes harvested from mouse adipose tissue were infected with P. gingivalis, and inflammation (TNF-α; adiponectin/adipokines), oxidative stress, and adipogenic marker (FAS, CEBPα, and PPAR-γ) expression were measured. Furthermore, effect of PGC-1α knockdown on Kavain action was evaluated. Results showed that P. gingivalis worsens adipocyte dysfunction through increase of TNF-α, IL-6, and iNOS and decrease of PGC-1α and adiponectin. Interestingly, although Kavain obliterated P. gingivalis-induced proinflammatory effects in wild-type cells, Kavain did not affect PGC-1α-deficient cells, strongly advocating for Kavain effects being mediated by PGC-1α. In vivo adipocytes challenged with i.p. injection of P. gingivalis alone or P. gingivalis and Kavain displayed the same phenotype as in vitro adipocytes. Altogether, our findings established anti-inflammatory and antioxidant effects of Kavain on adipocytes and emphasized protective action against P. gingivalis-induced adipogenesis. The use of compounds such as Kavain offer a portal to potential therapeutic approaches to counter chronic inflammation in obesity-related diseases.

The development of a bead-based multiplex immunoassay for the detection of IgG antibodies to CMV and EBV

Latent infection with Cytomegalovirus (CMV) or Epstein-Bar virus (EBV) is associated with compromised immune responses. The commercially available ELISA-kits provide a semi-quantitative or qualitative detection of IgG antibodies against either CMV or EBV. To reduce the amount of sample needed and improve throughput and range of quantitation compared to ELISAs, a multiplex immunoassay (MIA) for the simultaneous quantitative detection of antibodies against CMV and two antigens of EBV (EBV capsid antigen (EBV-VCA) and EBV nuclear antigen 1 (EBNA-1)) was developed and standardized.Our assay shows a good correlation with the separate ELISAs, has a high specificity and is much more sensitive than the ELISAs. The MIA allows faster analysis of samples and can be combined with the MIA for detection of antibodies to measles, mumps, rubella and varicella zoster (MMRV) as published previously.In conclusion, the CMV-EBV MIA is a reliable assay that allows for more efficient detection of specific antibodies to CMV and EBV. This MIA therefore is especially useful for large-scale surveillance studies.

Maternal late-gestation metabolic stress is associated with changes in immune and metabolic responses of dairy calves

Metabolic stress in periparturient dairy cows is characterized by excessive lipid mobilization, inflammation, and oxidative stress that is associated with immune dysfunction. Thus, metabolic stress around the time calving is linked to the development of various early-lactation health disorders. Maternal status during late pregnancy can have carryover effects on several health and production variables of neonatal calves. However, the effects of metabolic stress during gestation on metabolic and immune responses of newborn calves remain unknown. Thus, we aimed to investigate whether metabolic stress in late-gestation dairy cows is associated with changes in the metabolic and immune responses of their offspring during the first month of life. Holstein-Friesian cows (n = 12) were blood sampled at 28 and 15 d before expected calving. The average between these 2 sampling points in the serum concentrations of nonesterified fatty acids (NEFA), haptoglobin (Hp), and oxidant status index (OSi)-defined as the ratio between reactive oxygen and nitrogen species and total antioxidant potential-were calculated as indicators of the degree of lipid mobilization, inflammation, and oxidant status (OS), respectively. Calves were subsequently divided into groups (n = 6 each) according to their dams' high or low degree of lipid mobilization, inflammation, and OS. The metabolic responses of calves in each of these groups were compared weekly throughout their first month of life by assessing serum concentration of NEFA, Hp, and OSi. Additionally, whole blood was obtained from calves at each sampling period and subjected to a lipopolysaccharide (LPS)-stimulated tumor necrosis factor-α (TNF-α) production assay to assess cell-mediated innate immunity against induced inflammatory responses, using high (5 μg/mL of blood) and low (10 ng/mL) concentrations of LPS. Calves born to cows with higher NEFA or OSi showed lower body weight at birth and throughout the study, whereas no association between any of the maternal groups and average daily gain at 4 wk of age was identified. Serum concentrations of reactive oxygen and nitrogen species were higher in calves exposed to higher maternal NEFA concentrations or OSi when compared with calves born to cows with lower values of these biomarkers. Calves exposed to high maternal OS also had higher circulating concentrations of Hp and TNF-α, indicating greater basal inflammatory responses when compared with calves born to cows with a lower OSi. In contrast, LPS-induced inflammatory responses were less robust in calves exposed to higher maternal biomarkers of inflammation or OS, suggesting compromised immune responses to microbial agonists. Collectively, these data suggest that prenatal exposure to maternal parameters of metabolic stress may adversely affect some metabolic and inflammatory responses of the offspring that could influence disease susceptibility.

I-107 Optimisation of a therapeutic vaccine; the importance of immune modulation

Vacc-4X is a p24 (gag) peptide based vaccine, shown to reduce viral load (HIVRNA) in HAART interrupted patients, confirmed in a randomised phase II study, which also confirmed vaccination had no effect on the CD4 count. A programme to improve the efficacy of Vacc4X has included peptide modifications to increase uptake by dendritic cells and the breadth of the responses to these peptides. A recent study (Sorensen B et al, ARHRV 2017) showed that in 3 cohorts of patients, antibodies to the novel heterodimeric construct designed to enhance the immunogenicity of this region containing C5 (501-512) and gp41 (732-44), was associated with slower disease progression and lower viral loads, antibodies to the C5 (501-506) domain correlated with preserved CD4 counts. It is proposed to combine this construct with the Vacc4X to enhance efficacy. These patient cohorts are all long term infected patients with compromised immune responses, even on HAART. The IMiDs, including Lenalidomide, have been shown to enhance immune responses to cell based vaccines in-vivo and Prevnar in clinical trials. Priming patients with Lenalidomide before Vacc4X led to an increase in CD4 counts in a small randomised study. It is proposed that if Lenalidomide had been given for longer, the effect would have been more significant. In addition, an immune modulator, M.vaccae, has been shown to reduce the incidence of TB in a randomised study in HIV infected subjects in Africa. M.vaccae and its commercial derivative (IMM-101) have been shown to be ideal adjuvants for anticancer based vaccines. It is proposed that immune modulation by Lenalidomide and IMM-101 could enhance clinical benefit seen with Vacc4X and enhanced responses to C5.

Parasitological contamination of mussels and oysters

The literature on human mussel-borne protozoan and helminthic infections is widely dispersed in epidemiological and parasitological journals. This review is focused on humans as hosts for protozoan, trematode and nematode parasites associated with consumption of mussels. These infections are caused mainly by protozoans transferred as cysts and oocysts or trematodes transferred as cercariae or metacercariae. The main scope of the article covers the following genera: Cryptosporidium, Giardia, Toxoplasma, microsporidia, and Fasciola. Foods regarded until recently as quite exotic are currently becoming increasingly available to consumers. To avoid certain parasitic infections, consumers need to know the risk factors associated with consumption of popular sea foods, such as mussels. The article contains information that may be useful to persons with compromised immune response....

Probiotici kao dodaci u ishrani

Many studies have shown that the use of probiotics acts positively on a disturbed intestinal ecosystem. Probiotics are defined as living, non-pathogenic microorganisms (usually bacteria), which confer a health benefit on the host when administrated in adequate amounts. Probiotics mechanisms described so far include adhesion to the surface of intestinal epithelium, competition with pathogens for receptors and nutrients, improvement of mucosal barrier function and maintenance of intestinal integrity, promotion of innate and acquired immune response, elaboration of bactericins and modulation of cellular kinetics. Dysbiosis of endogenous microbiota can lead to compromised immune responses and manifestations of various autoimmune diseases. Even some local and systemic metabolites of probiotic have been identified to have anti-inflammatory activity and may modify autoimmune diseases. The list of diseases that can benefit from the use of probiotics is long and includes acute diarrhea, urogenital infections, allergies, lactose intolerance, cystic fibrosis, carcinoma, inflammatory bowel disease, teeth and mouth disease, etc. The aim of this paper is to summarize the latest information from the currently available scientific literature on the role of probiotics in human health and disease.

The major leaf ferredoxin Fd2 regulates plant innate immunity in Arabidopsis.

Ferredoxins, the major distributors for electrons to various acceptor systems in plastids, contribute to redox regulation and antioxidant defence in plants. However, their function in plant immunity is not fully understood. In this study, we show that the expression of the major leaf ferredoxin gene Fd2 is suppressed by Pseudomonas syringae pv. tomato (Pst) DC3000 infection, and that knockout of Fd2 (Fd2-KO) in Arabidopsis increases the plant's susceptibility to both Pst DC3000 and Golovinomyces cichoracearum. On Pst DC3000 infection, the Fd2-KO mutant accumulates increased levels of jasmonic acid and displays compromised salicylic acid-related immune responses. Fd2-KO also shows defects in the accumulation of reactive oxygen species induced by pathogen-associated molecular pattern-triggered immunity. However, Fd2-KO shows enhanced R-protein-mediated resistance to Pst DC3000/AvrRpt2 infection, suggesting that Fd2 plays a negative role in effector-triggered immunity. Furthermore, Fd2 interacts with FIBRILLIN4 (FIB4), a harpin-binding protein localized in chloroplasts. Interestingly, Fd2, but not FIB4, localizes to stromules that extend from chloroplasts. Taken together, our results demonstrate that Fd2 plays an important role in plant immunity.

Small Molecule Mediated Restoration of Mitochondrial Function Augments Anti-Mycobacterial Activity of Human Macrophages Subjected to Cholesterol Induced Asymptomatic Dyslipidemia.

Mycobacterium tuberculosis (M.tb) infection manifests into tuberculosis (TB) in a small fraction of the infected population that comprises the TB susceptible group. Identifying the factors potentiating susceptibility to TB persistence is one of the prime agenda of TB control programs. Recently, WHO recognized diabetes as a risk factor for TB disease progression. The closely related pathological state of metabolic imbalance, dyslipidemia, is yet another emerging risk factor involving deregulation in host immune responses. While high cholesterol levels are clinically proven condition for perturbations in cardiac health, a significant fraction of population these days suffer from borderline risk cholesterol profiles. This apparently healthy population is susceptible to various health risks placing them in the “pre-disease” range. Our study focuses on determining the role of such asymptomatic dyslipidemia as a potential risk factor for susceptibility to TB persistence. Macrophages exposed to sub-pathological levels of cholesterol for chronic period, besides impaired release of TNF-α, could not clear intracellular pathogenic mycobacteria effectively as compared to the unexposed cells. These cells also allowed persistence of opportunistic mycobacterial infection by M. avium and M. bovis BCG, indicating highly compromised immune response. The cholesterol-treated macrophages developed a foamy phenotype with a significant increase in intracellular lipid-bodies prior to M.tb infection, potentially contributing to pre-disease state for tuberculosis infection. The foamy phenotype, known to support M.tb infection, increased several fold upon infection in these cells. Additionally, mitochondrial morphology and function were perturbed, more so during infection in cholesterol treated cells. Pharmacological supplementation with small molecule M1 that restored mitochondrial structural and functional integrity limited M.tb survival more effectively in cholesterol exposed macrophages. Mechanistically, M1 molecule promoted clearance of mycobacteria by reducing total cellular lipid content and restoring mitochondrial morphology and function to its steady state. We further supported our observations by infection assays in PBMC-derived macrophages from clinically healthy volunteers with borderline risk cholesterol profiles. With these observations, we propose that prolonged exposure to sub-pathological cholesterol can lead to asymptomatic susceptibility to M.tb persistence. Use of small molecules like M1 sets yet another strategy for host-directed therapy where re-functioning of mitochondria in cholesterol abused macrophages can improve M.tb clearance.

Limited Colonization Undermined by Inadequate Early Immune Responses Defines the Dynamics of Decidual Listeriosis.

The bacterial pathogen Listeria monocytogenes causes foodborne systemic disease in pregnant women, which can lead to preterm labor, stillbirth, or severe neonatal disease. Colonization of the maternal decidua appears to be an initial step in the maternal component of the disease as well as bacterial transmission to the placenta and fetus. Host-pathogen interactions in the decidua during this early stage of infection remain poorly understood. Here, we assessed the dynamics of L. monocytogenes infection in primary human decidual organ cultures and in the murine decidua in vivo A high inoculum was necessary to infect both human and mouse deciduas, and the data support the existence of a barrier to initial colonization of the murine decidua. If successful, however, colonization in both species was followed by significant bacterial expansion associated with an inability of the decidua to mount appropriate innate cellular immune responses. The innate immune deficits included the failure of bacterial foci to attract macrophages and NK cells, cell types known to be important for early defenses against L. monocytogenes in the spleen, as well as a decrease in the tissue density of inflammatory Ly6Chi monocytes in vivo These results suggest that the infectivity of the decidua is not the result of an enhanced recruitment of L. monocytogenes to the gestational uterus but rather is due to compromised local innate cellular immune responses.

Inflammatory markers as risk factors for infection with multidrug-resistant microbes in diabetic foot subjects

BackgroundDiabetic foot ulcers (DFUs), a dreadful microvascular complication of diabetes is responsible for substantial increase in morbidity and mortality. Infection, not a cause, but a consequence in DFUs that accounts for minor or major limb loss. The current study aimed to evaluate the microbial etiology of infected diabetic foot ulcers in northern tertiary care hospital, assessment of risk factors and role of inflammatory markers involved in colonization of multidrug-resistant organisms (MDROs) and their impact on the outcome. MethodsPus aspirates and soft tissue samples from 65 patients with infected DFUs were collected and processed for aerobic culture analysis. Serum concentrations of IL-6 and TNF-α were determined by enzyme linked immuno-sorbent assay. ResultsAerobic gram-negative isolates were more commonly present (74.7%), followed by gram-positive aerobes (25.2%). Fifty-seven percent patients were positive for MDROs. IL-6 (pg/mL) was significantly lower in diabetic patients with MDROs infected foot ulcers than without (47.0±17.2 vs. 78.3±22.1 vs. p=<0.001) and TNF-α (pg/mL) was also significantly diminished in MDROs infected subjects than without (144.2±25.8 vs. 168.7±20.9, p<0.001) respectively. ConclusionsIn this study diabetic foot wounds harbored by MDROs were associated with longer duration of ulcer and increased ulcer size. Poor glycemic control was also a confounding factor in mounting MDROs infected ulcers. The declined levels WBCs and neutrophils as well as of cytokines IL-6 and TNF-alpha explains compromised immune responses of host in multi drug resistant infections.

Immunogenicity and safety of high-dose hepatitis B vaccine among drug users: A randomized, open-labeled, blank-controlled trial

ABSTRACT Due to the low uptake, adherence, and completion of vaccination among drug users, and their compromised immune responses to hepatitis B vaccination, the current practice of hepatitis B vaccination may not provide optimal protection. The aim of this study was to evaluate the immunogenicity and safety of 60 µg and 20 µg hepatitis B vaccines among drug users. A randomized, open-labeled, blank-controlled trial was conducted among drug users at 2 drug rehabilitation centers in China. The eligible participants were drug users who were serologically negative for the hepatitis B surface antigen (HBsAg) and the hepatitis B surface antibody (anti-HBs). Participants were randomized in a ratio of 1:1:1 to receive 20 µg (IM20 group) or 60 µg (IM60 group) of hepatitis B vaccine or blank control at months 0, 1, and 6, and followed at months 6, 7, and 12. Seroconversion rates of 94.7% and 92.6% were observed in IM20 and IM60 groups at month 7, and correspondingly decreased to 89.5% and 91.7% respectively at month 12. The IM60 group showed significantly higher geometric mean concentrations (GMCs) of anti-HBs (2022.5 and 676.7 mIU mL–1) than the IM20 group did (909.6 and 470.5 mIU mL–1) at months 7 and 12 (P < 0.05). No safety concerns associated with vaccination were noted. Three-dose intramuscular immunization with hepatitis B vaccines showed good immunogenicity among the drug users.

Superparasitism, immune response and optimum progeny yield in the gregarious parasitoid Palmistichus elaeisis.

The subsequent deposition of an egg clutch by a female parasitoid into a host already parasitised either by itself or a conspecific (i.e. superparasitism) is a counterintuitive adaptive strategy, particularly considering the female parasitoid's ability to recognise the parasitised hosts. Such a scenario suggests that the adaptive value of superparasitism depends on the number of clutches laid in the same host, with consequences for parasitoid progeny yield. Here, we tested whether such is the case for the gregarious parasitoid Palmistichus elaeisis and explored its underlying basis. Allowing female parasitoids to lay multiple egg clutches in a single melonworm host pupa, parasitoid progeny and fitness exhibited a peak or optimum at three egg clutches laid per host pupa. In addition, haemocyte count, encapsulation and melanisation decreased with the number of egg clutches laid per host pupa. An optimum number of three clutches laid per host pupa was detected for P. elaeisis. As immune response via haemocyte production, encapsulation and melanisation decreased with the number of clutches laid per host, the higher parasitoid yield and fitness observed is the likely consequence of a compromised immune response coupled with an accommodative (i.e. scramble) larval competitive strategy allowing enough resources for optimum balance of parasitoid number and quality produced. © 2017 Society of Chemical Industry.

IL-23, IFN-α, and IFN-β in the vaginal fluid of patients suffering from vulvovaginal candidosis

The study included 202 non-pregnant women; 71 patients with clinical symptoms of VVC and 131 asymptomatic patients served as control. IL-23, IFN-α, and IFN-β were measured in the vaginal fluid by ELISA. Microbiological cultures were used for Candida detection. C. albicans was detected in 67.6% of patients, C. glabrata in 2 1.1% of patients, and 5.6% were infected with C. krusei or coinfected with C. albicans and C. krusei. Levels of IL-23 (p < 0.001) and IFN-β (p < 0.017) were significantly lower in the VVC group. IFN-α was elevated in the VVC group compared to the asymptomatic patients (p < 0.001). IL-23 and IEFN-β seem to play a protective role against VVC. Decreased levels in VVC patients suggest a compromised local immune response at the time of occurrence of symptoms. In contrast, IFN-α seems to be released once the infection has occurred. These cytokines may be prospective targets in the treatment and prevention of primary and recurrent vaginal infections with Candida species.

A double-stranded RNA binding protein, HYL1, regulates plant immunity via the jasmonic acid pathway

MicroRNA (miRNA) and small interference RNA (siRNA) regulate not only plant growth and development, but also various responses to stress, including biotic stress, through post-transcriptional gene regulation. Hyponastic leaves 1 (HYL1), a double-stranded RNA binding protein, plays an important role in miRNA and siRNA processing, along with Dicer-like 1 (DCL1) and Hua Enhancer 1 (HEN1). Of five double-stranded RNA binding protein (DRB) deficient mutants in Arabidopsis, only the hyl1 mutant compromised innate immune responses to Pseudomonas syringae pv. tomato (Pst) DC3000 hrcC − infection when compared to wild-type plants. This was similar to the response of the hen1 mutant. Furthermore, the hyl1 mutant was susceptible to Pst (avrRpt2) infections, and showed a delay in the hypersensitive response that should result from gene-for-gene interactions between RPS2 and AvrRpt2. These results suggest that HYL1 is a major contributor in the DRB family, influencing miRNA and siRNA biogenesis and therefore playing essential roles in PAMP- and effect-triggered immune responses in plants. DNA microarray analysis revealed that the expression of genes involved in jasmonic acid (JA) biosynthesis, signal transduction, and downstream responses was significantly upregulated in the hyl1 mutant compared with wild-type plants. Consistent with this, transgenic plants overexpressing HYL1 are hypersensitive to the necrotrophic pathogen Botrytis cinerea, of which resistance is mainly regulated by JA. These results elucidate the importance of small RNA-mediated JA regulation in plant immunity.

Inflammation, vitamin D and dendritic cell precursors in chronic kidney disease.

Decreased blood dendritic cell precursors (DCP) count is linked with atherosclerotic disease, while reduction of circulating DCP is also seen in patients with chronic kidney disease (CKD). As poor vitamin D status could be linked to a compromised innate immune response, we hypothesized that vitamin D status might be involved in the decrease in circulating DCP in CKD. Moreover, the potential role of inflammation was considered. Circulating myeloid (mDCP), plasmacytoid (pDCP) and total DCP (tDCP) were analysed using flow cytometry in 287 patients with CKD stage 3. Serum 25(OH)D and 1,25(OH)2D levels were measured using enzyme-linked immunosorbent assays (ELISA), interleukin (IL)-6, IL-10 and tumour necrosis factor (TNF)-α using cytometric bead array, C-reactive protein (CRP) using a high-sensitivity (hs) ELISA. Contrary to our hypothesis, there was no association between vitamin D levels and DCP, although their number was decreased significantly in CKD (P < 0·001). Instead, mDCP (r = -0·211) and tDCP (r = -0·188,) were associated slightly negatively with hsCRP but positively with the estimated glomerular filtration rate (eGFR, r = 0·314 for tDCP). According to multivariate linear regression, only higher hsCRP concentration and the presence of diabetes mellitus had a significant negative influence on DCP count (P < 0·03, respectively) but not vitamin D, age and eGFR. A significant impact of vitamin D on the reduction of circulating DCP in CKD 3 patients can be neglected. Instead, inflammation as a common phenomenon in CKD and diabetes mellitus had the main influence on the decrease in DCP. Thus, a potential role for DCP as a sensitive marker of inflammation and cardiovascular risk should be elucidated in future studies.

A Genetic Screen Identifies a Requirement for Cysteine-Rich-Receptor-Like Kinases in Rice NH1 (OsNPR1)-Mediated Immunity.

Systemic acquired resistance, mediated by the Arabidopsis NPR1 gene and the rice NH1 gene, confers broad-spectrum immunity to diverse pathogens. NPR1 and NH1 interact with TGA transcription factors to activate downstream defense genes. Despite the importance of this defense response, the signaling components downstream of NPR1/NH1 and TGA proteins are poorly defined. Here we report the identification of a rice mutant, snim1, which suppresses NH1-mediated immunity and demonstrate that two genes encoding previously uncharacterized cysteine-rich-receptor-like kinases (CRK6 and CRK10), complement the snim1 mutant phenotype. Silencing of CRK6 and CRK10 genes individually in the parental genetic background recreates the snim1 phenotype. We identified a rice mutant in the Kitaake genetic background with a frameshift mutation in crk10; this mutant also displays a compromised immune response highlighting the important role of crk10. We also show that elevated levels of NH1 expression lead to enhanced CRK10 expression and that the rice TGA2.1 protein binds to the CRK10 promoter. These experiments demonstrate a requirement for CRKs in NH1-mediated immunity and establish a molecular link between NH1 and induction of CRK10 expression.