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Cleopatra K. Mugyenyi Salenna R. Elliott Fiona J. McCallum Robin F. Anders Kevin Marsh James G. Beeson 《PloS one》2013,8(7)
Background
Antibodies to P. falciparum apical membrane protein 1 (AMA1) may contribute to protective immunity against clinical malaria by inhibiting blood stage growth of P. falciparum, and AMA1 is a leading malaria vaccine candidate. Currently, there is limited knowledge of the acquisition of strain-specific and cross-reactive antibodies to AMA1 in humans, or the acquisition of invasion-inhibitory antibodies to AMA1.Methodology/Findings
We examined the acquisition of human antibodies to specific polymorphic invasion-inhibitory and non-inhibitory AMA1 epitopes, defined by the monoclonal antibodies 1F9 and 2C5, respectively. Naturally acquired antibodies were measured in cohorts of Kenyan children and adults. Antibodies to the invasion-inhibitory 1F9 epitope and non-inhibitory 2C5 epitope were measured indirectly by competition ELISA. Antibodies to the 1F9 and 2C5 epitopes were acquired by children and correlated with exposure, and higher antibody levels and prevalence were observed with increasing age and with active P. falciparum infection. Of note, the prevalence of antibodies to the inhibitory 1F9 epitope was lower than antibodies to AMA1 or the 2C5 epitope. Antibodies to AMA1 ectodomain, the 1F9 or 2C5 epitopes, or a combination of responses, showed some association with protection from P. falciparum malaria in a prospective longitudinal study. Furthermore, antibodies to the invasion-inhibitory 1F9 epitope were positively correlated with parasite growth-inhibitory activity of serum antibodies.Conclusions/Significance
Individuals acquire antibodies to functional, polymorphic epitopes of AMA1 that may contribute to protective immunity, and these findings have implications for AMA1 vaccine development. Measuring antibodies to the 1F9 epitope by competition ELISA may be a valuable approach to assessing human antibodies with invasion-inhibitory activity in studies of acquired immunity and vaccine trials of AMA1. 相似文献3.
Pine needle growth and fine structure after prolonged acid rain treatment in the subarctic 总被引:1,自引:0,他引:1
The growth and morphology of Scots pine needles were studied in a long-term acid rain experiment in the far north of Finnish Lapland. Pine trees 5 m tall of age 50–70 years were exposed, by spraying the foliage and soil from a height of 2 m, to either clean water (IC) or acidified water over the period 1985–1992, the acidification site being divided into sub-areas in which the precipitation contained two levels of either sulphuric (Sm, Sh) or nitric (Nm, Nh) acid, or both (SNm, SNh). The treatments with medium and high sulphate-S over eight consecutive years yielded a total sulphur deposition of 3·4 and 17·1 gm−2, respectively, and those with medium and high nitrate-N a total nitrogen deposition of 1·1 and 5·9 g m−2. Needles were collected for light and electron microscopy, growth measurements and morphometry. Growth in branch height had decreased by about 40% after 6 years of SNm or SNh treatment, and needle growth by 15% in the SNh trees as compared with the irrigated control trees (IC), although decreases were statistically significant only with respect to the non-irrigated control trees (DC). Growth of branches and needles was slightly better in the Nh treatment than in the IC group. The areas of the whole needle, the mesophyll and the phloem decreased in response to SNh treatment as compared with IC or DC, and a statistically significant decrease of about 30–40% was seen in the area of the xylem in comparison with DC. Cellular damage was observed following the acid treatments, especially with a high acid load. The damage was manifested in collapse of the cellular compartments, increases in lipid accumulations and swelling or disorganization of the protoplast. Increased vacuolization of the cytoplasm, plasmalemma irregularities and chilling-type damage to the mitochondria were also observed. 相似文献
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CK Bower J McGuire MA Daeschel 《Journal of industrial microbiology & biotechnology》1995,15(3):227-233
The efficacy of the antimicrobial peptide nisin was examined after adsorption to silica surfaces. Three protocols were used to evaluate nisin's activity against adhered cells ofListeria monocytogenes: bioassay usingPediococcus pentosaceous FBB 61-2 as the sensitive indicator strain; visualization and enumeration of cells by microscopic image analysis; and viability of adhered cells as determined by lodonitrotetrazolium violet uptake and crystallization. The activity of adsorbed nisin was highly dependent upon conditions of adsorption. The highest antimicrobial activity of adsorbed nisin occurred with high concentrations of nisin (1.0 mg ml–1) and brief contact times (1 h) on surfaces of low hydrophobicity. Sequential adsorption of a second protein (-lactoglobulin or bovine serum albumin) onto surfaces consistently resulted in decreased nisin activity. These data provide direction for the development of applications to limit microbial attachment on food contact surfaces through the use of adsorbed antimicrobial peptides. 相似文献
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Depletion of regulatory T cells in HIV infection is associated with immune activation 总被引:15,自引:0,他引:15
Eggena MP Barugahare B Jones N Okello M Mutalya S Kityo C Mugyenyi P Cao H 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(7):4407-4414
Immune activation during chronic HIV infection is a strong clinical predictor of death and may mediate CD4(+) T cell depletion. Regulatory T cells (Tregs) are CD4(+)CD25(bright)CD62L(high) cells that actively down-regulate immune responses. We asked whether loss of Tregs during HIV infection mediates immune activation in a cross-sectional study of 81 HIV-positive Ugandan volunteers. We found that Treg number is strongly correlated with both CD4(+) and CD8(+) T cell activation. In multivariate modeling, this relationship between Treg depletion and CD4(+) T cell activation was stronger than any other clinical factor examined, including viral load and absolute CD4 count. Tregs appear to decline at different rates compared with other CD4(+) T cells, resulting in an increased regulator to helper ratio in many patients with advanced disease. We hypothesize that this skewing may contribute to T cell effector dysfunction. Our findings suggest Tregs are a major contributor to the immune activation observed during chronic HIV infection. 相似文献
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Eui-Ju Hong Se-Hyung Park Kyung-Chul Choi Peter CK Leung Eui-Bae Jeung 《Reproductive biology and endocrinology : RB&E》2006,4(1):49-12
Environmental estrogenic compounds which bind to the estrogen receptor (ER) can block or alter endogenous functions of estrogen
in reproductive and developmental stages. A microarray technology is a very valuable method for the prediction of hormone-responsive
activities in various gene expressions. Thus, we investigated the altered gene expression by estrogen and endocrine disruptors
(EDs) using microarray technology in the uterus of immature rats. In this study, the expression levels of only 555 genes (7.42%)
among the 7636 genes spotted on microarray chips were enhanced by more than two-fold following treatment with estradiol (E2),
suggesting that direct or rapid response to E2 is widespread at the mRNA levels in these genes. In addition, elevated expression
levels of the genes (over 2-fold) were observed by diethylstilbestrol (DES; 9.01%), octyl-phenol (OP; 8.81%), nonyl-phenol
(NP; 9.51%), bisphenol-A (BPA; 8.26%) or genistein (9.97%) in the uterus of immature rats. The expression levels of representative
genes, i.e., calbindin-D9k (CaBP-9k; vitamin D-dependent calcium-binding protein), oxytocin, adipocyte complement related
protein (MW 30 kDa), lactate dehydrogenase A and calcium binding protein A6 (S100a6; calcyclin), were confirmed in these tissues
by real-time PCR. In addition, the mRNA levels of these genes by real-time PCR were increased at follicular phase when E2
level was elevated during estrous cycle of adult female rats. In conclusion, these results indicate distinct altered expression
of responsive genes following exposure to E2 and estrogenic compounds, and implicate distinct effects of endogenous E2 and
environmental endocrine disrupting chemicals in the uterus of immature rats. 相似文献
7.
McCallum FJ Persson KE Mugyenyi CK Fowkes FJ Simpson JA Richards JS Williams TN Marsh K Beeson JG 《PloS one》2008,3(10):e3571
Background
Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity in humans. However, the acquisition and activity of these antibodies is not well understood.Methods
We tested dialysed serum and purified immunoglobulins from Kenyan children and adults for inhibition of P. falciparum blood-stage growth in vitro using different parasite lines. Serum antibodies were measured by ELISA to blood-stage parasite antigens, extracted from P. falciparum schizonts, and to recombinant merozoite surface protein 1 (42 kDa C-terminal fragment, MSP1-42).Results
Antibodies to blood-stage antigens present in schizont protein extract and to recombinant MSP1-42 significantly increased with age and were highly correlated. In contrast, growth-inhibitory activity was not strongly associated with age and tended to decline marginally with increasing age and exposure, with young children demonstrating the highest inhibitory activity. Comparison of growth-inhibitory activity among samples collected from the same population at different time points suggested that malaria transmission intensity influenced the level of growth-inhibitory antibodies. Antibodies to recombinant MSP1-42 were not associated with growth inhibition and high immunoglobulin G levels were poorly predictive of inhibitory activity. The level of inhibitory activity against different isolates varied.Conclusions
Children can acquire growth-inhibitory antibodies at a young age, but once they are acquired they do not appear to be boosted by on-going exposure. Inhibitory antibodies may play a role in protection from early childhood malaria. 相似文献8.
Abstract Segment 9 of male Raphidioptera, comprising tergite, sternite, gonocoxites, gonostyli and gonapophyses, is a benchmark for homologies in the male and female terminalia of the three Neuropterida orders Raphidioptera, Megaloptera and Neuroptera. The segments relating to genitalia are 9, 10 and 11 in males and 7, 8 and 9 in females. Results from holomorphological and recent molecular cladistic analyses of Neuropterida agree in supporting the sister‐group relationships between: (1) the Raphidioptera and the clade Megaloptera + Neuroptera, and (2) the suborder Nevrorthiformia and all other Neuroptera. The main discrepancy between the results of these studies is the nonmonophyly of the suborder Hemerobiiformia in the molecular analysis. The monophyly of the Megaloptera (which has been repeatedly questioned) is further corroborated by a hitherto overlooked ground pattern autapomorphy: the presence of eversible sacs within the complex of the fused gonocoxites 11 in Corydalidae and Sialidae. The recently discovered paired complex of gonocoxites 10 (parameres) in Nipponeurorthus (Nevrorthidae) indicates that the curious apex of sternite 9 of Nevrorthus and Austroneurorthus is the amalgamation of the sclerites of gonocoxites 10 with sternite 9, interpreted as synapomorphic. In the molecular study, the Nevrorthidae, Sisyridae and Osmylidae branch off in consecutive splitting events, a result that is supported by the analysis of male genital sclerites reported here. Extraordinary parallel apomorphies (e.g. excessive enlargement and modification of gonocoxites 10 ending in a thread‐like ‘penisfilum’) in derived representatives of Coniopterygidae, Berothidae, Rhachiberothidae and Mantispidae corroborate the dilarid clade of the morphological analysis and leads us to hypothesize a sister‐group relationship of the Coniopterygidae with the dilarid clade. A re‐interpretation of the tignum of Chrysopidae as gonocoxites 11 means that the structure previously called the gonarcus represents the fused gonocoxites 9. In Hemerobiidae, the corresponding sclerite is consequently also homologized as fused gonocoxites 9. The enlargement of the lateral wings of the gonocoxites in both families is interpreted as a synapomorphy. Excessive enlargement of gonostyli 11 in the Polystoechotid clade and Myrmeleontiformia supports a sister‐group relationship of these two clades. The occurrence of certain serial homologues of female genitalia structures (gonocoxites and gonapophyses), such as the digitiform processus together with the flat appendices in segment 8 of certain Myrmeleontidae, or the wart‐like processus together with the flat circular sclerites in segment 7 of certain Berothidae, as well as the presence of gonocoxites 8 as pseudosternites in certain Nemopteridae and Coniopterygidae, are probably character reversals. The digitiform processus of tergite 9 (pseudogonocoxites) in Rhachiberothidae and Austroberothella (Berothidae) are either independently developed acquisitions with a function in oviposition, or are homologous sclerites, possibly of epipleurite origin. 相似文献
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DAVIDE BADANO ULRIKE ASPÖCK HORST ASPÖCK PIERFILIPPO CERRETTI 《Systematic Entomology》2017,42(1):94-117
The suborder Myrmeleontiformia is a derived lineage of lacewings (Insecta: Neuroptera) including the families Psychopsidae, Nemopteridae, Nymphidae, Ascalaphidae and Myrmeleontidae. In particular, Myrmeleontidae (antlions) are the most diverse neuropteran family, representing a conspicuous component of the insect fauna of xeric environments. We present the first detailed quantitative phylogenetic analysis of Myrmeleontiformia, based on 107 larval morphological and behavioural characters for 36 genera whose larvae are known (including at least one representative of all the subfamilies of the suborder). Four related families were used as outgroups to polarize character states. Phylogenetic analyses were conducted using both parsimony and Bayesian methods. The reconstructions resulting from our analyses corroborate the monophyly of Myrmeleontiformia. Within this clade, Psychopsidae are recovered as the sister family to all the remaining taxa. Nemopteridae (including both subfamilies Nemopterinae and Crocinae) are recovered as monophyletic and sister to the clade comprising Nymphidae + (Myrmeleontidae + Ascalaphidae). Nymphidae consist of two well‐supported clades corresponding to the subfamilies Nymphinae and Myiodactylinae. Our results suggest that Ascalaphidae may not be monophyletic, as they collapse into an unresolved polytomy under the Bayesian analysis. In addition, the recovered phylogenetic relationships diverge from the traditional classification scheme for ascalaphids. Myrmeleontidae are reconstructed as monophyletic, with the subfamilies Stilbopteryginae, Palparinae and Myrmeleontinae. We retrieved a strongly supported clade comprising taxa with a fossorial habit of the preimaginal instars, which represents a major antlion radiation, also including the monophyletic pit‐trap building species. 相似文献
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Marlene Neethling Conrad A Matthee Rauri CK Bowie Sophie von der Heyden 《BMC evolutionary biology》2008,8(1):325