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1.
Environ Int ; 190: 108749, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38885552

ABSTRACT

The Chicago Department of Public Health tested wastewater samples for the presence of Monkeypox Virus (MPXV) from March 13 through June 26, 2023. There were persistent detections prior to reported cases. This indicated the baseline levels of MPXV prevalence might warrant routine monitoring. Detections in areas without corresponding reported clinical cases might highlight areas where cases are being under-reported by traditional surveillance.

2.
Microorganisms ; 12(3)2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38543678

ABSTRACT

Microbial proton-pump rhodopsin (PPR)-based phototrophy, a light-harvesting mechanism different from chlorophyll-based photosystems, may contribute significantly to solar energy entry into the marine ecosystem. PPR transforms solar energy into cellular energy that is used for various metabolic processes in the cells or flagellar movement. Although rhodopsins or their encoding genes have been documented in a wide phylogenetic range of cultured dinoflagellates, information is limited about how widespread and how spatiotemporally dynamical dinoflagellate PPR (DiPPR) are in natural marine ecosystems. In this study, we investigated DiPPR in Long Island Sound (LIS), a temperate estuary of the Atlantic Ocean between Connecticut and Long Island, New York, USA. We isolated six novel full-length dinoflagellate proton-pump rhodopsin cDNAs, expanding the DiPPR database that is crucial to PPR research. Based on these new sequences and existing sequences of DiPPR, we designed primers and conducted quantitative PCR and sequencing to determine the abundance and diversity of DiPPR genes spatially and temporally throughout a year in the water samples collected from LIS. DiPPR genes were found year-round and throughout LIS but with higher abundances in the eutrophic Western Sound and in April and July. The gene diversity data suggest that there are at least five distinct rhodopsin-harboring groups of dinoflagellates throughout the year. The abundance of DiPPR genes, measured as copy number per mL of seawater, appeared not to be influenced by water temperature or nitrogen nutrient concentration but exhibited weak negative correlations with orthophosphate concentration and salinity and a positive correlation with the abundance of DiPPR-harboring dinoflagellates. This first quantitative profiling of PPR in natural plankton reveals the prevalence and dynamics of this plastid-independent photoenergy harvesting mechanism in a temperate estuary and provides efficient DiPPR primers potentially useful for future research. Furthermore, this study shed light on the potential role of DiPPR in phosphor nutrition and dinoflagellate population, which warrants further studies.

3.
Sci Total Environ ; 912: 169551, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38135071

ABSTRACT

Influenza is a respiratory illness that can result in serious outcomes, particularly among persons who are immunocompromised, aged <5 years or aged >65 years. Traditional influenza surveillance approaches rely upon syndromic surveillance of emergency departments and public health reporting from clinicians and laboratories. Wastewater surveillance infrastructure developed to monitor SARS-CoV-2 is being used for influenza surveillance in the Chicago area. The goal was to evaluate timeliness and correlations between influenza virus detected through wastewater surveillance and traditional influenza surveillance measures to assess utility of wastewater surveillance for influenza at the county level. Specifically, we measured correlations between influenza virus gene copies in wastewater samples and 1) the number of intensive care unit admissions associated with a diagnosis of influenza, 2) the percentage emergency department (ED) visits for influenza-like-illness, and 3) the percentage of ED visits with influenza diagnosis at discharge2 in Cook County. Influenza concentrations in wastewater were strongly correlated with traditional influenza surveillance measures, particularly for catchment areas serving >100,000 residents. Wastewater indicators lagged traditional influenza surveillance measures by approximately one week when analyzed in cross-correlations. Although wastewater data lagged traditional influenza surveillance measures in this analysis, it can serve as a useful surveillance tool as a complement to syndromic surveillance; it is a form of influenza surveillance that does not rely on healthcare-seeking behavior or reporting by healthcare providers.


Subject(s)
Influenza, Human , Humans , Influenza, Human/epidemiology , Wastewater , Wastewater-Based Epidemiological Monitoring , Illinois/epidemiology , Sentinel Surveillance
4.
Environ Microbiol ; 25(12): 3435-3449, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37941484

ABSTRACT

The blue mussel (Mytilus edulis) is a suspension feeder which has been used in gut-microbiome surveys. Although raw 16S sequence data are often publicly available, unifying secondary analyses are lacking. The present work analysed raw data from seven projects conducted by one group over 7 years. Although each project had different motivations, experimental designs and conclusions, all selected samples were from the guts of M. edulis collected from a single location in Long Island Sound. The goal of this analysis was to determine which independent factors (e.g., collection date, depuration status) were responsible for governing composition and diversity in the gut microbiomes. Results indicated that whether mussels had undergone depuration, defined here as voidance of faeces in a controlled, no-food period, was the primary factor that governed gut microbiome composition. Gut microbiomes from non-depurated mussels were mixtures of resident and transient communities and were influenced by temporal factors. Resident communities from depurated mussels were influenced by the final food source and length of time host mussels were held under laboratory conditions. These findings reinforce the paradigm that gut microbiota are divided into resident and transient components and suggest that depuration status should be taken into consideration when designing and interpreting future experiments.


Subject(s)
Gastrointestinal Microbiome , Mytilus edulis , Mytilus , Animals , Seafood
5.
Front Psychol ; 14: 1125131, 2023.
Article in English | MEDLINE | ID: mdl-37325730

ABSTRACT

Introduction: Mazes are linguistic disfluencies such as filled pauses, repetitions, or revisions of grammatical, phonological, or lexical aspects of words that do not contribute to the meaning of a sentence. Bilingual children are believed to increase the numbers of mazes in their native or heritage language, the minority language, as they become more proficient in the second language, the societal language. Mazes may increase over time in bilingual Spanish-speaking children as they become more proficient in English, the societal language in the United States. However, current studies have not been conducted longitudinally. Higher rates of mazes in the heritage language over time may be due to changes in language proficiency and differences in processing demands in the children as they use more complex language. Moreover, children with developmental language disorder (DLD) can also present higher rates of mazes than children with typical language. Heritage speakers, therefore, are at risk of being misdiagnosed with DLD due to high rates of mazes. Currently, we do not understand what the typical rates of mazes are as heritage speakers get older and become more proficient in the societal language. The current study examined the type and frequency of Spanish mazes longitudinally in a group of 22 Spanish heritage speakers with and without DLD and determined the changes over time. Methods: A total of 11 children with typical language development (TLD) and 11 with DLD participated in this 5-year longitudinal study. Using a wordless picture book, children completed a retelling task in Spanish during the spring of each academic year (PK to 3rd grade) as part of a 5-h testing battery. Narratives were transcribed and coded for types of mazes (filled pauses, repetitions, grammatical revisions, phonological revisions, and lexical revisions). Results and conclusion: The results of the study indicate that TLD children increased their overall percentage of mazed words and utterances. The opposite pattern was observed in the DLD group, which decreased their percentage of mazed words and utterances. In contrast, both groups demonstrated a decrease in repetitions in first grade and an increase in third grade. Additionally, the TLD and DLD children decreased in the percentage of fillers in first grade and then increased in the third grade. Results suggest that maze use is quite variable in heritage speakers and does not necessarily differentiate groups. Clinicians should not rely solely on mazes to determine ability status. In fact, high use of mazes can reflect typical language development.

6.
Lang Speech Hear Serv Sch ; 53(2): 532-541, 2022 04 11.
Article in English | MEDLINE | ID: mdl-35271346

ABSTRACT

PURPOSE: The purpose of the study was to examine the change in specific English microstructure features according to language ability in preschool Spanish-English dual language learners. METHOD: We collected English narratives from 22 Spanish-English dual language learners with typical language development (TD) and 22 Spanish-English dual language learners with developmental language disorder (DLD) at the beginning and end of their first year in Head Start. Children came from Spanish-speaking homes and were exposed to English and Spanish in their preschool classrooms. We analyzed children's use of English microstructure across time using the Narrative Assessment Protocol. RESULTS: Both groups showed improvement in overall English microstructure use, although children with TD made greater gains than children with DLD. Phrase structure (noun phrases, coordinating conjunctions, and prepositional phrases) increased in both groups, but more so in children with TD than with DLD. Sentence structure (compound, complex, negative, and interrogative sentences) increased in both groups. Verb use, noun use (Tier 2 nouns and nouns marked with plural and possessive endings), and modifiers (adverbs and adjectives) neither changed across time nor differed between groups. CONCLUSIONS: Spanish-English dual language learners who attend Head Start and come from Spanish-speaking homes, regardless of language ability, may not readily acquire verbs, nouns, and modifiers during their first year of formal English exposure, suggesting that they would benefit from explicit instruction in these areas. Preschool Spanish-English dual language learners with DLD may make less progress than their peers with TD in phrase structure use, indicating that explicit instruction in this microstructure feature may be beneficial for children with DLD.


Subject(s)
Language Development Disorders , Multilingualism , Child , Child Language , Child, Preschool , Humans , Language , Language Development , Language Development Disorders/diagnosis , Language Tests
7.
Rev. logop. foniatr. audiol. (Ed. impr.) ; 41(4): 197-203, Oct-Dic, 2021.
Article in English | IBECS | ID: ibc-227650

ABSTRACT

The purpose of the current paper is to provide a review of the Narrative Language Measures (NLM) for use with Spanish-speaking preschool children. We review the format, scoring, reliability, and validity of the NLM. The NLM can be used for progress monitoring of narrative skills, and for benchmark assessment in the classroom. The results of the review indicate that the measure has good reliability and concurrent validity; however, additional validation is needed for different populations, such as monolingual Spanish speakers, and students from diverse income levels, given that the validation was done mostly with low-income children. It is recommended that additional validation be completed and that those using the NLM consider cultural and linguistic variations.(AU)


El propósito de este artículo es proporcionar una revisión de las Medidas de Lenguaje Narrativo (NLM) para su uso en niños preescolares de lengua española. Revisamos el formato, la puntuación, la fiabilidad y la validez de la NLM. La NLM puede utilizarse para el seguimiento del progreso de las habilidades narrativas y para la evaluación de referencia en el aula. Los resultados de la revisión indican que la medida tiene una buena fiabilidad y validez concurrente; sin embargo, se necesita una validación adicional para diferentes poblaciones, como los hispanohablantes monolingües, y los estudiantes de diversos niveles de ingresos, dado que la validación se hizo principalmente en niños de bajos ingresos. Se recomienda que se realice una validación adicional y que quienes utilicen la NLM tengan en cuenta las variaciones culturales y lingüísticas.(AU)


Subject(s)
Humans , Male , Female , Child, Preschool , Language Development , Narration , Language Disorders , Students , Child Language , Language Tests , Speech, Language and Hearing Sciences , Audiology
8.
Anim Microbiome ; 2(1): 27, 2020 Aug 04.
Article in English | MEDLINE | ID: mdl-33499990

ABSTRACT

BACKGROUND: The skin microbiome of marine fish is thought to come from bacteria in the surrounding water during the larval stages, although it is not clear how different water conditions affect the microbial communities in the water and, in turn, the composition and development of the larval skin microbiome. In aquaculture, water conditions are especially important; claywater and greenwater are often used in larval rearing tanks to increase water turbidity. Here, we explored the effects of these water additives on microbial communities in rearing water and on the skin of first-feeding sablefish larvae using 16S rRNA gene sequencing. We evaluated three treatments: greenwater, claywater, and greenwater with a switch to claywater after 1 week. RESULTS: We observed additive-specific effects on rearing water microbial communities that coincided with the addition of larvae and rotifer feed to the tanks, such as an increase in Vibrionaceae in greenwater tanks. Additionally, microbial communities from experimental tank water, especially those in claywater, began to resemble larval skin microbiomes by the end of the experiment. The differential effects of the additives on larval sablefish skin microbiomes were largest during the first week, post-first feed. Bacteria associated with greenwater, including Vibrionaceae and Pseudoalteromonas spp., were found on larval skin a week after the switch to claywater. In addition to additive-specific effects, larval skin microbiomes also retained bacterial families likely acquired from their hatchery silos. CONCLUSIONS: Our results suggest that larval sablefish skin microbiomes are most sensitive to the surrounding seawater up to 1 week following the yolk-sac stage and that claywater substituted for greenwater after 1 week post-first feed does not significantly impact skin-associated microbial communities. However, the larval skin microbiome changes over time under all experimental conditions. Furthermore, our findings suggest a potential two-way interaction between microbial communities on the host and the surrounding environment. To our knowledge, this is one of the few studies to suggest that fish might influence the microbial community of the seawater.

9.
mSphere ; 4(6)2019 12 11.
Article in English | MEDLINE | ID: mdl-31826972

ABSTRACT

Gut microbial community structure was evaluated for two species of bivalve molluscs, the eastern oyster (Crassostrea virginica) and the blue mussel (Mytilus edulis) collected from Long Island Sound, Connecticut, over the course of a year. These bivalves utilize a shared feeding mechanism, which may result in similar gut microbial communities. Their particle diet, marine aggregates, and surrounding environment, aggregate-free seawater (AFSW), were also collected for comparison. Due to the suspension-feeding activities of bivalves, the potential for aggregate- and AFSW-associated microbiota to influence their microbial communities may be significant. Both taxonomic and functional diversity of the samples were assessed. 16S rRNA gene amplicon sequencing indicated that oysters and mussels maintained similar, but not identical, gut microbiomes, with some temporal variation. Throughout the year, bivalve species had gut microbial community compositions that were more similar to one another than to aggregates. Within a month, bivalves shared on average a quarter of their total operational taxonomic units (OTUs) with each other and a 10th of their total OTUs with aggregates. During months with warm water temperatures, individuals within each of the four sample types had similar alpha diversity, but again, temporal variation was observed. On a functional level, bivalve gut microbial communities exhibited variation attributed to host species and season. Unlike oysters, mussel gut bacterial communities maintained high richness and evenness values throughout the year, even when values for the particle diet and AFSW were reduced. Overall, a core gut bivalve microbiome was present, and it was partially influenced by the marine aggregate microbial community.IMPORTANCE This work investigates the influence that extrinsic factors, diet, and the environment can have on the microbiomes of shellfish. Over the course of a year, the gut microbial communities of two species of bivalves, oysters and mussels, held under identical conditions in coastal marine waters were compared. While the mussels and oysters harbored gut microbial communities with similar composition, on a functional level, they exhibited species and temporal variation. These results indicate that intrinsic factors influence the bivalve microbiome, resulting in species variability, even when environmental conditions, feeding mechanism, and particle diet are constant. Seasonal and multispecies comparisons for bivalve-associated microbial communities are rare, and we believe this research represents an important contribution. The results presented here advance our understanding of the symbiotic interactions between marine invertebrates, the microbial communities they harbor, and the environment.


Subject(s)
Bacteria/classification , Crassostrea/microbiology , Gastrointestinal Microbiome , Mytilus edulis/microbiology , Seawater/microbiology , Animals , Bacteria/genetics , Cluster Analysis , Connecticut , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Metagenomics , Phylogeny , RNA, Ribosomal, 16S/genetics , Seasons , Sequence Analysis, DNA
10.
Ecol Evol ; 6(20): 7397-7408, 2016 10.
Article in English | MEDLINE | ID: mdl-28725407

ABSTRACT

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria in oysters. Simulations were conducted over a realistic range of concentrations of bacteria and aggregates and incorporated the dependence of pseudofeces production on particulate matter. The model shows that the contribution of aggregate-attached bacteria depends strongly on the unattached bacteria, which form the colonization pool for aggregates and are directly captured by the simulated oysters. The concentration of aggregates is also important, but its effect depends on the concentration of unattached bacteria. At high bacterial concentrations, aggregates contribute the majority of bacteria in the oysters. At low concentrations of unattached bacteria, aggregates have a neutral or even a slightly negative effect on bacterial accumulation. These results provide the first evidence suggesting that the concentration of aggregates could influence uptake of pathogenic bacteria in bivalves and show that the tendency of a bacterial species to remain attached to aggregates is a key factor for understanding species-specific accumulation.

11.
Tob Control ; 23(4): 285-90, 2014 Jul.
Article in English | MEDLINE | ID: mdl-23322312

ABSTRACT

OBJECTIVE: Social marketing is commonly proposed to counteract advertising and other messages that promote unhealthy products. However, public service campaigns can also 'boomerang' or ironically increase the unhealthy behaviours they are designed to discourage. The present study examined whether antismoking public service announcements (PSAs) could increase smoking behaviour immediately following exposure. METHODS: In an experimental study, 56 smokers were randomly assigned to watch a short television segment with a commercial break that included either (1) a Philip Morris 'QuitAssist' PSA; (2) a Legacy 'truth' antismoking PSA; or (3) a control PSA. Smoking behaviour was assessed during a short break immediately following television viewing. RESULTS: Participants who saw the Philip Morris antismoking PSA were significantly more likely to smoke during a break (42%) compared with participants in the control condition (11%), and participants in the 'truth' condition were marginally more likely to smoke (33%). These differences could not be explained by factors such as mood or level of addiction, and effects occurred outside of participants' conscious awareness. CONCLUSIONS: These findings provide preliminary evidence that antismoking campaigns could ironically increase immediate smoking behaviours among smokers. The long-term benefits of proven public health campaigns, including 'truth,' are likely to outweigh any short-term boomerang effects. However, industry-sponsored messages in which companies have an economic incentive to increase consumption behaviours should be treated with scepticism and evaluated independently.


Subject(s)
Advertising/methods , Behavior, Addictive/psychology , Persuasive Communication , Smoking Cessation/psychology , Smoking/psychology , Adult , Female , Health Promotion/methods , Humans , Male , Mass Media , Middle Aged , Pilot Projects , Self Efficacy , Smoking Cessation/methods , Smoking Prevention
12.
J Microbiol Methods ; 97: 20-4, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24333911

ABSTRACT

Biolog MicroPlates(TM) (e.g. EcoPlate(TM), MT2 MicroPlate(TM), GN MicroPlate(TM)) are useful tools for characterizing microbial communities, providing community-level physiological profiles to terrestrial and aquatic ecologists. The more recently designed Biolog EcoPlates have been used frequently in aquatic ecology with success. This study, however, reveals one major problem when using EcoPlates to evaluate samples within an estuarine or seawater matrix. At concentrations greater than 100 parts per million, the cation calcium begins to interfere with the microplate chemistry, causing false positive readings. Experiments, in which multiple treatments of natural and artificial seawater were tested, as well as calcium-addition experiments, demonstrate that calcium inhibits complete dissolution of the minimal growth medium in wells. Future studies involving Biolog EcoPlates and MicroPlates should take this effect into account, and the dilution of samples is strongly recommended to diminish the "calcium effect."


Subject(s)
Bacteria/isolation & purification , Calcium/metabolism , Microbiological Techniques/standards , Water Microbiology , Bacteria/classification , False Positive Reactions , Reproducibility of Results , Seaweed/chemistry
13.
J Virol ; 79(1): 619-21, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15596856

ABSTRACT

The incidence of type 1 diabetes (T1D) is decreased in nonobese diabetic mice expressing the complete cassette of adenovirus early region 3 (E3) immunomodulating genes in pancreatic beta cells. Embedded among the antiapoptotic E3 genes is one encoding an adenovirus death protein (ADP), which contributes to release of virion particles by promoting cell lysis. Because removal of this proapoptotic protein might have further enhanced the ability of E3 proteins to prevent T1D, an ADP-inactivated E3 construct was tested. Significantly, deletion of ADP did not improve the diabetes-protective effect of an E3 gene cassette.


Subject(s)
Adenovirus E3 Proteins/genetics , Adenovirus E3 Proteins/metabolism , Diabetes Mellitus, Type 1/prevention & control , Gene Deletion , Islets of Langerhans/metabolism , Adenovirus E3 Proteins/chemistry , Amino Acid Sequence , Animals , Diabetes Mellitus, Type 1/epidemiology , Female , Incidence , Mice , Mice, Inbred NOD , Molecular Sequence Data , Transgenes
14.
J Virol ; 79(2): 1045-52, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15613333

ABSTRACT

Type 1 diabetes acceleration in nonobese diabetic (NOD) mice through coxsackievirus B4 (CVB4) infection requires a preexisting critical mass of autoreactive T cells in pancreatic islets, and in the absence of this insulitic threshold, CVB4 infection leads to long-term disease protection. To understand this acceleration and protection process, we challenged 8- and 12-week-old NOD mice containing a disruption in interleukin-4 (IL-4) or gamma interferon (IFN-gamma) genes (NOD IL-4-/- and NOD IFN-gamma-/-, respectively) with a diabetogenic, pancreatropic Edwards strain of CVB4. The elimination of IL-4 did not alter the rate of insulitis or diabetes development in NOD mice, while the elimination of IFN-gamma delayed these events several weeks. CVB4 infection in 8-week-old mice only significantly accelerated the onset of diabetes in a subset of standard, but not IL-4- or IFN-gamma-deficient, NOD mice. Long-term diabetes protection was established in standard NOD mice as well as in the NOD IFN-gamma-/- mice that did not rapidly develop disease following CVB4 infection at 8 weeks of age. When mice were infected at 12 weeks of age, the onset of diabetes was accelerated in NOD IL-4-/- mice, while neither acceleration nor long-term protection was elicited in NOD IFN-gamma-/- mice. No differences were observed in the kinetics of CVB4 clearance in pancreases from NOD, NOD IL-4-/-, and NOD IFN-gamma-/- mice. Collectively, these results suggest that at the insulitis threshold at which CVB4 infection can first accelerate the onset of diabetes in NOD mice, IL-4 as well as IFN-gamma contributes to this pathogenic process. The protective mechanism against diabetes elicited in NOD mice infected with CVB4 prior to the development of a critical threshold level of insulitis requires neither IL-4 nor IFN-gamma.


Subject(s)
Diabetes Mellitus, Type 1/etiology , Enterovirus B, Human , Enterovirus Infections/complications , Interferon-gamma/physiology , Interleukin-4/physiology , Animals , Diabetes Mellitus, Type 1/prevention & control , Female , Islets of Langerhans/pathology , Mice , Mice, Inbred NOD , Pancreas/virology
15.
J Immunol ; 173(6): 3791-800, 2004 Sep 15.
Article in English | MEDLINE | ID: mdl-15356126

ABSTRACT

For unknown reasons, the common MHC class I variants encoded by the H2g7 haplotype (Kd, Db) aberrantly elicit autoreactive CD8 T cell responses essential to type 1 diabetes development when expressed in NOD mice, but not other strains. In this study, we show that interactive non-MHC genes allow a NOD-derived diabetogenic CD8 T cell clonotype (AI4) to be negatively selected at far greater efficiency in C57BL/6 mice congenically expressing H2g7 (B6.H2g7). However, the few AI4 T cells escaping negative selection in B6.H2g7 mice are exported from the thymus more efficiently, and are more functionally aggressive than those of NOD origin. This provides mechanistic insight to previous findings that resistant mouse strains carry some genes conferring greater diabetes susceptibility than the corresponding NOD allele. In the B6.H2g7 stock, non-MHC gene-controlled elevations in TCR expression are associated with both enhanced negative selection of diabetogenic CD8 T cells and increased aggressiveness of those escaping this process. An implication of this finding is that the same phenotype, in this case relatively high TCR expression levels, could have double-edged sword effects, contributing to type 1 diabetes resistance at one level of T cell development, but at another actually promoting pathogenesis.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Cell Death/genetics , Cell Death/immunology , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Genetic Predisposition to Disease , H-2 Antigens/genetics , Animals , Antigens, Differentiation, T-Lymphocyte/physiology , Apoptosis/immunology , Cell Differentiation/immunology , Cell Membrane/immunology , Cell Membrane/metabolism , Cell Movement/genetics , Cell Movement/immunology , Clonal Deletion/genetics , Clonal Deletion/immunology , Clone Cells , Diabetes Mellitus, Type 1/pathology , Female , H-2 Antigens/physiology , Homeostasis/genetics , Homeostasis/immunology , Immune Tolerance/genetics , Lymphopenia/genetics , Lymphopenia/immunology , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Inbred NOD , Mice, SCID , Mice, Transgenic , Receptors, Antigen, T-Cell/biosynthesis , Thymus Gland/immunology , Thymus Gland/pathology
16.
Biochemistry ; 42(51): 15102-13, 2003 Dec 30.
Article in English | MEDLINE | ID: mdl-14690420

ABSTRACT

Threonyl-tRNA synthetase (ThrRS) must discriminate among closely related amino acids to maintain the fidelity of protein synthesis. Here, a pre-steady state kinetic analysis of the ThRS-catalyzed adenylation reaction was carried out by monitoring changes in intrinsic tryptophan fluorescence. Stopped flow fluorimetry for the forward reaction gave a saturable fluorescence quench whose apparent rate increased hyperbolically with ATP concentration, consistent with a two-step mechanism in which rapid substrate binding precedes an isomerization step. From similar experiments, the equilibrium dissociation constants for dissociation of ATP from the E.Thr complex (K(3) = 450 +/- 180 microM) and threonine from the E.ATP complex (K'(4) = 135 microM) and the forward rate constant for adenylation (k(+5) = 29 +/- 4 s(-1)) were determined. A saturable fluorescence increase accompanied the pyrophosphorolysis of the E.Thr - AMP complex, affording the dissociation constant for PP(i) (K(6) = 170 +/- 50 microM) and the reverse rate constant (k(-5) = 47 +/- 4 s(-1)). The longer side chain of beta-hydroxynorvaline increased the apparent dissociation constant (K(4[HNV]) = 6.8 +/- 2.8 mM) with only a small reduction in the forward rate (k'(+5[HNV]) = 20 +/- 3.1 s(-1)). In contrast, two nonproductive substrates, threoninol and the adenylate analogue 5'-O-[N-(L-threonyl)sulfamoyl]adenosine (Thr-AMS), exhibited linear increases in k(app) with ligand concentration, suggesting that their binding is slow relative to isomerization. The proposed mechanism is consistent with steady state kinetic parameters. The role of threonine binding loop residue Trp434 in fluorescence changes was established by mutagenesis. The combined kinetic and molecular genetic analyses presented here support the principle of induced fit in the ThrRS-catalyzed adenylation reaction, in which substrate binding drives conformational changes that orient substrates and active site groups for catalysis.


Subject(s)
Adenine Nucleotides/chemistry , Adenosine/analogs & derivatives , Escherichia coli Proteins/chemistry , Threonine-tRNA Ligase/chemistry , Threonine/chemistry , Adenosine/chemistry , Adenosine Triphosphate/chemistry , Binding Sites , Catalysis , Diphosphates/chemistry , Kinetics , Phosphorylation , Protein Conformation , Spectrometry, Fluorescence , Threonine/analogs & derivatives , Tryptophan/chemistry
17.
Ann N Y Acad Sci ; 1005: 148-56, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14679049

ABSTRACT

Recent advances in islet transplantation have enabled physicians to cure type 1 autoimmune diabetes, but at the cost of lifelong immunosuppression with its attendant side effects and long-term health risks. To eliminate the need for immunosuppression, researchers have developed methods for inducing tolerance to transplanted allografts. Tolerance-based transplantation using costimulation blockade has proven remarkably successful in many animal model systems. The most widely used animal model system for studying islet transplantation in type 1-like autoimmune diabetes is the NOD mouse. Unfortunately, this strain has proven resistant to costimulation blockade-based transplantation tolerance protocols that are successful in chemically diabetic mice given islet grafts. It has been assumed that resistance to transplantation tolerance in the NOD mouse is (1) related to autoimmunity directed against its pancreatic beta cells, (2) a consequence of that autoimmunity, and (3) under the control of the same genes that control autoimmunity. In this review, we provide arguments to challenge these assumptions. We describe a new animal model and a new conceptual framework based on data indicating that the mechanisms responsible for resistance to transplantation tolerance and beta cell autoimmunity are not identical. We believe that the recent discoveries we describe will have important implications for the development of tolerance-based transplantation therapies and their translation from the laboratory to the clinic.


Subject(s)
Immune Tolerance , Islets of Langerhans Transplantation , Islets of Langerhans/immunology , Animals , Mice , Mice, Inbred NOD
19.
J Immunol ; 171(1): 185-95, 2003 Jul 01.
Article in English | MEDLINE | ID: mdl-12816997

ABSTRACT

Curing type 1 diabetes by islet transplantation requires overcoming both allorejection and recurrent autoimmunity. This has been achieved with systemic immunosuppression, but tolerance induction would be preferable. Most islet allotransplant tolerance induction protocols have been tested in nonobese diabetic (NOD) mice, and most have failed. Failure has been attributed to the underlying autoimmunity, assuming that autoimmunity and resistance to transplantation tolerance have a common basis. Out of concern that NOD biology could be misleading in this regard, we tested the hypothesis that autoimmunity and resistance to transplantation tolerance in NOD mice are distinct phenotypes. Unexpectedly, we observed that (NOD x C57BL/6)F(1) mice, which have no diabetes, nonetheless resist prolongation of skin allografts by costimulation blockade. Further analyses revealed that the F(1) mice shared the dendritic cell maturation defects and abnormal CD4(+) T cell responses of the NOD but had lost its defects in macrophage maturation and NK cell activity. We conclude that resistance to allograft tolerance induction in the NOD mouse is not a direct consequence of overt autoimmunity and that autoimmunity and resistance to costimulation blockade-induced transplantation tolerance phenotypes in NOD mice can be dissociated genetically. The outcomes of tolerance induction protocols tested in NOD mice may not accurately predict outcomes in human subjects.


Subject(s)
Autoimmune Diseases/genetics , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Genetic Predisposition to Disease , Lymphocyte Activation/immunology , Transplantation Tolerance/genetics , Animals , Antibodies, Monoclonal/administration & dosage , Antigens, CD/biosynthesis , Autoimmune Diseases/pathology , B7-2 Antigen , Bone Marrow Cells/immunology , Bone Marrow Cells/pathology , CD4-CD8 Ratio , CD40 Antigens/immunology , CD40 Ligand/immunology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/pathology , Cell Adhesion/genetics , Cell Adhesion/immunology , Cell Count , Cell Differentiation/genetics , Cell Differentiation/immunology , Cells, Cultured , Crosses, Genetic , Cytotoxicity, Immunologic/genetics , Dendritic Cells/immunology , Dendritic Cells/pathology , Diabetes Mellitus, Type 1/pathology , Female , Genetic Markers , Graft Survival/genetics , Graft Survival/immunology , Homozygote , Immunity, Innate/genetics , Injections, Intravenous , Killer Cells, Natural/immunology , Killer Cells, Natural/pathology , Lymphocyte Transfusion , Lymphopenia/genetics , Lymphopenia/immunology , Lymphopenia/pathology , Macrophages/cytology , Macrophages/immunology , Male , Membrane Glycoproteins/biosynthesis , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Inbred NOD , Mice, Knockout , Receptors, Interleukin-2/biosynthesis , Skin Transplantation/immunology
20.
Diabetes ; 52(5): 1119-27, 2003 May.
Article in English | MEDLINE | ID: mdl-12716741

ABSTRACT

Genes in the early region 3 (E3) of the adenovirus genome allow the virus to evade host immune responses by interfering with major histocompatibility (MHC) class I-mediated antigen presentation and tumor necrosis factor-alpha (TNF-alpha)- or Fas-induced apoptosis of infected cells. Autoimmune type 1 diabetes (T1D) is inhibited in NOD mice transgenically expressing all E3 genes under control of a rat insulin promoter (RIPE3/NOD). For dissecting the protective mechanisms afforded by various E3 genes, they were subdivided into RIP-driven transgene constructs. Strong T1D protection mediated at the beta-cell level characterized DL704/NOD mice lacking the E3 gp19K gene suppressing MHC class I expression but retaining the 10.4K, 14.5K, and 14.7K genes inhibiting Fas- or TNF-alpha-induced apoptosis and TNF-alpha-induced NF-kB activation. Much weaker protection characterized DL309/NOD mice expressing the gp19K but not the 10.4K, 14.5K, and 14.7K genes. While RIPE3/NOD splenocytes had an unexpected decrease in ability to adoptively transfer T1D, splenocytes from both the DL704 and DL309 stocks efficiently did so. These findings indicate that all E3 genes must be expressed to inhibit the diabetogenic potential of NOD immune cells. They also demonstrate that the antiapoptotic E3 genes most effectively protect pancreatic beta-cells from diabetogenic immune responses.


Subject(s)
Adenoviridae/genetics , Diabetes Mellitus, Type 1/prevention & control , Diabetes Mellitus, Type 1/virology , Genome, Viral , Animals , Bone Marrow Cells/pathology , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , Female , Insulin/genetics , Major Histocompatibility Complex , Male , Mice , Mice, Inbred NOD , Molecular Weight , Promoter Regions, Genetic , Rats , Viral Proteins/genetics
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