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1.
Arthritis Rheumatol ; 76(6): 823-835, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38229482

ABSTRACT

Systemic lupus erythematosus (SLE) is three times more common and its manifestations are more severe in African American women compared to women of other races. It is not clear whether this is due to genetic differences or factors related to the physical or social environments, differences in health care, or a combination of these factors. Health disparities in patients with SLE between African American patients and persons of other races have been reported since the 1960s and are correlated with measures of lower socioeconomic status. Risk factors for these disparities have been demonstrated, but whether their mitigation improves outcomes for African American patients has not been tested except in self-efficacy. In 2002, the first true US population-based study of patients with SLE with death certificate records was conducted, which demonstrated a wide disparity between the number of African American women and White women dying from SLE. Five years ago, another study showed that SLE mortality rates in the United States had improved but that the African American patient mortality disparity persisted. Between 2014 and 2021, one study demonstrated racism's deleterious effects in patients with SLE. Racism may have been the unmeasured confounder, the proverbial "elephant in the room"-unnamed and unstudied. The etymology of "risk factor" has evolved from environmental risk factors to social determinants to now include structural injustice/structural racism. Racism in the United States has a centuries-long existence and is deeply ingrained in US society, making its detection and resolution difficult. However, racism being man made means Man can choose to change the it. Health disparities in patients with SLE should be addressed by viewing health care as a basic human right. We offer a conceptual framework and goals for both individual and national actions.


Subject(s)
Black or African American , Healthcare Disparities , Lupus Erythematosus, Systemic , Humans , Lupus Erythematosus, Systemic/ethnology , United States/epidemiology , Healthcare Disparities/ethnology , Female , Health Status Disparities , Racism , Risk Factors
2.
PLoS One ; 18(12): e0295067, 2023.
Article in English | MEDLINE | ID: mdl-38091326

ABSTRACT

Few areas within the Great Lakes basin are currently free from impact of human activities, and it is important to study these reference conditions for comparison with degraded sites in those regions. Here, we use radio telemetry to investigate habitat use, movement, and habitat selection of a population of the endangered (Federally in Canada) Blanding's turtle (Emydoidea blandingii, BLTU) inhabiting a mostly undisturbed archipelago located at the northern shore of Mnidoo gamii (Georgian Bay), Ontario over two active seasons (May to September 2021 and 2022). We found a mean home range of 16.21 ha for females (n = 7) and 15.10 ha for males (n = 7). Of the five habitat classes (Marsh, Open Water, Rock, Peatland, and Forest), females used all except Peatland during the nesting season, and both sexes used all five habitat classes throughout both active seasons in 2021 and 2022. Disproportionate habitat use was detected at the landscape scale but not at the home range scale which was consistent with the hypothesis that adult Blanding's turtles residing in relatively undisturbed sites with abundant habitat types use all habitat types according to their availability. We also observed the use of open, deep water by Blanding's Turtles as travel corridors for nesting and mating. Effective future conservation strategies should prioritize the protection and connectivity of relatively undisturbed wetlands, forests, and rock barrens in this region and use this study as a reference condition to compare BLTU habitat use and movement across disturbance gradients within Georgian Bay.


Subject(s)
Bays , Turtles , Animals , Female , Male , Ecosystem , Ontario , Water , Telemetry , Animal Migration
4.
Genet Med ; 23(8): 1543-1550, 2021 08.
Article in English | MEDLINE | ID: mdl-33875845

ABSTRACT

PURPOSE: To assess olipudase alfa enzyme replacement therapy for non-central nervous system manifestations of acid sphingomyelinase deficiency (ASMD) in children. METHODS: This phase 1/2, international, multicenter, open-label trial (ASCEND-Peds/NCT02292654) administered intravenous olipudase alfa every 2 weeks with intrapatient dose escalation to 3 mg/kg. Primary outcome was safety through week 64. Secondary outcomes included pharmacokinetics, spleen and liver volumes, lung diffusing capacity (DLCO), lipid profiles, and height through week 52. RESULTS: Twenty patients were enrolled: four adolescents (12-17 years), nine children (6-11 years), and seven infants/early child (1-5 years). Most adverse events were mild or moderate, including infusion-associated reactions (primarily urticaria, pyrexia, and/or vomiting) in 11 patients. Three patients had serious treatment-related events: one with transient asymptomatic alanine aminotransferase increases, another with urticaria and rash (antidrug antibody positive [ADA+]), and a third with an anaphylactic reaction (ADA+) who underwent desensitization and reached the 3 mg/kg maintenance dose. Mean splenomegaly and hepatomegaly improved by >40% (p < 0.0001). Mean % predicted DLCO improved by 32.9% (p = 0.0053) in patients able to perform the test. Lipid profiles and elevated liver transaminase levels normalized. Mean height Z-scores improved by 0.56 (p < 0.0001). CONCLUSION: In this study in children with chronic ASMD, olipudase alfa was generally well-tolerated with significant, comprehensive improvements in disease pathology across a range of clinically relevant endpoints.


Subject(s)
Niemann-Pick Disease, Type A , Adolescent , Child , Child, Preschool , Enzyme Replacement Therapy , Humans , Infant , Liver , Niemann-Pick Disease, Type A/drug therapy , Niemann-Pick Disease, Type A/genetics , Recombinant Proteins/therapeutic use , Sphingomyelin Phosphodiesterase/genetics
5.
Ecol Evol ; 9(17): 9794-9803, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31534694

ABSTRACT

Roads are one of the most widespread human-caused habitat modifications that can increase wildlife mortality rates and alter behavior. Roads can act as barriers with variable permeability to movement and can increase distances wildlife travel to access habitats. Movement is energetically costly, and avoidance of roads could therefore impact an animal's energy budget. We tested whether reptiles avoid roads or road crossings and explored whether the energetic consequences of road avoidance decreased individual fitness. Using telemetry data from Blanding's turtles (Emydoidea blandingii; 11,658 locations of 286 turtles from 15 sites) and eastern massasaugas (Sistrurus catenatus; 1,868 locations of 49 snakes from 3 sites), we compared frequency of observed road crossings and use of road-adjacent habitat by reptiles to expected frequencies based on simulated correlated random walks. Turtles and snakes did not avoid habitats near roads, but both species avoided road crossings. Compared with simulations, turtles made fewer crossings of paved roads with low speed limits and more crossings of paved roads with high speed limits. Snakes made fewer crossings of all road types than expected based on simulated paths. Turtles traveled longer daily distances when their home range contained roads, but the predicted energetic cost was negligible: substantially less than the cost of producing one egg. Snakes with roads in their home range did not travel further per day than snakes without roads in their home range. We found that turtles and snakes avoided crossing roads, but road avoidance is unlikely to impact fitness through energetic expenditures. Therefore, mortality from vehicle strikes remains the most significant impact of roads on reptile populations.

6.
Environ Monit Assess ; 191(9): 597, 2019 Aug 28.
Article in English | MEDLINE | ID: mdl-31463617

ABSTRACT

Long-term monitoring programs can identify environmental trends or reveal limitations to protocols, as long as their results are analysed appropriately. While monitoring programs are not necessarily hypothesis-driven, their data are important for conservation and can guide improvements to monitoring programs. Here, we present a case study using dynamic occupancy models to guide the optimization of time and effort in a long-term terrestrial salamander monitoring program. To ensure a detailed analysis, we analysed the available long-term data to first identify estimates of occupancy and detection parameters for the salamanders. Using these estimates, we created simulations to identify the optimal number of years for monitoring and the optimal allocation of spatial and temporal survey replicates. Our data support previous claims that monitoring programs should be allowed to run for at least a decade. We also found that in order to obtain accurate estimates of species occupancy, programs should consider appropriate partitioning of monitoring effort across spatial and temporal scales. We show how analyses of long-term monitoring datasets are valuable not only for trend detection but also for the development of templates to guide the design and optimization of similar programs.


Subject(s)
Environmental Monitoring/methods , Urodela/growth & development , Animals , Population Density , Population Surveillance
7.
Dis Aquat Organ ; 132(3): 221-227, 2019 Jan 24.
Article in English | MEDLINE | ID: mdl-31188138

ABSTRACT

An adult male snapping turtle with marked palpebral edema and multifocal skin ulceration was found alive in a marsh in southern Ontario in summer 2017. The turtle was transported to a rehabilitation facility and died 4 d after arrival. The carcass was submitted to the Canadian Wildlife Health Cooperative for post-mortem examination. Gross lesions included ulcerative conjunctivitis, necrotizing stomatitis, and splenomegaly. Microscopically, this corresponded to multisystemic fibrinonecrotizing vasculitis and severe fibrinous splenic necrosis. Liver tissue tested positive for frog virus 3-like ranavirus and negative for herpesvirus via polymerase chain reaction. The gross and microscopic lesions were consistent with previous reports of ranavirus infection in turtles and were severe enough to have been the cause of death in this case. This is the first report of morbidity and mortality in a common snapping turtle with a ranavirus infection, and the first reported case of ranavirus infection in a reptile in Canada. Ranaviruses are considered to be an emerging infectious disease in chelonians as they are increasing in distribution, prevalence, and host range.


Subject(s)
Ranavirus , Animals , Animals, Wild , Canada , Male , Reptiles
8.
J Environ Manage ; 234: 357-366, 2019 Mar 15.
Article in English | MEDLINE | ID: mdl-30639859

ABSTRACT

Eutrophication from agricultural runoff is a global problem, often resulting in formation of anoxic zones in receiving water bodies. The Nottawasaga River Watershed (NRW) is dominated by agricultural land-use, and drains into Nottawasaga Bay, Georgian Bay (Lake Huron). A fundamental feature of the NRW is the Minesing Wetlands, a Ramsar site and the largest inland wetland in southern Ontario. We used total phosphorus (TP) concentration-discharge relationships to estimate annual loading from six sub-watersheds and compared these against published models, which did not offer a way to account for the unique properties of the Minesing Wetlands. We developed predictive loading models specifically for the NRW to account for these characteristics, which accurately predict daily summer base-flow TP (r2 = 0.76, p = <0.0001) and total suspended solids (TSS; r2 = 0.65, p = <0.0001) loads for 11 subwatersheds using geomorphic and land-cover variables. Drainage area and % pasture land were the most significant predictive variables driving spatial variability in TP and TSS loading rates among subwatersheds. The positive relationship between TP and % wetland (r2 = 0.22, p = 0.0063) also suggested that the Minesing Wetlands are a source of nutrients to the Nottawasaga River. Watershed geomorphology (e.g. slope) was a good predictor of land cover, and produced accurate loading estimates. This study is the first to offer a new approach to predict TP and TSS loading rates during the growing season using readily available geospatial data.


Subject(s)
Phosphorus , Rivers , Environmental Monitoring , Lakes , Ontario , Wetlands
9.
PLoS One ; 13(2): e0192134, 2018.
Article in English | MEDLINE | ID: mdl-29444129

ABSTRACT

Point Pelee National Park, located at the southern-most tip of Canada's mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931-2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.


Subject(s)
Amphibians , Conservation of Natural Resources/methods , Ecosystem , Reptiles , Animals , Introduced Species , Ontario , Wetlands
10.
Arthritis Rheumatol ; 70(2): 266-276, 2018 02.
Article in English | MEDLINE | ID: mdl-29073347

ABSTRACT

OBJECTIVE: To evaluate the efficacy and safety of atacicept, an antagonist of B lymphocyte stimulator/APRIL-mediated B cell activation, in patients with systemic lupus erythematosus (SLE). METHODS: ADDRESS II is a 24-week, multicenter, randomized, double-blind, placebo-controlled, parallel-arm, phase IIb study evaluating the safety and efficacy of atacicept in patients with SLE (ClinicalTrials.gov identifier NCT01972568). Patients with active, autoantibody-positive SLE receiving standard therapy were randomized (1:1:1) to receive atacicept (75 mg or 150 mg) or placebo for 24 weeks. The primary end point was the SLE responder index 4 (SRI-4) at week 24. RESULTS: The intent-to-treat (ITT) population included 306 patients. There was a trend toward an improved SRI-4 response rate with atacicept 75 mg (57.8%; adjusted odds ratio [OR] 1.78, P = 0.045) and 150 mg (53.8%; adjusted OR 1.56, P = 0.121) at week 24 as compared with placebo (44.0%) (primary analysis; using the screening visit as baseline). In a prespecified sensitivity analysis using study day 1 as baseline, a significantly larger proportion of patients receiving atacicept 75 mg and 150 mg achieved an SRI-4 response at week 24 compared with placebo. In predefined subpopulations with high levels of disease activity (HDA) at baseline, serologically active disease, or both, statistically significant improvements in the SRI-4 and SRI-6 response rates were seen with atacicept versus placebo. A severe risk of disease flare was reduced with atacicept therapy in both the ITT and the HDA populations. The risks of serious adverse events and serious or severe infection were not increased with atacicept as compared with placebo. CONCLUSION: Atacicept treatment showed evidence of efficacy in SLE, particularly in HDA and serologically active patients. Reductions in disease activity and severe flare were observed with atacicept treatment, with an acceptable safety profile.


Subject(s)
B-Cell Activating Factor/antagonists & inhibitors , Lupus Erythematosus, Systemic/drug therapy , Recombinant Fusion Proteins/therapeutic use , Tumor Necrosis Factor Ligand Superfamily Member 13/antagonists & inhibitors , Adult , Biomarkers/blood , Double-Blind Method , Female , Glucocorticoids/administration & dosage , Humans , Male , Middle Aged , Recombinant Fusion Proteins/adverse effects , Severity of Illness Index , Treatment Outcome
11.
Hum Genet ; 130(6): 807-15, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21695597

ABSTRACT

The major histocompatibility complex (MHC) on chromosome 6p21 is a key contributor to the genetic basis of systemic lupus erythematosus (SLE). Although SLE affects African Americans disproportionately compared to European Americans, there has been no comprehensive analysis of the MHC region in relationship to SLE in African Americans. We conducted a screening of the MHC region for 1,536 single nucleotide polymorphisms (SNPs) and the deletion of the C4A gene in a SLE case-control study (380 cases, 765 age-matched controls) nested within the prospective Black Women's Health Study. We also genotyped 1,509 ancestral informative markers throughout the genome to estimate European ancestry to control for population stratification due to population admixture. The most strongly associated SNP with SLE was the rs9271366 (odds ratio, OR = 1.70, p = 5.6 × 10(-5)) near the HLA-DRB1 gene. Conditional haplotype analysis revealed three other SNPs, rs204890 (OR = 1.86, p = 1.2 × 10(-4)), rs2071349 (OR = 1.53, p = 1.0 × 10(-3)), and rs2844580 (OR = 1.43, p = 1.3 × 10(-3)), to be associated with SLE independent of the rs9271366 SNP. In univariate analysis, the OR for the C4A deletion was 1.38, p = 0.075, but after simultaneous adjustment for the other four SNPs the odds ratio was 1.01, p = 0.98. A genotype score combining the four newly identified SNPs showed an additive risk according to the number of high-risk alleles (OR = 1.67 per high-risk allele, p < 0.0001). Our strongest signal, the rs9271366 SNP, was also associated with higher risk of SLE in a previous Chinese genome-wide association study (GWAS). In addition, two SNPs found in a GWAS of European ancestry women were confirmed in our study, indicating that African Americans share some genetic risk factors for SLE with European and Chinese subjects. In summary, we found four independent signals in the MHC region associated with risk of SLE in African American women.


Subject(s)
Lupus Erythematosus, Systemic/genetics , Lupus Erythematosus, Systemic/immunology , Major Histocompatibility Complex/genetics , Adult , Black or African American , Alleles , Asian People , Case-Control Studies , Complement C4a/genetics , Female , Genetic Predisposition to Disease , Genotype , Haplotypes , Humans , Lupus Erythematosus, Systemic/ethnology , Odds Ratio , Polymorphism, Single Nucleotide , Prospective Studies , Risk Factors , White People
12.
Arthritis Care Res (Hoboken) ; 62(4): 559-68, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20391512

ABSTRACT

OBJECTIVE: The Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) is a validated instrument for assessing organ damage in systemic lupus erythematosus (SLE). Trained physicians must complete it, thus limiting utility where this is impossible. METHODS: We developed and pilot tested a self-assessed organ damage instrument, the Lupus Damage Index Questionnaire (LDIQ), in 37 SLE subjects and 7 physicians. After refinement, 569 English-speaking SLE subjects and 14 rheumatologists from 11 international SLE clinics participated in validation. Subjects and physicians completed the instruments separately. We calculated sensitivity, specificity, Spearman's correlations, and agreement using the SDI as the gold standard. Six hundred five SLE participants in the community-based National Data Bank for Rheumatic Diseases (NDB) study completed the LDIQ and we assessed correlations with outcome and disability measures. RESULTS: The mean LDIQ score was 3.3 (range 0-16) and the mean SDI score was 1.5 (range 0-9). The LDIQ had a moderately high correlation with the SDI (Spearman's r = 0.50, P < 0.001). Specificities of individual LDIQ items were >80%, except for neuropathy. Sensitivities were variable and lowest for damage, with <1% prevalence. Agreement between the SDI and LDIQ was >85% for all but neuropathy, reduced renal function, deforming arthritis, and alopecia. In the NDB, the LDIQ correlated well with the comorbidity index (r = 0.45), the Short Form 36 physical component scale (r = 0.43), the Medical Research Council dyspnea scale (r = 0.40), disability (r = 0.37), and the Systemic Lupus Erythematosus Activity Questionnaire score (r = 0.37). CONCLUSION: The metric properties of the LDIQ are good compared with the SDI. It has construct validity and correlations with health assessments similar to the SDI. The LDIQ should allow expansion of SLE research. Its ultimate value will be determined in longitudinal studies.


Subject(s)
Lupus Erythematosus, Systemic/diagnosis , Severity of Illness Index , Surveys and Questionnaires , Adult , Aged , Female , Humans , Lupus Erythematosus, Systemic/complications , Male , Middle Aged , Quality of Life , Sensitivity and Specificity
13.
Environ Manage ; 45(5): 1040-51, 2010 May.
Article in English | MEDLINE | ID: mdl-20358198

ABSTRACT

Over the next half century the human population is expected to grow rapidly, resulting in the conversion of rural areas into cities. Wetlands in these regions are therefore under threat, even though they have important ecosystem services and functions. Many obligate marsh-nesting birds in North America have shown declines over the past 40 years, and it is important to evaluate marsh bird community response to increased urbanization. We surveyed 20 coastal marshes in southern Ontario, Canada, and found that obligate marsh-nesting birds preferred rural over urban wetlands, generalist marsh-nesting birds showed no preference, while synanthropic species showed a trend towards increased richness and abundance in urban marshes. The Index of Marsh Bird Community Integrity (IMBCI) was calculated for each wetland and we found significantly higher scores in rural compared to urban wetlands. The presence of a forested buffer surrounding the marsh was not an important factor in predicting the distribution of generalists, obligates, synanthropic species, or the IMBCI. More isolated marshes had a lower species richness of obligate marsh-nesters and a lower IMBCI than less isolated marshes. Based on our results, we recommend that urban land use is not the dominant land use within 1000 m from any wetland, as it negatively affects the abundance and richness of obligate marsh-nesters, and the overall integrity of the avian community. We also recommend that all existing wetlands be conserved to mitigate against isolation effects and to preserve biodiversity.


Subject(s)
Birds/growth & development , Conservation of Natural Resources/methods , Environmental Monitoring/methods , Urbanization , Wetlands , Animals , Conservation of Natural Resources/statistics & numerical data , Environmental Monitoring/statistics & numerical data , Geographic Information Systems , Ontario , Population Dynamics
14.
Environ Manage ; 44(3): 456-67, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19597867

ABSTRACT

We used a GIS-based approach to examine the influence of road density and physical watershed features (watershed size, wetland cover, and bedrock type) on water quality in coastal marshes of Georgian Bay, Ontario. We created a GIS that included landscape information and water-quality data from a 9-year synoptic survey of 105 coastal marshes covering 28 quaternary watersheds. Multiple regressions and partial correlations were used to discern confounding effects of human-induced (road density) versus natural physical watershed determinants of water quality. Road density was the dominant factor influencing many water quality variables, showing positive correlations with specific conductivity (COND), total suspended solids (TSS), and inorganic suspended solids (ISS) and a negative correlation with overall Water Quality Index scores. Road density also showed positive correlations with total nitrate nitrogen (TNN) and total phosphorus (TP). By comparison, larger watershed area was the main factor leading to elevated TP concentrations. The proportion of the watershed occupied by wetlands explained the largest amount of variation in TNN concentrations (negative correlation) and was also negatively correlated with COND and positively correlated with TSS and ISS when we controlled for road density. Bedrock type did not have a significant effect in any of the models. Our findings suggest that road density is currently the overriding factor governing water quality of coastal marshes in Georgian Bay during the summer low-flow period. We recommend that natural variation in physical watershed characteristics be considered when developing water quality standards and management practices for freshwater coastal areas.


Subject(s)
Environmental Monitoring , Water Pollutants/analysis , Wetlands , Automobiles , Environment Design , Geographic Information Systems , Humans , Ontario , Water Movements
15.
Arthritis Res Ther ; 11(3): R97, 2009.
Article in English | MEDLINE | ID: mdl-19555469

ABSTRACT

INTRODUCTION: Rheumatoid arthritis (RA) is more common in females than males and sex steroid hormones may in part explain this difference. We conducted a case-control study nested within two prospective studies to determine the associations between plasma steroid hormones measured prior to RA onset and polymorphisms in the androgen receptor (AR), estrogen receptor 2 (ESR2), aromatase (CYP19) and progesterone receptor (PGR) genes and RA risk. METHODS: We genotyped AR, ESR2, CYP19, PGR SNPs and the AR CAG repeat in RA case-control studies nested within the Nurses' Health Study (NHS), NHS II (449 RA cases, 449 controls) and the Women's Health Study (72 cases, and 202 controls). All controls were matched on cohort, age, Caucasian race, menopausal status, and postmenopausal hormone use. We measured plasma dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone binding globulin in 132 pre-RA samples and 396 matched controls in the NHS cohorts. We used conditional logistic regression models adjusted for potential confounders to assess RA risk. RESULTS: Mean age of RA diagnosis was 55 years in both cohorts; 58% of cases were rheumatoid factor positive at diagnosis. There was no significant association between plasma DHEAS, total testosterone, or calculated free testosterone and risk of future RA. There was no association between individual variants or haplotypes in any of the genes and RA or seropositive RA, nor any association for the AR CAG repeat. CONCLUSIONS: Steroid hormone levels measured at a single time point prior to RA onset were not associated with RA risk in this study. Our findings do not suggest that androgens or the AR, ESR2, PGR, and CYP19 genes are important to RA risk in women.


Subject(s)
Androgens/blood , Androgens/genetics , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/genetics , Adult , Aged , Arthritis, Rheumatoid/epidemiology , Case-Control Studies , Cohort Studies , Double-Blind Method , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pilot Projects , Polymorphism, Genetic/genetics , Prospective Studies , Receptors, Androgen/blood , Receptors, Androgen/genetics , Risk Factors
16.
Genome Res ; 19(5): 757-69, 2009 May.
Article in English | MEDLINE | ID: mdl-19411600

ABSTRACT

Natural killer (NK) cells contribute to the essential functions of innate immunity and reproduction. Various genes encode NK cell receptors that recognize the major histocompatibility complex (MHC) Class I molecules expressed by other cells. For primate NK cells, the killer-cell immunoglobulin-like receptors (KIR) are a variable and rapidly evolving family of MHC Class I receptors. Studied here is KIR3DL1/S1, which encodes receptors for highly polymorphic human HLA-A and -B and comprises three ancient allelic lineages that have been preserved by balancing selection throughout human evolution. While the 3DS1 lineage of activating receptors has been conserved, the two 3DL1 lineages of inhibitory receptors were diversified through inter-lineage recombination with each other and with 3DS1. Prominent targets for recombination were D0-domain polymorphisms, which modulate enhancer function, and dimorphism at position 283 in the D2 domain, which influences inhibitory function. In African populations, unequal crossing over between the 3DL1 and 3DL2 genes produced a deleted KIR haplotype in which the telomeric "half" was reduced to a single fusion gene with functional properties distinct from its 3DL1 and 3DL2 parents. Conversely, in Eurasian populations, duplication of the KIR3DL1/S1 locus by unequal crossing over has enabled individuals to carry and express alleles of all three KIR3DL1/S1 lineages. These results demonstrate how meiotic recombination combines with an ancient, preserved diversity to create new KIR phenotypes upon which natural selection acts. A consequence of such recombination is to blur the distinction between alleles and loci in the rapidly evolving human KIR gene family.


Subject(s)
Alleles , Genetic Variation/genetics , Haplotypes/genetics , Meiosis/genetics , Receptors, Natural Killer Cell/genetics , Recombination, Genetic/genetics , Amino Acid Sequence , Cell Line , Evolution, Molecular , Humans , Models, Genetic , Molecular Sequence Data , Phenotype , Receptors, KIR/genetics , Receptors, KIR3DL1/genetics
17.
PLoS One ; 3(2): e1576, 2008 Feb 13.
Article in English | MEDLINE | ID: mdl-18270567

ABSTRACT

Classically, HLA-DR expressed on antigen presenting cells (APC) initiates lymphocyte activation via presentation of peptides to TCR bearing CD4+ T-Cells. Here we demonstrate that HLA-DR alpha 2 domain (sHLA-DRalpha2) also induces negative signals by engaging TIRC7 on lymphocytes. This interaction inhibits proliferation and induces apoptosis in CD4+ and CD8+ T-cells via activation of the intrinsic pathway. Proliferation inhibition is associated with SHP-1 recruitment by TIRC7, decreased phosphorylation of STAT4, TCR-zeta chain & ZAP70, and inhibition of IFN-gamma and FasL expression. HLA-DRalpha2 and TIRC7 co-localize at the APC-T cell interaction site. Triggering HLA-DR - TIRC7 pathway demonstrates that sHLA-DRalpha2 treatment inhibits proinflammatory-inflammatory cytokine expression in APC & T cells after lipopolysaccaride (LPS) stimulation in vitro and induces apoptosis in vivo. These results suggest a novel antiproliferative role for HLA-DR mediated via TIRC7, revise the notion of an exclusive stimulatory interaction of HLA-DR with CD4+ T cells and highlights a novel physiologically relevant regulatory pathway.


Subject(s)
Apoptosis , HLA-DR Antigens/metabolism , Inflammation/immunology , Lymphocytes/immunology , Signal Transduction , Vacuolar Proton-Translocating ATPases/metabolism , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , Cell Proliferation , Cells, Cultured , Humans , Lymphocytes/cytology
18.
Nat Genet ; 39(9): 1092-9, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17694054

ABSTRACT

Interactions of killer cell immunoglobulin-like receptors (KIRs) with major histocompatibility complex (MHC) class I ligands diversify natural killer cell responses to infection. By analyzing sequence variation in diverse human populations, we show that the KIR3DL1/S1 locus encodes two lineages of polymorphic inhibitory KIR3DL1 allotypes that recognize Bw4 epitopes of protein">HLA-A and HLA-B and one lineage of conserved activating KIR3DS1 allotypes, also implicated in Bw4 recognition. Balancing selection has maintained these three lineages for over 3 million years. Variation was selected at D1 and D2 domain residues that contact HLA class I and at two sites on D0, the domain that enhances the binding of KIR3D to HLA class I. HLA-B variants that gained Bw4 through interallelic microconversion are also products of selection. A worldwide comparison uncovers unusual KIR3DL1/S1 evolution in modern sub-Saharan Africans. Balancing selection is weak and confined to D0, KIR3DS1 is rare and KIR3DL1 allotypes with similar binding sites predominate. Natural killer cells express the dominant KIR3DL1 at a high frequency and with high surface density, providing strong responses to cells perturbed in Bw4 expression.


Subject(s)
Black People/genetics , Receptors, KIR3DL1/genetics , Receptors, KIR3DS1/genetics , Selection, Genetic , Alleles , Amino Acid Sequence , Binding Sites/genetics , Gene Frequency , Genetics, Population , HLA-B Antigens/chemistry , HLA-B Antigens/genetics , Humans , Linkage Disequilibrium , Molecular Sequence Data , Phylogeny , Polymorphism, Genetic , Protein Structure, Tertiary , Receptors, KIR3DL1/chemistry , Receptors, KIR3DS1/chemistry , Sequence Homology, Amino Acid
19.
Arthritis Rheum ; 56(1): 244-54, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17195228

ABSTRACT

OBJECTIVE: The high prevalence of systemic lupus erythematosus (SLE) among African American women may be due to environmental exposures, genetic factors, or a combination of factors. Our goal was to assess association of residential proximity to hazardous waste sites and genetic variation in 3 glutathione Stransferase (GST) genes (GSTM1, GSTT1, and GSTP1) with age at diagnosis of SLE. METHODS: Residential histories were obtained by interviewing 93 SLE patients from 3 predominantly African American neighborhoods in Boston. Residential addresses and locations of 416 hazardous waste sites in the study area were geocoded using ArcView software. Time-varying Cox models were used to study the effect of residential proximity to hazardous sites, GST genotype, and interaction between genotype and exposure in determining age at diagnosis. RESULTS: The prevalence of SLE among African American women in these neighborhoods was 3.56 SLE cases per 1,000. Homozygosity for GSTM1-null and GSTP1 Ile105Val in combination was associated with earlier SLE diagnosis (P = 0.03), but there was no association with proximity to 416 hazardous sites. Available data on specific site contaminants suggested that, at a subset of 67 sites, there was higher potential risk for exposure to volatile organic compounds (P < 0.05 with Bonferroni correction). GST genotypes had a significant interaction with proximity (P = 0.03) in analyses limited to these sites. CONCLUSION: There was no independent association between residential proximity to hazardous waste sites and the risk of earlier SLE diagnosis in this urban population. However, analysis of a limited number of sites indicated that the risk of earlier SLE associated with proximity to hazardous sites might be modulated by GST polymorphisms.


Subject(s)
Environmental Exposure/adverse effects , Genetic Predisposition to Disease , Glutathione Transferase/genetics , Hazardous Waste/adverse effects , Lupus Erythematosus, Systemic , Polymorphism, Genetic , Adolescent , Adult , Black or African American/ethnology , Black or African American/statistics & numerical data , Aged , Boston/epidemiology , Female , Genotype , Humans , Lupus Erythematosus, Systemic/enzymology , Lupus Erythematosus, Systemic/ethnology , Lupus Erythematosus, Systemic/genetics , Middle Aged , Proportional Hazards Models , Risk Factors , Time Factors
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