The Experts below are selected from a list of 119010 Experts worldwide ranked by ideXlab platform
Ericka L Anderson - One of the best experts on this subject based on the ideXlab platform.
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recurrent group a streptococcus tonsillitis is an immunosusceptibility Disease involving antibody deficiency and aberrant tfh cells
Science Translational Medicine, 2019Co-Authors: Jennifer M Dan, Colin Havenardaughton, Kayla Kendric, Rita Alkolla, Kirti Kaushik, Sandy L Rosales, Ericka L AndersonAbstract:"Strep throat" is highly prevalent among children, yet it is unknown why only some children develop recurrent tonsillitis (RT), a common indication for tonsillectomy. To gain insights into this classic Childhood Disease, we performed phenotypic, genotypic, and functional studies on pediatric group A Streptococcus (GAS) RT and non-RT tonsils from two independent cohorts. GAS RT tonsils had smaller germinal centers, with an underrepresentation of GAS-specific CD4+ germinal center T follicular helper (GC-TFH) cells. RT children exhibited reduced antibody responses to an important GAS virulence factor, streptococcal pyrogenic exotoxin A (SpeA). Risk and protective human leukocyte antigen (HLA) class II alleles for RT were identified. Lastly, SpeA induced granzyme B production in GC-TFH cells from RT tonsils with the capacity to kill B cells and the potential to hobble the germinal center response. These observations suggest that RT is a multifactorial Disease and that contributors to RT susceptibility include HLA class II differences, aberrant SpeA-activated GC-TFH cells, and lower SpeA antibody titers.
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evidence that recurrent group a streptococcus tonsillitis is an immunosusceptibility Disease involving antibody deficiency and aberrant tfh cells
bioRxiv, 2018Co-Authors: Jennifer M Dan, Colin Havenardaughton, Kayla Kendric, Kirti Kaushik, Sandy L Rosales, Ericka L Anderson, Christopher N Larock, Pandurangan Vijayanand, Gregory SeumoisAbstract:Recurrent Group A Streptococcus (GAS) tonsillitis (RT) is a common indication for pediatric tonsillectomy. Strep throat is highly prevalent among children; yet, it is unknown why some children develop RT. To gain insights into this classic Childhood Disease, we performed phenotypic, genotypic, and functional studies on pediatric GAS RT and non-RT tonsils. We observed significantly smaller germinal centers in GAS RT tonsils, and underrepresentation of GAS-specific germinal center follicular helper (GC Tfh) CD4+ T cells. RT children exhibited reduced antibody responses to GAS virulence factor SpeA. Risk and protective HLA Class II alleles for RT were identified. Finally, SpeA induced granzyme B+ GC Tfh cells in RT tonsils that had capacity to kill B cells. Together, these observations suggest that RT susceptibility can occur due to genetic differences that can result in aberrant GC Tfh cells and poor antibody responses to GAS SpeA.
Jennifer M Dan - One of the best experts on this subject based on the ideXlab platform.
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recurrent group a streptococcus tonsillitis is an immunosusceptibility Disease involving antibody deficiency and aberrant tfh cells
Science Translational Medicine, 2019Co-Authors: Jennifer M Dan, Colin Havenardaughton, Kayla Kendric, Rita Alkolla, Kirti Kaushik, Sandy L Rosales, Ericka L AndersonAbstract:"Strep throat" is highly prevalent among children, yet it is unknown why only some children develop recurrent tonsillitis (RT), a common indication for tonsillectomy. To gain insights into this classic Childhood Disease, we performed phenotypic, genotypic, and functional studies on pediatric group A Streptococcus (GAS) RT and non-RT tonsils from two independent cohorts. GAS RT tonsils had smaller germinal centers, with an underrepresentation of GAS-specific CD4+ germinal center T follicular helper (GC-TFH) cells. RT children exhibited reduced antibody responses to an important GAS virulence factor, streptococcal pyrogenic exotoxin A (SpeA). Risk and protective human leukocyte antigen (HLA) class II alleles for RT were identified. Lastly, SpeA induced granzyme B production in GC-TFH cells from RT tonsils with the capacity to kill B cells and the potential to hobble the germinal center response. These observations suggest that RT is a multifactorial Disease and that contributors to RT susceptibility include HLA class II differences, aberrant SpeA-activated GC-TFH cells, and lower SpeA antibody titers.
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evidence that recurrent group a streptococcus tonsillitis is an immunosusceptibility Disease involving antibody deficiency and aberrant tfh cells
bioRxiv, 2018Co-Authors: Jennifer M Dan, Colin Havenardaughton, Kayla Kendric, Kirti Kaushik, Sandy L Rosales, Ericka L Anderson, Christopher N Larock, Pandurangan Vijayanand, Gregory SeumoisAbstract:Recurrent Group A Streptococcus (GAS) tonsillitis (RT) is a common indication for pediatric tonsillectomy. Strep throat is highly prevalent among children; yet, it is unknown why some children develop RT. To gain insights into this classic Childhood Disease, we performed phenotypic, genotypic, and functional studies on pediatric GAS RT and non-RT tonsils. We observed significantly smaller germinal centers in GAS RT tonsils, and underrepresentation of GAS-specific germinal center follicular helper (GC Tfh) CD4+ T cells. RT children exhibited reduced antibody responses to GAS virulence factor SpeA. Risk and protective HLA Class II alleles for RT were identified. Finally, SpeA induced granzyme B+ GC Tfh cells in RT tonsils that had capacity to kill B cells. Together, these observations suggest that RT susceptibility can occur due to genetic differences that can result in aberrant GC Tfh cells and poor antibody responses to GAS SpeA.
Pejman Rohani - One of the best experts on this subject based on the ideXlab platform.
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human birth seasonality latitudinal gradient and interplay with Childhood Disease dynamics
Proceedings of The Royal Society B: Biological Sciences, 2014Co-Authors: Micaela Martinezbakker, Kevin M Bakker, Aaron A King, Pejman RohaniAbstract:More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious Disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on Childhood Disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.
Kevin M Bakker - One of the best experts on this subject based on the ideXlab platform.
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digital epidemiology reveals global Childhood Disease seasonality and the effects of immunization
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Kevin M Bakker, Micaela Martinezbakker, Barbara Helm, Tyler J StevensonAbstract:Public health surveillance systems are important for tracking Disease dynamics. In recent years, social and real-time digital data sources have provided new means of studying Disease transmission. Such affordable and accessible data have the potential to offer new insights into Disease epidemiology at national and international scales. We used the extensive information repository Google Trends to examine the digital epidemiology of a common Childhood Disease, chicken pox, caused by varicella zoster virus (VZV), over an 11-y period. We (i) report robust seasonal information-seeking behavior for chicken pox using Google data from 36 countries, (ii) validate Google data using clinical chicken pox cases, (iii) demonstrate that Google data can be used to identify recurrent seasonal outbreaks and forecast their magnitude and seasonal timing, and (iv) reveal that VZV immunization significantly dampened seasonal cycles in information-seeking behavior. Our findings provide strong evidence that VZV transmission is seasonal and that seasonal peaks show remarkable latitudinal variation. We attribute the dampened seasonal cycles in chicken pox information-seeking behavior to VZV vaccine-induced reduction of seasonal transmission. These data and the methodological approaches provide a way to track the global burden of Childhood Disease and illustrate population-level effects of immunization. The global latitudinal patterns in outbreak seasonality could direct future studies of environmental and physiological drivers of Disease transmission.
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human birth seasonality latitudinal gradient and interplay with Childhood Disease dynamics
Proceedings of The Royal Society B: Biological Sciences, 2014Co-Authors: Micaela Martinezbakker, Kevin M Bakker, Aaron A King, Pejman RohaniAbstract:More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious Disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on Childhood Disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.
Micaela Martinezbakker - One of the best experts on this subject based on the ideXlab platform.
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digital epidemiology reveals global Childhood Disease seasonality and the effects of immunization
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Kevin M Bakker, Micaela Martinezbakker, Barbara Helm, Tyler J StevensonAbstract:Public health surveillance systems are important for tracking Disease dynamics. In recent years, social and real-time digital data sources have provided new means of studying Disease transmission. Such affordable and accessible data have the potential to offer new insights into Disease epidemiology at national and international scales. We used the extensive information repository Google Trends to examine the digital epidemiology of a common Childhood Disease, chicken pox, caused by varicella zoster virus (VZV), over an 11-y period. We (i) report robust seasonal information-seeking behavior for chicken pox using Google data from 36 countries, (ii) validate Google data using clinical chicken pox cases, (iii) demonstrate that Google data can be used to identify recurrent seasonal outbreaks and forecast their magnitude and seasonal timing, and (iv) reveal that VZV immunization significantly dampened seasonal cycles in information-seeking behavior. Our findings provide strong evidence that VZV transmission is seasonal and that seasonal peaks show remarkable latitudinal variation. We attribute the dampened seasonal cycles in chicken pox information-seeking behavior to VZV vaccine-induced reduction of seasonal transmission. These data and the methodological approaches provide a way to track the global burden of Childhood Disease and illustrate population-level effects of immunization. The global latitudinal patterns in outbreak seasonality could direct future studies of environmental and physiological drivers of Disease transmission.
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human birth seasonality latitudinal gradient and interplay with Childhood Disease dynamics
Proceedings of The Royal Society B: Biological Sciences, 2014Co-Authors: Micaela Martinezbakker, Kevin M Bakker, Aaron A King, Pejman RohaniAbstract:More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious Disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on Childhood Disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.