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Gretchen E Hofmann - One of the best experts on this subject based on the ideXlab platform.
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is cold the new hot elevated ubiquitin Conjugated Protein levels in tissues of antarctic fish as evidence for cold denaturation of Proteins in vivo
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2007Co-Authors: Anne E Todgham, Elizabeth A Hoaglund, Gretchen E HofmannAbstract:Levels of ubiquitin (Ub)-Conjugated Proteins, as an index of misfolded or damaged Proteins, were measured in notothenioid fishes, with both Antarctic (Trematomus bernacchii, T. pennellii, Pagothenia borchgrevinki) and non-Antarctic (Notothenia angustata, Bovichtus variegatus) distributions, as well as non-notothenioid fish from the Antarctic (Lycodichthys dearborni, Family Zoarcidae) and New Zealand (Bellapiscis medius, Family Tripterygiidae), in an effort to better understand the effect that inhabiting a sub-zero environment has on maintaining the integrity of the cellular Protein pool. Overall, levels of Ub-Conjugated Proteins in cold-adapted Antarctic fishes were significantly higher than New Zealand fishes in gill, liver, heart and spleen tissues suggesting that life at sub-zero temperatures impacts Protein homeostasis. The highest tissue levels of ubiquitinated Proteins were found in the spleen of all fish. Ub conjugate levels in the New Zealand N. angustata, more closely resembled levels measured in other Antarctic fishes than levels measured in other New Zealand species, likely reflecting their recent shared ancestry with Antarctic notothenioids.
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adjusting the thermostat the threshold induction temperature for the heat shock response in intertidal mussels genus mytilus changes as a function of thermal history
The Journal of Experimental Biology, 2001Co-Authors: Bradley A Buckley, Marieeve Owen, Gretchen E HofmannAbstract:Spatio-temporal variation in heat-shock gene expression gives organisms the ability to respond to changing thermal environments. The temperature at which heat-shock genes are induced, the threshold induction temperature, varies as a function of the recent thermal history of an organism. To elucidate the mechanism by which this plasticity in gene expression is achieved, we determined heat-shock Protein (Hsp) induction threshold temperatures in the intertidal mussel Mytilus trossulus collected from the field in February and again in August. In a separate experiment, threshold induction temperatures, endogenous levels of both the constitutive and inducible isoforms of Hsps from the 70 kDa family and the quantity of ubiquitinated Proteins (a measure of cellular Protein denaturation) were measured in M. trossulus after either 6 weeks of cold acclimation in the laboratory or acclimatization to warm, summer temperatures in the field over the same period. In addition, we quantified levels of activated heat-shock transcription factor 1 (HSF1) in both groups of mussels (HSF1 inducibly transactivates all classes of Hsp genes). Lastly, we compared the temperature of HSF1 activation with the induction threshold temperature in the congeneric M. californianus. It was found that the threshold induction temperature in M. trossulus was 23 degrees C in February and 28 degrees C in August. This agreed with the acclimation/acclimatization experiment, in which mussels acclimated in seawater tables to a constant temperature of 10-11 degrees C for 6 weeks displayed a threshold induction temperature of 20-23 degrees C compared with 26-29 degrees C for individuals that were experiencing considerably warmer body temperatures in the intertidal zone over the same period. This coincided with a significant increase in the inducible isoform of Hsp70 in warm-acclimatized individuals but no increase in the constitutive isoform or in HSF1. Levels of ubiquitin-Conjugated Protein were significantly higher in the field mussels than in the laboratory-acclimated individuals. Finally, the temperature of HSF1 activation in M. californianus was found to be approximately 9 degrees C lower than the induction threshold for this species.
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adjusting the thermostat the threshold induction temperature for the heat shock response in intertidal mussels genus mytilus changes as a function of thermal history
The Journal of Experimental Biology, 2001Co-Authors: Bradley A Buckley, Marieeve Owen, Gretchen E HofmannAbstract:SUMMARY Spatio-temporal variation in heat-shock gene expression gives organisms the ability to respond to changing thermal environments. The temperature at which heat-shock genes are induced, the threshold induction temperature, varies as a function of the recent thermal history of an organism. To elucidate the mechanism by which this plasticity in gene expression is achieved, we determined heat-shock Protein (Hsp) induction threshold temperatures in the intertidal mussel Mytilus trossulus collected from the field in February and again in August. In a separate experiment, threshold induction temperatures, endogenous levels of both the constitutive and inducible isoforms of Hsps from the 70 kDa family and the quantity of ubiquitinated Proteins (a measure of cellular Protein denaturation) were measured in M. trossulus after either 6 weeks of cold acclimation in the laboratory or acclimatization to warm, summer temperatures in the field over the same period. In addition, we quantified levels of activated heat-shock transcription factor 1 (HSF1) in both groups of mussels (HSF1 inducibly transactivates all classes of Hsp genes). Lastly, we compared the temperature of HSF1 activation with the induction threshold temperature in the congeneric M. californianus . It was found that the threshold induction temperature in M. trossulus was 23°C in February and 28°C in August. This agreed with the acclimation/acclimatization experiment, in which mussels acclimated in seawater tables to a constant temperature of 10–11°C for 6 weeks displayed a threshold induction temperature of 20–23°C compared with 26–29°C for individuals that were experiencing considerably warmer body temperatures in the intertidal zone over the same period. This coincided with a significant increase in the inducible isoform of Hsp70 in warm-acclimatized individuals but no increase in the constitutive isoform or in HSF1. Levels of ubiquitin-Conjugated Protein were significantly higher in the field mussels than in the laboratory-acclimated individuals. Finally, the temperature of HSF1 activation in M. californianus was found to be approximately 9°C lower than the induction threshold for this species.
Ralph M. Steinman - One of the best experts on this subject based on the ideXlab platform.
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Targeting Leishmania major Antigens to Dendritic Cells In Vivo Induces Protective Immunity
2016Co-Authors: Ines Matos, Ralph M. Steinman, Olga Mizenina, Ashira Lubkin, Juliana IdoyagaAbstract:Efficient vaccination against the parasite Leishmania major, the causative agent of human cutaneous leishmaniasis, requires development of type 1 T-helper (Th1) CD4+ T cell immunity. Because of their unique capacity to initiate and modulate immune responses, dendritic cells (DCs) are attractive targets for development of novel vaccines. In this study, for the first time, we investigated the capacity of a DC-targeted vaccine to induce protective responses against L. major. To this end, we genetically engineered the N-terminal portion of the stress-inducible 1 Protein of L. major (LmSTI1a) into anti-DEC205/ CD205 (DEC) monoclonal antibody (mAb) and thereby delivered the Conjugated Protein to DEC+ DCs in situ in the intact animal. Delivery of LmSTI1a to adjuvant-matured DCs increased the frequency of antigen-specific CD4+ T cells producing IFN-c+, IL-2+, and TNF-a+ in two different strains of mice (C57BL/6 and Balb/c), while such responses were not observed with the same doses of a control Ig-LmSTI1a mAb without receptor affinity or with non-targeted LmSTI1a Protein. Using a peptide library for LmSTI1a, we identified at least two distinct CD4+ T cell mimetopes in each MHC class II haplotype, consistent with the induction of broad immunity. When we compared T cell immune responses generated after targeting DCs with LmSTI1a or other L. major antigens, including LACK (Leishmania receptor for activated C kinase) and LeIF (Leishmania eukaryotic ribosomal elongation and initiation factor 4a), we found that LmSTI1a was superior for generation of IFN-c-producing CD4+ T cells, which correlated with higher protection of susceptible Balb/c mice to a challenge with L
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broad t cell immunity to the lcrv virulence Protein is induced by targeted delivery to dec 205 cd205 positive mouse dendritic cells
European Journal of Immunology, 2008Co-Authors: Chae Gyu Park, Sung Ho Park, Young Sun Kang, Rebecca M. Lynch, Haekyung Lee, Bradford S. Powell, Ralph M. SteinmanAbstract:There is a need for a more efficient vaccine against the bacterium Yersinia pestis, the agent of pneumonic plague. The F1-LcrV (F1-V) subunit vaccine in alhydrogel is known to induce humoral immunity. In this study, we utilized DC to investigate cellular immunity. We genetically engineered the LcrV virulence Protein into the anti-DEC-205/CD205 mAb and thereby targeted the Conjugated Protein directly to mouse DEC-205+ DC in situ. We observed antigen-specific CD4+ T cell immunity measured by intracellular staining for IFN-γ in three different mouse strains (C57BL/6, BALB/c, and C3H/HeJ), while we could not observe such T cell responses with F1-V vaccine in alhydrogel. Using a peptide library for LcrV Protein, we identified two or more distinct CD4+ T cell mimetopes in each MHC haplotype, consistent with the induction of broad immunity. When compared to nontargeted standard Protein vaccine, DC targeting greatly increased the efficiency for inducing IFN-γ-producing T cells. The targeted LcrV Protein induced antibody responses to a similar extent as the F1-V subunit vaccine, but Th1-dependent IgG2a and IgG2c isotypes were observed only after anti-DEC-205:LcrV mAb immunization. This study sets the stage for the analysis of functional roles of IFN-γ-producing T cells in Y. pestis infection.
Young Sun Kang - One of the best experts on this subject based on the ideXlab platform.
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broad t cell immunity to the lcrv virulence Protein is induced by targeted delivery to dec 205 cd205 positive mouse dendritic cells
European Journal of Immunology, 2008Co-Authors: Chae Gyu Park, Sung Ho Park, Young Sun Kang, Rebecca M. Lynch, Haekyung Lee, Bradford S. Powell, Ralph M. SteinmanAbstract:There is a need for a more efficient vaccine against the bacterium Yersinia pestis, the agent of pneumonic plague. The F1-LcrV (F1-V) subunit vaccine in alhydrogel is known to induce humoral immunity. In this study, we utilized DC to investigate cellular immunity. We genetically engineered the LcrV virulence Protein into the anti-DEC-205/CD205 mAb and thereby targeted the Conjugated Protein directly to mouse DEC-205+ DC in situ. We observed antigen-specific CD4+ T cell immunity measured by intracellular staining for IFN-γ in three different mouse strains (C57BL/6, BALB/c, and C3H/HeJ), while we could not observe such T cell responses with F1-V vaccine in alhydrogel. Using a peptide library for LcrV Protein, we identified two or more distinct CD4+ T cell mimetopes in each MHC haplotype, consistent with the induction of broad immunity. When compared to nontargeted standard Protein vaccine, DC targeting greatly increased the efficiency for inducing IFN-γ-producing T cells. The targeted LcrV Protein induced antibody responses to a similar extent as the F1-V subunit vaccine, but Th1-dependent IgG2a and IgG2c isotypes were observed only after anti-DEC-205:LcrV mAb immunization. This study sets the stage for the analysis of functional roles of IFN-γ-producing T cells in Y. pestis infection.
Jones, Lyndon W. - One of the best experts on this subject based on the ideXlab platform.
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Composition of incubation solution impacts in vitro Protein uptake to silicone hydrogel contact lenses
Molecular Vision, 2012Co-Authors: Jadi Salsabeel, Heynen, Miriam L., Luensmann Doerte, Jones, Lyndon W.Abstract:Jadi, S., Heynen, M., Luensmann, D., & Jones, L. (2012). Composition of incubation solution impacts in vitro Protein uptake to silicone hydrogel contact lenses. Molecular Vision, 18, 337–347.Purpose: To determine the impact of incubation solution composition on Protein deposition to silicone hydrogel (SH) contact lenses using a simplistic and a complex model of the tear film. Methods: Three SH materials – senofilcon A (SA), lotrafilcon B (LB), and balafilcon A (BA) – were incubated in two different solutions; Solution A was a simplistic augmented buffered saline solution containing a single Protein, whereas Solution B was a complex artificial tear solution (ATS), containing the augmented buffered saline solution in addition to Proteins, lipids, and mucins (pH=7.4). The Proteins of interest (lysozyme, lactoferrin, albumin) were radiolabeled with Iodine-125 (2% Protein of interest) and the accumulation of the Conjugated Protein to the lens materials was determined after 1, 7, 14, and 28 days of incubation. Protein deposition was measured using a gamma counter and the raw data were translated into absolute amounts (µg/lens) via extrapolation from standards. Results: After 28 days, lysozyme uptake was significantly lower on BA lenses when incubated in Solution A (33.7 μg) compared to Solution B (56.2 μg), p0.05. LB lenses also deposited similar amounts of lysozyme for both solutions (Solution A: 5.0 μg, Solution B: 4.7 μg, p>0.05). After 28 days, BA lenses accumulated approximately twice the amount of lactoferrin than the other lens materials, with 30.3 μg depositing when exposed to Solution A and 22.0 μg with Solution B. The difference between the two solutions was statistically significant (p0.05). After 28 days, albumin deposition onto BA lenses was significantly greater when lenses were incubated in Solution B (1.7 μg) compared to Solution A (0.9 μg), p0.05). LB lenses incubated in Solution A deposited more albumin compared to Solution B (0.9 μg versus 0.6 μg), p=0.003. Discussion: Protein deposition onto SH materials varied when contact lenses were incubated in either a complex ATS compared to a single Protein solution. More lysozyme accumulated onto BA lenses incubated in a complex analog of the human tear film, whereas lactoferrin deposited onto SA lenses independent of incubation solution composition. To better mimic the ex vivo environment, future studies should use more appropriate analogs of the tear film.This study was funded by the Centre for Contact Lens Research (CCLR) at the University of Waterloo and by the Canadian Optometric Education Trust Fund (COETF)
Bradley A Buckley - One of the best experts on this subject based on the ideXlab platform.
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adjusting the thermostat the threshold induction temperature for the heat shock response in intertidal mussels genus mytilus changes as a function of thermal history
The Journal of Experimental Biology, 2001Co-Authors: Bradley A Buckley, Marieeve Owen, Gretchen E HofmannAbstract:Spatio-temporal variation in heat-shock gene expression gives organisms the ability to respond to changing thermal environments. The temperature at which heat-shock genes are induced, the threshold induction temperature, varies as a function of the recent thermal history of an organism. To elucidate the mechanism by which this plasticity in gene expression is achieved, we determined heat-shock Protein (Hsp) induction threshold temperatures in the intertidal mussel Mytilus trossulus collected from the field in February and again in August. In a separate experiment, threshold induction temperatures, endogenous levels of both the constitutive and inducible isoforms of Hsps from the 70 kDa family and the quantity of ubiquitinated Proteins (a measure of cellular Protein denaturation) were measured in M. trossulus after either 6 weeks of cold acclimation in the laboratory or acclimatization to warm, summer temperatures in the field over the same period. In addition, we quantified levels of activated heat-shock transcription factor 1 (HSF1) in both groups of mussels (HSF1 inducibly transactivates all classes of Hsp genes). Lastly, we compared the temperature of HSF1 activation with the induction threshold temperature in the congeneric M. californianus. It was found that the threshold induction temperature in M. trossulus was 23 degrees C in February and 28 degrees C in August. This agreed with the acclimation/acclimatization experiment, in which mussels acclimated in seawater tables to a constant temperature of 10-11 degrees C for 6 weeks displayed a threshold induction temperature of 20-23 degrees C compared with 26-29 degrees C for individuals that were experiencing considerably warmer body temperatures in the intertidal zone over the same period. This coincided with a significant increase in the inducible isoform of Hsp70 in warm-acclimatized individuals but no increase in the constitutive isoform or in HSF1. Levels of ubiquitin-Conjugated Protein were significantly higher in the field mussels than in the laboratory-acclimated individuals. Finally, the temperature of HSF1 activation in M. californianus was found to be approximately 9 degrees C lower than the induction threshold for this species.
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adjusting the thermostat the threshold induction temperature for the heat shock response in intertidal mussels genus mytilus changes as a function of thermal history
The Journal of Experimental Biology, 2001Co-Authors: Bradley A Buckley, Marieeve Owen, Gretchen E HofmannAbstract:SUMMARY Spatio-temporal variation in heat-shock gene expression gives organisms the ability to respond to changing thermal environments. The temperature at which heat-shock genes are induced, the threshold induction temperature, varies as a function of the recent thermal history of an organism. To elucidate the mechanism by which this plasticity in gene expression is achieved, we determined heat-shock Protein (Hsp) induction threshold temperatures in the intertidal mussel Mytilus trossulus collected from the field in February and again in August. In a separate experiment, threshold induction temperatures, endogenous levels of both the constitutive and inducible isoforms of Hsps from the 70 kDa family and the quantity of ubiquitinated Proteins (a measure of cellular Protein denaturation) were measured in M. trossulus after either 6 weeks of cold acclimation in the laboratory or acclimatization to warm, summer temperatures in the field over the same period. In addition, we quantified levels of activated heat-shock transcription factor 1 (HSF1) in both groups of mussels (HSF1 inducibly transactivates all classes of Hsp genes). Lastly, we compared the temperature of HSF1 activation with the induction threshold temperature in the congeneric M. californianus . It was found that the threshold induction temperature in M. trossulus was 23°C in February and 28°C in August. This agreed with the acclimation/acclimatization experiment, in which mussels acclimated in seawater tables to a constant temperature of 10–11°C for 6 weeks displayed a threshold induction temperature of 20–23°C compared with 26–29°C for individuals that were experiencing considerably warmer body temperatures in the intertidal zone over the same period. This coincided with a significant increase in the inducible isoform of Hsp70 in warm-acclimatized individuals but no increase in the constitutive isoform or in HSF1. Levels of ubiquitin-Conjugated Protein were significantly higher in the field mussels than in the laboratory-acclimated individuals. Finally, the temperature of HSF1 activation in M. californianus was found to be approximately 9°C lower than the induction threshold for this species.