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Herpes Simplex Virus-1 Fine-Tunes Host's Autophagic Response to Infection: A Comprehensive Analysis in Productive Infection Models.

Yakoub AM, Shukla D - PLoS ONE (2015)

Bottom Line: The autophagic response of the host cell was suggested to be regulated by HSV-1.We found that autophagy was slightly inhibited in one cell type, while in other cell types autophagy maintained its basal levels mostly unchanged during productive infection.This study refines the concept of HSV-1-mediated autophagy regulation to imply either inhibition, or prevention of activation, of the innate immune pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of Illinois, Chicago, IL United States of America, 60612; Department of Ophthalmology and Visual Sciences, University of Illinois Medical Center, Chicago, IL United States of America, 60612.

ABSTRACT
Herpes simplex virus-1 (HSV-1) infection causes severe conditions, with serious complications, including corneal blindness from uncontrolled ocular infections. An important cellular defense mechanism against HSV-1 infection is autophagy. The autophagic response of the host cell was suggested to be regulated by HSV-1. In this study, we performed a detailed analysis of autophagy in multiple HSV-1-targeted cell types, and under various infection conditions that recapitulate a productive infection model. We found that autophagy was slightly inhibited in one cell type, while in other cell types autophagy maintained its basal levels mostly unchanged during productive infection. This study refines the concept of HSV-1-mediated autophagy regulation to imply either inhibition, or prevention of activation, of the innate immune pathway.

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Related in: MedlinePlus

Analysis of Autophagy in HSV-1 Infection of HeLa Cells.A. HeLa cells were uninfected (mock), or infected with different strains of HSV-1 (KOS or McKrae). At 2 hpi, the cells were harvested, lysed, and the lysate was immunoblotted for LC3 levels. B. Uninfected or infected HeLa cells were harvested at 6 hpi, lysed, and immunoblotted. C. Immunoblotting of Uninfected or infected HeLa cells at 12 hpi. D. Immunoblotting of Uninfected or infected HeLa cells at 30 hpi. E. Quantification of LC3-II levels in (A-D), normalized to the housekeeping protein GAPDH.
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pone.0124646.g001: Analysis of Autophagy in HSV-1 Infection of HeLa Cells.A. HeLa cells were uninfected (mock), or infected with different strains of HSV-1 (KOS or McKrae). At 2 hpi, the cells were harvested, lysed, and the lysate was immunoblotted for LC3 levels. B. Uninfected or infected HeLa cells were harvested at 6 hpi, lysed, and immunoblotted. C. Immunoblotting of Uninfected or infected HeLa cells at 12 hpi. D. Immunoblotting of Uninfected or infected HeLa cells at 30 hpi. E. Quantification of LC3-II levels in (A-D), normalized to the housekeeping protein GAPDH.

Mentions: To understand the regulation of autophagy in infection, we assessed the autophagic flux of the cells as a function of infection over time. Therefore we infected HeLa cells with the HSV-1 strains KOS or McKrae at MOI of 5. Mock- or HSV-1-infected cells were monitored at various time points after infection, to assess early and late responses. At each time point, autophagy was monitored via immunoblotting of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, an indicator of autophagic activity of the cells [23]. We found that autophagy levels were minimally inhibited at early points of infection (2 hours post-infection (hpi)) by both virus strains (Fig 1A and 1E). However, most effect (which did not exceed ~50% inhibition of the basal autophagy levels) was seen at 6 hpi (Fig 1B and 1E). At 12 and 30 hpi, gradual, and relative de-repression of autophagy was observed (Fig 1C, 1D and 1E). These results indicate that HSV-1 regulates autophagy in HeLa cells, via modest transient inhibition, which is consistent with previously reported observations in other systems [11, 14].


Herpes Simplex Virus-1 Fine-Tunes Host's Autophagic Response to Infection: A Comprehensive Analysis in Productive Infection Models.

Yakoub AM, Shukla D - PLoS ONE (2015)

Analysis of Autophagy in HSV-1 Infection of HeLa Cells.A. HeLa cells were uninfected (mock), or infected with different strains of HSV-1 (KOS or McKrae). At 2 hpi, the cells were harvested, lysed, and the lysate was immunoblotted for LC3 levels. B. Uninfected or infected HeLa cells were harvested at 6 hpi, lysed, and immunoblotted. C. Immunoblotting of Uninfected or infected HeLa cells at 12 hpi. D. Immunoblotting of Uninfected or infected HeLa cells at 30 hpi. E. Quantification of LC3-II levels in (A-D), normalized to the housekeeping protein GAPDH.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403807&req=5

pone.0124646.g001: Analysis of Autophagy in HSV-1 Infection of HeLa Cells.A. HeLa cells were uninfected (mock), or infected with different strains of HSV-1 (KOS or McKrae). At 2 hpi, the cells were harvested, lysed, and the lysate was immunoblotted for LC3 levels. B. Uninfected or infected HeLa cells were harvested at 6 hpi, lysed, and immunoblotted. C. Immunoblotting of Uninfected or infected HeLa cells at 12 hpi. D. Immunoblotting of Uninfected or infected HeLa cells at 30 hpi. E. Quantification of LC3-II levels in (A-D), normalized to the housekeeping protein GAPDH.
Mentions: To understand the regulation of autophagy in infection, we assessed the autophagic flux of the cells as a function of infection over time. Therefore we infected HeLa cells with the HSV-1 strains KOS or McKrae at MOI of 5. Mock- or HSV-1-infected cells were monitored at various time points after infection, to assess early and late responses. At each time point, autophagy was monitored via immunoblotting of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, an indicator of autophagic activity of the cells [23]. We found that autophagy levels were minimally inhibited at early points of infection (2 hours post-infection (hpi)) by both virus strains (Fig 1A and 1E). However, most effect (which did not exceed ~50% inhibition of the basal autophagy levels) was seen at 6 hpi (Fig 1B and 1E). At 12 and 30 hpi, gradual, and relative de-repression of autophagy was observed (Fig 1C, 1D and 1E). These results indicate that HSV-1 regulates autophagy in HeLa cells, via modest transient inhibition, which is consistent with previously reported observations in other systems [11, 14].

Bottom Line: The autophagic response of the host cell was suggested to be regulated by HSV-1.We found that autophagy was slightly inhibited in one cell type, while in other cell types autophagy maintained its basal levels mostly unchanged during productive infection.This study refines the concept of HSV-1-mediated autophagy regulation to imply either inhibition, or prevention of activation, of the innate immune pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of Illinois, Chicago, IL United States of America, 60612; Department of Ophthalmology and Visual Sciences, University of Illinois Medical Center, Chicago, IL United States of America, 60612.

ABSTRACT
Herpes simplex virus-1 (HSV-1) infection causes severe conditions, with serious complications, including corneal blindness from uncontrolled ocular infections. An important cellular defense mechanism against HSV-1 infection is autophagy. The autophagic response of the host cell was suggested to be regulated by HSV-1. In this study, we performed a detailed analysis of autophagy in multiple HSV-1-targeted cell types, and under various infection conditions that recapitulate a productive infection model. We found that autophagy was slightly inhibited in one cell type, while in other cell types autophagy maintained its basal levels mostly unchanged during productive infection. This study refines the concept of HSV-1-mediated autophagy regulation to imply either inhibition, or prevention of activation, of the innate immune pathway.

Show MeSH
Related in: MedlinePlus