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Post-Spaceflight (STS-135) Mouse Splenocytes Demonstrate Altered Activation Properties and Surface Molecule Expression.

Hwang SA, Crucian B, Sams C, Actor JK - PLoS ONE (2015)

Bottom Line: Stimulation with ConA led to decrease in CD4+ population but increased CD4+CD25+ cells compared to ground controls.Consequently, flight splenocytes with or without TLR-agonist stimulation showed a decrease in CD11c+MHC I+, CD11c+MHC II+, and CD11c+CD86+ cells compared to ground controls.Production of IFN-γ was decreased and IL-2 was increased from ConA stimulated flight splenocytes.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, Texas, United States of America.

ABSTRACT
Alterations in immune function have been documented during or post-spaceflight and in ground based models of microgravity. Identification of immune parameters that are dysregulated during spaceflight is an important step in mitigating crew health risks during deep space missions. The in vitro analysis of leukocyte activity post-spaceflight in both human and animal species is primarily focused on lymphocytic function. This report completes a broader spectrum analysis of mouse lymphocyte and monocyte changes post 13 days orbital flight (mission STS-135). Analysis includes an examination in surface markers for cell activation, and antigen presentation and co-stimulatory molecules. Cytokine production was measured after stimulation with T-cell mitogen or TLR-2, TLR-4, or TLR-5 agonists. Splenocyte surface marker analysis immediate post-spaceflight and after in vitro culture demonstrated unique changes in phenotypic populations between the flight mice and matched treatment ground controls. Post-spaceflight splenocytes (flight splenocytes) had lower expression intensity of CD4+CD25+ and CD8+CD25+ cells, lower percentage of CD11c+MHC II+ cells, and higher percentage of CD11c+MHC I+ populations compared to ground controls. The flight splenocytes demonstrated an increase in phagocytic activity. Stimulation with ConA led to decrease in CD4+ population but increased CD4+CD25+ cells compared to ground controls. Culturing with TLR agonists led to a decrease in CD11c+ population in splenocytes isolated from flight mice compared to ground controls. Consequently, flight splenocytes with or without TLR-agonist stimulation showed a decrease in CD11c+MHC I+, CD11c+MHC II+, and CD11c+CD86+ cells compared to ground controls. Production of IFN-γ was decreased and IL-2 was increased from ConA stimulated flight splenocytes. This study demonstrated that expression of surface molecules can be affected by conditions of spaceflight and impaired responsiveness persists under culture conditions in vitro.

No MeSH data available.


Related in: MedlinePlus

Cell population differences in total splenocytes collected from ground control mice.Splenocytes collected immediately post-sacrifice of ground control mice were stained with CD4, CD8, MHC I, MHC II, and CD11c. Analysis was conducted by flow cytometry. (2a) Example of gating strategy between flight mice and ground controls. (2b) Example of positive population composition of each gate identified in 2a from ground AEM control mice. (2c) Graph of percent positive and MFI from each marker of splenocytes from AEM control mice.
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pone.0124380.g002: Cell population differences in total splenocytes collected from ground control mice.Splenocytes collected immediately post-sacrifice of ground control mice were stained with CD4, CD8, MHC I, MHC II, and CD11c. Analysis was conducted by flow cytometry. (2a) Example of gating strategy between flight mice and ground controls. (2b) Example of positive population composition of each gate identified in 2a from ground AEM control mice. (2c) Graph of percent positive and MFI from each marker of splenocytes from AEM control mice.

Mentions: Upon culture for 24 hours in cell media, relative marker expression for the splenocyte population shifted. Cultured splenocytes isolated from ground control mice exhibited an increase in cell density in G3 compared to cultured splenocytes isolated from flight mice (Fig 2a). Examination revealed that G3 population has higher percentage of CD8+ and MHC I+ cells. It was also noted that G3 population also displayed increased surface expression of CD8+ as indicated by increased mean fluorescent intensity (MFI). Cell populations of G2 and G4 display surface marker expression typical of dendritic cells and macrophages (Fig 2b and 2c). These data suggests that in vitro culturing of splenocytes from ground control mice enhances relative abundance of CD8 T-cell marker expression compared to splenocytes collected from the mice post-spaceflight.


Post-Spaceflight (STS-135) Mouse Splenocytes Demonstrate Altered Activation Properties and Surface Molecule Expression.

Hwang SA, Crucian B, Sams C, Actor JK - PLoS ONE (2015)

Cell population differences in total splenocytes collected from ground control mice.Splenocytes collected immediately post-sacrifice of ground control mice were stained with CD4, CD8, MHC I, MHC II, and CD11c. Analysis was conducted by flow cytometry. (2a) Example of gating strategy between flight mice and ground controls. (2b) Example of positive population composition of each gate identified in 2a from ground AEM control mice. (2c) Graph of percent positive and MFI from each marker of splenocytes from AEM control mice.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430214&req=5

pone.0124380.g002: Cell population differences in total splenocytes collected from ground control mice.Splenocytes collected immediately post-sacrifice of ground control mice were stained with CD4, CD8, MHC I, MHC II, and CD11c. Analysis was conducted by flow cytometry. (2a) Example of gating strategy between flight mice and ground controls. (2b) Example of positive population composition of each gate identified in 2a from ground AEM control mice. (2c) Graph of percent positive and MFI from each marker of splenocytes from AEM control mice.
Mentions: Upon culture for 24 hours in cell media, relative marker expression for the splenocyte population shifted. Cultured splenocytes isolated from ground control mice exhibited an increase in cell density in G3 compared to cultured splenocytes isolated from flight mice (Fig 2a). Examination revealed that G3 population has higher percentage of CD8+ and MHC I+ cells. It was also noted that G3 population also displayed increased surface expression of CD8+ as indicated by increased mean fluorescent intensity (MFI). Cell populations of G2 and G4 display surface marker expression typical of dendritic cells and macrophages (Fig 2b and 2c). These data suggests that in vitro culturing of splenocytes from ground control mice enhances relative abundance of CD8 T-cell marker expression compared to splenocytes collected from the mice post-spaceflight.

Bottom Line: Stimulation with ConA led to decrease in CD4+ population but increased CD4+CD25+ cells compared to ground controls.Consequently, flight splenocytes with or without TLR-agonist stimulation showed a decrease in CD11c+MHC I+, CD11c+MHC II+, and CD11c+CD86+ cells compared to ground controls.Production of IFN-γ was decreased and IL-2 was increased from ConA stimulated flight splenocytes.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston, Houston, Texas, United States of America.

ABSTRACT
Alterations in immune function have been documented during or post-spaceflight and in ground based models of microgravity. Identification of immune parameters that are dysregulated during spaceflight is an important step in mitigating crew health risks during deep space missions. The in vitro analysis of leukocyte activity post-spaceflight in both human and animal species is primarily focused on lymphocytic function. This report completes a broader spectrum analysis of mouse lymphocyte and monocyte changes post 13 days orbital flight (mission STS-135). Analysis includes an examination in surface markers for cell activation, and antigen presentation and co-stimulatory molecules. Cytokine production was measured after stimulation with T-cell mitogen or TLR-2, TLR-4, or TLR-5 agonists. Splenocyte surface marker analysis immediate post-spaceflight and after in vitro culture demonstrated unique changes in phenotypic populations between the flight mice and matched treatment ground controls. Post-spaceflight splenocytes (flight splenocytes) had lower expression intensity of CD4+CD25+ and CD8+CD25+ cells, lower percentage of CD11c+MHC II+ cells, and higher percentage of CD11c+MHC I+ populations compared to ground controls. The flight splenocytes demonstrated an increase in phagocytic activity. Stimulation with ConA led to decrease in CD4+ population but increased CD4+CD25+ cells compared to ground controls. Culturing with TLR agonists led to a decrease in CD11c+ population in splenocytes isolated from flight mice compared to ground controls. Consequently, flight splenocytes with or without TLR-agonist stimulation showed a decrease in CD11c+MHC I+, CD11c+MHC II+, and CD11c+CD86+ cells compared to ground controls. Production of IFN-γ was decreased and IL-2 was increased from ConA stimulated flight splenocytes. This study demonstrated that expression of surface molecules can be affected by conditions of spaceflight and impaired responsiveness persists under culture conditions in vitro.

No MeSH data available.


Related in: MedlinePlus