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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

Antigen presentation molecule expression under TLR agonist stimulation.Flight (solid square) or ground AEM control (open circle) splenocytes were cultured in DMEM with 10% FBS with or without TLR agonists for 24 hours. Cells were collected and stained for expression of MHC I (H-2kb) and MHC II (I-Ab). (7a) Representative dot plot of MHC I+ populations. (7b) Percent positive and MFI of MHC I expression from G2 and G3 populations. *** = p<0.001.
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pone.0124380.g007: Antigen presentation molecule expression under TLR agonist stimulation.Flight (solid square) or ground AEM control (open circle) splenocytes were cultured in DMEM with 10% FBS with or without TLR agonists for 24 hours. Cells were collected and stained for expression of MHC I (H-2kb) and MHC II (I-Ab). (7a) Representative dot plot of MHC I+ populations. (7b) Percent positive and MFI of MHC I expression from G2 and G3 populations. *** = p<0.001.

Mentions: Surface expression of MHC I from flight mice or ground controls demonstrated two distinct populations. One population exhibited low intensity of MHC I expression that is well confined to G3. The other population had a diverse intensity range of MHC I expression that was generally higher compared to those in G2 (Fig 7a). Analysis of MHC I allowed grouping into MHC Ilo (G3) and MHC Ihi (G2) populations. In percent population analysis of MHC I expression, no differences were observed for any of the TLR agonist conditions between splenocytes isolated from flight mice or ground controls. Interestingly, there was an across the board decrease of MHC I MFI from splenocytes isolated from flight mice compared to ground controls in the G2 (MHC Ihi) population. This trend was completely reversed in the G3 (MHC Ilo) population in MHC I MFI, with splenocytes from flight mice demonstrating a significant increase in expression intensity compared to ground controls (Fig 7b). No differences were observed in expression of MHC II between flight mice and ground controls (data not shown).


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)

Antigen presentation molecule expression under TLR agonist stimulation.Flight (solid square) or ground AEM control (open circle) splenocytes were cultured in DMEM with 10% FBS with or without TLR agonists for 24 hours. Cells were collected and stained for expression of MHC I (H-2kb) and MHC II (I-Ab). (7a) Representative dot plot of MHC I+ populations. (7b) Percent positive and MFI of MHC I expression from G2 and G3 populations. *** = p<0.001.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0124380.g007: Antigen presentation molecule expression under TLR agonist stimulation.Flight (solid square) or ground AEM control (open circle) splenocytes were cultured in DMEM with 10% FBS with or without TLR agonists for 24 hours. Cells were collected and stained for expression of MHC I (H-2kb) and MHC II (I-Ab). (7a) Representative dot plot of MHC I+ populations. (7b) Percent positive and MFI of MHC I expression from G2 and G3 populations. *** = p<0.001.
Mentions: Surface expression of MHC I from flight mice or ground controls demonstrated two distinct populations. One population exhibited low intensity of MHC I expression that is well confined to G3. The other population had a diverse intensity range of MHC I expression that was generally higher compared to those in G2 (Fig 7a). Analysis of MHC I allowed grouping into MHC Ilo (G3) and MHC Ihi (G2) populations. In percent population analysis of MHC I expression, no differences were observed for any of the TLR agonist conditions between splenocytes isolated from flight mice or ground controls. Interestingly, there was an across the board decrease of MHC I MFI from splenocytes isolated from flight mice compared to ground controls in the G2 (MHC Ihi) population. This trend was completely reversed in the G3 (MHC Ilo) population in MHC I MFI, with splenocytes from flight mice demonstrating a significant increase in expression intensity compared to ground controls (Fig 7b). No differences were observed in expression of MHC II between flight mice and ground controls (data not shown).

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