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Phenotypic and functional analyses of NK and NKT-like populations during the early stages of chikungunya infection.

Thanapati S, Das R, Tripathy AS - Front Microbiol (2015)

Bottom Line: Higher percentages of perforin(+)CD3(-)CD56(+) and perforin(+)CD3(+)CD56(+) cells were observed in acute and convalescent patients, respectively.IFN-γ expression on NK cells of convalescent patients and on NKT-like cells of both patient groups was indicative of the regulatory role of NK and NKT-like cells.Collectively, these data showed that higher expression of activating receptors on NK/NKT-like cells and perforin(+) NK cells in acute patients could be responsible for increased cytotoxicity.

View Article: PubMed Central - PubMed

Affiliation: Hepatitis Group, National Institute of Virology Pune, India.

ABSTRACT
The aim of this study was to characterize NK (CD56(+)CD3(-)) and NKT-like cell (CD56(+)CD3(+)) responses early after chikungunya infection. Expression profiling and functional analysis of T/NK/NKT-like cells were performed on samples from 56 acute and 31 convalescent chikungunya patients and 56 control individuals. The percentages of NK cells were high in both patient groups, whereas NKT-like cell percentages were high only in the convalescent group. The percentages of NKp30(+)CD3(-)CD56(+), NKp30(+)CD3(+)CD56(+), CD244(+)CD3(-)CD56(+), and CD244(+)CD3(+)CD56(+)cells were high, whereas the percentages of NKG2D(+)CD3(-)CD56(+) and NKG2D(+)CD3(+)CD56(+)cells were low in both patient groups. The percentages of NKp44(+)CD3(-)CD56(+) cells were high in both patient groups, whereas the percentages of NKp44(+)CD3(+)CD56(+) cells were higher in the acute group than in convalescent and control groups. The percentages of NKp46(+)CD3(-)CD56(+) cells were high in both patient groups. Higher percentages of perforin(+)CD3(-)CD56(+) and perforin(+)CD3(+)CD56(+) cells were observed in acute and convalescent patients, respectively. Higher cytotoxic activity was observed in acute patients than in controls. IFN-γ expression on NK cells of convalescent patients and on NKT-like cells of both patient groups was indicative of the regulatory role of NK and NKT-like cells. Collectively, these data showed that higher expression of activating receptors on NK/NKT-like cells and perforin(+) NK cells in acute patients could be responsible for increased cytotoxicity. The observed expression of perforin(+) NK cells in the acute phase and IFN-γ(+) NKT-like cells in the subsequent convalescent stage showed that NK/NKT-like cells mount an early and efficient response to chikungunya virus. Further study of the molecular mechanisms that limit viral dissemination/establishment of chronic disease will aid in understanding how NK/NKT-like cells control chikungunya infection.

No MeSH data available.


Related in: MedlinePlus

IFN-γ responses by ELISPOT. Box plots are showing IFN-γ responses by PBMCs from 18 control subjects, 13 acute, and 15 convalescent patients, stimulated with CHIK antigen (inactivated CHIKV 10 μg/106 PBMCs). Y axis is showing spot forming cells (SFCs) per 105 million cells. Plot shows IFN-γ responses by unstimulated PBMCs before subtraction from stimulated PBMCs well (spontaneous IFN-γ production) and after subtraction of spots in unstimulated PBMCs well from stimulated well (CHIKV specific IFN-γ production). Non-parametric Kolmogorov–Smirnov test was used for intergroup comparison. p < 0.05 is considered significant.
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Figure 6: IFN-γ responses by ELISPOT. Box plots are showing IFN-γ responses by PBMCs from 18 control subjects, 13 acute, and 15 convalescent patients, stimulated with CHIK antigen (inactivated CHIKV 10 μg/106 PBMCs). Y axis is showing spot forming cells (SFCs) per 105 million cells. Plot shows IFN-γ responses by unstimulated PBMCs before subtraction from stimulated PBMCs well (spontaneous IFN-γ production) and after subtraction of spots in unstimulated PBMCs well from stimulated well (CHIKV specific IFN-γ production). Non-parametric Kolmogorov–Smirnov test was used for intergroup comparison. p < 0.05 is considered significant.

Mentions: To determine the CHIKV-specific IFN-γ response, we performed an ELISPOT assay using whole CHIKV virus particles as antigens. In the control group (n = 18), the IFN-γ responses in unstimulated, CHIKV-stimulated, and PHA-stimulated cells were 1 (0−6), 2 (0−13), and 113 (25−248) SFCs/105 cells, respectively. In the acute patient group (n = 13), the IFN-γ responses in unstimulated, CHIKV-stimulated, and PHA-stimulated cells were 36 (18−61), 41 (22−70), and 165 (52−390), respectively. In the convalescent group (n = 15), the corresponding figures were 36 (15−58), 53 (20−148), and 152 (31−339). IFN-γ responses in unstimulated cells of both patient groups were higher than in controls (Figure 6). IFN-γ spots in the antigen-stimulated wells for the control, acute, and convalescent groups were 1 (0−8), 7 (0−22), and 20 (0−107), respectively, after subtracting the average number of spots in unstimulated wells from antigen-stimulated wells in each category. CHIKV-specific IFN-γ responses were higher in the convalescent group than in the control group (p = 0.016) (Figure 6).


Phenotypic and functional analyses of NK and NKT-like populations during the early stages of chikungunya infection.

Thanapati S, Das R, Tripathy AS - Front Microbiol (2015)

IFN-γ responses by ELISPOT. Box plots are showing IFN-γ responses by PBMCs from 18 control subjects, 13 acute, and 15 convalescent patients, stimulated with CHIK antigen (inactivated CHIKV 10 μg/106 PBMCs). Y axis is showing spot forming cells (SFCs) per 105 million cells. Plot shows IFN-γ responses by unstimulated PBMCs before subtraction from stimulated PBMCs well (spontaneous IFN-γ production) and after subtraction of spots in unstimulated PBMCs well from stimulated well (CHIKV specific IFN-γ production). Non-parametric Kolmogorov–Smirnov test was used for intergroup comparison. p < 0.05 is considered significant.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555083&req=5

Figure 6: IFN-γ responses by ELISPOT. Box plots are showing IFN-γ responses by PBMCs from 18 control subjects, 13 acute, and 15 convalescent patients, stimulated with CHIK antigen (inactivated CHIKV 10 μg/106 PBMCs). Y axis is showing spot forming cells (SFCs) per 105 million cells. Plot shows IFN-γ responses by unstimulated PBMCs before subtraction from stimulated PBMCs well (spontaneous IFN-γ production) and after subtraction of spots in unstimulated PBMCs well from stimulated well (CHIKV specific IFN-γ production). Non-parametric Kolmogorov–Smirnov test was used for intergroup comparison. p < 0.05 is considered significant.
Mentions: To determine the CHIKV-specific IFN-γ response, we performed an ELISPOT assay using whole CHIKV virus particles as antigens. In the control group (n = 18), the IFN-γ responses in unstimulated, CHIKV-stimulated, and PHA-stimulated cells were 1 (0−6), 2 (0−13), and 113 (25−248) SFCs/105 cells, respectively. In the acute patient group (n = 13), the IFN-γ responses in unstimulated, CHIKV-stimulated, and PHA-stimulated cells were 36 (18−61), 41 (22−70), and 165 (52−390), respectively. In the convalescent group (n = 15), the corresponding figures were 36 (15−58), 53 (20−148), and 152 (31−339). IFN-γ responses in unstimulated cells of both patient groups were higher than in controls (Figure 6). IFN-γ spots in the antigen-stimulated wells for the control, acute, and convalescent groups were 1 (0−8), 7 (0−22), and 20 (0−107), respectively, after subtracting the average number of spots in unstimulated wells from antigen-stimulated wells in each category. CHIKV-specific IFN-γ responses were higher in the convalescent group than in the control group (p = 0.016) (Figure 6).

Bottom Line: Higher percentages of perforin(+)CD3(-)CD56(+) and perforin(+)CD3(+)CD56(+) cells were observed in acute and convalescent patients, respectively.IFN-γ expression on NK cells of convalescent patients and on NKT-like cells of both patient groups was indicative of the regulatory role of NK and NKT-like cells.Collectively, these data showed that higher expression of activating receptors on NK/NKT-like cells and perforin(+) NK cells in acute patients could be responsible for increased cytotoxicity.

View Article: PubMed Central - PubMed

Affiliation: Hepatitis Group, National Institute of Virology Pune, India.

ABSTRACT
The aim of this study was to characterize NK (CD56(+)CD3(-)) and NKT-like cell (CD56(+)CD3(+)) responses early after chikungunya infection. Expression profiling and functional analysis of T/NK/NKT-like cells were performed on samples from 56 acute and 31 convalescent chikungunya patients and 56 control individuals. The percentages of NK cells were high in both patient groups, whereas NKT-like cell percentages were high only in the convalescent group. The percentages of NKp30(+)CD3(-)CD56(+), NKp30(+)CD3(+)CD56(+), CD244(+)CD3(-)CD56(+), and CD244(+)CD3(+)CD56(+)cells were high, whereas the percentages of NKG2D(+)CD3(-)CD56(+) and NKG2D(+)CD3(+)CD56(+)cells were low in both patient groups. The percentages of NKp44(+)CD3(-)CD56(+) cells were high in both patient groups, whereas the percentages of NKp44(+)CD3(+)CD56(+) cells were higher in the acute group than in convalescent and control groups. The percentages of NKp46(+)CD3(-)CD56(+) cells were high in both patient groups. Higher percentages of perforin(+)CD3(-)CD56(+) and perforin(+)CD3(+)CD56(+) cells were observed in acute and convalescent patients, respectively. Higher cytotoxic activity was observed in acute patients than in controls. IFN-γ expression on NK cells of convalescent patients and on NKT-like cells of both patient groups was indicative of the regulatory role of NK and NKT-like cells. Collectively, these data showed that higher expression of activating receptors on NK/NKT-like cells and perforin(+) NK cells in acute patients could be responsible for increased cytotoxicity. The observed expression of perforin(+) NK cells in the acute phase and IFN-γ(+) NKT-like cells in the subsequent convalescent stage showed that NK/NKT-like cells mount an early and efficient response to chikungunya virus. Further study of the molecular mechanisms that limit viral dissemination/establishment of chronic disease will aid in understanding how NK/NKT-like cells control chikungunya infection.

No MeSH data available.


Related in: MedlinePlus