The Effect of Acute Physical Exercise on Natural Killer Cells Populations and Cytokine Levels in Healthy Women

Abstract

Physical exercise generates a systemic response in the immune system. It has been observed that cell populations respond to exercise stimuli, especially Natural Killer cells, whose number increase within minutes of starting physical exertion. This study aimed to evaluate the acute effect of moderate- and high-intensity exercise on immunological markers in healthy women. As specific objectives, the percentages of CD3^-CD56⁺ Natural Killer total cells, CD56^brightCD16^dim effector subpopulation, CD56^dimCD16^bright cytotoxic subpopulation, NKG2A inhibition receptor, NKG2D activation receptor, and NKT cells were analyzed. In addition, the levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70, and TNF and the chemokines CCL5/RANTES, CXCL9/MIG, CCL2/MCP-1, and CXCL10/IP-10 were also analyzed. Natural Killer total cells showed an increase in their percentage in both exercise protocols (p = 0.001 for the moderate-intensity group and p = 0.023 for the high-intensity group); however, only in the high-intensity exercise session was there an increase in the CD56^dimCD16^bright cytotoxic subpopulation (p = 0.014), as well as a decrease in CD56^brightCD16^dim effector subpopulation (p = 0.001) and their NKG2A inhibition receptor (p = 0.043). An increase in IL-6 was observed after the high-intensity exercise session (p = 0.025). Conclusions. Physical exercise influences immunological markers and shows an acute response to moderate- or high-intensity exercise.

Keywords: Natural Killer cells; cytokine profile; exercise.

Figure 1

Fluorescence Minus One (FMO) and Gate Strategy. Representation of the Fluorescence control Minus One. The dot plot of the unstained control, FMO control, and fully stained sample is shown for each fluorochrome. The blue line represents the limit of the unstained sample, and the red line the FMO limit. The Gate Strategy shows the analysis of NK total cells, their NK effectors CD56^brightCD16^dim and NK cytotoxic CD56^dimCD16^bright subpopulations, and their NKG2A and NKG2D receptors, as well as NKT cells CD3⁺CD56⁺. Subpopulations of NK cells were derived from the NK total population CD3^-CD56⁺.

Figure 2

Acute response of the Natural Killer sub-populationto a single load of physical exercise at moderate and high intensity and the difference in response between both intensities Paired Student’s t-test for related samples and Student’s t-test for independent samples. * significant differences p-value < 0.05.

Figure 3

Acute response of the cytokine profile to a single load of physical exercise at moderate and high intensity and the difference in response between both intensities. Paired Student’s t-test for related samples and Student’s t-test for independent samples. * significant differences p-value < 0.05.

Figure 4

Acute response of the chemokines profile to a single load of physical exercise at moderate and high intensity and the difference in response between both intensities Paired Student’s t-test for related samples and Student’s t-test for independent samples.