Effect Of NE On NK92-MI Cell Migration And Chemokine Receptor Expression

PrefaceThe concept of stress is originally introduced by Endocrinologist H. Selye in the 1930s, which refers to the nonspecific systemic reactions induced by various internal and external stimulus, including physiological factors, psychological factors, or both of them. Stress can cause cardiovascular system, central nervous system, and immune system disorder, or even serious diseases and death. With the social development, environmental changes, and rapid pace of life, stress has been a threat to human health which can not be ignored.It is widely believed that stress impairs immune function. However, existing studies have shown that chronic stress suppresses immune function while short-term acute stress can enhance immune function and health, which partially dues to the effect of stress hormones on immune cells migration. The number of human peripheral blood NK cells rapidly increased during acute stress. This response reflects a release of NK cells from various reservoirs. Nevertheless, articles which refer to how stress impacts such redistribution of NK cells are scarce. Therefore, we detected NK92-MI cell migration and chemokine receptor expression, treated by NE, to understand the possible mechanisms which regulate such redistribution.Materials and Methods1. Transwell assay was applied to detect NK92-MI cells migration, which were induced by different concentration of NE (5×10-12M,5×10-10M,5×10-9M,5×10-8M, 5×10-6M).2. Treated NK92-MI cells with different concentration of NE (5×10-12M,5×10-10M, 5×10-9M,5×10-8M,5×10-6M) for 20 minutes,40 minutes,1 hour,2 hours, and 4 hours respectively. Real-Time PCR was applied to detect chemokine receptor CCR5, CCR7, CXCR3, CXCR4, CX3CR1 mRNA expression of different experimental groups, and then detected chemokine receptor mRNA expression afterβ-adrenergic receptor blocker propranolol was administrated.4. Treated NK92-MI cells with different concentration of NE (5×10-10M,5×10-9M, 5×10-8M) for 1 hour. Flow cytometry was applied to detect NK92-MI cells surface chemokine receptor CCR5 expression of different experimental groups.5. MTT assay was applied to detect the cytotoxicity of NK92-MI cells which were treated by different concentration of NE for 1 hour.Results1. High concentration of NE (5×10-6M,5×10-8M,5×10-9M) significantly promoted NK92-MI cells migration (P<0.05). With NE concentration decreased, such activity became weak, or even disappeared.2. Real-Time PCR results showed CCR5 and CX3CR1 mRNA expression changed significantly, trending consistently.5×10-9M NE group had the most obvious activity. When NK92-MI cells were treated by such concentration of NE for 1 hour, CCR5 and CX3CR1 mRNA expressed the most.5×10-7M propranolol blocked this activity.3. FACS results suggested that CCR5 didn't express on the NK92-MI cells surface.4. When the ratio of NK92-MI cells to K562 cells is 4 to 1, high concentration of NE (5×10-5M,5×10-6M) significantly suppressed the cytotoxicity of NK92-MI cells (P＜0.05). Other concentration of NE (5×10-7M,5×10-8M,5×10-9M,5×10-10M, 5×10-11M,5×10-12M) suppressed such cytotoxicity, but the difference was not significant comparing with control group (P>0.05).ConclusionsStress concentration of NE can promote NK92-MI cell migration directly and does not suppress the cytotoxicity significantly. Stress concentration of NE can enhance chemokine receptor CCR5 and CX3CR1 mRNA expression obviously when NK92-MI cells are treated for 1 hour, and this activity can be blocked by nonselectiveβ-adrenergic receptor blocker propranolol. However, FACS results suggested that CCR5 didn't express on the NK92-MI cells surface.