サイトカイン濃度勾配が好中球の推進機構へ及ぼす影響に関する研究

-膜特性を考慮したサイトカインの濃度輸送について-

抄録

In the immunological systems, the neutrophil’s motion is considered to be propelled by concentration gradient of cytokine. However, the mechanism of propulsion has not been elucidated yet in the previous researches. Assuming that neutrophil moves by the concentration Marangoni effect, concentration gradient of cytokine on the surrounding fluid and neutrophil membrane is experimentally examined. In our previous investigations, it was found that the concentration gradient on the neutrophil membrane repeats positive and negative ⁽¹⁾. Moreover, it was found that a neutrophil has pseudopods near the inner wall surface of the blood vessel ⁽²⁾. In this study, the effect of pseudopods is investigated.

As for the experimental methods, the neutrophils are observed by a microscope. Concentration gradient of surrounding fluid is generated by inserting cytokine solution into the neutrophil dispersion. Using CCD camera, the neutrophil’s propulsion and concentration distribution are obtained by measuring emission intensity of fluorescent substance FITC. Based on the neutrophil velocity obtained from this observation, the effects of pseudopods on the propulsion mechanism are evaluated. The result shows that the propulsion mechanism of the neutrophils depends on the cytokine concentration with or without pseudopods. It is also found that neutrophils with pseudopods move slower than the neutrophils without pseudopods.