Philothermal and chemotactic locomotion of leukocytes. Method and results

A newly developed technique for quantitating the locomotion of polymorphonuclear leukocyte (PMN) populations in temperature gradients has revealed that PMNs accumulate toward higher temperatures. The experiments yield measurements of the numbers of cells that adhere to glass and migrate from a cell suspension through a liquid/gel meniscus into a glass/agarose interface, and of their spatial distribution at subsequent time intervals. Cell locomotion was investigated as a function of the magnitude, sign, and temporal variation of the temperature gradient, the cell concentration in the source suspension, and the presence or absence of chemoattractant gradients. It was found (1) that a temperature gradient stimulates crossing of the meniscus toward higher temperatures, (2) that only a portion of the cells reverses direction of locomotion in response to reversal of the temperature gradient after the cells have traversed the meniscus, and (3) that the distribution of cells in the migration space depends on cell concentration, suggesting that the dynamics of PMN locomotion depend on cell-cell interactions.