Chemotactic factor receptor modulation and cytoskeletal structures

The microfilament-disrupting agents cytochalasins A, B, and D were shown to impair the binding of the chemotactic factors [3H]formylmethionylleucylphenylalanine and 125 I-labeled crystal-induced chemotactic factor to their neutrophil receptor. Scatchard plot analysis revealed a decrease of the available binding sites in the cytochalasin B-treated cells. Cytochalasin B showed the same inhibitory profile on intact cells and on a membrane-rich preparation, suggesting that the effect was not dependent on an intact microfilament apparatus. The microtubule modifiers colchicine and vinblastine had no effect on the binding of the chemotactic factor to its cell receptors