Chemotaxis of human leucocytes: II. Effects of lectins, colchicine, cytochalasin B, cyclic nucleotides and immuno-stimulatory products.

Drugs or products acting as chemo-modulators were assayed for their effect on the chemotactic activity of human normal neutrophils by a method of direct microscopic observation. Lectins (PHA-P and Con A) have an inhibitory effect at the level of 10 micrograms/ml. Colchicine and Cytochalasin B have also an inhibitory effect at the level of 0.25.10(-6)M/ml and 0.20 micrograms/ml. For the cyclic nucleotides: dibutyryl cAMP and products such as norepinephrine, aminophylline that raise the cellular level of cAMP have an inhibitory effect, and whereas cGMP and carbamylcholine have a stimulatory effect Imidazole and levamisole, have some enhancement of chemotaxis but it is not significant. Lectins by binding to cell surface receptors which assume the recognition of a chemotactic gradient in the environment, colchicine and cytochalasin B by interfering with the cytoskeletal elements (microtubules and microfilaments) cyclic nucleotides involved in the metabolic activity during the cell motility. The data show that the integrity of one of these three sequences is necessary for the normal activity of chemotasxis. Animal and human models (i.e. mutant mouse bg/bg and Chediak-Higashi syndrome) give some clue of their interrelation.