The Pathophysiology of Phagocytes

No survey of clinically important immunological phenomena would be complete without consideration of the functions of phagocytic cells. They play a pivotal role in the immune response by kiling microbes, by presenting antigens to lymphocytes and by serving as supportive, accessory cells to lymphocytes, at least partly by releasing soluble factors. The phagocytes of the body, professional and non professional, consist of two specialized groups of cells: granulocytes, which can be mobilized rapidly and which reach inflamed sites quickly and in large numbers, and which are highly efficient at dealing with many types of injury and infection but which have no capacity for differentiation and live only a short time; and the mononuclear phagocyte system consisting partly of motile cells which respond initially more slowly than neutrophils but which can differentiate in sites of inflammation into cells which are more efficient in various functions than the cells from which they originated. Many mononuclear phagocytes are fixed cells located in tissues where they act as trays or filters for material circulating through the tissue. Phagocytes, which usually function as the primary defender in infections, have also been implicated as effector cells in several conditions characterized by a destructive inflammatory response.

In vivo and in vitro HeNe laser effects on phagocyte functions

The goal of this work was to evaluate the effect of helium-neon (HeNe) laser irradiation on immunocompetent cells. We used the in vivo skin window method and in vitro granulocyte function tests. The study of cellular migration showed a marked decrease in vitro and in vivo in a dose-independent manner. Superoxide release was not modified by laser irradiation. The granulocyte's aggregation, when using PHA and PMA, presented a reduction that was statistically very significant, not as a subordinate dose. An increase of the release of ATP was demonstrated only at 4 joules and precedes granulocyte aggregation. When using Ca2+ ionophore A23187 as stimulus, laser irradiation at 1, 2 or 4J did not show any modification of granulocyte aggregation. The monoclonal antibody 60.1, which identifies a membrane antigen fundamental for aggregation and chemotaxis, is expressed in normal amounts on granulocyte membranes both before and after irradiation with a HeNe laser. In fact, Laser irradiation preferentially attacks the area of the cellular centrosome that determines a modification of cellular morphology. The electron microscope and immunofluorescence study with a monoclonal antibody have pointed out a disorganization of the microtubules. The alteration of some of the granulocyte functions is correlated to the damage in the centrioles. The granulocyte mitochondrial system and surface membrane remain intact, and this explains the normal production and release of free radicals. Further experiments are necessary to evaluate the clinical application of lasers in various diseases with immunophagocytic pathogenesis.