The chemical aspects of immunity / by H. Gideon Wells.

  • Harry Gideon Wells
Date:
1925
Catalogue details

Licence: In copyright

Credit: The chemical aspects of immunity / by H. Gideon Wells. Source: Wellcome Collection.

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    are acted upon by substances lowering surface tension, show that it is possible to cause such droplets to simulate in a most remarkable way the behavior of leucocytes and amebse. However, it is not established that all the manifestations of chemotaxis and phagocytosis depend on surface tension alterations. Phagocytosis, the ingestion of the bacteria or foreign particles by the cells, seems to be merely an extension of the process of chemotaxis, the cell flowing about the particle to which it has been attracted. In order that phagocytosis may take place it is necessary that both col- loids and electrolytes be present. The phagocytosis of bacteria is greatly augmented by the presence of specific substances which are increased in amount by immunization. These activating substances, called opsonins or tropins, seem to be true antibodies, but it has not yet been determined whether they are different from the antibodies responsible for the other immunological reactions. Neither has it been determined to how great an extent the infecting bacteria are devital- ized by the antibodies of the plasma before they are taken up by the phagocytes, and how much of the destruction of virulent bacteria is accomplished within the phagocytic cell. Fundamentally, serum bacteriolysis and bacterial destruction by phagocytosis seem to be the same—in each case specific antibody sensi- tization prepares the bacterium for lysis by enzymes, either inside or outside the cells that furnish the lytic enzyme. It would seem that opsonization and phagocytosis constitute but one of a series of similar processes by which foreign proteins are re- moved from the blood and tissue; i.e., by lysis by extracellular en- zymes when this is possible, as it is with simple protein aggregates (albuminolysis) and with some of the more labile cells (hemolysis, bacteriolysis) ; but in the case of more resistant structures, notably Gram-positive cocci and acid-fast bacilli, extracellular lysis being un- successful, these protein structures are taken within the cells where a greater concentration of enzymes may destroy them. references 1 See review by F. P. Gay, Physiological Reviews, 1924 (4), 191. 2 Wells, Chemical Pathology,” 4th Ed., 1920, Chap. XI, pp. 247-267. s Wells, H. G., Chemical Pathology, 1st Edition, W. B. Saunders Co., 1907- 4 Munch, med. Woch., 1906 (53), 2041. 6 Anatomical Record, 1912 (6), 91. 8 Jour. Gen. Physiol., 1921 (3), 465; 1923 (5), 31X« 7 W. O. Fenn, Jour. Gen. Physiol., 1921 (3), 439. 575! J922 (4), 330 3731 7923 (5), >43. 169. 8 Jour. Hyg., 1920 (19), 3°9-