Transpleural Mobilization of Clasmatocytes with Coincident Streptococcus Protection.

Abstract

In a recent article 1 we have shown that the presence of granulation tissue in the parietal pleura of the rabbit, produced by previous introduction into the pleural cavity of indifferent substances, protects the animal against many fatal doses of a streptococcus that normally causes a fatal pleurisy. The marked phagocytosis of the streptococcus by the clasmatocytes, which are the predominating cells in this granulation tissue, is regarded as responsible for this type of active resistance against our invasive microorganism. In a more general way we should regard the accumulation of these rather mobile and resistant mononuclear cells of the connective tissue, as responsible for at least certain instances of local immunity.

In the latest of our published experiments we have indicated that clasmatocytes accumulated in the parietal wall of one pleural cavity may be transferred to the other pleural cavity and there likewise protect against the streptococcus. A granulating right pleural wall was effected in a routine fashion by injecting aleuronat-starch mixture or gum arabic broth three days previously. The parietal wall of the treated cavity is from five to ten times as thick as usual, but the wall of the opposite cavity remains normal. If one injects multiple fatal doses of the streptococcus into the left untreated cavity, the rabbit, however, recovers perfectly, although sterilization of the cavity is distinctly slower than when the infection takes place on the right treated side. Histological examination at this stage of the two sides shows that the originally treated right pleura is thickened as usual but consists of myxomatous tissue in place of the densely cellular granulation tissue usually met with.