Energization of lymphocytes transforming to macrophages in human inflammation

Abstract

Transformation of circulating small lymphocytes to macrophages in cell culture and phytohemagglutinin or immunologic stimulation of peripheral blood lymphocyte transformation into large primitive stem cells capable of mitotic division have previously been demonstrated. We have directed our attention to the mode of energization of lymphocytic hypertropy to macrophages in vivo. Appropriately controlled Hotchkiss-Lillie alcoholic-PAS (glycogen) reactivity was followed in the exudative leukocytes responding to an antigenic stimulus in human skin windows. At a critical stage (6–14 hr) of inflammation, in which migration of neutrophils was equalled by migration of lymphocytes, glycogen from neutrophils was shed as cytoplasmic particulates and fragments into the exudative fluids to gain access to the lymphocytes or, more commonly, glycogen transfer was effected by neutrophil-lymphocyte apposition. In such transfers, glycogen first surrounded the lymphocytic cytoplasmic membrane, became incorporated into the membrane, appeared in pinocytotic aggregates just beneath the membrane, and finally underwent dispersion and glycolysis within the cytoplasm. The small number of responding monocytes and histocytes similarly acquired additional glycogen from the neutrophils as they became activated to macrophages. In human skin windows, as in peripheral blood cultures, the infrequent monocytes were identified by direct measurements as well as by structural characteristics. In insulin-deficient patients, neutrophilic cytoplasmic glycogen accumulated in excessive amounts as transfer to lymphocytes failed.