Changes in Cellular Enzyme Levels and Extracellular Release of Lysosomal Acid Hydrolases in Macrophages Exposed to Group a Streptococcal Cell Wall Substance

Abstract

Infection by group A streptococci may lead to chronic inflammatory lesions of the myocardium, heart valves, joints, and skin. The pathogenesis of these lesions remains uncertain (1), and several experimental animal models have been used to study chronic inflammation induced by group A streptococci and their extracellular products (2). Cell wall preparations containing only type-specific polysaccharide and peptidoglycan (PPG) 1 have the capacity to induce chronic-recurring granulomatous lesions in the skin of rabbits (3), lesions resembling those of rheumatic fever in the hearts of mice (4) and rabbits (5), and severe polyarthritis in rats (6). Available evidence indicates that PPG induces inflammatory lesions by direct interaction with infiltrating leukocytes, rather than by an immunopathologic mechanism (7). In experimental lesions, PPG becomes associated with macrophages (3), and it appears that these cells lack .the ability to digest the material (5, 8-11). These observations have led us to investigate the effects of PPG on mouse peritoneal macrophages maintained in culture. We have found that PPG, at concentrations which do not appear to be cytotoxic, induces marked morphologic and biochemical changes in these cells. They undergo a three-to fourfold increase in size, and there is a significant elevation in the levels of acid hydrolases and other cellular enzymes. Furthermore, there is a selective release of the hydrolases into the extracellular environment with no detectable loss of cell viability. Materials and MethodsMaterials.--Bovine pancreatic ribonuclease (type I-A), twice crystallized pancreatic trypsin (type III), phenolphthalein glucuronic acid 0.01 M, pH 7.0; o-nitrophenyl-/3-1)-galactopyranoside, leucine-2-naphthylamide, ¢z-naphthyl acid phosphate and glycogen type II (from

Selective Effects of Glucocerebroside (Gaucher's Storage Material) on Macrophage Cultures

“…The addition of GL1 caused an increase in the release of the monokine, LAF, the lysosomal enzyme, hexosaminidase, and the cytoplasmic enzyme, LDH, in a dosedependent fashion. The increase in release of LDH indicatps cell damage (15,16). It is noteworthy that the release of LAF and hexosaminidase was particularly elevated at toxic doses of GL1, although an apparent increase in LAF release was observed in cultures with no detectable elevation of LDH release (with GL1 at -20 ,ug/ml or less).…”

Human Alveolar Macrophage Growth Factor for Fibroblasts

“…This peak contained 1.2 Ag protein and a total relative growth promoting activity of 105. Gel filtration of the major DEAE cellulose peak on Sephadex G-75 revealed one significant peak of fibroblast growth-promoting activity with an apparent molecular weight of 18,000; this peak contained 60 ng protein with a total relative growth promoting activity of 104. Thus, assuming a molecular weight of 18,000, the alveolar macrophage-derived growth factor appears to be active in the nanomolar to picomolar range.…”

The differentiation state of monocytic cells affects their susceptibility to infection and the effects of infection by dengue virus

“…Increases in trypan blue-staining cells were particularly marked in virus-antibody complex infections (Table 2). A second quantitative method used to study the cytolytic effect was measurement of the enzyme lactate dehydrogenase (LDH) released into the supernatant fluid, as described by Davies et al (1974). Differentiated U937 cells disperse unevenly at a low cell density and have a high serum requirement.…”

“…Medium was changed 24 h before measurements. At 3 and 7 days post-infection adherent cells were stained with trypan blue and LDH was measured in adherent cell and supernatant fractions (Davies et al, 1974) using Sigma kit LDH-L10. Viability loss is expressed as percentage of cells staining blue or supernatant LDH as a percentage of total LDH.…”