Zymosan phagocytosis by mouse peritoneal macrophages is increased by apoHDL- and not by intact HDL-covered particles

Abstract

The uptake of lipids and lipoprotein particles by macrophages undergoes phagocytic activation and the formation of foam cells are key events in atherosclerosis. In this study we determined how intact high density lipoproteins (HDL) and apolipoproteins-HDL (removal of the lipid component from HDL, i.e., apoHDL) influence the phagocytosis of zymosan by mouse peritoneal macrophages. Zymosan particles preincubated together with lipoproteins or alone (control) were incubated with the macrophages. Phagocytosis activity was reported as the percent of macrophages that internalized three or more zymosan particles. HDL co-incubated with zymosan did not influence the overall uptake of zymosan particles compared to apoHDL, which greatly enhanced the ability of the particle to be phagocytized (P<0.001). Part of this effect might be related to a greater binding of apoHDL to the particles compared to that of HDL (P<0.05). We conclude that this can be a useful method to study the ability of lipoproteins, including modified lipoproteins obtained from subjects with genetic forms of hyperlipidemia, to opsonize particles such as red blood cells and thus to investigate the processes that control the formation of foam cells and the mechanisms of atherogenesis.

Further characterization of a highly attenuated Yersinia pestis CO92 mutant deleted for the genes encoding Braun lipoprotein and plasminogen activator protease in murine alveolar and primary human macrophages

“…In comparison, MH-S and RAW 264.7 murine macrophages both exhibited greater zymosan bead uptake (25 to 60%), and this difference was most likely related to the source of macrophages: human versus murine. A similar uptake rate of zymosan beads (~23.6%) was reported for the murine peritoneal macrophages [58]. …”

High-Density Lipoprotein Inhibits the Uptake of Modified Low- Density Lipoprotein and the Expression of CD36 and FcγRI

“…We observed that the uptake of LDL and mLDL diminished in the presence of HDL in both cell lines, as demonstrated by the decrease in FITC-relative fluorescence intensity. This finding is in line with our previous data showing that HDL inhibits the uptake of triacylglycerol-rich emulsion particles in mouse peritoneal macrophages 21,22) . We believe that THP-1 and U-937 cells may have catalyzed the mild oxidation of LDL (moxLDL) since we demonstrated that LDL is minimally oxidized in vitro by macrophages 14) affecting its recognition by LDL receptor 45) .…”

“…We have previously demonstrated that HDL diminishes the capacity of macrophages to promote the phagocytosis of zymosan (an insoluble fraction of yeast cell walls) and uptake of triacylglycerol-rich emulsion particles in mouse peritoneal macrophages 21,22) .…”

Temporal expression of cyclooxygenase-2 in peritoneal macrophages of rats and effects of panax notoginseng saponins

“…The cells were cultured at 37 °C in humidified air with 5 % CO 2 for 1 h. Non-bound cells were removed by washing. And the macrophages were resuspended with 0.2 % trypsin and washed with PBS [17]. Twenty microliters of a cell suspension was smeared on slides, air-dried at room temperature, fixed in methanol for 10 minutes, and then stained with Giemsa.…”

“…Non-bound cells were removed by washing. And the macrophages were resuspended with 0.2 % trypsin [17]. Real-time PCR was performed as described previously [18，19].…”