Expression of macrophage CD14 receptor in the course of experimental inflammatory responses induced by lipopolysaccharide and muramyl dipeptide

Abstract

AbstrACt:The aim of this study was to determine whether expression of CD14 on macrophages is regulated differently during initiation and resolution of the inflammatory response caused by CD14-dependent (lipopolysaccharide) and CD14-independent (muramyldipeptide) bacterial signals. In cell suspensions from the site of inflammation we observed two types of macrophages: non-vacuolized ( N MAC) and vacuolized ( V MAC) cells. N MAC (monocyte-like cells) were dominant during the early stage of the inflammatory response, whilst V MAC contained phagocytosed apoptotic neutrophils in various stages of digestion. These latter cells were dominant during resolution (particularly at the last time point of 168 h). Intramammary instillation of muramyldipeptide (MDP) and lipopolysaccharide (LPS) resulted in a significant increase in the total count of CD14+ N MAC after 24 h (muramyldipeptide P < 0.01 and lipopolysaccharide P < 0.05) compared to phosphate buffered saline (PBS). During resolution of the inflammatory response, a gradual decrease in the total count of CD14+ N MAC was observed. The difference compared with PBS was significant at 48 h and 72 h after instillation of both bacterial agents (muramyldipeptide: P < 0.05; lipopolysaccharide: P < 0.05). A lower total count of CD14+ V MAC was observed as an effect of MDP and LPS at 24 h after induction (P < 0.05), when compared to PBS. During resolution, the total count of CD14+ V MAC increased. Differences (P < 0.01) were observed at 72 h and 168 h after LPS compared to PBS. We therefore assume that the expression of CD14 on macrophages is not regulated differently during the inflammatory responses caused by CD14-dependent and CD14-independent bacterial signals. On the other hand, the stage of the inflammatory response to MDP and LPS played an important role in the regulation of CD14 expression on macrophages.

Effect of Lipopolysaccharide and Muramyl Dipeptide on Apoptosis of Bovine Mammary Gland Lymphocytes

“…The biggest increase occurred after using LPS. These findings are not surprising, and they are consistent with previous studies [ 30 , 34 ]. The lymphocyte ratio in the differential cell count gradually increased after LPS induction in comparison with controls; and also after MDP induction, where the increase in lymphocyte ratio was greater.…”

“…In our experiments, we used 5 μg of LPS or 500μg of MDP. Such concentrations have been chosen because they have been tested and used before [ 30 , 34 ]. We used lower concentrations of LPS than MDP because it is a stronger inducer of inflammation.…”

Effect of Streptococcus uberis infections on cell population of bovine mammary gland

“…These inflammatory macrophages are called nonvacuolized macrophages (Jensen and Eberhart, 1975;Sladek and Rysanek, 2008). Structural changes occur during the maturation to fully immunocompetent cells.…”

“…Such cells increase in size and show abundant cytoplasm containing many granules (Wardley et al, 1976). These cells are called as vacuolized macrophages (Jensen and Eberhart, 1975;Sladek and Rysanek, 2008). These macrophages represent a dominant population of macrophages in the resolution of the inflammatory response (Wardley et al, 1976;Sladek and Rysanek, 2008).…”

Interaction of an opportunistic fungus Purpureocillium lilacinum with human macrophages and dendritic cells

“…For differentiation into DCs, monocytes were incubated in the presence of 100U/mL recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF; Peprotech, Rocky Hill, NJ, USA) and 1,000U/mL recombinant human interleukin-4 (rhIL-4; Peprotech) as described above 17,18 . For phenotypic evaluation, cells were washed with 200µl PBS containing 0.1% bovine serum albumin and 0.01% sodium azide and stained with fl uorescein isothiocyanate (FITC)-conjugated monoclonal antibodies against cluster of differentiation 14 (CD14) and peridinin-chlorophyll protein-cyanine dye (PerCPCy5.5)-conjugated CD209, also known as dendritic cell-specifi c intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) [19][20][21] , on ice for 60min. Cells were washed and analyzed using an Accuri C6 fl ow cytometer (Accuri Cytometers Inc., Ann Arbor, MI, USA) and the FlowJo TM software (Tree Star, Ashland, OR,USA).…”