Search results

Sort By:

Limit search:

Recognition of apoptotic cells by human peripheral blood monocytes does not alter their ability to phagocytize and kill Staphylococcus aureus

100%

Zuba E., Weglarczyk K., Barczyk K., Pryjma J.

Archivum Immunologiae et Therapiae Experimentalis

2004

vol. 52

issue 1

50-58

During acute inflammation, leukocyte infiltration is mostly neutrophilic, but later monocytes prevail. The majority of inflammatory cells, particularly neutrophilic polymorphonuclear leukocytes (PMNs), become apoptotic at later stages of inflammation and are phagocytosed by neighboring cells, mostly by macrophages. Recently, it has been found that human peripheral blood monocytes also recognize apoptotic cells, which primes them to increased production of interleukin (IL)-10 ? a cytokine known to reduce phagocytes' ability to engulf and kill pathogens. Based on the above, we studied monocytes' ability to phagocytose and kill Staphylococcus aureus while in contact with apoptotic cells. Materials Monocytes isolated by elutriation were co-cultured with apoptotic PMNs or Jurkat cells and exposed to viable, human serum-opsonized S.aureus. To induce apoptosis PMNs were cultured overnight while Jurkat cells were UV-treated. Apoptosis, phagocytosis of bacteria and intracellular superoxide production were measured by flow cytometry. Production of reactive oxygen species was also followed by measurement of chemiluminescence. The bactericidal effect was determined by standard colony forming units method. Data presented show that contact of monocytes with apoptotic neutrophils and Jurkat cells had no influence on monocyte phagocytosis of S. aureus, the generation of reactive oxygen species, or the killing of bacteria.The data obtained suggest that monocytes attracted to the inflammatory site are not deficient in their ability to cope with pathogens after contact with apoptotic cells despite increased production of IL-10.

Biological activity of dendritic cells generated from cord blood CD34+ hematopoietic progenitors in IL-7- and IL-13-conditioned cultures

100%

Mytar B., Stec M., Weglarczyk K., Zembala M.

2009

vol. 59

issue 1

67-74

Introduction: Dendritic cells (DCs) are required for initiation of the immune response and may therefore be used for the production of cancer vaccines. As mature DCs (mDCs) are the most potent antigen-presenting cells, there is increasing interest in generating them ex vivo. The present study was designed to obtain mDCs from CD34+ hematopoietic progenitors by culturing them in different media. Materials and Methods: Cord blood CD34+ hematopoietic progenitors were expanded for 7 days in FST medium containing fms-related tyrosine kinase 3 ligand (Flt3-L), stem cell factor (SCF), and thrombopoietin (TPO). Then the cells were divided into three parts and cultured for 21 days in different media: FST medium or FST enriched in interleukin (IL)-3 (FST3 medium) or supplemented with IL-7 and IL-13 (FST713 medium). At the end of culture part of the cells was harvested, counted, and analyzed while the other part was matured with proinflammatory cytokines for 2 days. The cells' phenotypes, ability to induce proliferation of allogeneic lymphocytes in the mixed lymphocyte reaction (allo-MLR), chemotaxis, phagocytosis, and O2? production were determined. Results: The average fold increase of DCs at the end of culture in FST medium was 127, in FST3 1043, and in FST713 71. In comparison with the other media, FST713 medium supported the generation of mDCs that were characterized by higher expressions of CD83, costimulatory molecules, and HLA-DR, enhanced ability to induce allo-MLR and migration to macrophage inflammatory protein (MIP) 3?, poor phagocytosis, and O2? production. Conclusions: This study indicates that FST713 medium allows the generation of limited numbers of more mature DCs, while FST3 medium leads to the production of immature DCs in high numbers.

Refine search results

2 Archivum Immunologiae et Therapiae Experimentalis

1 2009

1 2004

2 Weglarczyk K.

1 Barczyk K.

1 Mytar B.

1 Pryjma J.

1 Stec M.

1 Zembala M.

1 Zuba E.

Search results

Recognition of apoptotic cells by human peripheral blood monocytes does not alter their ability to phagocytize and kill Staphylococcus aureus

Biological activity of dendritic cells generated from cord blood CD34+ hematopoietic progenitors in IL-7- and IL-13-conditioned cultures