Search results for "macrophage"
showing 10 items of 781 documents
In vitro synthesis of factor B of the alternative pathway of complement activation by mouse peritoneal macrophages
1976
Factor B of the alternative pathway of complement activation was shown to be synthesized and secreted by unstimulated mouse peritoneal macrophages. The activity of B in the culture supernatants from macrophage monolayers was detected by consumption of C3 in reaction mixtures containing supernatant and guinea pig factors C3, D and insoluble C3b. Using a monospecific antiserum, factor B in concentrated culture supernatants was shown by immunodiffusion and immunoelectrophoresis to be identical to factor B in mouse plasma and to form a characteristic complex with cobra venom factor in the presence of D. A steady rate of factor B secretion was observed for 4 days providing the medium was changed…
Influence of Macrophage Activation on the Synthesis of Complement Components C2, C3, C4
1982
Macrophages are a major site of complement synthesis. In the guinea pig production of complement components C1, C2, C4, C3, D, B, and P by peritoneal macrophages has been demonstrated (reviewed in Ref. 1). Whereas marked differences exist in biological activity between resident, elicited and activated macrophages (2), we investigated whether this holds true for the synthesis and secretion of complement components C2, C3, and C4.
Direct Toll-Like Receptor-Mediated Stimulation of Hematopoietic Stem and Progenitor Cells Occurs In Vivo and Promotes Differentiation Toward Macropha…
2012
Abstract As Toll-like receptors (TLRs) are expressed by hematopoietic stem and progenitor cells (HSPCs), they may play a role in hematopoiesis in response to pathogens during infection. We show here that TLR2, TLR4, and TLR9 agonists (tripalmitoyl-S-glyceryl-L-Cys-Ser-(Lys)4 [Pam3CSK4], lipopolysaccharide [LPS], and CpG oligodeoxynucleotide [ODN]) induce the in vitro differentiation of purified murine lineage negative cells (Lin−) as well as HSPCs (identified as Lin− c-Kit+ Sca-1+ IL-7Rα− [LKS] cells) toward macrophages (Mph), through a myeloid differentiation factor 88 (MyD88)-dependent pathway. In order to investigate the possible direct interaction of soluble microorganism-associated mol…
Hemophagocytic Lymphohistiocytosis in Early Infancy- Pitfall of Differentiation between Hereditary and Infectious Reasons
2018
Abstract Hemophagocytic Lymphohistiocytosis (HLH) is characterized by pathologic immune activation which occurs either as a familial disorder or as an acquired condition. The diagnosis of HLH requires the presence of five out of nine criteria: fever, splenomegaly, pancytopenia, hypertriglyceridemia, hypofibrinogenemia, hemophagocytosis in bone marrow, hyperferritinemia, low or absent natural killer cell activity and high level of soluble interleukin-2 receptor. Here we present a 6-month-old girl with parents from Southern Italy. She suffered from hepatosplenomegaly and a recurrent high fever for 3 months' duration. On admission, she showed neurological symptoms including irritability and ne…
Macrophage MerTK promotes profibrogenic cross-talk with hepatic stellate cells via soluble mediators
2022
Background & aims: Activation of Kupffer cells and recruitment of monocytes are key events in fibrogenesis. These cells release soluble mediators which induce the activation of hepatic stellate cells (HSCs), the main fibrogenic cell type within the liver. Mer tyrosine kinase (MerTK) signaling regulates multiple processes in macrophages and has been implicated in the pathogenesis of non-alcoholic steatohepatitis-related fibrosis. In this study, we explored if MerTK activation in macrophages influences the profibrogenic phenotype of HSCs. Methods: Macrophages were derived from THP-1 cells or differentiated from peripheral blood monocytes towards MerTK+/CD206+/CD163+/CD209- macrophages. Th…
Stimulation of pancreas and gastric carcinoma cell growth by interleukin 3 and granulocyte-macrophage colony-stimulating factor.
1991
Hematopoietic growth factors have recently been well characterized by complementary DNA scloning. For human epidermal growth factor, granulocyte-macrophage colony-stimulating factor recombinant proteins have been expressed in Escherichia coli . To reduce the toxic side effects of chemotherapy on the bone marrow, recombinant human granulocyte-macrophage colony—stimulating factor and recombinant human interleukin 3 were applied to patients suffering of gastrointestinal cancers. To determine the influence of recombinant human granulocyte-macrophage colony—stimulating factor and recombinant human interleukin 3 on human pancreas and gastric cancer cell cells in vitro, a sensitive microculture te…
Expression of Ia-antigens on guinea pig Kupffer cells
1986
Summary The expression of the Ia-antigen on guinea pig Kupffer cells was studied employing two monoclonal antibodies against two different determinants of the Ia-molecule. The study was performed in situ on liver sections and on isolated highly purified Kupffer cells kept in culture up to 6 days. The influence of guinea pig hepatocyte culture supernatant and of supernatants of phytohemoagglutinin (PHA)-stimulated human peripheral blood lymphocytes (PBL) on the Ia expression was measured. Immunofluorescence staining of cryostat sections revealed that the monoclonal antibodies used are able to detect Ia-antigens on liver macrophages in situ. The in vitro studies strongly suggest that all Kupf…
Changes in immunohistochemical levels and subcellular localization after therapy and correlation and colocalization with CD68 suggest a pathogenetic …
2011
In an earlier work, the role of heat shock protein (Hsp60) in the pathogenesis of ulcerative colitis (UC) was suggested by its significant increase in the pathological mucosa parallel with an increase in inflammatory cells. More data in this direction are reported in this work. We analyzed by immunohistochemistry biopsies of colon tissue from 2 groups of patients with UC and treated with either 5-aminosalicylic acid (5-ASA) alone or in combination with a probiotic. We looked for inflammatory markers and Hsp60. Both the treatments were effective in reducing symptoms but the group treated with both 5-ASA and probiotics showed better clinical results. Amelioration of symptoms was associated wi…
Cell types infected in human cytomegalovirus placentitis identified by immunohistochemical double staining
1993
Chronic villitis is almost always present in intrauterine infection with human cytomegalovirus (HCMV). The inflammatory response to this virus has been described in detail. However, little is known about the types of placental cells that may be infected by HCMV and six cases of HCMV placentitis were thus investigated to identify the vulnerable cell types. Immunohistochemical double staining analyses were performed using antibodies to HCMV immediate early antigens and to specific cellular marker proteins. Fixed connective tissue cells could be demonstrated to be the predominantly infected cell type in each placental tissue. Endothelial cells and macrophages were also found to be infected in …
The viral chemokine MCK-2 of murine cytomegalovirus promotes infection as part of a gH/gL/MCK-2 complex.
2013
Human cytomegalovirus (HCMV) forms two gH/gL glycoprotein complexes, gH/gL/gO and gH/gL/pUL(128,130,131A), which determine the tropism, the entry pathways and the mode of spread of the virus. For murine cytomegalovirus (MCMV), which serves as a model for HCMV, a gH/gL/gO complex functionally homologous to the HCMV gH/gL/gO complex has been described. Knock-out of MCMV gO does impair, but not abolish, virus spread indicating that also MCMV might form an alternative gH/gL complex. Here, we show that the MCMV CC chemokine MCK-2 forms a complex with the glycoprotein gH, a complex which is incorporated into the virion. We could additionally show that mutants lacking both, gO and MCK-2 are not ab…