Project description:Influence of soluble Siglec-14 on macrophage poloarization was examined by analyzing the transcripts from human macrophages cultured in the presence or absence of recombinant soluble Siglec-14 protein
Project description:Siglec-1 is a macrophage lectin-like receptor that mediates sialic acid-dependent cellular interactions. It was shown previously to promote inflammation in autoimmune disease through suppressing the expansion of regulatory T cells (Tregs). We have investigated the molecular basis for Siglec-1 binding to these cells using in vitro-induced Tregs. A proximity labelling and proteomics strategy were used to identify glycoproteins expressed by activated Tregs that may function as Siglec-1 counter-receptors.
Project description:In response to microenvironmental signals macrophages undergo different activation, indicated as classic/M1 and alternative/M2 polarization. C-Myc transcription factor could be an essential player in M2 polarization. Functional relevance of c-Myc in M2 macrophage biology is investigated by evaluating the effect of 100-58F4, on the transcriptional profile induced on human macrophages by IL-4. Human monocytes were obtained from normal donor buffy coats by two-step gradient centrifugation using Ficoll (Biochrom) and Percoll (Amersham). Non-adherent cells were discarded, and the purified monocytes were incubated for 7 days in RPMI 1640 (Biochom) supplemented with 10% FCS (HyClone) and 100 ng/mL M-CSF to obtain resting macrophages. Macrophage polarization was obtained by removing the culture medium and culturing cells in RPMI 1640 supplemented with 10% FCS and 100 ng/mL LPS plus 20 ng/mL IFN-gamma (M1 polarization) or 20 ng/mL IL-4 (M2 polarization) for 24 h. When needed, chemical inhibitors were added with IL-4.
Project description:Acquisition of a new strain of non-typeable Haemophilus influenzae (NTHi) is often associated with exacerbation of chronic obstructive pulmonary disease (COPD). We have previously reported that COPD patients who are homozygous null for SIGLEC14 gene is less susceptible to COPD exacerbation than those who have wild-type allele with functional SIGLEC14 gene. In order to gain insight into the mechanism behind the COPD exacerbation, and to find new clues that may lead to the discovery of objective biomarker of COPD exacerbation, Siglec-14/THP-1 and Siglec-5/THP-1 cell lines, which mimic monocytes from homozygous wild-type and homozygous SIGLEC14-null person, respectively, were incubated with or without NTHi, and their gene expression profiles were compared by using Affymetrix Human Genome U133 Plus 2.0 Array. Four samples (2 cell lines x 2 conditions) were analyzed. No replicates were made.
Project description:The model describes the mechanisms by which macrophages differentiate into a given phenotype. The model shows that both extracellular and intracellular signalling are both important for that process. More specifically, STAT1 activity favors macrophages polarization towards M1 phenotype and STAT6 activity favors macrophage polarization towards M2 phenotype. However, these polarizations are can be reversed by molecular signalling.
Project description:to determine whether hydroxymethyl butyrate alters macrophage polarization bone marrow derived macrophages were treated with HMB alone or in combination with LPS for 48h