KLF4 and CD55 expression and function depend on each other.

The transcription factor Kruppel-like factor 4 (KLF4) regulates the expression of immunosuppressive and anti-thrombotic proteins. Despite its importance in maintaining homeostasis, the signals that control its expression and the mechanism of its transactivation remain unclarified. CD55 [aka decay accelerating factor (DAF)], now known to be a regulator of T and B cell responses, biases between pro- and anti-inflammatory processes by controlling autocrine C3a and C5a receptor (C3ar1/C5ar1) signaling in cells.

A novel role for CD55 in granulocyte homeostasis and anti-bacterial host defense.

Background: In addition to its complement-regulating activity, CD55 is a ligand of the adhesion class G protein-coupled receptor CD97; however, the relevance of this interaction has remained elusive. We previously showed that mice lacking a functional CD97 gene have increased numbers of granulocytes.

Methodology/results: Here, we demonstrate that CD55-deficient mice display a comparable phenotype with about two-fold more circulating granulocytes in the blood stream, the marginated pool, and the spleen.

Long-term-infected telomerase-immortalized endothelial cells: a model for Kaposi's sarcoma-associated herpesvirus latency in vitro and in vivo.

Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease. Most KS tumor cells are latently infected with KSHV and are of endothelial origin. While PEL-derived cell lines maintain KSHV indefinitely, all KS tumor-derived cells to date have lost viral genomes upon ex vivo cultivation.

The latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus modulates cellular gene expression and protects lymphoid cells from p16 INK4A-induced cell cycle arrest.

Latently infected Kaposi's sarcoma-associated herpes-virus (KSHV)-associated tumor cells have both endothelial and lymphoid origins and express a limited set of latent viral genes. One such gene, ORF73, encodes the latency-associated nuclear antigen (LANA), a multifunctional protein that plays roles in viral DNA replication, episome maintenance, and transcriptional regulation. LANA interacts with cellular proteins involved in transcriptional regulation such as the tumor suppressors, retinoblastoma (Rb) and p53, and RING3 family members.

c-Met expression in gastric cancer with liver metastasis.

Liver metastasis is one of the poor prognostic factors for gastric cancer. Hepatocyte growth factor (HGF) and its receptor, c-Met, have been reported to be related to the proliferation of carcinoma cells. We examined c-Met and HGF expression in stage IV gastric cancers (n = 121) and compared the results in groups with liver metastasis (n = 47, LM group) and without liver metastasis (n = 74, no-LM group).