Search results for " Glycoproteins"

TLR3-induced activation of mast cells modulates CD8+ T-cell recruitment.

2005

AbstractMast cells play an important role in host defense against various pathogens, but their role in viral infection has not been clarified in detail. dsRNA, synthesized by various types of viruses and mimicked by polyinosinic-polycytidylic acid (poly(I:C)) is recognized by Toll-like receptor 3 (TLR3). In this study, we demonstrate that poly(I:C) injection in vivo potently stimulates peritoneal mast cells to up-regulate a number of different costimulatory molecules. Therefore, we examined the expression and the functional significance of TLR3 activation in mast cells. Mast cells express TLR3 on the cell surface and intracellularly. After stimulation of mast cells with poly(I:C) and Newcas…

Endoplasmic reticulum‐resident chaperones modulate the inflammatory and angiogenic responses of endothelial cells

2015

SummaryBackground Wound healing depends on a well-balanced regulation of inflammation and angiogenesis. In chronic wounds the healing process is disturbed and inflammation persists. Regulation of wound closure is controlled by transmembrane and extracellular proteins, the folding and maturation of which occur in the endoplasmic reticulum (ER) by ER-resident chaperone machinery. Objectives To study the role of the ER-resident chaperones BiP/Grp78, its cochaperone Mdg1/ERdJ4, and Grp94 in chronic, nonhealing wounds. Methods Immunohistochemical staining of these chaperones in individual human biopsies and investigation of the possible role of BiP and Mdg1 in endothelial cells, focusing on thei…

Chemotactic migration of human diploid fibroblasts is inhibited by contactinhibin.

1992

Ectodomain shedding of L1 adhesion molecule promotes cell migration by autocrine binding to integrins.

2001

The L1 adhesion molecule plays an important role in axon guidance and cell migration in the nervous system. L1 is also expressed by many human carcinomas. In addition to cell surface expression, the L1 ectodomain can be released by a metalloproteinase, but the biological function of this process is unknown. Here we demonstrate that membrane-proximal cleavage of L1 can be detected in tumors and in the developing mouse brain. The shedding of L1 involved a disintegrin and metalloproteinase (ADAM)10, as transfection with dominant-negative ADAM10 completely abolishes L1 release. L1-transfected CHO cells (L1-CHO) showed enhanced haptotactic migration on fibronectin and laminin, which was blocked …

Differential expression of Cryptosporidium parvum genes encoding sporozoite surface antigens in infected HCT-8 host cells.

2006

Intracellular replication of Cryptosporidium parvum (Apicomplexa) involves the generation of several asexual and sexual forms of the parasite. During the stage conversions, complex mechanisms lead to differential structural and functional properties of the parasite. These require a well tuned gene transcription machinery. For the first time the gene expression of four surface proteins of C. parvum sporozoites, CP15, CP17, P23, and GP900 were analysed in parallel by reverse transcription polymerase chain reaction. In addition, CP17 and P23 antigens were detected in infected host cells by immunofluorescence using antisera raised against recombinant forms of the proteins. The results show that…

Generation of tumor-reactive CTL against the tumor-associated antigen HER2 using retrovirally transduced dendritic cells derived from CD34+ hemopoiet…

2000

Abstract Ag-specific CD8+ CTL are crucial for effective tumor rejection. Attempts to treat human malignancies by adoptive transfer of tumor-reactive CTL have been limited due to the difficulty of generating and expanding autologous CTL with defined Ag specificity. The current study examined whether human CTL can be generated against the tumor-associated Ag HER2 using autologous dendritic cells (DC) that had been genetically engineered to express HER2. DC progenitors were expanded by culturing CD34+ hemopoietic progenitor cells in the presence of the designer cytokine HyperIL-6. Proliferating precursor cells were infected by a retroviral vector encoding the HER2 Ag and further differentiated…

Inverse relationship of melanocyte differentiation antigen expression in melanoma tissues and CD8+ cytotoxic-T-cell responses: evidence for immunosel…

1996

Antigenic peptides derived from differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for MHC-restricted cytotoxic T lymphocytes (CTL). CTL directed against peptides derived from the Melan A/MART-1, tyrosinase and gp100/Pmel17 antigens can be detected in melanoma patients and in healthy controls. The presence of defined antigenic peptides and corresponding precursor CTL in patients with metastatic melanoma opens perspectives for the development of antigen-specific tumor vaccines. In this study, we examined the expression of Melan A/MART-1, tyrosinase and gp100lPmel17 in fresh melanoma tissues of HLA-A2+ patients and the spontaneous CTL rea…

Inhibition of the NKp30 activating receptor by pp65 of human cytomegalovirus.

2005

Human cytomegalovirus, a chief pathogen in immunocompromised people, can persist in a healthy immunocompetent host throughout life without being eliminated by the immune system. Here we show that pp65, the main tegument protein of human cytomegalovirus, inhibited natural killer cell cytotoxicity by an interaction with the activating receptor NKp30. This interaction was direct and specific, leading to dissociation of the linked CD3zeta from NKp30 and, consequently, to reduced killing. Thus, pp65 is a ligand for the NKp30 receptor and demonstrates a unique mechanism by which an intracellular viral protein causes general suppression of natural killer cell cytotoxicity by specific interaction w…

A novel epitope of N-CAM defines precursors of human adherent NK cells

2004

AbstractActivated, adherent natural killer (A-NK) cells represent a distinct subpopulation of interleukin (IL)-2-stimulated NK cells, which are selectively endowed with the increased expression of integrins and ability to adhere to solid surfaces, migrate into, infiltrate, and destroy cancerous tissues. The present study defines the phenotype and functions of precursors of A-NK (pre-A-NK) cells in humans. Peripheral blood pre-A-NK cells, in contrast to the rest of NK cells, express a novel epitope of CD56 neuronal cell adhesion molecule, termed ANK-1, and increased cell-surface levels of integrins. Pre-A-NK cells also express low levels of CD56 and CD161, and some express CD162 receptor, do…

P-selectin glycoprotein ligand-1 as a potential target for humoral immunotherapy of multiple myeloma.

2008

Monoclonal antibodies (mAbs), successfully adopted in the treatment of several haematological malignancies, have proved almost ineffective in multiple myeloma (MM), because of the lack of an appropriate antigen for targeting and killing MM cells. Here, we demonstrate that PSGL1, the major ligand of P-Selectin, a marker of plasmacytic differentiation expressed at high levels on normal and neoplastic plasma cells, may represent a novel target for mAb-mediated MM immunotherapy. The primary effectors of mAb-induced cell-death, complement-mediated lysis (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC), were investigated using U266B1 and LP1 cell-lines as models. Along with immunolo…