Zebrafish Mhc class II ? chain-encoding genes: polymorphism, expression, and function

1993 ◽  
Vol 38 (6) ◽  
Author(s):  
Holger S�ltmann ◽  
WernerE. Mayer ◽  
Felipe Figueroa ◽  
Colm O'hUigin ◽  
Jan Klein
Keyword(s):  
Mhc Class Ii ◽  
Class Ii ◽  
And Function ◽  
Encoding Genes

Evolution of MHC class II &; chain-encoding genes in the Lake Tana barbel species flock (Barbus intermedius complex)

1996 ◽  
Vol 44 (6) ◽  
pp. 419-431 ◽  
Author(s):  
Brian Dixon ◽  
Leo A. J. Nagelkerke ◽  
Ferdinand A. Sibbing ◽  
Egbert Egberts ◽  
René J. M. Stet
Keyword(s):  
Mhc Class Ii ◽  
Class Ii ◽  
Species Flock ◽  
Lake Tana ◽  
Encoding Genes ◽  
Barbus Intermedius

Erythropoietin as a Novel Pro-Inflammatory Mediator of Macrophages.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3596-3596
Author(s):  
Lilach Lifshitz ◽  
Galit Tabak ◽  
Max Gassman ◽  
Moshe Mittelman ◽  
Drorit Neumann
Keyword(s):  
Mhc Class Ii ◽  
Phagocytic Activity ◽  
Surface Expression ◽  
Class Ii ◽  
Experimental Models ◽  
Splenic Macrophage ◽  
And Function ◽  
Inflammatory Macrophages

Abstract Abstract 3596 Poster Board III-533 The immunomodulatory effects of erythropoietin (EPO) on the cellular and humoral compartments of the immune system were originally described by our group in multiple myeloma patients and have been further elucidated in murine experimental models (Mittelman, 2001; Katz 2005; 2007; Prutchi-Sagiv, 2006). However, the mechanisms of action by which EPO affects lymphocyte number and function are still unknown, particularly since lymphocytes do not carry EPO receptors (EPO-R). We thus set to unravel mechanisms underlying the anti-neoplastic immunomodulatory action of EPO. These studies led us to the novel discovery that dendritic cells (DCs) express EPO-R, and that EPO enhances their survival and function (Prutchi-Sagiv, 2008; Lifshitz, 2009). Here we focus on macrophages as an additional EPO target, since in analogy to DCs, macrophages are also antigen presenting cells, and serve as key effectors of the innate immune response. Using murine models, we first explored the in-vivo effects of EPO using recombinant human EPO (rHuEPO, EPREXR, JC)-injected mice, as well as transgenic mice over-expressing human EPO (termed tg6). EPO treatment was associated with an increased splenic macrophage population, detected by F4/80 expression, and an increased number of macrophages expressing CD11b, CD80 and MHC class II. We further explored the effect of in-vivo EPO administration in an inflammatory model exploiting thioglygollate injection to induce recruitment of peritoneal inflammatory macrophages. The inflammatory macrophages obtained from both EPO injected and from tg6 mice displayed increased expression of F4/80, CD11b, CD80 and MHC class II and augmented phagocytic activity, as compared to the control counterparts. These results are supported by in-vitro studies in bone marrow derived macrophages (BMDMs). We show that BMDMs express EPO-R mRNA, as detected by RT-PCR. In-vitro stimulation of the BMDMs with rHuEPO activated multiple signaling pathways including STAT1, STAT5, MAPK, AKT and NFkB indicating macrophage activation via surface EPO-R. EPO treatment of the BMDMs up-regulated their surface expression of CD11b, F4/80 and CD80, as well as enhanced their phagocytic activity. EPO treatment of LPS-stimulated BMDMs augmented IL-12 secretion, and decreased IL-10 secretion. In conclusion our results show that macrophages are direct targets of EPO and that EPO treatment enhances their pro-inflammatory activity and function. These findings point to the multifunctional role of EPO and may advance its clinical applications as an anti-neoplastic immunomodulator. Disclosures: Mittelman: BioGAL- Start up (inactive): Equity Ownership, Patents & Royalties. Off Label Use: Non erythroid effects: immune, anti-cancer (all under investigation).

Molecular structure and function of CD4 on murine egg plasma membrane

Zygote ◽  
1995 ◽  
Vol 3 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Mao Wu Guo ◽  
Toshiki Watanabe ◽  
Etsuko Mori ◽  
Tsuneatsu Mori
Keyword(s):  
Plasma Membrane ◽  
Mhc Class Ii ◽  
Expression System ◽  
Direct Interaction ◽  
Baculovirus Expression System ◽  
Class Ii ◽  
Sf9 Cells ◽  
Sperm Cells ◽  
Nuclear Polyhedrosis ◽  
And Function

SummaryIn the present study, the expression of the CD4 molecule on murine egg plasma membrane was confirmed by the indirect immunofluorescence (IIF) method. The full-length CD4 cDNA from murine eggs was synthesised by the reverse transcriptase-polymerase chain reaction (RT-PCR) method and its authenticity verified by Southern blot hybridisation using an end-labelled internal oligonucleotide. The results of DNA sequencing showed that the nucleotide sequence of the cDNA of CD4 from murine egg mRNA was identical to that of immune T cells. To demonstrate the direct interaction of CD4 from murine egg with murine sperm cells bearing MHC (major histocompatibility complex) class II molecule, we employed a baculovirus expression system to generate CD4 on the surface of Spodoptera frugiperda (Sf9) cells. Expression of CD4 on Sf9 cells infected with autographa californica nuclear polyhedrosis virus (AcNPV)-CD4 was demonstrated by IIF and immunoblotting. The CD4-expressing Sf9 cells adhered to MHC class II-bearing sperm cells since the adhension was specifically blocked by anti-CD4 monoclonal antibody (mAb) or anti-monomorphic region of MHC class II mAb. Taking our previous and present experimental results together, they strongly suggest that intercellular membrane adhesion between two gametes at the fusion step in fertilisation is mediated by the MHC class II molecule located on the posterior region of the sperm head and the CD4 molecule on egg plasma membrane.

scholarly journals The invariant chain is required for intracellular transport and function of major histocompatibility complex class II molecules.

1994 ◽  
Vol 179 (2) ◽  
pp. 681-694 ◽  
Author(s):  
E A Elliott ◽  
J R Drake ◽  
S Amigorena ◽  
J Elsemore ◽  
P Webster ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Intracellular Transport ◽  
Class Ii ◽  
Misfolded Proteins ◽  
Invariant Chain ◽  
Major Histocompatibility ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
And Function

The major histocompatibility complex (MHC) class II-associated invariant chain (Ii) is thought to act as a chaperone that assists class II during folding, assembly, and transport. To define more precisely the role of Ii chain in regulating class II function, we have investigated in detail the biosynthesis, transport, and intracellular distribution of class II molecules in splenocytes from mice bearing a deletion of the Ii gene. As observed previously, the absence of Ii chain caused significant reduction in both class II-restricted antigen presentation and expression of class II molecules at the cell surface because of the intracellular accumulation of alpha and beta chains. Whereas much of the newly synthesized MHC molecules enter a high molecular weight aggregate characteristic of misfolded proteins, most of the alpha and beta chains form dimers and acquire epitopes characteristic of properly folded complexes. Although the complexes do not bind endogenously processed peptides, class II molecules that reach the surface are competent to bind peptides added to the medium, further demonstrating that at least some of the complexes fold properly. Similar to misfolded proteins, however, the alpha and beta chains are poorly terminally glycosylated, suggesting that they fail to reach the Golgi complex. As demonstrated by double label confocal and electron microscope immunocytochemistry, class II molecules were found in a subcompartment of the endoplasmic reticulum and in a population of small nonlysosomal vesicles possibly corresponding to the intermediate compartment or cis-Golgi network. Thus, although alpha and beta chains can fold and form dimers on their own, the absence of Ii chain causes them to be recognized as "misfolded" and retained in the same compartments as bona fide misfolded proteins.

scholarly journals Lamina propria macrophages in the human gastrointestinal mucosa: their distribution, immunohistological phenotype, and function.

1996 ◽  
Vol 44 (7) ◽  
pp. 721-731 ◽  
Author(s):  
R Nagashima ◽  
K Maeda ◽  
Y Imai ◽  
T Takahashi
Keyword(s):  
Epithelial Cell ◽  
Lamina Propria ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Double Staining ◽  
Gastrointestinal Mucosa ◽  
Double Positive ◽  
Cellular Debris ◽  
And Function

In this study we systematically investigated the cellular distribution, immunohistochemical phenotype, and mucosal disposal function of macrophages in the lamina propria of the human gastrointestinal mucosa (lamina propria macrophages; LPMs). In all tissues examined, most of these LPMs accumulated beneath the epithelial layer that covered the apex of the lamina propria of the mucosa. These cells expressed normal levels of common macrophage markers such as CD68, LN5, lysozyme, ferritin, and alpha 1-anti-chymotrypsin. In addition, they expressed high levels of 25F9 (a market for a certain subpopulation of macrophages), MHC Class II molecules, and CD74 (MHC Class II-associated invariant chain). Interestingly, LPMs possessed some epithelial cell-associated antigens such as cytokeratin, carcinoembryonic antigen (CEA), and Ber-Ep4 in their cytoplasm. Ultrastructurally, these antigens were associated with cellular debris ingested by LPMs, which were recognized as apoptotic fragments by in situ end-labeling. Furthermore, double positive-labeled granules were seen in LPMs by double staining for epithelial cell-associated antigens and in situ end-labeling. These observations suggest that one of the major functions of LPMs is the disposal of apoptotic epithelial cells and that LPMs may be involved in the regulation of mucosal epithelial renewal.

Allelic variation in transcription modulates MHC class II expression and function

1999 ◽  
Vol 1 (11) ◽  
pp. 919-927 ◽  
Author(s):  
Jon S Beaty ◽  
Teresa L Sukiennicki ◽  
Gerald T Nepom
Keyword(s):  
Mhc Class Ii ◽  
Allelic Variation ◽  
Class Ii ◽  
And Function

Interactions of CD4 with MHC class II molecules, T cell receptors and p56 lck

1993 ◽  
Vol 342 (1299) ◽  
pp. 13-24 ◽  
Keyword(s):  
T Cell ◽  
Mhc Class Ii ◽  
T Cell Receptors ◽  
Protein Tyrosine Kinase ◽  
Cell Receptor ◽  
Class Ii ◽  
Cell Receptors ◽  
Multimeric Complex ◽  
And Function ◽  
Immunoglobulin Supergene Family

CD4 and CD8 are members of the immunoglobulin supergene family of proteins, and function as co-receptors with the T cell receptor (TCR) in binding MHC class II or class I molecules, respectively. Within this multimeric complex, CD4 interacts with three distinct ligands. CD4 interacts through its D1 and D2 domains with MHC class II proteins, through its D3 and D4 domains with T cell receptors, and through its cytoplasmic tail with p56 lck , a src -related, protein tyrosine kinase. Each of these interactions is important in the function of CD4 and will be discussed in turn.

Sign in / Sign up

Export Citation Format

Share Document