Diversity of MHC class II DAB1 in the koala (Phascolarctos cinereus)

2012 ◽  
Vol 60 (1) ◽  
pp. 1 ◽  
Author(s):  
Sarah E. Jobbins ◽  
Claire E. Sanderson ◽  
Joanna E. Griffith ◽  
Mark B. Krockenberger ◽  
Katherine Belov ◽  
...  
Keyword(s):  
Immune Response ◽  
Mhc Class Ii ◽  
Genetic Research ◽  
Class Ii ◽  
Population Diversity ◽  
Environment Interaction ◽  
Phascolarctos Cinereus ◽  
Mhc Molecules ◽  
Adaptive Immune ◽  
Class Ii Mhc

The host immune response is an important factor determining the outcome of the host–pathogen–environment interaction. At the gateway between the innate and adaptive immune systems are MHC molecules, which facilitate antigen presentation to T lymphocytes, and initiate the adaptive immune response. Despite their integral role in adaptive immunity, the genes encoding class II MHC molecules have not been examined directly in koalas. Furthermore, indirect historical evidence suggests that this species might lack functional diversity in class II MHC genes, with potential implications for disease susceptibility. We have examined diversity in the β chain genes of the koala class II MHC DA gene family and identified 23 alleles, including several atypical alleles. The levels of diversity observed are consistent with other marsupial and eutherian species, and do not support the paucity of variation suggested by the early literature. These findings are relevant to the conservation management of koalas and provide both a benchmark for maintaining population diversity and a platform for further conservation genetic research in this species.

MHC Sınıf I ve MHC Sınıf II Gen Düzenlenmesi

2020 ◽  
Vol 8 (3) ◽  
pp. 144-156
Author(s):  
Şule KARATAŞ ◽  
Fatma SAVRAN OĞUZ
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Gene Regulation ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Regulation Mechanisms

Introduction: Peptides obtained by processing intracellular and extracellular antigens are presented to T cells to stimulate the immune response. This presentation is made by peptide receptors called major histocompatibility complex (MHC) molecules. The regulation mechanisms of MHC molecules, which have similar roles in the immune response, especially at the gene level, have significant differences according to their class. Objective: Class I and class II MHC molecules encoded by MHC genes on the short arm of the sixth chromosome are peptide receptors that stimulate T cell response. These peptides, which will enable the recognition of the antigen from which they originate, are loaded into MHC molecules and presented to T cells. Although the principles of loading and delivering peptides are similar for both molecules, the peptide sources and peptide loading mechanisms are different. In addition, class I molecules are expressed in all nucleated cells while class II molecules are expressed only in Antigen Presentation Cells (APC). These differences; It shows that MHC class I is not expressed by exactly the same transcriptional mechanisms as MHC class II. In our article, we aimed to compare the gene expressions of both classes and reveal their similarities and differences. Discussion and Conclusion: A better understanding of the transcriptional mechanisms of MHC molecules will reveal the role of these molecules in diseases more clearly. In our review, we discussed MHC gene regulation mechanisms with presence of existing informations, which is specific to the MHC class, for contribute to future research. Keywords: MHC class I, MHC class II, MHC gene regulation, promoter, SXY module, transcription

Role of Class-II Major Histocompatibility Complex (MHC)-Antigen–Positive Donor Leukocytes in Transfusion-Induced Alloimmunization to Donor Class-I MHC Antigens

Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 690-694
Author(s):  
K.J. Kao ◽  
M.L.U. del Rosario
Keyword(s):  
Immune Response ◽  
Peripheral Blood ◽  
Class Ii ◽  
Class I ◽  
Mononuclear Leukocytes ◽  
Class I Mhc ◽  
Mhc Antigens ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Mhc Antigen

It has been shown that peripheral-blood mononuclear leukocytes (MNL) are responsible for transfusion-induced alloimmunization to donor major histocompatability complex (MHC) antigens. However, it is not known which subset of MNL is responsible for this immune response. Because elimination of class-II MHC antigen-positive passenger leukocytes effectively prolongs the survival of allografts, it has been hypothesized that class-II positive MNL are responsible for immunizing transfusion recipients to donor MHC antigens. To test this hypothesis, two different approaches were used. First, we compared the alloantigenicity of BALB/c mice (H-2d) peripheral blood MNL before and after depletion of class-II positive cells. CBA mice (H-2k) were used as transfusion recipients. Antibody development to donor class-I H-2 antigens was determined by flow cytometry and enzyme-linked immunoassay. After four weekly transfusions of MNL depleted for class-II positive cells, only 25% of recipient mice developed antibodies to donor H-2d antigens. In contrast, all mice transfused with control MNL became immunized. Second, we studied the alloantigenicity of peripheral MNL from C57BL/6 mice (H-2b) with homozygous deficiency of class-II MHC molecules in H-2 disparate recipient mice. After transfusions with class-II MHC molecule-deficient MNL, 0% of BALB/c, 40% of C57BR, and 25% of CBA-recipient mice developed antibodies to donor H-2b antigen. All control recipient mice were immunized. The antibody activities of the controls were also higher than those in the treatment group who became immunized. Thus, our study shows that class-II MHC antigen-positive MNL play a significant role in transfusion-induced alloimmunization to donor class-I MHC antigens. The results also support the hypothesis that direct antigen presentation by donor class-II positive MNL to the immune system of transfusion recipients is critical for the initiation of humoral immune response to donor MHC antigens.

scholarly journals Polarized Expression of CD74 by Gastric Epithelial Cells

2005 ◽  
Vol 53 (12) ◽  
pp. 1481-1489 ◽  
Author(s):  
Carlos A. Barrera ◽  
Ellen J. Beswick ◽  
Johanna C. Sierra ◽  
David Bland ◽  
Rosario Espejo ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mhc Class Ii ◽  
Cell Biology ◽  
Constitutive Expression ◽  
Class Ii ◽  
Protein Isoforms ◽  
Apical Surface ◽  
Gastric Epithelial Cells ◽  
Mhc Molecules ◽  
Class Ii Mhc

CD74 is known as the major histocompatibility complex (MHC) class II-associated invariant chain (Ii) that regulates the cell biology and functions of MHC class II molecules. Class II MHC and Ii expression was believed to be restricted to classical antigen-presenting cells (APC); however, during inflammation, other cell types, including mucosal epithelial cells, have also been reported to express class II MHC molecules. Given the importance of Ii in the biology of class II MHC, we sought to examine the expression of Ii by gastric epithelial cells (GEC) to determine whether class II MHC molecules in these nonconventional APC cells were under the control of Ii and to further support the role that these cells may play in local immune and inflammatory responses during Helicobacter pylori infection. Thus we examined the expression of Ii on GEC from human biopsy samples and then confirmed this observation using independent methods on several GEC lines. The mRNA for Ii was detected by RT-PCR, and the various protein isoforms were also detected. Interestingly, these cells have a high level expression of surface Ii, which is polarized to the apical surface. These studies are the first to demonstrate the constitutive expression of Ii by human GEC.

scholarly journals Genetic Dissection of Primary and Secondary Responses to a Widespread Natural Pathogen of the Gut,Eimeria vermiformis

2000 ◽  
Vol 68 (11) ◽  
pp. 6273-6280 ◽  
Author(s):  
Adrian L. Smith ◽  
Adrian C. Hayday
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Primary Response ◽  
Class I ◽  
Class Ii Mhc ◽  
Ifn Γ ◽  
Αβ T Cells

ABSTRACT Because most pathogens initially challenge the body at epithelial surfaces, it is important to dissect the mechanisms that underlie T-cell responses to infected epithelial cells in vivo. The coccidian parasites of the genus Eimeria are protozoan gut pathogens that elicit a potent, protective immune response in a wide range of host species. CD4+ αβ T cells and gamma interferon (IFN-γ) are centrally implicated in the primary immunoprotective response. To define any additional requirements for the primary response and to develop a comparison between the primary and the secondary response, we have studied Eimeria infections of a broad range of genetically altered mice. We find that a full-strength primary response depends on β2-microglobulin (class I major histocompatibility complex [MHC] and class II MHC and on IFN-γ and interleukin-6 (IL-6) but not on TAP1, perforin, IL-4, Fas ligand, or inducible nitric oxide synthetase. Indeed, MHC class II-deficient and IFN-γ-deficient mice are as susceptible to primary infection as mice deficient in all αβ T cells. Strikingly, the requirements for a highly effective αβ-T-cell-driven memory response are less stringent, requiring neither IFN-γ nor IL-6 nor class I MHC. The class II MHC dependence was also reduced, with adoptively transferable immunity developing in MHC class II−/− mice. Besides the improved depiction of an immune response to a natural gut pathogen, the finding that effective memory can be elicited in the absence of primary effector responses appears to create latitude in the design of vaccine strategies.

Role of Class-II Major Histocompatibility Complex (MHC)-Antigen–Positive Donor Leukocytes in Transfusion-Induced Alloimmunization to Donor Class-I MHC Antigens

Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 690-694 ◽  
Author(s):  
K.J. Kao ◽  
M.L.U. del Rosario
Keyword(s):  
Immune Response ◽  
Peripheral Blood ◽  
Class Ii ◽  
Class I ◽  
Mononuclear Leukocytes ◽  
Class I Mhc ◽  
Mhc Antigens ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Mhc Antigen

Abstract It has been shown that peripheral-blood mononuclear leukocytes (MNL) are responsible for transfusion-induced alloimmunization to donor major histocompatability complex (MHC) antigens. However, it is not known which subset of MNL is responsible for this immune response. Because elimination of class-II MHC antigen-positive passenger leukocytes effectively prolongs the survival of allografts, it has been hypothesized that class-II positive MNL are responsible for immunizing transfusion recipients to donor MHC antigens. To test this hypothesis, two different approaches were used. First, we compared the alloantigenicity of BALB/c mice (H-2d) peripheral blood MNL before and after depletion of class-II positive cells. CBA mice (H-2k) were used as transfusion recipients. Antibody development to donor class-I H-2 antigens was determined by flow cytometry and enzyme-linked immunoassay. After four weekly transfusions of MNL depleted for class-II positive cells, only 25% of recipient mice developed antibodies to donor H-2d antigens. In contrast, all mice transfused with control MNL became immunized. Second, we studied the alloantigenicity of peripheral MNL from C57BL/6 mice (H-2b) with homozygous deficiency of class-II MHC molecules in H-2 disparate recipient mice. After transfusions with class-II MHC molecule-deficient MNL, 0% of BALB/c, 40% of C57BR, and 25% of CBA-recipient mice developed antibodies to donor H-2b antigen. All control recipient mice were immunized. The antibody activities of the controls were also higher than those in the treatment group who became immunized. Thus, our study shows that class-II MHC antigen-positive MNL play a significant role in transfusion-induced alloimmunization to donor class-I MHC antigens. The results also support the hypothesis that direct antigen presentation by donor class-II positive MNL to the immune system of transfusion recipients is critical for the initiation of humoral immune response to donor MHC antigens.

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

Phosphorylation of class I but not class II MHC molecules by membrane-localized protein kinase C

1989 ◽  
Vol 26 (12) ◽  
pp. 1095-1104 ◽  
Author(s):  
Teresa Burke ◽  
Karen Pollok ◽  
William Cushley ◽  
E. Charles Snow
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Class Ii ◽  
Class I ◽  
Mhc Molecules ◽  
Kinase C ◽  
Class Ii Mhc

scholarly journals CD1 and Major Histocompatibility Complex II Molecules Follow a Different Course during Dendritic Cell Maturation

2003 ◽  
Vol 14 (8) ◽  
pp. 3378-3388 ◽  
Author(s):  
Nicole N. van der Wel ◽  
Masahiko Sugita ◽  
Donna M. Fluitsma ◽  
Xaiochun Cao ◽  
Gerty Schreibelt ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Major Histocompatibility Complex ◽  
Dendritic Cell ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Dendritic Cell Maturation ◽  
Cell Maturation ◽  
Major Histocompatibility ◽  
Mhc Molecules ◽  
Histocompatibility Complex

The maturation of dendritic cells is accompanied by the redistribution of major histocompatibility complex (MHC) class II molecules from the lysosomal MHC class II compartment to the plasma membrane to mediate presentation of peptide antigens. Besides MHC molecules, dendritic cells also express CD1 molecules that mediate presentation of lipid antigens. Herein, we show that in human monocyte-derived dendritic cells, unlike MHC class II, the steady-state distribution of lysosomal CD1b and CD1c isoforms was unperturbed in response to lipopolysaccharide-induced maturation. However, the lysosomes in these cells underwent a dramatic reorganization into electron dense tubules with altered lysosomal protein composition. These structures matured into novel and morphologically unique compartments, here termed mature dendritic cell lysosomes (MDL). Furthermore, we show that upon activation mature dendritic cells do not lose their ability of efficient clathrin-mediated endocytosis as demonstrated for CD1b and transferrin receptor molecules. Thus, the constitutive endocytosis of CD1b molecules and the differential sorting of MHC class II from lysosomes separate peptide- and lipid antigen-presenting molecules during dendritic cell maturation.

scholarly journals Characterization of Structural Features Controlling the Receptiveness of Empty Class II MHC Molecules

PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18662 ◽  
Author(s):  
Bernd Rupp ◽  
Sebastian Günther ◽  
Talat Makhmoor ◽  
Andreas Schlundt ◽  
Katharina Dickhaut ◽  
...  
Keyword(s):  
Class Ii ◽  
Structural Features ◽  
Mhc Molecules ◽  
Class Ii Mhc

scholarly journals Signaling through class II MHC molecules

Ensho Saisei ◽  
2001 ◽  
Vol 21 (5) ◽  
pp. 541-555
Author(s):  
Sho Matsushita
Keyword(s):  
Class Ii ◽  
Mhc Molecules ◽  
Class Ii Mhc
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