scholarly journals Presence and regulation of messenger ribonucleic acids encoding components of the class II major histocompatibility complex-associated antigen processing pathway in the bovine corpus luteum

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Matthew J Cannon ◽  
John S Davis ◽  
Joy L Pate
Keyword(s):  
Corpus Luteum ◽  
Estrous Cycle ◽  
Antigen Processing ◽  
Class Ii ◽  
Luteal Cells ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Class Ii Mhc ◽  
Luteal Tissue ◽  
Antigen Presenting

Luteal cells express class II major histocompatibility complex (MHC) molecules and can stimulate T lymphocyte proliferationin vitro. However, it is unknown whether luteal cells express the intracellular components necessary to process the peptides presented by class II MHC molecules. The objective of the present study was to examine the expression and regulation of three major class II-associated antigen processing components – class II MHC-associated invariant chain (Ii), DMα and DMβ – in luteal tissue. Corpora lutea were collected early in the estrous cycle, during midcycle and late in the estrous cycle, and at various times following administration of a luteolytic dose of prostaglandin F2α(PGF2α) to the cow. Northern analysis revealed the presence of mRNA encoding each of the class II MHC-associated antigen processing proteins in luteal tissue. Ii mRNA concentrations did not change during the estrous cycle, whereas DMα and DMβ mRNA concentrations were highest in midcycle luteal tissue compared with either early or late luteal tissue. Tumor necrosis factor-α (TNF-α) reduced DMα mRNA concentrations in cultured luteal cells in the presence of LH or PGF2α. DMα and DMβ mRNA were also present in highly enriched cultures of luteal endothelial (CLENDO) cells, and DMα mRNA concentrations were greater in CLENDO cultures compared with mixed luteal cell cultures. Expression of invariant chain, DMα and DMβ genes indicates that cells within the corpus luteum express the minimal requirements to act as functional antigen-presenting cells, and the observation that CLENDO cells are a source of DMα and DMβ mRNA indicates that non-immune cells within the corpus luteum may function as antigen-presenting cells.

scholarly journals The class II major histocompatibility complex molecule BoLA-DR is expressed by endothelial cells of the bovine corpus luteum

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 991-1003 ◽  
Author(s):  
Matthew J Cannon ◽  
John S Davis ◽  
Joy L Pate
Keyword(s):  
Endothelial Cells ◽  
Major Histocompatibility Complex ◽  
Corpus Luteum ◽  
Single Cells ◽  
Cell Types ◽  
Class Ii ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Mrna Concentration ◽  
Class Ii Mhc

Cells expressing class II major histocompatibility complex (MHC) molecules are found within the corpus luteum (CL) of several species. Expression and localization of class II MHC molecules in the bovine CL were examined in the present study. Immunohistochemical evaluation revealed class II MHC molecules on single cells in early CL (days 4 and 5 post-estrus). Two class II MHC-expressing cell types were observed in midcycle CL (days 10–12 post-estrus), single cells similar to those observed in the early CL, and endothelial cells. Not all endothelial cells expressed class II MHC, and further investigation revealed expression of only one type of class II MHC molecule, DR, on endothelial cells. Class II MHC was also localized to endothelial cells in late CL (day 18 post-estrus). Steroidogenic luteal cells were negative for class II MHC throughout the estrous cycle. Quantitative RT-PCR revealed higher (P< 0.05) concentrations of mRNA encoding the α-subunit of DR (DRA) in late CL when compared with those in the early CL.DRAmRNA abundance was also measured in cultures of mixed luteal and luteal endothelial (CLENDO) cells, in the presence or absence of tumor necrosis factor-α (TNF). No differences were found in theDRAmRNA concentration between mixed luteal and CLENDO cell cultures, and TNF had no effect onDRAmRNA concentration in both cell types. Expression of DR by endothelial cells of the midcycle CL may induce anergy of T lymphocytes, or stimulate them to secrete products that enhance normal luteal function.

scholarly journals The Effect of Class II Major Histocompatibility Complex Expression on Adherence of Helicobacter pylori and Induction of Apoptosis in Gastric Epithelial Cells: A Mechanism for T Helper Cell Type 1–mediated Damage

1998 ◽  
Vol 187 (10) ◽  
pp. 1659-1669 ◽  
Author(s):  
Xuejun Fan ◽  
Sheila E. Crowe ◽  
Simon Behar ◽  
Harshani Gunasena ◽  
Gang Ye ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Class Ii ◽  
Gastric Epithelial Cells ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Class Ii Mhc ◽  
Ifn Γ ◽  
Induction Of Apoptosis ◽  
H Pylori

Helicobacter pylori infection is associated with gastric epithelial damage, including apoptosis, ulceration, and cancer. Although bacterial factors and the host response are believed to contribute to gastric disease, no receptor has been identified that explains how the bacteria attach and signal the host cell to undergo apoptosis. Using H. pylori as “bait” to capture receptor proteins in solubilized membranes of gastric epithelial cells, class II major histocompatibility complex (MHC) molecules were identified as a possible receptor. Signaling through class II MHC molecules leading to the induction of apoptosis was confirmed using cross-linking IgM antibodies to surface class II MHC molecules. Moreover, binding of H. pylori and the induction of apoptosis were inhibited by antibodies recognizing class II MHC. Since type 1 T helper cells are present during infection and produce interferon (IFN)-γ, which increases class II MHC expression, gastric epithelial cell lines were exposed to H. pylori in the presence or absence of IFN-γ. IFN-γ increased the attachment of the bacteria as well as the induction of apoptosis in gastric epithelial cells. In contrast to MHC II–negative cell lines, H. pylori induced apoptosis in cells expressing class II MHC molecules constitutively or after gene transfection. These data describe a novel receptor for H. pylori and provide a mechanism by which bacteria and the host response interact in the pathogenesis of gastric epithelial cell damage.

scholarly journals Suppressive effect of antibody on processing of T cell epitopes.

1993 ◽  
Vol 178 (4) ◽  
pp. 1459-1463 ◽  
Author(s):  
C Watts ◽  
A Lanzavecchia
Keyword(s):  
T Cell ◽  
Antigen Processing ◽  
Suppressive Effect ◽  
T Cell Epitopes ◽  
Strong Suppression ◽  
Lysosomal Ph ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Formed Part ◽  
Antigen Presenting

Immunoglobulins drive efficient antigen capture by antigen presenting cells for processing and presentation on class II MHC-molecules. High affinity antibody/antigen interactions are stable at endosomal/lysosomal pH thus altering the substrate for antigen processing. We show that this can result in strong suppression of presentation of some T cell epitopes. This effect was observed when the antibody specificity was a B cell surface Ig, or formed part of an immune complex. In the latter case the presence of the suppressing antibody boosts presentation of other T cell epitopes through enhanced uptake into Fc receptor bearing cells. The influence of bound antibodies on the outcome of antigen processing may influence with T cell epitopes dominate T cell responses and may change the focus of the response with time.

scholarly journals A class II MHC-targeted vaccine elicits immunity against SARS-CoV-2 and its variants

2021 ◽  
Vol 118 (44) ◽  
pp. e2116147118
Author(s):  
Novalia Pishesha ◽  
Thibault J. Harmand ◽  
Paul W. Rothlauf ◽  
Patrique Praest ◽  
Ryan K. Alexander ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Neutralizing Antibodies ◽  
High Titer ◽  
Developed Countries ◽  
Class Ii ◽  
T Cell Response ◽  
Humoral And Cellular Immunity ◽  
Histocompatibility Complex ◽  
Class Ii Mhc ◽  
Antigen Presenting

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in over 100 million infections and millions of deaths. Effective vaccines remain the best hope of curtailing SARS-CoV-2 transmission, morbidity, and mortality. The vaccines in current use require cold storage and sophisticated manufacturing capacity, which complicates their distribution, especially in less developed countries. We report the development of a candidate SARS-CoV-2 vaccine that is purely protein based and directly targets antigen-presenting cells. It consists of the SARS-CoV-2 Spike receptor-binding domain (SpikeRBD) fused to an alpaca-derived nanobody that recognizes class II major histocompatibility complex antigens (VHHMHCII). This vaccine elicits robust humoral and cellular immunity against SARS-CoV-2 and its variants. Both young and aged mice immunized with two doses of VHHMHCII-SpikeRBD elicit high-titer binding and neutralizing antibodies. Immunization also induces strong cellular immunity, including a robust CD8 T cell response. VHHMHCII-SpikeRBD is stable for at least 7 d at room temperature and can be lyophilized without loss of efficacy.

scholarly journals A novel antigen-processing-defective phenotype in major histocompatibility complex class II-positive CIITA transfectants is corrected by interferon-gamma.

1995 ◽  
Vol 182 (6) ◽  
pp. 1793-1799 ◽  
Author(s):  
C A Siegrist ◽  
E Martinez-Soria ◽  
I Kern ◽  
B Mach
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Interferon Gamma ◽  
Antigen Processing ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Invariant Chain ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Antigen Presenting

Presentation of exogenous protein antigens to T lymphocytes is based on the intersection of two complex pathways: (a) synthesis, assembly, and transport of major histocompatibility complex (MHC) class II-invariant chain complexes from the endoplasmic reticulum to a specialized endosomal compartment, and (b) endocytosis, denaturation, and proteolysis of antigens followed by loading of antigenic peptides onto newly synthesized MHC class II molecules. It is believed that expression of MHC class II heterodimers, invariant chain and human leukocyte antigen-DM is both necessary and sufficient to reconstitute a functional MHC class II loading compartment in antigen-presenting cells. Expression of each of these essential molecules is under the control of the MHC class II transactivator CIITA. Unexpectedly, however, whereas interferon gamma stimulation does confer effective antigen-processing function to nonprofessional antigen presenting cells, such as melanoma cells, expression of the CIITA transactivator alone is not sufficient. Activation of antigen-specific T cells thus requires additional CIITA-independent factor(s), and such factor(s) can be induced by interferon gamma.

scholarly journals Xenogeneic proliferation and lymphokine production are dependent on CD4+ helper T cells and self antigen-presenting cells in the mouse.

1990 ◽  
Vol 172 (2) ◽  
pp. 567-575 ◽  
Author(s):  
R D Moses ◽  
R N Pierson ◽  
H J Winn ◽  
H Auchincloss
Keyword(s):  
T Cells ◽  
Interleukin 2 ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Helper T Cells ◽  
Spleen Cells ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Antigen Presenting ◽  
Self Antigen

We studied proliferation and interleukin 2 production by B6 mouse spleen cells in response to stimulation by irradiated cynomolgus monkey spleen cells and compared the results with responses against whole MHC-disparate allogeneic controls (BALB/c). We found that (a) primary xenogeneic helper responses were absent, whereas primary allogeneic responses were brisk, (b) secondary xenogeneic helper responses were dependent on CD4+ T cells and responder antigen-presenting cells (APCs), whereas allogeneic responses could be mediated by either CD4+ or CD8+ T cells independently and were primarily dependent on the presence of stimulator APCs, and (c) secondary xenogeneic helper responses were blocked by an antibody directed against responder class II MHC molecules. These results suggest that mouse helper T cells recognize disparate xenoantigens as processed peptides in association with self class II MHC molecules, similar to the recognition of nominal antigens and unlike direct allo-recognition.

Roles for asparagine endopeptidase in class II MHC-restricted antigen processing

2003 ◽  
Vol 70 ◽  
pp. 31-38 ◽  
Author(s):  
Colin Watts ◽  
Daniela Mazzeo ◽  
Michelle A. West ◽  
Stephen P. Matthews ◽  
Doreen Keane ◽  
...  
Keyword(s):  
T Cell ◽  
Antigen Processing ◽  
Adaptive Immune Response ◽  
Class Ii ◽  
Specific Class ◽  
T Cell Epitopes ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Few Data ◽  
Peptide Display

The adaptive immune response depends on the creation of suitable peptides from foreign antigens for display on MHC molecules to T lymphocytes. Similarly, MHC-restricted display of peptides derived from self proteins results in the elimination of many potentially autoreactive T cells. Different proteolytic systems are used to generate the peptides that are displayed as T cell epitopes on class I compared with class II MHC molecules. In the case of class II MHC molecules, the proteases that reside within the endosome/lysosome system of antigen-presenting cells are responsible; surprisingly, however, there are relatively few data on which enzymes are involved. Recently we have asked whether proteolysis is required simply in a generic sense, or whether the action of particular enzymes is needed to generate specific class II MHC-associated T cell epitopes. Using the recently identified mammalian asparagine endopeptidase as an example, we review recent evidence that individual enzymes can make clear and non-redundant contributions to MHC-restricted peptide display.

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