scholarly journals Somatic genetics of CDR3 control TCR V-domain rotational probability effecting germline CDR2 scanning of polymorphic MHC

2019 ◽  
Author(s):  
Joseph S. Murray
Keyword(s):  
Integral Equation ◽  
Genetic Linkage ◽  
Alpha Helix ◽  
Volumetric Density ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Hla Dq ◽  
Relative Affinity ◽  
Triple Integral Equation

AbstractThe mechanism which adapts the T-cell antigen receptor (TCR) within a given major histocompatibility complex (MHC; HLA, in humans) genotype is essential for protection against pathogens. Historically attributed to relative affinity, genetically vast TCRs are surprisingly focused towards a micromolar affinity for their respective peptide (p) plus MHC (pMHC) ligands. Thus, the somatic diversity of the TCR with respect to MHC restriction, and (ultimately) to pathogens, remains enigmatic. Here, we derive a triple integral equation (from fixed geometry) for any given V-domain in TCR bound to pMHC. We examine solved complexes involving HLA-DR and HLA-DQ, where genetic linkage to the TCR is most profound. Certain V-beta domains displayed rare geometry within this panel—specifying a very low (highly-restricted) rotational probability/volumetric density (dV). Remarkably, hydrogen (H)-bond charge-relays distinguished these structures from the others; suggesting that CDR3 binding chemistry dictates CDR2 contacts on the respective MHC-II alpha-helix.

scholarly journals Somatic genetics of CDR3 control TCR V-domain rotational probability and germline CDR2 scanning of polymorphic MHC

2021 ◽  
Author(s):  
Joseph Murray
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
Genetic Linkage ◽  
Alpha Helix ◽  
Volumetric Density ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Hla Dq ◽  
Relative Affinity

Abstract The mechanism which adapts the T-cell antigen receptor (TCR) within a given major histocompatibility complex (MHC/HLA) genotype is essential for protection against pathogens. Historically attributed to relative affinity, genetically vast TCRs are surprisingly focused towards a micromolar affinity for their respective peptide (p) plus MHC (pMHC) ligands. Thus, the somatic diversity of the TCR with respect to MHC-restriction, and (ultimately) to pathogens, remains enigmatic. Here, we derive a triple integral solution (from fixed geometry) for any given V domain in TCR bound to pMHC. Solved complexes involving HLA-DR and HLA-DQ, where genetic linkage to the TCR is most profound, were examined in detail. Certain V domains displayed rare geometry within this panel—specifying a restricted rotational probability/volumetric density (dV). Remarkably, hydrogen (H) bond charge-relays distinguished these structures from the others; suggesting that CDR3 binding chemistry dictates CDR2 contacts on the opposite MHC-II alpha helix. Together, these data suggest that TCR recapitulate dV and specialise target pMHC recognition, i.e., a dynamics alternative to a relative TCR-affinity based mechanism.

scholarly journals Inhibition of HLA-DR Assembly, Transport, and Loading by Human Cytomegalovirus Glycoprotein US3: a Novel Mechanism for Evading Major Histocompatibility Complex Class II Antigen Presentation

2002 ◽  
Vol 76 (21) ◽  
pp. 10929-10941 ◽  
Author(s):  
Nagendra R. Hegde ◽  
Roman A. Tomazin ◽  
Todd W. Wisner ◽  
Claire Dunn ◽  
Jessica M. Boname ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
Antigen Presentation ◽  
Class Ii ◽  
Complex Class ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Antigen Presentation Pathway ◽  
Presentation Pathway

ABSTRACT Human cytomegalovirus (HCMV) establishes persistent lifelong infections and replicates slowly. To withstand robust immunity, HCMV utilizes numerous immune evasion strategies. The HCMV gene cassette encoding US2 to US11 encodes four homologous glycoproteins, US2, US3, US6, and US11, that inhibit the major histocompatibility complex class I (MHC-I) antigen presentation pathway, probably inhibiting recognition by CD8+ T lymphocytes. US2 also inhibits the MHC-II antigen presentation pathway, causing degradation of human leukocyte antigen (HLA)-DR-α and -DM-α and preventing recognition by CD4+ T cells. We investigated the effects of seven of the US2 to US11 glycoproteins on the MHC-II pathway. Each of the glycoproteins was expressed by using replication-defective adenovirus vectors. In addition to US2, US3 inhibited recognition of antigen by CD4+ T cells by a novel mechanism. US3 bound to class II α/β complexes in the endoplasmic reticulum (ER), reducing their association with Ii. Class II molecules moved normally from the ER to the Golgi apparatus in US3-expressing cells but were not sorted efficiently to the class II loading compartment. As a consequence, formation of peptide-loaded class II complexes was reduced. We concluded that US3 and US2 can collaborate to inhibit class II-mediated presentation of endogenous HCMV antigens to CD4+ T cells, allowing virus-infected cells to resist recognition by CD4+ T cells.

scholarly journals Major Histocompatibility Complex Class II Molecules Promote Human Immunodeficiency Virus Type 1 Assembly and Budding to Late Endosomal/Multivesicular Body Compartments

2006 ◽  
Vol 80 (19) ◽  
pp. 9789-9797 ◽  
Author(s):  
Andrés Finzi ◽  
Alexandre Brunet ◽  
Yong Xiao ◽  
Jacques Thibodeau ◽  
Éric A. Cohen
Keyword(s):  
Multivesicular Body ◽  
Complex Class ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Immunodeficiency Virus ◽  
Intracellular Compartments ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) assembly, budding, and release occur mostly at the plasma membrane in T lymphocytes as well as in established nonlymphoid cell lines, while in macrophages these processes occur primarily in intracellular compartments that harbor late endosomal/multivesicular body (LE/MVB) markers, including human leukocyte antigen DR (HLA-DR). Major histocompatibility complex class II molecules (MHC-II), which are expressed in macrophages and activated T cells, have been previously reported to induce the formation of multilaminar and multivesicular endocytic MHC-II-like structures analogous to MVB upon their expression in HEK 293 cells. Here, we have examined the role of MHC-II in HIV-1 Gag targeting as well as in virus assembly and release. Expression of HLA-DR in nonlymphoid cell lines induced a relocation of Gag to intracellular compartments that harbored LE/MVB markers and increased the accumulation of viral particles assembling intracellularly. Consequently, viral production and release from the cell surface was found to be substantially decreased in HLA-DR-expressing cells. This process was specific, since it was not observed with HLA-DR molecules lacking their cytoplasmic tails, nor with structurally related but functionally distinct MHC-II molecules such as HLA-DM or HLA-DO. Importantly, virus released intracellularly in HLA-DR-expressing cells retained infectivity. Overall, these results suggest a role of MHC-II molecules in promoting HIV-1 assembly and budding to LE/MVB and raise the possibility that this activity might be part of a normal pathway of virus production in cell types physiologically expressing MHC-II molecules, such as macrophages.

scholarly journals An Isotype-specific Activator of Major Histocompatibility Complex (MHC) Class II Genes That Is Independent of Class II Transactivator

1997 ◽  
Vol 185 (11) ◽  
pp. 1885-1895 ◽  
Author(s):  
John Douhan ◽  
Rebecca Lieberson ◽  
Joan H.M. Knoll ◽  
Hong Zhou ◽  
Laurie H. Glimcher
Keyword(s):  
Major Histocompatibility Complex ◽  
Cell Line ◽  
Mhc Class Ii ◽  
Ectopic Expression ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Class Ii Transactivator ◽  
Histocompatibility Complex ◽  
Hla Dr ◽  
Hla Dq

Patients with one type of major histocompatibility complex class II combined immunodeficiency have mutations in a gene termed class II transactivator (CIITA), which coordinately controls the transcription of the three major human class II genes, HLA-DR, -DQ, and -DP. However, the experimentally derived B-lymphoblastoid cell line, clone 13, expresses high levels of HLADQ in the absence of HLA-DR and HLA-DP, despite its mapping by complementation analysis to this group. It was possible that one of the clone 13 CIITA alleles bore a mutation that allowed HLA-DQ, but not HLA-DR or -DP transcription. Alternatively, another factor, distinct from CIITA, might control HLA-DQ expression. We report here that ectopic expression of CIITA cDNAs derived by reverse transcriptase polymerase chain reaction from clone 13 do not restore expression of HLA-DQ in another CIITA-deficient cell line, RJ2.2.5. In addition, no CIITA protein is detectable in clone 13 nuclear extracts. In contrast, somatic cell fusion between clone 13 and RJ2.2.5 restored expression of the HLA-DQ haplotype encoded by the RJ2.2.5 DQB gene. Taken together, these data demonstrate the existence of an HLA-DQ isotype-specific trans-acting factor, which functions independently of CIITA.

Relationship of Major Histocompatibility Complex Class II Genes to Inhibitor Antibody Formation in Hemophilia A

1990 ◽  
Vol 64 (04) ◽  
pp. 564-568 ◽  
Author(s):  
Lloyd E Lippert ◽  
Lyman Mc A Fisher ◽  
Lawrence B Schook
Keyword(s):  
Major Histocompatibility Complex ◽  
Factor Viii ◽  
Antibody Formation ◽  
Rflp Analysis ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Odds Ratios ◽  
Inhibitory Antibody ◽  
Histocompatibility Complex ◽  
Hla Dr

SummaryApproximately 14% of transfused hemophiliacs develop an anti-factor VIII inhibitory antibody which specifically neutralizes factor VIII procoagulant activity. In this study an association of the major histocompatibility complex (MHC) with inhibitor antibody formation was evaluated by restriction fragment length polymorphism (RFLP) analysis using BamHI, EcoRI, HindII, PstI, PvuII and TaqI digested genomic DNA probed with DP beta, DQ alpha, DQ beta and DR beta class II MHC gene probes. The RFLP patterns for 16 non-inhibitor and 11 inhibitor hemophiliac patients were analyzed. These 24 enzyme:probe combinations generated 231 fragments. Fifteen (15) fragments associated with the inhibitor phenotype; odds ratios ranged from 5.1 to 45 and lower bounds of 95% confidence intervals were > 1.000 for all 15 fragments. Five (5) fragments associated with non-inhibitors, with odds ratios ranging from 6.4 to 51.7. This report establishes a MHC related genetic basis for the inhibitor phenotype. No statistically significant differences in the distribution of serologically defined HLA-DR phenotypes were observed between the inhibitor and non-inhibitor groups.

scholarly journals Activation of autophagy reverses gemcitabine-induced immune inhibition of RAW264.7 macrophages by promoting TNF-α, IL-6 and MHC-II expression

2021 ◽  
Author(s):  
Shanshan Jiang ◽  
Rong Wang ◽  
Lu Han ◽  
Kudelaidi Kuerban ◽  
Li Ye ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Interferon Γ ◽  
Mhc Ii ◽  
Western Blot Method ◽  
Raw264.7 Macrophages ◽  
Histocompatibility Complex ◽  
Tnf Α ◽  
Factor Α ◽  
Cell Cycle Status ◽  
M1 Type

AbstractThis research aims to investigate the effect of gemcitabine (GEM) on various activities and functions of macrophages. Phagocytosis, cell autophagy and reactive oxygen species (ROS) were analysed by laser scanning confocal microscope. The cell cycle status and major histocompatibility complex II (MHC-II) expression were examined by flow cytometry. Inflammatory cytokine secretion such as tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) was detected by Elisa assay. The expression of proteins was analysed by western blot method. The results revealed that GEM-induced immune inhibition of M1-type RAW264.7 macrophages activated by interferon-γ (IFN-γ) and lipopolysaccharide (LPS). We also found that GEM inhibited autophagy, as evidenced by the reduced formation of autophagosome-like vacuoles and autophagosomes. Further study showed that incubation of activated macrophages with the autophagy inhibitor 3-MA induced immune suppression. In contrast, treatment with the autophagy inducer trehalose (Tre) restored phagocytosis, TNF-α and IL-6 secretion, and MHC-II expression in GEM-induced immune-inhibited macrophages. GEM reduced immune effect of M1-type RAW264.7 macrophages via inhibiting TNF-α, IL-6 and MHC-II expression. Furthermore, activation of autophagy by Tre reversed GEM-induced immune inhibition of RAW264.7 macrophages.

First report on the antibody verification of HLA-DR, HLA-DQ and HLA-DP epitopes recorded in the HLA Epitope Registry

2014 ◽  
Vol 75 (11) ◽  
pp. 1097-1103 ◽  
Author(s):  
Rene J. Duquesnoy ◽  
Marilyn Marrari ◽  
Anat R. Tambur ◽  
Arend Mulder ◽  
Luiz Cláudio Demes da Mata Sousa ◽  
...  
Keyword(s):  
First Report ◽  
Hla Dr ◽  
Hla Dq

scholarly journals Cytokines in chronic inflammatory arthritis. IV. Granulocyte/macrophage colony-stimulating factor-mediated induction of class II MHC antigen on human monocytes: a possible role in rheumatoid arthritis.

1989 ◽  
Vol 170 (3) ◽  
pp. 865-875 ◽  
Author(s):  
J M Alvaro-Gracia ◽  
N J Zvaifler ◽  
G S Firestein
Keyword(s):  
Rheumatoid Arthritis ◽  
Class Ii ◽  
Tnf Alpha ◽  
Blood Monocytes ◽  
Ifn Gamma ◽  
Normal Peripheral Blood ◽  
Gm Csf ◽  
Hla Dr ◽  
Class Ii Mhc ◽  
Hla Dq

Granulocyte/macrophage CSF (GM-CSF) has recently been identified in rheumatoid arthritis (RA) synovial effusions. To study a potential role for GM-CSF and other cytokines on the induction of HLA-DR expression on monocytes and synovial macrophages, we analyzed the relative ability of recombinant human cytokines to induce the surface expression of class II MHC antigens on normal peripheral blood monocytes by FACS analysis. GM-CSF (800 U/ml) (mean fluorescence channel 2.54 +/- 0.33 times the control, p less than 0.001) and IFN-gamma (100 U/ml) (5.14 +/- 0.60, p less than 0.001) were the most potent inducers of HLA-DR. TNF-alpha and IL-4 also increased HLA-DR expression, although to a lesser degree [1.31 +/- 0.06 (p less than 0.02) and 1.20 +/- 0.03 (p less than 0.01), respectively]. IL-1 (40 U/ml), IL-2 (10 ng/ml), IL-3 (50 U/ml), IL-6 (100 U/ml), and CSF-1 (1,000 U/ml) did not affect surface HLA-DR density. GM-CSF also increased HLA-DR mRNA expression and surface HLA-DQ expression, but decreased CD14 (a monocyte/macrophage antigen) expression. The effect of GM-CSF on HLA-DR was not mediated by the generation of IFN-gamma in vitro because it was not blocked by anti-IFN-gamma mAb. GM-CSF was additive with IL-4 and low amounts (less than 3 U/ml) of IFN-gamma and synergistic with TNF-alpha. Because we have recently reported that supernatants of cultured RA synovial cells produce a non-IFN-gamma factor that induces HLA-DR on monocytes, we then attempted to neutralize this factor with specific anti-GM-CSF mAb. Four separate synovial tissue supernatants were studied, and the antibody neutralized the HLA-DR-inducing factor in each (p less than 0.01).

scholarly journals High Levels of a Major Histocompatibility Complex II–Self Peptide Complex on Dendritic Cells from the T Cell Areas of Lymph Nodes

1997 ◽  
Vol 186 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Kayo Inaba ◽  
Maggie Pack ◽  
Muneo Inaba ◽  
Hiraki Sakuta ◽  
Frank Isdell ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Mhc I ◽  
Peptide Complex ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Peripheral Lymph ◽  
Free Media ◽  
Very High

T lymphocytes recirculate continually through the T cell areas of peripheral lymph nodes. During each passage, the T cells survey the surface of large dendritic cells (DCs), also known as interdigitating cells. However, these DCs have been difficult to release from the lymph node. By emphasizing the use of calcium-free media, as shown by Vremec et al. (Vremec, D., M. Zorbas, R. Scollay, D.J. Saunders, C.F. Ardavin, L. Wu, and K. Shortman. 1992. J. Exp. Med. 176:47–58.), we have been able to release and enrich DCs from the T cell areas. The DCs express the CD11c leukocyte integrin, the DEC-205 multilectin receptor for antigen presentation, the intracellular granule antigens which are recognized by monoclonal antibodies M342, 2A1, and MIDC-8, very high levels of MHC I and MHC II, and abundant accessory molecules such as CD40, CD54, and CD86. When examined with the Y-Ae monoclonal which recognizes complexes formed between I-Ab and a peptide derived from I-Eα, the T cell area DCs expressed the highest levels. The enriched DCs also stimulated a T-T hybridoma specific for this MHC II–peptide complex, and the hybridoma underwent apoptosis. Therefore DCs within the T cell areas can be isolated. Because they present very high levels of self peptides, these DCs should be considered in the regulation of self reactivity in the periphery.

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