scholarly journals Allelic diversity and patterns of selection at the major histocompatibility complex class I and II loci in a threatened shorebird, the Snowy Plover (Charadrius nivosus)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Medardo Cruz-López ◽  
Guillermo Fernández ◽  
Helen Hipperson ◽  
Eduardo Palacios ◽  
John Cavitt ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Balancing Selection ◽  
Allelic Diversity ◽  
Class Ii ◽  
Class I ◽  
Mhc Genes ◽  
Snowy Plover ◽  
Snowy Plovers ◽  
Private Alleles

Abstract Background Understanding the structure and variability of adaptive loci such as the major histocompatibility complex (MHC) genes is a primary research goal for evolutionary and conservation genetics. Typically, classical MHC genes show high polymorphism and are under strong balancing selection, as their products trigger the adaptive immune response in vertebrates. Here, we assess the allelic diversity and patterns of selection for MHC class I and class II loci in a threatened shorebird with highly flexible mating and parental care behaviour, the Snowy Plover (Charadrius nivosus) across its broad geographic range. Results We determined the allelic and nucleotide diversity for MHC class I and class II genes using samples of 250 individuals from eight breeding population of Snowy Plovers. We found 40 alleles at MHC class I and six alleles at MHC class II, with individuals carrying two to seven different alleles (mean 3.70) at MHC class I and up to two alleles (mean 1.45) at MHC class II. Diversity was higher in the peptide-binding region, which suggests balancing selection. The MHC class I locus showed stronger signatures of both positive and negative selection than the MHC class II locus. Most alleles were present in more than one population. If present, private alleles generally occurred at very low frequencies in each population, except for the private alleles of MHC class I in one island population (Puerto Rico, lineage tenuirostris). Conclusion Snowy Plovers exhibited an intermediate level of diversity at the MHC, similar to that reported in other Charadriiformes. The differences found in the patterns of selection between the class I and II loci are consistent with the hypothesis that different mechanisms shape the sequence evolution of MHC class I and class II genes. The rarity of private alleles across populations is consistent with high natal and breeding dispersal and the low genetic structure previously observed at neutral genetic markers in this species.

MHC reflects fine-scale habitat structure in white-tailed eagles Haliaeetus albicilla

2021 ◽  
Author(s):  
Piotr Minias ◽  
Aleksandra Janiszewska ◽  
Ewa Pikus ◽  
Tomasz Zadworny ◽  
Dariusz Anderwald
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Habitat Structure ◽  
Balancing Selection ◽  
Strong Support ◽  
Class Ii ◽  
Class I ◽  
Fluctuating Selection ◽  
Haliaeetus Albicilla ◽  
Habitat Variation

Abstract The Major Histocompatibility Complex (MHC) genes code for key immune receptors responsible for recognition of intra- and extra-cellular pathogens (MHC class I and class II, respectively). It was hypothesized that MHC polymorphism can be maintained via fluctuating selection resulting from between-habitat variation in pathogen regimes. We examined associations between MHC class I and class II genes and habitat structure in an apex avian predator, the white-tailed eagle Haliaeetus albicilla. We genotyped MHC class I and class II genes in ca. 150 white-tailed eagle chicks from nearly one hundred nesting territories distributed across three distinct populations in Poland. Habitat structure was quantified at the levels of foraging territories and directly at the nest sites. We found strong support for associations of habitat traits with diversity and allelic composition at the MHC class II. Forest area within territory and forest productivity were identified as the major habitat predictors of MHC class II polymorphism, while other habitat traits (distance to nearest open water, grassland and water area within territory or understory presence) showed fewer associations with class II alleles. In contrast, there was little support for associations between MHC class I genes and habitat structure. All significant associations were apparent at the within- rather than between-population level. Our results suggest that extra-cellular (rather than intra-cellular) pathogens may exert much stronger selective pressure on the white-tailed eagle. Associations of habitat structure with MHC class II may reflect fluctuating (balancing) selection which maintains MHC diversity within populations.

scholarly journals Major Histocompatibility Complex (MHC) Genes and Disease Resistance in Fish

2019 ◽  
Author(s):  
Takuya Yamaguchi ◽  
Johannes M. Dijkstra
Keyword(s):  
Disease Resistance ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Teleost Fish ◽  
Class Ii ◽  
Point Of View ◽  
Class I ◽  
Mhc Genes ◽  
Histocompatibility Complex ◽  
Genomic Regions

The basic pattern of MHC variation in fish, with MHC class I versus class II, and polymorphic classical versus nonpolymorphic nonclassical, is similar in fish and mammals. Nevertheless, in many or all teleost fishes, important differences with mammalian or human MHC were observed: (1) The allelic/haplotype diversification levels of classical MHC class I genes tend to be much higher than in mammals; (2) Teleost fish classical MHC class I and class II loci are not linked. The present article summarizes previous studies that performed quantitative trait loci (QTL) analysis for mapping differences in teleost fish disease resistance, and discusses them from MHC point of view. Overall, those studies suggest the possible importance of genomic regions including classical MHC class II and nonclassical MHC class I genes, whereas similar observations were not made for the genomic regions with the highly diversified classical MHC class I alleles. The present study is a review and discussion of the fish MHC situation.

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

scholarly journals Identification of MHC class II restricted T-cell-mediated reactivity against MHC class I binding Mycobacterium tuberculosis peptides

Immunology ◽  
2011 ◽  
Vol 132 (4) ◽  
pp. 482-491 ◽  
Author(s):  
Mingjun Wang ◽  
Sheila T. Tang ◽  
Anette Stryhn ◽  
Sune Justesen ◽  
Mette V. Larsen ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I

Towards a systems understanding of MHC class I and MHC class II antigen presentation

2011 ◽  
Vol 11 (12) ◽  
pp. 823-836 ◽  
Author(s):  
Jacques Neefjes ◽  
Marlieke L. M. Jongsma ◽  
Petra Paul ◽  
Oddmund Bakke
Keyword(s):  
Antigen Presentation ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Class Ii Antigen ◽  
Mhc Class Ii Antigen

scholarly journals Lymphoid Tumors ofXenopus laeviswith Different Capacities for Growth in Larvae and Adults

1994 ◽  
Vol 3 (4) ◽  
pp. 297-307 ◽  
Author(s):  
Jacques Robert ◽  
Chantal Guiet ◽  
Louis Du Pasquier
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Cell Lineage ◽  
Cell Types ◽  
Class Ii ◽  
Class I ◽  
Specific Marker

Three new lymphoid tumors offering an assortment of variants in terms of MHC class I expressions, MHC class II expression, and Ig gene transcription have been discovered in the amphibianXenopus. One was developed in an individual of the isogenic LG15 clone (LG15/0), one in a frog of the LG15/40 clone (derived from a small egg recombinant of LG15), and one (ff-2) in a maleffsib of the individual in which MAR1, the first lymphoid tumor in Xenopus was found 2 years ago. These tumors developed primarily as thymus outgrowths and were transplantable in histocompatible tadpoles but not in nonhistocompatible hosts. Whereas LG15/0 and LG15/40 tumor cells also grow in adult LG15 frogs, theff-2 tumor, like the MAR1 cell line, is rejected by adultffanimals. Using flow cytometry with fluorescence-labeled antibodies and immunoprecipitation analysis, we could demonstrate that, like MAR1, these three new tumors express on their cell surface lymphopoietic markers recognized by mAbs FIF6 and RC47, as well as T-cell lineage markers recognized by mAbs AM22 (CD8-1ike) and X21.2, but not by immunologobulin (Ig) nor MHC class II molecules. Another lymphocyte-specific marker AM15 is expressed by 15/0 and 15/40 but notff-2 tumor cells. Theff-2 tumor cell expresses MHC class molecule in association withβ2-microglobulin on the surface, 15/40 cells contain cytoplasmic Iαchain that is barely detected at the cell surface by fluocytometry, and 15/0 cells do not synthesize class Iαchain at all. The three new tumors all produce large amounts of IgM mRNA of two different sizes but no Ig protein on the membrane nor in the cytoplasm. All tumor cell types synthesize large amount of Myc mRNA and MHC class I-like transcripts considered to be non classical.

Mouse Schwann cells activate MHC class I and II restricted T-cell responses, but require external peptide processing for MHC class II presentation

2010 ◽  
Vol 37 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Gerd Meyer zu Hörste ◽  
Holger Heidenreich ◽  
Anne K. Mausberg ◽  
Helmar C. Lehmann ◽  
Anneloor L.M.A. ten Asbroek ◽  
...  
Keyword(s):  
T Cell ◽  
Schwann Cells ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
T Cell Responses ◽  
Class Ii ◽  
Class I ◽  
Peptide Processing ◽  
Cell Responses

Expression of MHC class I, MHC class II, and cancer germline antigens in neuroblastoma

2004 ◽  
Vol 54 (4) ◽  
pp. 400-406 ◽  
Author(s):  
Matthias W�lfl ◽  
Achim A. Jungbluth ◽  
Federico Garrido ◽  
Teresa Cabrera ◽  
Sharon Meyen-Southard ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Class I Mhc ◽  
Cancer Germline

scholarly journals The Major Histocompatibility Complex of Old World Camels—A Synopsis

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1200 ◽  
Author(s):  
Plasil ◽  
Wijkmark ◽  
Elbers ◽  
Oppelt ◽  
Burger ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Class Iii ◽  
Old World ◽  
Histocompatibility Complex ◽  
Mhc Class Iii ◽  
Antigen Presenting

This study brings new information on major histocompatibility complex (MHC) class III sub-region genes in Old World camels and integrates current knowledge of the MHC region into a comprehensive overview for Old World camels. Out of the MHC class III genes characterized, TNFA and the LY6 gene family showed high levels of conservation, characteristic for MHC class III loci in general. For comparison, an MHC class II gene TAP1, not coding for antigen presenting molecules but functionally related to MHC antigen presenting functions was studied. TAP1 had many SNPs, even higher than the MHC class I and II genes encoding antigen presenting molecules. Based on this knowledge and using new camel genomic resources, we constructed an improved genomic map of the entire MHC region of Old World camels. The MHC class III sub-region shows a standard organization similar to that of pig or cattle. The overall genomic structure of the camel MHC is more similar to pig MHC than to cattle MHC. This conclusion is supported by differences in the organization of the MHC class II sub-region, absence of functional DY genes, different organization of MIC genes in the MHC class I sub-region, and generally closer evolutionary relationships of camel and porcine MHC gene sequences analyzed so far.

scholarly journals Major Histocompatibility Complex Class II and Programmed Death Ligand 1 Expression Predict Outcome After Programmed Death 1 Blockade in Classic Hodgkin Lymphoma

2018 ◽  
Vol 36 (10) ◽  
pp. 942-950 ◽  
Author(s):  
Margaretha G.M. Roemer ◽  
Robert A. Redd ◽  
Fathima Zumla Cader ◽  
Christine J. Pak ◽  
Sara Abdelrahman ◽  
...  
Keyword(s):  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Histocompatibility Complex ◽  
Classic Hodgkin Lymphoma ◽  
Programmed Death ◽  
Clinical Responses ◽  
Programmed Death 1 ◽  
Cell Expression

Purpose Hodgkin Reed-Sternberg (HRS) cells evade antitumor immunity by multiple means, including gains of 9p24.1/ CD274(PD-L1)/ PDCD1LG2(PD-L2) and perturbed antigen presentation. Programmed death 1 (PD-1) receptor blockade is active in classic Hodgkin lymphoma (cHL) despite reported deficiencies of major histocompatibility complex (MHC) class I expression on HRS cells. Herein, we assess bases of sensitivity to PD-1 blockade in patients with relapsed/refractory cHL who were treated with nivolumab (anti–PD-1) in the CheckMate 205 trial. Methods HRS cells from archival tumor biopsies were evaluated for 9p24.1 alterations by fluorescence in situ hybridization and for expression of PD ligand 1 (PD-L1) and the antigen presentation pathway components—β2-microglobulin, MHC class I, and MHC class II—by immunohistochemistry. These parameters were correlated with clinical responses and progression-free survival (PFS) after PD-1 blockade. Results Patients with higher-level 9p24.1 copy gain and increased PD-L1 expression on HRS cells had superior PFS. HRS cell expression of β2-microglobulin/MHC class I was not predictive for complete remission or PFS after nivolumab therapy. In contrast, HRS cell expression of MHC class II was predictive for complete remission. In patients with a > 12-month interval between myeloablative autologous stem-cell transplantation and nivolumab therapy, HRS cell expression of MHC class II was associated with prolonged PFS. Conclusion Genetically driven PD-L1 expression and MHC class II positivity on HRS cells are potential predictors of favorable outcome after PD-1 blockade. In cHL, clinical responses to nivolumab were not dependent on HRS cell expression of MHC class I.

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