scholarly journals Tolerance and autoimmunity to erythroid differentiation (B-G) major histocompatibility complex alloantigens of the chicken.

1982 ◽  
Vol 156 (2) ◽  
pp. 321-336 ◽  
Author(s):  
C Havele ◽  
T G Wegmann ◽  
B M Longenecker

Hematopoietic chimeras were produced at four different stages of ontogeny between two allogeneic strains of chickens. All chimeras produced by parabiosis at day 12 of embryogenesis and the majority (83%) of the ones produced at day 15 by intravenous injection of allogeneic stem cells remained healthy, chimeric, and specifically tolerant at both the humoral and cell-mediated level throughout a long examination period. Chimeras generated at day 17 of embryogenesis demonstrated specific unresponsiveness at the cell-mediated level but produced specific anti-donor alloantibodies directed against erythrocyte-associated major histocompatibility complex (MHC) (B-G) antigens. These chimeras and a minority (17%) of the chimeras generated at day 15 of embryogenesis developed severe antibody-mediated autoimmune hemolytic anemia after the 5th mo of age and succumbed to massive bursal lymphomas and metastases by the 10th mo of age. The immunological and pathological characteristics of these birds appear to reflect an autoimmune state rather than one of tolerance. Erythroid chimeras generated at day 21 of ontogenic development displayed normal levels of GVH reactivity. These birds were eventually able to eliminate the chimeric state and remained healthy until deliberately killed. These results show that there is a critical period in embryogenesis during which the induction of allogeneic erythrocytic chimerism leads to the development, in adult life, of severe autoimmune anemia, B cell lymphomas, and death. B-G MHC antigens are erythroid differentiation antigens of the chicken. Polymorphic determinants on B-G antigens appear to be important cross-reactive determinants (with environmental bacteria), against which a high background immunity exists. Evidence is presented that the immune response to B-G antigens is responsible for the development of autoimmunity and other pathological events that follow and that tolerance to class I MHC antigens (B-F antigens) shared by lymphocytes erythrocytes is maintained at the same time that B-G tolerance is broken.

1983 ◽  
Vol 157 (2) ◽  
pp. 720-729 ◽  
Author(s):  
S L Swain ◽  
R W Dutton ◽  
R Schwab ◽  
J Yamamoto

Human T cells respond strongly to mouse major histocompatibility complex (MHC) antigens. The response is directed predominantly to the polymorphic determinants of the MHC antigens and there is little or no response to the nonpolymorphic determinants or to non-MHC antigens. Human cytotoxic T lymphocytes (CTL) are generated specific for the mouse class I MHC antigens and the CTL effectors are blocked by anti-Leu-2a antisera. Human interleukin 2-producing T cells are generated specific for mouse class II antigens and their induction is blocked by anti-Leu-3a antisera. These and other considerations lead us to propose a model for the T cell receptor that provides an explanation for several of the features of T cell recognition. In this model, the recognition of the "class" (I or II) of MHC antigen is separate from the recognition of the polymorphic determinants. We suggest that the initial recognition of the conserved "class" determinants positions another domain of the receptor so that it can only engage with the part of the MHC molecule carrying the polymorphic determinants.


2017 ◽  
Author(s):  
Matthew R. Semler ◽  
Roger W. Wiseman ◽  
Julie A. Karl ◽  
Michael E. Graham ◽  
Samantha M. Gieger ◽  
...  

AbstractPig-tailed macaques (Macaca nemestrina, Mane) are important models for human immunodeficiency virus (HIV) studies. Their infectability with minimally modified HIV makes them a uniquely valuable animal model to mimic human infection with HIV and progression to acquired immunodeficiency syndrome (AIDS). However, variation in the pig-tailed macaque major histocompatibility complex (MHC) and the impact of individual transcripts on the pathogenesis of HIV and other infectious diseases is understudied compared to rhesus and cynomolgus macaques. In this study, we used Pacific Biosciences single-molecule real-time circular consensus sequencing to describe full-length MHC class I (MHC-I) transcripts for 194 pig-tailed macaques from three breeding centers. We then used the full-length sequences to inferMane-AandMane-Bhaplotypes containing groups of MHC-I transcripts that co-segregate due to physical linkage. In total, we characterized full-length open reading frames (ORFs) for 313Mane-A,Mane-B, andMane-Isequences that defined 86Mane-Aand 106Mane-BMHC-I haplotypes. Pacific Biosciences technology allows us to resolve theseMane-AandMane-Bhaplotypes to the level of synonymous allelic variants. The newly defined haplotypes and transcript sequences containing full-length ORFs provide an important resource for infectious disease researchers as certain MHC haplotypes have been shown to provide exceptional control of simian immunodeficiency virus (SIV) replication and prevention of AIDS-like disease in nonhuman primates. The increased allelic resolution provided by Pacific Biosciences sequencing also benefits transplant research by allowing researchers to more specifically match haplotypes between donors and recipients to the level of nonsynonymous allelic variation, thus reducing the risk of graft-versus-host disease.


1998 ◽  
Vol 72 (1) ◽  
pp. 460-466 ◽  
Author(s):  
Tara L. Chapman ◽  
Pamela J. Bjorkman

ABSTRACT Both human and murine cytomegaloviruses (HCMV and MCMV) down-regulate expression of conventional class I major histocompatibility complex (MHC) molecules at the surfaces of infected cells. This allows the infected cells to evade recognition by cytotoxic T cells but leaves them susceptible to natural killer cells, which lyse cells that lack class I molecules. Both HCMV and MCMV encode class I MHC heavy-chain homologs that may function in immune response evasion. We previously showed that a soluble form of the HCMV class I homolog (UL18) expressed in Chinese hamster ovary cells binds the class I MHC light-chain β2-microglobulin and a mixture of endogenous peptides (M. L. Fahnestock, J. L. Johnson, R. M. R. Feldman, J. M. Neveu, W. S. Lane, and P. J. Bjorkman, Immunity 3:583–590, 1995). Consistent with this observation, sequence comparisons suggest that UL18 contains the well-characterized groove that serves as the binding site in MHC molecules for peptides derived from endogenous and foreign proteins. By contrast, the MCMV homolog (m144) contains a substantial deletion within the counterpart of its α2 domain and might not be expected to contain a groove capable of binding peptides. We have now expressed a soluble version of m144 and verified that it forms a heavy chain–β2-microglobulin complex. By contrast to UL18 and classical class I MHC molecules, m144 does not associate with endogenous peptides yet is thermally stable. These results suggest that UL18 and m144 differ structurally and might therefore serve different functions for their respective viruses.


2012 ◽  
Vol 513 (2) ◽  
pp. 223-228 ◽  
Author(s):  
Rodrigo Fabrizzio Inácio ◽  
Renata Graciele Zanon ◽  
Liana Verinaud ◽  
Alexandre Leite Rodrigues de Oliveira

2013 ◽  
Vol 288 (45) ◽  
pp. 32797-32808 ◽  
Author(s):  
Andy van Hateren ◽  
Rachel Carter ◽  
Alistair Bailey ◽  
Nasia Kontouli ◽  
Anthony P. Williams ◽  
...  

2000 ◽  
Vol 74 (19) ◽  
pp. 9256-9266 ◽  
Author(s):  
Sylvie Le Gall ◽  
Florence Buseyne ◽  
Alicja Trocha ◽  
Bruce D. Walker ◽  
Jean-Michel Heard ◽  
...  

ABSTRACT The human immunodeficiency virus type 1 Nef protein alters the post-Golgi stages of major histocompatibility complex class I (MHC-I) biogenesis. Presumed mechanisms involve the disclosure of a cryptic tyrosine-based sorting signal (YSQA) located in the cytoplasmic tail of HLA-A and -B heavy chains. We changed this signal for a prototypic sorting motif (YSQI or YSQL). Modified HLA-A2 molecules, termed A2-endo, displayed constitutively low surface levels and accumulated in a region close to or within the Golgi apparatus, a behavior reminiscent of wild-type HLA-A2 in Nef-expressing cells. However, several lines of evidence indicate that the action of prototypic signals on MHC-I trafficking differs from that of Nef. Internalization of surface A2-endo was more rapid and was associated with efficient recycling to the surface. A transdominant-negative mutant of dynamin-1 inhibited A2-endo constitutive internalization and Nef-induced CD4 down-regulation, whereas it did not affect the activity of Nef on MHC-I. Moreover, trafficking of A2-endo was still affected by the viral protein, indicating additive effects of prototypic signals and Nef. Therefore, distinct trafficking pathways regulate clathrin-dependent and Nef-induced MHC-I modulation.


Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3566-3573 ◽  
Author(s):  
Søren Skov ◽  
Mette Nielsen ◽  
Søren Bregenholt ◽  
Niels Ødum ◽  
Mogens H. Claesson

Abstract Activation of Janus tyrosine kinases (Jak) and Signal transducers and activators of transcription (Stat) after ligation of major histocompatibility complex class I (MHC-I) was explored in Jurkat T cells. Cross-linking of MHC-I mediated tyrosine phosphorylation of Tyk2, but not Jak1, Jak2, and Jak3. In addition, the transcription factor Stat-3 was tyrosine phosphorylated in the cytoplasma and subsequently translocated to the cell nucleus. Data obtained by electrophoretic mobility shift assay suggested that the activated Stat-3 protein associates with the human serum-inducible element (hSIE) DNA-probe derived from the interferon-γ activated site (GAS) in the c-fos promoter, a common DNA sequence for Stat protein binding. An association between hSIE and Stat-3 after MHC-I ligation was directly demonstrated by precipitating Stat-3 from nuclear extracts with biotinylated hSIE probe and avidin-coupled agarose. To investigate the function of the activated Stat-3, Jurkat T cells were transiently transfected with a Stat-3 isoform lacking the transactivating domain. This dominant-negative acting Stat-3 isoform significantly inhibited apoptosis induced by ligation of MHC-I. In conclusion, our data suggest the involvement of the Jak/Stat signal pathway in MHC-I–induced signal transduction in T cells.


2010 ◽  
Vol 84 (10) ◽  
pp. 5443-5447 ◽  
Author(s):  
Thomas C. Friedrich ◽  
Shari M. Piaskowski ◽  
Enrique J. León ◽  
Jessica R. Furlott ◽  
Nicholas J. Maness ◽  
...  

ABSTRACT Human and simian immunodeficiency viruses (HIV and SIV) downregulate major histocompatibility complex class I (MHC-I) molecules from the surface of infected cells. Although this activity is conserved across viral isolates, its importance in AIDS pathogenesis is not clear. We therefore developed an assay to detect the level of MHC-I expression of SIV-infected cells directly ex vivo. Here we show that the extent of MHC-I downregulation is greatest in SIVmac239-infected macaques that never effectively control virus replication. Our results suggest that a high level of MHC-I downregulation is a hallmark of fast disease progression in SIV infection.


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