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Biomedical subjects

M Jonker

Publications and source records attributed to M Jonker.

At least 19 recordsLinked to original sources

Mhc-DQB repertoire variation in hominoid and Old World primate species.

Comparison of 87 distinct Mhc-DQB sequences, obtained from 13 primate species, demonstrates that five out of eight trans-species Mhc-DQB allele lineages are at least 30 million years old and predate divergence of hominoid and Old World primate species. One lineage may be much older because its members are not only traced back in higher primates, but also are present in a New World primate species. Comparing Mhc-DQB repertoire variation in distinct species, allows one to pinpoint when certain polymorphisms were lost or gained in primate evolution. Heterogeneity observed among members of trans-species Mhc-DQB allele lineages can be explained in major part by point mutations, whereas intraexonic crossing-over is a potent mechanism in generating new allele lineages. The stability of Mhc-DQB polymorphisms is influenced by selective forces because distinct allele lineages appear to have accumulated nucleotide substitutions and amino acid replacements at different rates.

Alleles

Resistance to collagen-induced arthritis in a nonhuman primate species maps to the major histocompatibility complex class I region.

Type II collagen-induced arthritis (CIA) is an experimentally inducible autoimmune disorder that is, just like several forms of human arthritis, influenced by a genetic background. Immunization of young rhesus monkeys (Macaca mulatta) with type II collagen (CII) induced CIA in about 70% of the animals. One major histocompatibility complex (MHC) class I allele was present only in young animals resistant to CIA and absent in arthritic animals. This strong association suggests that the MHC class I allele itself, or a closely linked gene, determines resistance to CIA. The mechanism controlling the resistance to CIA becomes less efficient in aged animals since older rhesus monkeys, which were positive for the resistance marker, developed a mild form of arthritis. At the cellular level it is demonstrated that resistance to CIA is reflected by a low responsiveness of T cells to CII. This association between a specified MHC class I allele and resistance to an autoimmune disease points at the importance of the MHC class I region in the regulation of the immune response to an autoantigen.

Alleles

Evolutionary relationships among the primate Mhc-DQA1 and DQA2 alleles.

The variation of the Mhc-DQA1 and DQA2 loci of ten different primate species (hominoids and Old World monkeys) was studied in order to obtain an insight in the processes that generate polymorphism of major histocompatibility complex (Mhc) class II genes and to establish the evolutionary relationships of their alleles. To that end nucleotide sequences of 36 Mhc class II DQA1 and seven DQA2 second exons were determined and phylogenetic trees that illustrate their evolutionary relationships were constructed. We demonstrate the existence of four primate Mhc-DQA1 allele lineages, two of which probably existed before the separation of the ancestors of the hominoids and Old World monkeys (approximately 22-28 million years ago). Mhc-DQA2 sequences were found only in the hominoid species and showed little diversity. We found no evidence for a major contribution of recombinational events to the generation of allelic diversity of the primate Mhc-DQA1 locus. Instead, our data suggest that the primate Mhc-DQA1 and DQA2 loci are relatively stable entities that mutated primarily as a result of point mutations.

Alleles

Mhc-DRB diversity of the chimpanzee (Pan troglodytes).

Fifty-four chimpanzee Patr-DRB and five human HLA-DRB second exons were cloned and sequenced from thirty-five chimpanzees and four human B-cell lines and compared with known Mhc-DRB sequences of these two species. Equivalents of the HLA-DRB1*02, -DRB1*03, -DRB1*07 allelic lineages and the HLA-DRB3, -DRB4, -DRB5, -DRB6, and -DRB7 loci were all found in the chimpanzee. In addition, two chimpanzee Patr-DRB lineages (Patr-DRBX and -DRBY) were found for which no human counterparts have been described. None of the Patr-DRB sequences is identical to known HLA-DRB sequences. The Patr-DRB1*0702 and HLA-DRB1*0701 alleles are the most similar sequences in a comparison between the two species and differ by only two nucleotides out of 246 sequenced. Equivalents of the HLA-DRB1*01, -DRB1*04, and -DRB1*09 alleles were not found in our sample of chimpanzees. A per locus comparison of the number of Patr-DRB alleles with the HLA-DRB alleles shows that the Patr-DRB3, -DRB4, -DRB5, and -DRB6 locus are, thus far, more polymorphic than their human homologs. The polymorphism of the Patr-DRB1 locus seems to be less extensive than that reported for the HLA-DRB1 locus. Nevertheless, the Patr-DRB1 locus seems to be the most polymorphic of the Patr-DRB loci. Phylogenetic analyses indicate that the HLA-DRB1*09 allele may have originated from a recombination between a Mhc-DRB5 allele and the DRB1 allele of a Mhc-DR7 haplotype. Although recombination seems to increase the diversity of the Patr-DRB alleles, its contribution to the generation of Patr-DRB variation is probably low. Hence, most Patr-DRB diversity presumably accumulated via recurrent point mutations. Finally, two distinct Patr-DRB haplotypes are deduced, one of which (the chimpanzee equivalent of the HLA-DR7 haplotype) is probably older than 6-8 million years.

Amino Acid Sequence

Evolutionary stability of transspecies major histocompatibility complex class II DRB lineages in humans and rhesus monkeys.

Sequence analysis of rhesus monkey (Macaca mulatta) polymorphic second exon of major histocompatibility complex class II DRB subregion genes demonstrates the existence of at least 34 alleles. Some of these rhesus monkey alleles are very similar (or nearly identical) to HLA-DRB alleles. These data demonstrate that members of the lineages for Mhc-DRB1*03, -DRB1*04, -DRB1*10, and the loci of Mhc-DRB3, -DRB4, -DRB5, and -DRB6 predate speciation of man and rhesus monkey and were already present 25 million years ago. Calculation of evolutionary rates suggests that the various allele lineages have differential stabilities. Furthermore, the data indicate that distinct species may not have inherited or lost transspecies Mhc-DRB lineages in evolution, because several allele lineages in rhesus monkeys appear to be absent in humans and vice versa.

Alleles

Collagen-induced arthritis in an outbred group of rhesus monkeys comprising responder and nonresponder animals. Relationship between the course of arthritis and collagen-specific immunity.

It is speculated that the autoimmune response to type II collagen (CII) is a driving force in the pathogenesis of human rheumatoid arthritis (RA). In this report, we describe the relationship between the induction of collagen arthritis and the CII-specific humoral, as well as cellular, immune response in rhesus monkeys. Ten of 14 monkeys immunized with bovine type II collagen (B-CII) developed polyarthritis. Susceptible animals showed a T cell response to B-CII; resistant animals did not. After the primary immunization, the humoral response to B-CII, as well as to rhesus monkey type II collagen, was dominated by antibodies of the IgM isotype in the susceptible animals and by antibodies of the IgG isotype in the resistant animals. Because of the close phylogenic relationship between the rhesus monkey and humans, these data contribute valuable information about the role of CII-specific immunity in the pathogenesis of human RA.

Animals

Major histocompatibility complex ancestral haplotypes in the chimpanzee: identification using C4 allotyping.

In humans, certain major histocompatibility complex (MHC) supratypes mark unique DNA segments which have been conserved from a common but remote ancestor. In order to determine whether these ancestral haplotypes (AHs) exist in nonhuman primates, C4 allotyping was undertaken on 71 chimpanzees. Four large pedigrees were available. There are at least seven codominant C4 alleles at two loci. Null alleles are also present. It was possible to assign class I, class II, and C4 alleles to 37 unrelated haplotypes; several supratypes occurred two or more times. These putative AHs included some with alleles which resemble those carried by certain human AHs. These data provide evidence that similar MHC AHs are present in the chimpanzee and human. The present approach provides a basis for comparative studies examining the evolutionary and functional significance of the MHC.

Animals

RFLP analysis of the rhesus monkey MHC class II DR subregion.

Restriction fragment length polymorphism (RFLP) analysis was performed on a panel of 39 serologically typed DR homozygous monkeys. DNA was digested with the restriction enzyme TaqI and hybridizations were carried out with a human leukocyte antigen (HLA)-DR beta 3'UT-specific probe. In addition a panel of 18 monkeys was analyzed comprising experimental autoimmune encephalomyelitis (EAE) susceptible and nonsusceptible animals. The number of DRB/TaqI fragments detected for the various DR specificities varied from two to six, suggesting that the number of DRB genes per haplotype is not constant. RFLP typing allows that most serologically defined DR specificities can be subdivided. This knowledge was applied to define the DR specificities of the animals used for EAE experiments.

Animals

Autoimmunity in non-human primates: the role of major histocompatibility complex and T cells, and implications for therapy.

Two autoimmune disease models were studied in rhesus monkeys: type II collagen-induced arthritis (CIA) and experimental allergic encephalomyelitis (EAE). Unrelated outbred animals were used in these studies. In both models disease resistant and susceptible individuals could be identified. Susceptibility correlated with in vitro cellular responsiveness to antigen in the CIA model. In both models resistant as well as susceptible individuals developed a humoral response to the inducing antigen. However, there is an indication that IgM antibodies play a crucial role in the induction of CIA. No clear association between major histocompatibility complex (MHC) type and disease incidence was found although a higher frequency of a certain DR type was observed in EAE susceptible monkeys. It is likely that both the antigen binding capacity of the MHC class II molecules and the T-cell repertoire play an important role in determining whether disease will develop or not.

Animals

Acquired resistance to type II collagen-induced arthritis in rhesus monkeys is reflected by a T cell low-responsiveness to the antigen.

Ten out of 14 rhesus monkeys developed arthritis after a single immunization with bovine type II collagen (B-CII). In contrast to primary resistant monkeys, arthritic animals showed a B-CII specific T cell proliferation during the induction phase of the disease. All surviving animals showed a full remission of the disease. Two monkeys acquired resistance to collagen-induced arthritis (CIA) after one period of disease, but in three animals a booster immunization with B-CII induced a slight flare-up. It is demonstrated that B-CII immunized rhesus monkeys have the capacity to restore resistance to CIA. The development of resistance to CIA is reflected by a decreased T cell responsiveness to B-CII. It is shown that the lack of IL-2 plays a role in B-CII-induced T cell low-responsiveness. A potential role of CD8+ T cells in the down regulation of the T cell response to B-CII is discussed.

Animals

Monoclonal antibodies for immunohistochemical labeling of immunocompetent cells in frozen sections of rhesus monkey tissues.

Twenty-eight anti-human and two rhesus specific monoclonal antibodies (MAbs) were evaluated for immunohistochemical peroxidase staining reactivity in rhesus monkeys lymph nodes, thymus, liver, and skin allografts. Reactivity with the following antigens was assessed: MHC class I, II-DR, -DQ, and -DP antigens; leukocyte markers CD1, CD2, CD3, CD4, CD8, CD14, CD16, CD25, CD57; a proliferation associated nuclear antigen; interferon-gamma and tumor necrosis factor-alpha. Twenty-three MAbs proved to be suitable for immunohistochemical staining on frozen sections.

Animals

Major histocompatibility complex class II-restricted antigen presentation across a species barrier: conservation of restriction determinants in evolution.

The existence of at least three alleles of the HLA-DRB3 gene within the human population is evident. These alleles express DRw52 determinants and react with monoclonal antibody (mAb) 7.3.19.1. The polymorphic epitope recognized by 7.3.19.1 is not only present on human cells but is also expressed on chimpanzee (Pan troglodytes) class II-positive cells. The 7.3.19.1 determinant already existed before speciation of man and chimpanzee, and is at least 5,000,000 yr old. Two-dimensional gel electrophoresis demonstrated that the various HLA- and Patr-DRw52 molecules that are reactive with 7.3.19.1 exhibit isoelectric point differences due to primary amino acid heterogeneity, as was confirmed by sequencing data. Sequence comparison allowed us to map the binding site of mAb 7.3.19.1 to the alpha helix of the major histocompatibility complex (MHC) class II DRB1 domain surrounding the antigen-binding cleft. Despite MHC sequence variation, chimpanzee antigen-presenting cells can present antigen (purified protein derivative) to human T cell lines and vice versa. Only the HLA- and Patr-DRw52 molecules were shown to function as restriction elements for antigen presentation across this species barrier. It is concluded that these particular restriction determinants probably have been conserved in evolution. The HLA- and Patr-DRw52 molecules represent alleles displaying polymorphism that has been selected for in evolution. Such "biomutants" may thus be more useful to study the biological significance of MHC molecules than MHC variants that have been generated by in vitro mutagenesis experiments.

Amino Acid Sequence

The chimpanzee major histocompatibility complex class II DR subregion contains an unexpectedly high number of beta-chain genes.

The major histocompatibility complex (MHC) class II DR subregion of the chimpanzee was studied by restriction fragment length polymorphism (RFLP) analysis. Genomic DNA obtained from a panel of 94 chimpanzees was digested with the restriction enzyme Taq I and hybridized with an HLA-DR beta probe specific for the 3' untranslated (UT) region. Such a screening revealed the existence of 14 distinct DRB/Taq I gene-associated fragments allowing the definition of 11 haplotypes. Segregation studies proved that the number of chimpanzee class II DRB/Taq I fragments is not constant and varies from three to six depending on the haplotype. Comparison of these data with a human reference panel manifested that some MHC DRB/Taq I fragments are shared by man and chimpanzee. Moreover, the number of HLA-DRB/Taq I gene-associated fragments detected in a panel of homozygous typing cells varies from one to three and corresponds with the number of HLA-DRB genes present for most haplotypes. However, a discrepancy is observed for the HLA-DR4, -DR7, and -DR9 haplotypes since a fourth HLA-DRB pseudogene present within these haplotypes lacks its 3' UT region and thus is not detected with the probe used. These results suggest that chimpanzees have a higher maximum number of DRB genes per haplotype than man. As a consequence, some chimpanzee haplotypes must show a dissimilar organization of the MHC DR subregion compared to their human equivalents. The implications of these findings are discussed in the context of the trans-species theory of MHC polymorphism.

Animals

Experimental immune mediated arthritis in rhesus monkeys. A model for human rheumatoid arthritis?

The induction of experimental arthritis in rhesus monkeys was studied by intradermal immunization of bovine type II collagen and antigens derived from Mycobacterium tuberculosis, Streptococcus pyogenes, and Eubacterium aerofaciens. The tested bacterial antigens proved to be not arthrogenic. Bovine type II collagen induced clinical arthritis in 50% of the rhesus monkeys. Type II collagen induced arthritis in rhesus monkeys proved to be a potential model to study clinical, serological, histological, genetic, and immunologic features associated with human RA.

Animals

CD4 and CD8 T cells from SIV-infected macaques have defective signaling responses after perturbation of either CD3 or CD2 receptors.

Single-cell clones, designated E11S, C11R, and A1S, were obtained from the HuT-78 T cell line persistently infected with an isolate of Simian immunodeficiency virus (SIV), SIV/Mne. The infected clones, unlike uncloned uninfected HuT-78 cells, no longer expressed the CD4 marker and, after their CD3 receptors were cross-linked, had dramatically reduced intracellular free calcium ([Ca2+]i) responses. In one clone, E11S, the unresponsiveness was not limited to the inositol phospholipid pathway of signaling since a reduction in CD3-mediated activation of protein tyrosine kinase-dependent phosphorylation also was evident in this SIV-infected clone. These results led us to test whether T lymphocytes from animals infected with SIV had defective [Ca2+]i responses prior to detectable changes in CD4 levels or lymphadenopathy. The [Ca2+]i responses to both CD3 mAb and CD2 mAb were 10-50% less in T cells from Walter Reed stage 2 animals than in healthy controls. This anergy was more pronounced in chronically infected animals progressing to Walter Reed stage 3/4. The responses of these animals could not be augmented even when combinations of CD3 and CD4 mAb were used. Both CD4+CD44lo T cells, which are not infected with SIV, and the CD4+CD44hi T cell subset, previously shown to be the reservoir of SIV infection in blood, had pronounced defective responses to CD3 mAb. Similarly, both CD4+ and CD8+ T cells were consistently unresponsive in chronically infected animals, again implying that an indirect mechanism, rather than SIV infection per se, may be responsible for this immune dysfunction.

Animals

The course of untreated acute rejection and effect of repeated anti-CD3 monoclonal antibody treatment in rhesus monkey liver transplantation.

The effect of single and repeated treatment of liver allograft rejection using an anti-CD3 monoclonal antibody (FN18) was studied in a rhesus monkey model. Eight RhLA-mismatched monkeys received initial postoperative immunosuppression with CsA/prednisolone for 28 days. After cessation, acute rejection occurred in all animals (days 28-50). Control animals (n = 3) receiving no rejection treatment developed a chronic progressive rejection and died at days 112-160. In the animals treated with FN18 (n = 5), the first acute rejection was successfully reversed. T lymphocytes were cleared from the peripheral blood and the graft. Increased class I and class II MHC-antigens on hepatocytes were reduced to normal levels within 5 days of treatment. The second rejection treatment remained ineffective in two animals with antiidiotypic antibodies to FN18 but was successful in two animals with a low antimouse response. These four animals survived 160-509 days. The results have a number of implications regarding the course of untreated rejection in human liver transplant recipients and repetitive rejection treatment with monoclonal antibodies.

Animals