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

Gel electrophoretic analysis of rhesus macaque major histocompatibility complex class II DR molecules

Rhesus macaque MHC class II DR molecules were isolated from radiolabeled B-cell line extracts by immunoprecipitation with the mAbs 7.3.19.1 and B8.11.2 and subsequently analyzed by 2D-gel electrophoresis. The B-cell lines used for this study were obtained from monkeys that are homozygous for the Mamu-DR region as defined by serologic techniques. Some of these animals have been selectively bred and originate from consanguineous matings. These analyses show that monkeys with the same allotyping may express different types of DR molecules. As in humans, the number of DR molecules expressed per haplotype is not constant and varies from 1 to 3, depending on the serologically defined Mamu-DR specificity, whereas it has been shown that the number of Mamu-DRB genes present per haplotype varies from 2 to 6. Therefore the present study also demonstrates that some of the rhesus macaque DR regions contain one or more pseudogenes.

Identification of antibody epitopes in the CB-11 peptide of bovine type II collagen recognized by sera from arthritis-susceptible and -resistant rhesus monkeys

Sera from eight rhesus monkeys that had been immunized with native bovine type II collagen were tested for antibodies to cyanogen bromide peptides (CB peptides) of type II collagen by Western blotting. The monkeys produced IgG antibodies to a number of different CB peptides, with five out of eight animals producing antibodies to the CB-11 peptide (four arthritic, one non-arthritic). Antibody epitopes on the CB-11 peptide of bovine type II collagen recognized by these sera were investigated by epitope mapping. Peptides (8-mers overlapping by seven amino acids) representing the CB-11 region were synthesised and the sera screened for binding to these peptides to determine areas of high IgG antibody binding to this region of type II collagen. The profiles obtained were not identical, though there were some epitopes that were commonly recognized. Antibodies to one epitope, also present in human type II collagen, were found only in the sera of two animals with the severest arthritis. The technique of epitope mapping has successfully identified a number of epitopes within the CB-11 peptide of type II collagen recognized by antibodies from bovine type II collagen-immunized monkeys. Studies on the relevance of responses to the identified epitopes can now be undertaken.

The mitogen-induced generation of interferon-gamma producing cells in cultures of rhesus monkey peripheral blood mononuclear cells is age-dependent

An enzyme-linked immunoabsorbent spot (ELISPOT) assay has been developed for measuring the frequency of interferon-gamma (IFN-gamma) producing cells in rhesus monkeys. Aged monkeys revealed, upon mitogenic stimulation, a significantly higher percentage of IFN-gamma secreting peripheral blood mononuclear cells (PBMC) compared to young animals. No correlation was found between the frequency of IFN-gamma producing PBMC and the mitogen-driven proliferation, indicating that in rhesus monkeys no direct correlation exists between these two activation parameters.

Acute side effects of homologous interleukin-3 in rhesus monkeys

Interleukin-3 treatment of juvenile rhesus monkeys elicits a dose- and time-dependent syndrome that includes urticaria, palpable lymph nodes, splenomegaly, thrombocytopenia, anemia, vomiting, diarrhea, intestinal bleeding, edema, and arthritis, apart from a strong stimulation of hemopoiesis. Arthritis was found to occur significantly more often in animals expressing the major histocompatibility complex alleles B9 and Dr5. Histological analysis revealed an abundance of mast cells in urticaria and, to a lesser extent, in lungs and synovia of arthritic joints. Active osteoclasts were abundant in ribs and arthritic joints. Extramedullary hemopoiesis was encountered in liver, spleen, and kidneys. The spleen showed deposits of hemosiderin, and in the liver, Kupffer cells were loaded with iron, indicating enhanced turnover of hemoglobin. Lymph nodes and bone marrow showed macrophages involved in hemophagocytosis, which probably contributed to the development of anemia and thrombopenia. Biochemical parameters in sera were indicative of parenchymal liver damage, with cholestasis and increased erythrocyte destruction. The side effects were strongly reduced in monkeys subjected to total body irradiation just before interleukin-3 treatment. Histamine antagonists were not significantly effective in preventing side effects, which is explained by the perpetual stimulation of basophilic granulocytes by exogenous interleukin-3. The nature of the side effects indicates that interleukin-3 may be involved in the pathogenesis of acute type hypersensitivity reactions and arthritis.

The anti-arthritic and immunosuppressive effects of cyclosporin A on collagen-induced arthritis in the rhesus monkey

The influence of cyclosporin A (CsA) on type II collagen-induced arthritis (CIA) in the rhesus monkey has been investigated. CsA was administered subcutaneously in a dose of 25 mg/kg per day during 9-18 days and additionally 12.5 mg/kg per day for 7 days. At this dosing regime no significant alterations of haematologic parameters were found, indicating that the toxicity of CsA was negligible. Administration of CsA after onset of arthritis had no beneficial effect, but when given between immunization and manifestation of clinical symptoms, CIA could be prevented completely. Moreover, these monkeys became resistant to the disease, because no arthritic activity could be observed upon a booster immunization with type II collagen (CII). The suppression of disease by CsA is reflected in reduced antibody levels to CII.

Resistance to collagen-induced arthritis in rats and rhesus monkeys after immunization with attenuated type II collagen

Immunization of susceptible rodent or primate species with type II collagen (b-CII) from bovine origin induces type II collagen-induced arthritis (CIA). The disease is characterized as a systemic polyarthritis associated with humoral and cellular autoimmunity to CII and shares similarity with human arthritic diseases. The objective of this study was to develop a procedure for induction of resistance to CIA in animals, which possess a certain major histocompatibility complex phenotype that makes them prone to develop CIA (susceptible). It is shown that by immunization with an attenuated form of CII, in which arthritogenic epitopes have been destroyed by heat denaturation, disease resistance is induced in a susceptible inbred rat strain (RT-1u) and in an outbred population of susceptible rhesus monkeys (lacking the Mamu-A26 allele). In both species the disease resistance is connected with modulation of anti-CII autoantibodies of the IgM isotype. This protocol may provide a basis for effective and safe methods to induce protection to autoimmune arthritis in those subjects that are genetically prone to develop such a disease.

Major histocompatibility complex class II DQ diversity in rhesus macaques

By the use of restriction fragment length polymorphism analysis 10 Taq I fragments could be identified for the MhcMamu-DQA1 region. A strong correlation exists between the occurrence of Mamu-DQA1/Taq I fragments and Mamu-DQA1 allelic sequence variation. Most restriction fragments correspond with a unique Mamu-DQA1 allele, with one exception being the Taq I 4.5 kb fragment that is associated with two Mamu-DQA1 alleles. The RFLP technique allowed the identification of 15 Mamu-DQB1/Taq I restriction fragments, whereas sequence analysis has permitted the characterization of at least 20 different Mamu-DQB1 alleles. In this communication two unpublished Mamu-DQB1 sequences are described. For Mamu-DQB1, on only four occasions was it possible to demonstrate a correlation between a certain fragment and an allelic sequence. These analyses, performed on material from truly homozygous animals, allowed us to define which combinations of Mamu-DQA1 and -DQB1 molecules form heterodimers at the cell surface. In addition, these studies are helpful in typing non-human primate species that are used in biomedical research.

Characterization of the rhesus macaque (Macaca mulatta) equivalent of HLA-F

Nucleotide sequence analysis of rhesus macaque major histocompatibility complex class I cDNAs allowed the identification of the orthologue of HLA-F, designated Mamu-F. Comparison of Mamu-F with earlier published human and chimpanzee orthologues demonstrated that these sequences share a high degree of similarity, both at the nucleotide and amino acid level, whereas a New World monkey (cotton-top tamarin) equivalent is more distantly related. Exon 7, encoding one of the cytoplasmatic domains, is absent for all primate Mhc-F cDNA sequences analyzed so far. In contrast to the human, chimpanzee, and rhesus macaque equivalents, the cotton-top tamarin Saoe-F gene seems to have accumulated far more nonsynonymous than synonymous differences.

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.