Red cell polymorphisms in nonhuman primates: a review

Tissue expression of antigens of ABH blood groups in species of New World Monkeys (Aotus infulatus, Callithrix jacchus, Sapajus apella and Saimiri sciureus)

ABH antigens are histo-antigens, but were first described on the surface of human erythrocytes. They are found in those cells only in great apes and humans, while in more primitive animals they are found in tissues and body fluids. ABH antigens are mainly distributed in tissues that are in contact with the external environment and may serve as ligands for pathogens in tissues or block their connection. Description of the distribution of these molecules in non-human primate tissues is restricted to a few tissues and species. This paper describes the expression of human A, B and H type antigens in different organs from four species of New World Primates, obtained from the Centro Nacional de Primatas, as well as comparing that expression with what has been described for humans. In this study, although the tissue description of the antigens is similar to the genetic model for humans, some differences in expression between some organs from those species and those of humans were found. The differences occurred mainly in endodermal organs that have secretory functions and are probably under the control of the human-type FUT-2 enzyme. In the mesodermal-origin organs there was a reduction or absence of A and B antigen marking, particularly in the H precursor substance, indicating that those organs are under the control of the human-type FUT-1 enzyme. These findings have demonstrated that there is similar ABH antigen reactivity in tissue distribution between the species, although there are some species-specific cases.

Reference values of hematology, biochemistry, and blood type in cynomolgus monkeys from cambodia origin

Cynomolgus monkeys as nonhuman primates are valuable animal models because they have a high level of human gene homology. There are many reference values for hematology and biochemistry of Cynomolgus monkeys that are needed for proper clinical diagnosis and biomedical research conduct. The body weight information and blood type are also key success factors in allogeneic or xenogeneic models. Moreover, the biological parameters could be different according to the origin of the Cynomolgus monkey. However, there are limited references provided, especially of Cambodia origin. In this study, we measured average body weight of 2,518 Cynomolgus monkeys and analyzed hematology and serum biochemistry using 119 males, and determined blood types in 642 monkeys with Cambodia origin. The average body weight of male Cynomolgus monkeys were 2.56±0.345 kg and female group was 2.43±0.330 kg at the age from 2 to 3 years. The male group showed relatively sharp increased average body weight from the 3 to 4 age period compared to the female group. In hematology and biochemistry, it was found that most of the data was similar when compared to other references even though some results showed differences. The ABO blood type result showed that type A, B, AB, and O was approximately 15.6, 33.3, 44.2, and 6.9%, respectively. The main blood type in this facility was B and AB. These biological background references of Cambodia origin could be used to provide important information to researchers who are using them in their biomedical research.

ABO research in the modern era of genomics

Research on ABO has advanced significantly in recent years. A database was established to manage the sequence information of an increasing number of novel alleles. Genome sequencings have identified ABO orthologues and paralogues in various organisms and enhanced the knowledge on the evolution of the ABO and related genes. The most prominent advancements include clarification of the association between ABO and different disease processes. For instance, ABO status affects the infectivity of certain strains of Helicobacter pylori and Noroviruses as well as the sequestration and rosetting of red blood cells infected with Plasmodium falciparum. Genome-wide association studies have conclusively linked the ABO locus to pancreatic cancer, venous thromboembolism, and myocardial infarction in the presence of coronary atherosclerosis. These findings suggest ABO's important role in determining an individual's susceptibility to such diseases. Furthermore, our understanding of the structures of A and B transferases and their enzymology has been dramatically improved. ABO has also become a research subject in neurobiology and the preparation of artificial/universal blood and became a topic in the pseudoscience of "blood type diets." With such new progress, it has become evident that ABO is a critical player in the modern era of genomic medicine. This article provides the most up-to-date information regarding ABO genomics.

The human-ABO blood groups of free-ranging long-tailed macaques (Macaca fascicularis) and parapatric rhesus macaques (M. mulatta) in Thailand

BACKGROUND

Long-tailed and rhesus macaques are widely used in biomedical research; therefore, the known blood group is important.

METHODS

The human-type ABO blood group was determined in wild or semi-wild long-tailed and rhesus macaques in Thailand. A total of 729 long-tailed and 160 rhesus macaques from 20 localities were temporarily caught.

RESULTS

The frequency profiles of blood groups, calculated by averaging the frequency of each troop in long-tailed and rhesus macaques, were AB > O > B > A at 29.6%, 27.4%, 27.2%, and 15.8%, and B > AB > A > O at 39.6%, 33.4%, 18.2%, and 8.8%, respectively. Irrespective of locality, the frequencies were AB > O > B > A of 29.6%, 28.0%, 24.4%, and 18.0%, and AB > B > A > O of 37.5%, 28.7%, 26.9%, and 6.9%, respectively, for all long-tailed and rhesus macaques. The frequency profile of blood groups in Thai rhesus macaques was somewhat similar to that in the parapatric long-tailed macaques; however, it was different from other rhesus populations where only group B was detected.

CONCLUSIONS

Our data support the hypothesis that Indochinese rhesus macaques are hybrids between rhesus and long-tailed macaques in the past.

Characterization of blood-borne transmission of simian foamy virus

BACKGROUND

Simian foamy virus (SFV) is an endemic, nonhuman primate (NHP) retrovirus that is transmitted to individuals who work with or hunt NHPs. The cross-species transmission of simian retroviruses is believed to be the etiology of human immunodeficiency virus and human T-lymphotropic virus infections in humans. Although SFV is not pathogenic in the native host, the shared ancestry with other simian retroviruses has brought into question the potential for acquired pathogenicity after cross-species transmission. This study examines whether SFV also shares the traits of transmissibility through the blood supply.

STUDY DESIGN AND METHODS

Within a controlled environment, blood from an SFV-infected monkey was transfused into an SFV-uninfected monkey. Evidence of infection, pathogenic effects, immune correlates, and viral shedding were followed for 6 months after transfusion.

RESULTS

Molecular evidence of SFV infection manifested 8 weeks after transfusion followed by seroconversion 1 week later. Quantitative analysis demonstrated that the highest level of detectable virus was concomitant with seroconversion followed by establishment of a viral "set-point." Analysis of circulating lymphocytes revealed changes early in infection. Potential routes of transmission of SFV and roles of site-specific immune response are suggested by the late appearance of SFV shedding in the saliva of the transfused animal.

CONCLUSION

The blood supply has historically provided a portal through which novel, occult viruses can become disseminated among humans. The demonstration of transmissibility of SFV through whole-blood transfusion, in an NHP model, contributes to the understanding of potential risks associated with blood donation by SFV-infected humans.

Acute and chronic vascular rejection in nonhuman primate kidney transplantation

A nonhuman primate (NHP) study was designed to evaluate in nonlife-supporting kidney allografts the progression from acute rejection with transplant endarteritis (TXA) to chronic rejection (CR) with sclerosing vasculopathy. Group G1 (n = 6) received high cyclosporine A (CsA) immunosuppression and showed neither TXA nor CR during 90 days post-transplantation. Group G2 (n = 6) received suboptimal CsA immunosuppression and showed severe TXA with graft loss within 46 days (median). Arterial intimal changes included infiltration of macrophages and T lymphocytes (CD3, CD4, CD8) with few myofibroblasts, abundant fibronectin/collagen IV, scant collagens I/III, high rate of cellular proliferation and no C4d accumulation along peritubular capillaries. Group G3 (n = 12) received suboptimal CsA and anti-rejection therapy (rabbit ATG + methylprednisolone + CsA) of TXA. Animals developed CR and lost grafts within 65 days (median). As compared to G2, the arterial intimal changes showed less macrophages and T lymphocytes, an increased number of myofibroblasts, abundant fibronectin/collagen IV and scar collagens I/III, C4d deposition along capillaries in 60% of animals and transplant glomerulopathy in 80% of animals. In conclusion, CR is an immune stimulated process initiated during TXA with the accumulation and proliferation of myofibroblasts, and progressive deposition of collagens in the intima. Our experimental design appears well suited to study events leading to CR.

Host Lewis phenotype-dependent Helicobacter pylori Lewis antigen expression in rhesus monkeys

Both human and H. pylori populations are polymorphic for the expression of Lewis antigens. Using an experimental H. pylori challenge of rhesus monkeys of differing Lewis phenotypes, we aimed to determine whether H. pylori populations adapt their Lewis phenotypes to those of their hosts. After inoculation of four monkeys with a mixture of seven strains identified by RAPD-polymerase chain reaction, H. pylori Lewis expression was followed in 86 isolates obtained over 40 wk. Host Lewis(a/b) secretion status was characterized by immunological assays. Fingerprints of the predominating strain (J166) were identical in all four animals after 40 wk, but its Lewis phenotype had substantial variability in individual hosts. At 40 wk, J166 populations from two Lewis(a-b+) animals predominantly expressed Lewis(y). In contrast, J166 populations had switched to a Lewis(x) dominant phenotype in the two Lewis(a+b-) animals; a frame shift in futC, regulating conversion of Lewis(x) to Lewis(y), accounted for the phenotypic switch. The results indicate that individual cells in H. pylori populations can change Lewis phenotypes during long-term colonization of natural hosts to resemble those of their hosts, providing evidence for host selection for bacterial phenotypes.

Oral efficacy of the new immunomodulator FTY720 in cynomolgus monkey kidney allotransplantation, given alone or in combination with cyclosporine or RAD

BACKGROUND

FTY720 is a novel immunomodulator with a unique mechanism of action, i.e. chemokine-dependent lymphocyte homing into secondary lymphoid organs associated with profound lymphocyte depletion in blood. We investigated its efficacy, either FTY720 alone or together with cyclosporine or the rapamycin derivative rapamycin derivative (RAD), in cynomolgus monkey kidney allotransplantation.

METHODS

Life-supporting allotransplantation was performed in bilaterally nephrectomized hosts. Compounds were given once daily by oral gavage. Monitoring was done by serum creatinine and urea, and rejection was concluded when values exceeded 500 micromol/L and 50 mmol/L, respectively (5-6 times the upper limit of reference values). Rejection was confirmed by graft histology. The termination point was set to 100 days after transplantation. In addition, animals were monitored for 24 hr drug concentrations and thorough inspection of potential adverse side effects.

RESULTS

FTY720 given alone at 3.0 mg/kg per day prolonged rejection-free survival (33-85 days, mean 24 hr concentration between 54 and 66 ng/mL [n=3]), but it was not efficacious at a 0.3 mg/kg per day dose. For cyclosporine alone, 30 mg/kg per day during maintenance was efficacious (average concentration above 100 ng/mL, historical data from our group), and for RAD alone 0.75 mg/kg per day (concentration above 10 ng/mL). Efficacious FTY720-cyclosporine-A (CsA) or FTY720-RAD combinations were established using 0.1-0.3 mg/kg per day FTY720, 10-30 mg/kg per day cyclosporine, and/or 0.25-0.50 mg/kg per day RAD. Compared with single-compound treatment, FTY720 effective doses and 24 hr trough concentrations were at least tenfold lower in combination treatment and those of cyclosporine and RAD about twofold lower, indicative of effective synergy between the compounds. Already at the lowest FTY720 dose tested (0.03 mg/kg per day), there was a profound lymphocyte depletion down to about 30% of pretransplant values, which further increased at the highest dose (3.0 mg/kg per day, to about 14% of pretransplant values). Lymphocyte depletion was reflected by a decrease in T and B subpopulations.

CONCLUSION

FTY720 is an effective immunosuppressant in prevention of acute kidney allograft rejection in cynomolgus monkeys and synergizes with cyclosporine and/or RAD in yielding rejection-free allograft survival.

Oral efficacy of the macrolide immunosuppressant SDZ RAD and of cyclosporine microemulsion in cynomolgus monkey kidney allotransplantation

BACKGROUND

40-O-(2-Hydroxyethyl)-rapamycin (SDZ RAD) is a novel, potent, macrolide immunosuppressant. Its efficacy in rodent transplantation models provided the rationale for us to evaluate the compound in a more relevant, large animal transplantation model.

METHODS

Life-supporting kidney allotransplantation was performed in cynomolgus monkeys: rejection was inferred from a rise in serum creatinine or urea and was subsequently confirmed by histopathology. This model was validated with the microemulsion formulation of cyclosporine (i.e., Neoral). Two studies with a microemulsion formulation of SDZ RAD were performed. First, in a dose-finding study, the SDZ RAD dose was reduced in a stepwise fashion until rejection occurred, either with SDZ RAD as monotherapy, or in combination with a fixed, suboptimal dose of cyclosporine. Second, an efficacy study was performed in which two fixed SDZ RAD doses (0.75 and 1.50 mg/kg/ day) were evaluated in monotherapy and compared with the same doses of rapamycin (sirolimus). All immunosuppressants were administered once daily by gastric gavage.

RESULTS

Untreated control animals rejected their grafts between 4 and 8 days after transplantation. Cyclosporine (initially at 150 mg/kg/day, reduced to 100 mg/kg/day 2 weeks after transplantation) yielded long-term (>100 days) rejection-free allograft survival in four of five animals. A 10 mg/kg/day dose of cyclosporine led to rejection between 10 and 27 days after transplantation and was considered suboptimal. In the dose-finding study with SDZ RAD monotherapy, rejection occurred in most of the cases (four of six animals) when a dose level of 0.63 mg/kg/day had been reached. Combined with suboptimal cyclosporine, this threshold SDZ RAD dose was about 2-fold lower. In the efficacy study, median graft survival with histologically proven rejection was 32 days (range 8-91 days, n=6) for 0.75 mg(kg/day SDZ RAD and 59 days (range 28-85 days, n=6) for 1.50 mg/kg/day SDZ RAD. For sirolimus, median graft survival was 43 days (range 5-103 days, n=7) for the 0.75 mg/kg/day dose and 56 days (range 8-103 days, n=8) for the 1.50 mg/kg/day dose. There was no statistically significant difference in efficacy between SDZ RAD and sirolimus.

CONCLUSION

SDZ RAD, in the absence of any other immunosuppressant and at doses that do not show any overt toxicity, considerably prolongs rejection-free survival of cynomolgus monkeys after life-supporting kidney allotransplantation.

Patterns of microsatellite polymorphism in the range-restricted bonobo (Pan paniscus): considerations for interspecific comparison with chimpanzees (P. troglodytes)

The endangered great ape, Pan paniscus (bonobo) has the smallest range of the African apes. Virtually nothing is known about the genetic diversity or genetic structure of this species, while substantial amounts of polymorphism have been reported for the bonobo's widespread congener, the chimpanzee (P. troglodytes). Given its restricted range, what is the extent of genetic variation in the bonobo relative to the chimpanzee, and is the bonobo genetically depauperate? To investigate patterns of genetic polymorphism, bonobos of wild origin were genotyped for 28 microsatellite loci. The mean number of alleles per locus (5.2) and the mean observed heterozygosity (0.52) in bonobos were similar to variation observed in a wild chimpanzee community (P. t. schweinfurthii). The rarer bonobo is not genetically depauperate and may have genetic diversity comparable to the eastern chimpanzee subspecies. Bonobos have approximately 55% of the allelic diversity and 66% of the observed heterozygosity exhibited by all three chimpanzee subspecies sampled across equatorial Africa. Resampling techniques were used to quantify the effects of sample size differences and number and choice of loci between bonobos and chimpanzees. The examination of these variables underscores their importance in accurately interpreting interspecific comparisons of diversity estimates.

Reactivity of anti-glycophorin monoclonal antibodies (Mabs) in tests with red cells of non-human primates

Seventy Mabs against human glycophorins (GP) and band 3 were tested with red blood cells (RBCs) of various non-human primates, from anthropoid apes to monkeys. Differences among Mabs reactivity in tests with non-human primate RBCs reflect the complexity of the immune reactions to human GPs and provide insights into aspects of evolution and a tool to epitope map.

Monoclonal antibodies directed against human Rh antigens in tests with red cells of non-human primates

Human anti-D (Rho) monoclonal antibodies (Mabs) of the IgG (70) and IgM (27) classes were tested with red blood cells (RBCs) of various non-human primates, from anthropoid apes to New World monkeys. Significant differences in reactivity were observed among antibodies of two classes depending on taxonomic position of primate animals. Only IgM Mabs gave positive reactions (9 out of 18 Mabs) with blood of Old World monkeys. Allotypic reactions with RBCs of African apes were produced by a majority of IgG Mabs but by very few IgM reagents, most of the latter reacting with RBCs of all chimpanzees and all gorillas tested. Eight out of 70 IgG anti-D defined chimpanzee polymorphisms related to chimpanzee Rc antigen which is the chimpanzee counterpart of human D antigen. Most of IgG anti-D Mabs (61/70) were found specific of Dgor antigen (gorilla counterpart of human antigen D). Most of anti-D which were found negative with all chimpanzee RBCs were also negative with human DIVb RBCs and most of anti-D which agglutinated human DIVb RBCs were positive with some or all chimpanzee blood samples. Differences among Mabs evidenced in tests with non-human primate RBCs reflect the complexity of the immune reactions to the human D antigen. The results obtained with anti-Rh Mabs of specificities other than D confirmed that chimpanzee, gorilla and gibbon express c-like epitopes and that antigens C, E, e are absent in non-human primates.