Search for mammalian type-C retrovirus polypeptides on infected animal cells and human tumor cell lines using interspecies-reacting antibodies

Cells producing endogenous and exogenous type-C retroviruses of murine, feline and primate origin were evaluated for expression of those virus-specific cell-surface antigens which cross-react with antibodies to interspecies determinants of mammalian type-C viral polypeptides. Surface polypeptides of cells replicating endogenous and exogenous type-C retroviruses were iodinated by the lactoperoxidase method. Labelled antigens were immunoprecipitated and analyzed in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. This method detected gp71 and less frequently p15E/p12E on the surface of virus-producing cells; in addition, p27 was found on F422 cells replicating feline leukemia virus. Antibodies to the membrane protein p15E displayed the broadest cross-reactivity but only antibodies to gp71 mediated complement-dependent interspecies cell lysis. The pattern of cross-reactivity reflected known genetic relationships among these mammalian viruses. Although antiserum to the simian sarcoma virus complex (SSV) was strongly cytotoxic to some human tumor cell lines, this reactivity could not be attributed to antibodies cross-reacting with SSV gp71.     

Immunoelectrophoretic characteristics ofOphiobolus graminis Sacc. as an aid in classification and determination

Antigens from four cultures ofO. graminis were compared immunoelectro-phoretically. Each culture produced a characteristic immunogram. More common antigens were found between the two cultures isolated from wheat or the two cultures isolated from oat than between a wheat and an oat isolate. Cell-wall antigens were the best reference antigens for serologic analysis of strain relationship. O. graminis antisera were cross-reacted with antigens from a number of other species of fungi. Relatively few of these cross-reacted with antisera to cell-wall antigens whereas more cross-reacted with antisera to whole-cell antigens.Immunoelectrophoretic analysis of antigens from a range of isolates ofO. graminis indicates specific immunograms which can be determined and separated from the immunograms developed by all other fungi when tested againstO. graminis antiserum. Immunoelectrophoresis can therefore be used as an aid in determiningO. graminis.     

CROSS-REACTIVITY OF ANTIBODIES TO HUMAN ANTIGENS WITH TISSUES OF THE BOTTLENOSE DOLPHIN, TURSIOPS TRUNCATUS, USING IMMUNOPEROXIDASE TECHNIQUES

Cross-species reactivity of 53 antibodies developed against human antigens was evaluated in the bottlenose dolphin Tursiops truncatus , using immunoperoxidase techniques, Strong cross-reactivity was demonstrated with antibodies against intermediate filaments, most hormones, but few leukocyte antigens. S100, NSE, F8RA, Factor XIIIa, and lactalbumin antibodies reacted, while HMB45, EMA, PLAP, and PSA did not. Polyclonal antibodies are much more likely to cross-react than are monoclonal antibodies. Twenty-four of 30 (80%) of polyclonals cross-reacted, while only 10 of 23 (43.5%) monoclonals cross-reacted. Some antigens are demonstrated only after using a special technique to unmask the antigen.     

Phenotypic Analysis of New World Primate Mononuclear Cell Surface Antigens

We have applied a panel of monoclonal antibodies against antigens present on the surface of human mononuclear cells to the study of mononuclear cell surface antigens expressed by seven species of New World primates. Antibodies to the sheep erythrocyte receptor (OKT11a) to a thymocyte antigen (OKT10), to the I region of the major histocompatibility locus (OKIa), and to an antigen found on the surface of human monocytes (OKM1) cross-reacted with mononuclear cell surface antigens of most of the species studied. Antibodies to antigens which have been correlated with functional capabilities in the human system (OKT4, OKT5, OKT8, 3A1) were much less reactive with platyrrhine mononuclear cells. These reagents may be quite useful in studies of primate phylogeny and immunology.     

Synthetic peptides induce antibodies in sheep against Taenia ovis

Summary Two peptides corresponding to putative protective regions located at the N- and C-termini of the host-protectiveT. ovis recombinant antigen, 45W, were synthesized. Antibodies raised against 45W and 45WB/X, a truncated from of 45W, were found to react strongly with the N-terminal peptide. When sheep were immunised with each peptide alone, the N-terminal peptide was found to be highly immunogenic, whereas the C-terminal peptide required conjugation to a carrier protein to be immunogenic. Both these immunogens elicited antibodies that cross-reacted with the parent protein; however, only antibodies directed toward the N-terminal peptide were able to bind antigens from theT. ovis oncosphere. Significant protection against challenge infection was not provided by any of the peptide immunogens used.     

Monoclonal antibodies as a tool for phylogenetic studies of major histocompatibility antigens and β 2-microglobulin

The cross-reactivity of several monoclonal antibodies recognizing monomorphic determinants of human HLA-A, B, C, and DR antigens and human 2-microglobulin (2m) has been studied on peripheral blood leukocytes in 24 different species. An monoclonal HLA-A-, B-, and C-specific antibody and four monoclonal HLA-DR-specific antibodies cross-reacted with cells from all the primate species tested. Furthermore, antibodies HLA-DR-specific were positive with peripheral blood leukocytes (PBL) from cows, goats, sheep, horses, and dogs. Two monoclonal 2m-specific antibodies, which were positive with PBL from certain primates, also reacted with cells from cows, goats, sheep, horses, and dogs. Two other #2m-specific antibodies reacted only with PBL from chimpanzees. No reaction could be detected with all our reagents in other classes tested (birds, reptiles, amphibians, and Teleostei).     

Relationship between lectin binding properties and the expression of blood group ABH antigens in vascular endothelia and red blood cells from 18 primate species

Summary The reactivity was examined of horseradish peroxidase labelledUlex europaeus agglutinin-I (UEA-I) andGriffonia simplicifolia agglutinin I-B₄ (GSAI-B₄) with red blood cells and vascular endothelium in formalin-fixed, paraffin embedded tissues from 18 primate species. The expression of blood group ABH antigens in these cells as well as secretions from other tissues was also examined by the indirect immunoperoxidase method using monoclonal anti-ABH antibodies as primary antibodies. In Prosimians and New World monkeys which lack ABH antigens on both red blood cells and endothelial cells, but produce these antigens in other tissue secretions, GSAI-B₄ always reacted with both red blood cells and endothelial cells. In Old World monkeys, which express blood group antigens on endothelial cells but not on red blood cells, neither GSAI-B₄ nor UEA-I reactivity were observed, except the endothelial cells from blood group B or O individuals occasionally reacted with GSAI-B₄ or UEA-I, respectively. Although UEA-I reactivity was not observed in the endothelial cells of gibbon, it reacted with these cells from chimpanzees. In these two anthropoid apes, both endothelial cells and red blood cells expressed ABH antigens as in humans. These results suggest the close evolutionary relationship between the expression of blood group ABH antigens and lectin binding properties of red blood cells and endothelial cells in primate species.     

Molecular characterization of HLA-A,B homologues in owl monkeys and other nonhuman primates

Mouse anti-HLA-A, B monoclonal antibodies have been used to study the homologues of HLA-A, B antigens in other primate species. Immunoprecipitates of primate histocompatibility antigens from extracts of radioactively labeled lymphocytes were analyzed by SDS-polyacrylamide electrophoresis. Primate histocompatibility antigens appear to have similar molecular structure to human HLA antigens. Owl monkeys, which react polymorphically with some monomorphic anti-HLA antibodies, showed biochemical differences which correlated with the serological polymorphism. An antibody (W6/32) which only reacts with the HLA/β ₂-microglobulin complex in humans and not with the free HLA heavy chain has the reverse specificity in some owl monkeys.     

A spectrin-like protein present on membranes of Amoeba proteus as studied with monoclonal antibodies

Monoclonal antibodies against a spectrin-like membrane-associated protein of xD amoebae. (Amoeba proteus) were used to determine the distribution of the protein and some of its characteristics. A total of 34 monoclonal antibodies recognizing different epitopes of the protein were obtained, of which seven stained cell membranes by indirect immunofluorescence. The spectrin-like protein had two subtypes of 225 and 220 kDa and several monoclonal antibodies cross-reacted with human erythrocyte spectrin when checked by indirect immunofluorescence staining and immunoblotting. Some of the antibodies also cross-reacted with antigens in HeLa cells and chick embryo fibroblasts. Polyclonal and monoclonal antibodies against Drosophila and human erythrocyte spectrins cross-reacted with the spectrin-like protein from amoebae. On the basis of these results, it was concluded that the protein is a spectrin. The protein was found on most cellular membranes of amoebae, including the plasma, nuclear, and phagosomal membranes, as well as symbiosome membranes.     

Failure to detect simian immunodeficiency virus infection in a large Cameroonian cohort with high non-human primate exposure

Hunting and butchering of wildlife in Central Africa are known risk factors for a variety of human diseases, including HIV/AIDS. Due to the high incidence of human exposure to body fluids of non-human primates, the significant prevalence of simian immunodeficiency virus (SIV) in non-human primates, and hunting/butchering associated cross-species transmission of other retroviruses in Central Africa, it is possible that SIV is actively transmitted to humans from primate species other than mangabeys, chimpanzees, and/or gorillas. We evaluated SIV transmission to humans by screening 2,436 individuals that hunt and butcher non-human primates, a population in which simian foamy virus and simian T-lymphotropic virus were previously detected. We identified 23 individuals with high seroreactivity to SIV. Nucleic acid sequences of SIV genes could not be detected, suggesting that SIV infection in humans could occur at a lower frequency than infections with other retroviruses, including simian foamy virus and simian T-lymphotropic virus. Additional studies on human populations at risk for non-human primate zoonosis are necessary to determine whether these results are due to viral/host characteristics or are indicative of low SIV prevalence in primate species consumed as bushmeat as compared to other retroviruses in Cameroon.     

Studies of murine malaria antigens using monoclonal antibodies. Production, selection, and characterization of antibodies

A panel of ten monoclonal antibodies made against Plasmodium chabaudi and Plasmodium yoelii infected mouse erythrocytes were used for characterization of antigens present in murine malaria. Screening of the antibodies in ELISA with different fractions of infected erythrocytes revealed both species-specific and fraction-specific monoclonal antibodies (MAbs), but also MAbs cross-reacting between the species. Two MAbs bound normal erythrocyte components. Subcellular localization of the target antigens was studied by immunofluorescence and their molecular identity by immunoblotting after SDS-PAGE. Of the MAbs to P. yoelii, one reacted with a cytoplasmic granule component of 137 k and two others reacted with vacuole-associated antigens of 26 k and 25/70/73 k, respectively. The latter antibodies cross-reacted with P. chabaudi antigens. Of the MAbs to P. chabaudi, all were species specific, one reacting with parasite surface antigens of 79 and 250 k and two with a vacuole-associated antigen of 70 k.     

Human–hamadryas baboon (Papio hamadryas) conflict in the Wonchit Valley,South Wollo,Ethiopia

Understanding the extent of human–primate conflict is crucial to the development of conservation and management strategies. We carried out this study in an unprotected area of central Ethiopia to examine the magnitude of human–hamadryas baboon (Papio hamadryas) conflict and to assess the attitude of local farmers towards baboons in Wonchit Valley. In 2014, we interviewed 119 adult respondents using a structured questionnaire. Local farmers considered hamadryas baboons to be the major pest in the area. All respondents reported that hamadryas baboons caused crop raiding and small livestock predation in the region. Respondents reported that a shortage of fruit producing wild trees and ready availability of crops were the main causes of conflict between farmers and hamadryas baboons. We found that hamadryas baboons damaged cereal crops at dusk and dawn during full moonlight, and most (89.9%) respondents claimed that they were not interested in hamadryas baboon conservation. Our results indicate that human–hamadryas baboon conflict has a strongly negative impact on both baboon conservation and local farmers. We suggest that to mitigate the human–hamadryas baboon conflict, job opportunities such as beekeeping should be introduced in the region.     

Genomewide ancestry and divergence patterns from low‐coverage sequencing data reveal a complex history of admixture in wild baboons

Naturally occurring admixture has now been documented in every major primate lineage, suggesting its key role in primate evolutionary history. Active primate hybrid zones can provide valuable insight into this process. Here, we investigate the history of admixture in one of the best‐studied natural primate hybrid zones, between yellow baboons (Papio cynocephalus) and anubis baboons (Papio anubis) in the Amboseli ecosystem of Kenya. We generated a new genome assembly for yellow baboon and low‐coverage genomewide resequencing data from yellow baboons, anubis baboons and known hybrids (n = 44). Using a novel composite likelihood method for estimating local ancestry from low‐coverage data, we found high levels of genetic diversity and genetic differentiation between the parent taxa, and excellent agreement between genome‐scale ancestry estimates and a priori pedigree, life history and morphology‐based estimates (r² = 0.899). However, even putatively unadmixed Amboseli yellow individuals carried a substantial proportion of anubis ancestry, presumably due to historical admixture. Further, the distribution of shared vs. fixed differences between a putatively unadmixed Amboseli yellow baboon and an unadmixed anubis baboon, both sequenced at high coverage, is inconsistent with simple isolation–migration or equilibrium migration models. Our findings suggest a complex process of intermittent contact that has occurred multiple times in baboon evolutionary history, despite no obvious fitness costs to hybrids or major geographic or behavioural barriers. In combination with the extensive phenotypic data available for baboon hybrids, our results provide valuable context for understanding the history of admixture in primates, including in our own lineage.     

Acute rejection is associated with antibodies to non-Gal antigens in baboons using Gal-knockout pig kidneys

We transplanted kidneys from alpha1,3-galactosyltransferase knockout (GalT-KO) pigs into six baboons using two different immunosuppressive regimens, but most of the baboons died from severe acute humoral xenograft rejection. Circulating induced antibodies to non-Gal antigens were markedly elevated at rejection, which mediated strong complement-dependent cytotoxicity against GalT-KO porcine target cells. These data suggest that antibodies to non-Gal antigens will present an additional barrier to transplantation of organs from GalT-KO pigs to humans.     

Hunting patterns and geographic profiling of white shark predation

Interspecific associations can arise for varied reasons including reduced predation risk and improved foraging success. In the case of bird–primate associations, birds typically appear to follow primate groups to harvest insects flushed by primates' movements. However, while previous studies have linked temporal changes in bird–primate associations to environmental conditions, few have assessed the additional effects of bird activity patterns and primate group behaviour and none have disentangled their potentially interdependent effects. Here, we test the hypothesis that foraging opportunities can drive interspecific associations in a previously undescribed bird–primate association between rock kestrels Falco rupicolus and chacma baboons Papio ursinus in central Namibia. Data were collected from two baboon groups and associated kestrels using instantaneous scan sampling during full-day follows over a 7-month field period, and analysed using generalized linear mixed models. We found that kestrel associations with baboons vary with season, show diurnal cycles and are more frequent when the baboons are in open desert habitat, engaged in travel foraging and in a large group. These patterns are statistically independent and consistent with the hypothesis that the kestrel–baboon association is driven by the foraging opportunities acquired by the kestrels. As the baboons do not appear to gain any benefits nor incur any costs from the association, we conclude that the kestrels are likely to be commensal with the baboons.     

Analysis of the Antigenic Relationships Among Trichomonas,Histomonas, Dientamoeba,and Entamoeba.* II. Gel Diffusion Methods

SYNOPSIS. Antisera were developed in rabbits against Trichomonas gallinae, Histomonas meleagridis, Dientamoeba fragilis, Entamoeba invadens, and Entamoeba histolytica. In reactions between these antisera and antigens prepared from each of the 5 species the most numerous and strongest precipitin lines appeared on gel diffusion agarose plates between the homologous antigens and antisera. Anti-Trichomonas serum cross-reacted most strongly with Histomonas, somewhat less with Dientamoeba, but gave no lines with the 2 species of Entamoeba. Anti-Histomonas serum cross-reacted strongly with both Trichomonas and Dientamoeba, and weakly with E. invadens and E. histolytica. Dientamoeba antiserum gave many precipitin lines with Histomonas, fewer with Trichomonas, and fewest with the 2 species of Entamoeba. Stronger reactions were noted between anti-Dientamoeba serum and E. invadens than between this serum and E. histolytica. Immune sera prepared against the 2 species of Entamoeba gave the most numerous precipitin lines in intrageneric cross-reactions, but the reaction between either of these antisera and Histomonas was weak. Somewhat stronger reactions were observed between the 2 anti-Entamoeba sera and Dientamoeba. Trichomonas failed to react with either of the anti-Entamoeba sera.     

A model of the gelada socio-ecological system

Data from three populations of gelada baboons are used to generate a model of the species' socio-ecology that relates time budget requirements to group size, day journey length, and relevant environmental parameters. The model is used to examine the range of environmental conditions under which gelada could survive. This analysis indicates that a grazing primate like the gelada would run out of available time for foraging at just above and just below the altitudes at which they are now found. This suggests that, contrary to previous supposition, gelada were not driven into a retreat habitat by more competitivePapio baboons, but rather withdrew from lower altitude habitats because they could not survive under these conditions as the climate deteriorated during the Holocene.     

In Vivo Transfer of cellular immunity to primates with transfer factor prepared from human or primate leucocytes

Dialyzable transfer factor (TF_d) prepared from a human donor and transfer factor (TF) from baboon whole cell lysates was administered to 3 species of nonhuman primates: baboons, cebus monkeys and marmosets. In vivo transfer was evaluated with in vivo skin test and in vitro blastogenic responses to multiple antigens. Transfer of cellular reactivity in all three nonhuman primate species was demonstrated with both human TF_d and baboon TF. A cumulative conversion rate of 45% for skin test responses and 65% for lymphocyte blastogenesis was demonstrated following human TF_d injection while conversion was 17% and 33% respectively following baboon TF. Specificity was supported by the absence of conversion to TF donor negative antigens. There were no signficant differences observed between the 3 recipient primate species.