Human babesiosis in ireland: Further observations and the medical significance of this infection

Three splenectomized persons in Yugoslavia, California, and Ireland have been reported to be infected by three different Babesia species; two cases were fatal. In a study of the site where the fatal infection was contracted in Ireland, blood samples from 36 persons who had recently been bitten by ticks were inoculated into two splenectomized calves; no response to Babesia divergens was detected. Field-collected Ixodes ricinus ticks inoculated into another splenectomized calf resulted in fever and recovery of the agent of tick-borne fever (Cytoecetes phagocytophilia). This attempt to determine the presence of latent infection in human beings with intact spleens should be repeated on a larger scale in areas with a demonstrably high incidence of Babesia in ticks and animals. Few places in the world are free of piroplasms; their presence may present a hazard to splenectomized persons or to those whose splenic function is deficient.     

Acquired Resistance to Babesia divergens in Experimental Calves

SYNOPSIS. One intact and 2 splenectomized calves were infected with Babesia divergens and the persistence of the parasites in the blood was followed by periodic subinoculations into susceptible splenectomized calves. After periods varying from 3–7 years the parasites failed to be demonstrable by this method. When the immunity of the animals was challenged by the intravenous injection of blood containing Babesia divergens , they were all resistant to reinfection. These observations add support to the suggestion that sterile immunity may play a part in the resistance of cattle to reinfection with B. divergens.     

RFLP analysis of theHLA-, ChLA-, andRhLA-DQ alpha chain gene regions: Conservation of restriction sites during evolution

Genomic DNA samples, derived from a panel of 60 chimpanzees and 45 rhesus monkeys, were digested with the restriction enzymesTaq I andBgl II and hybridized with an HLA-DQ alpha chain cDNA probe. The results were compared with the data available on a human reference panel. Use of the restriction enzymeTaq I and the DQ alpha chain probe allows the detection of fiveHLA-DQA1 and twoHLA-DQA2 gene-associated fragments within the human population. For the ChLA and RhLA systems, 3 and 7 different DQA1-associated restriction patterns were detected, respectively, while for the chimpanzee a nonpolymorphicDQA2 (DX alpha) gene-associated fragment was also observed. The equivalent of theHLA- andChLA-DQA2 genes appears to be absent in the rhesus monkey. TheChLA-DQA1 and-DQA2 gene-associated RFLP patterns are identical in man and chimpanzee, whereas such restriction site conservation is not seen in the rhesus monkey. The conclusion drawn is that the genetic organization of theHLA-DQA andChLA-DQA gene regions, and possibly some of their allelic variabilities, already existed before man and chimpanzee separated in evolution. Moreover, the particular duplication which led to the generation of theHLA- andChLA-DQA2 genes must have happened before speciation of members belonging to the superfamily Hominoidea (man, chimpanzee, etc), but probably after the separation of superfamily Cercopitecoidea (rhesus monkeys, baboons, etc.) from Hominoidea.     

The Uganda I/CDC strain of Plasmodium malariae in Aotus lemurinus griseimembra monkeys

Two lines of the Uganda I/CDC strain of Plasmodium malariae were studied in splenectomized Aotus lemurinus griseimembra monkeys. A line initially adapted to these monkeys from an infected chimpanzee failed to produce high-level parasite counts or mosquito infection in 13 of this type of monkey during 16 linear passages. Another line, originally adapted from the chimpanzee to Aotus azarae boliviensis, after 7 linear passages in 3 different types of Aotus was then passaged to 14 splenectomized A. lemurinus griseimembra. Geometric mean maximum parasitemia in these monkeys was 18,400/mm3. Mosquito infections were readily obtained during the period just after the parasite count rose above 1,000/mm3. Anopheles freeborni, An. stephensi, An. dirus, and 2 strains of An. gambiae supported the development of the parasite to the presence of sporozoites in the salivary glands. Two attempts to transmit the strain to other splenectomized A. lemurinus griseimembra by sporozoite inoculation were unsuccessful.     

Serum cholinesterase activities and inhibition profiles of nonhuman primates

Serum cholinesterase activities and inhibition profiles of 169 chimpanzees, 15 gorillas, 26 orangutans, seven gibbons, and 12 rhesus monkeys were determined. Mean values of activities against benzoylcholine (μmols/min/ml) and dibucaine, fluoride, and Ro 2-0683 numbers (percentage inhibition of benzoylcholine hydrolysis) are: chimpanzee, 2.276, 80, 64, and 97; gorilla, 9.403, 82, 71, and 96; orangutan, 0.747, 94, 6, and 98; gibbon, 0.071, 89, 7, and 94; and rhesus monkey, 0.859, 95, 10, and 99, respectively. Sernylan numbers were determined of the last 100 chimpanzee serums collected and of each of the gorilla, orangutan, gibbon, and rhesus monkey serums. Mean values of Sernylan numbers are: chimpanzee, 80; gorilla, 81; orangutan, 95; gibbon, 94; and rhesus monkey, 96. The chimpanzee and the gorilla have dibucaine, fluoride, Ro 2-0683, and Sernylan numbers within the range found in men who are homozygotes for the usual cholinesterase (genotype E₁^uE₁^u). No cholinesterase variant was found in any chimpanzee or gorilla. The orangutan, gibbon, and rhesus monkey have inhibition profiles that resemble one another, with higher dibucaine and Sernylan numbers and much lower fluoride numbers than the chimpanzee or the gorilla. The results of the inhibition tests suggest that the African apes, chimpanzee and gorilla, are related more closely to man than are the Asian apes, orangutan and gibbon.     

Development of a polymorphic strain of Plasmodium vivax in monkeys.

A strain of Plasmodium vivax from Thailand with a polymorphic repeat unit of the circumsporozoite protein was established in Saimiri sciureus boliviensis and 3 species of Aotus monkeys. All 11 attempts to transmit infection via sporozoite inoculation, 4 times to splenectomized S. sciureus boliviensis, 2 times to splenectomized Aotus nancymai, and 5 times to intact Saimiri monkeys, were successful. Anopheles freeborni, Anopheles stephensi, Anopheles dirus, and Anopheles gambiae mosquitoes were infected by feeding on parasitemic blood from a chimpanzee and an Aotus azarae boliviensis monkey. Our results indicate that this strain may be useful in antisporozoite vaccine trials.     

A CD4 domain important for HIV-mediated syncytium formation lies outside the virus binding site

HIV infection of chimpanzees results in a chronic viremia unaccompanied by the ultimately fatal immunodeficiency that marks HIV infection in man. We show here that expression of HIV envelope proteins allows syncytium formation between cells expressing human but not chimpanzee or macaque CD4. We find that the CD4 sequences regulating cell fusion lie outside the recognized virus binding site; in the simplest exchange, chimpanzee CD4 bearing human residue 87 supports syncytium formation, while human CD4 bearing chimpanzee residue 87 does not. Neither the equilibrium nor the forward rate constants for HIV-CD4 association are affected by substitution at position 87. Infection of human cells expressing chimpanzee CD4 is insensitive to lysosomotropic agents, suggesting that viral penetration under these circumstances does not require endocytosis. The benign course of HIV infection in chimpanzees may reflect the failure of the host to support direct cell to cell transmission of the virus.     

Molecular characterization of the interaction between porins of Neisseria gonorrhoeae and C4b-binding protein

Neisseria gonorrhoeae, the causative agent of gonorrhea, is a natural infection only in humans. The resistance of N. gonorrhoeae to normal human serum killing correlates with porin (Por)-mediated binding to the complement inhibitor, C4b-binding protein (C4BP). The entire binding site for both porin molecules resides within complement control protein domain 1 (CCP1) of C4BP. Only human and chimpanzee C4BPs bind to Por1B-bearing gonococci, whereas only human C4BP binds to Por1A strains. We have now used these species-specific differences in C4BP binding to gonococci to map the porin binding sites on CCP1 of C4BP. A comparison between human and chimpanzee or rhesus C4BP CCP1 revealed differences at 4 and 12 amino acid positions, respectively. These amino acids were targeted in the construction of 13 recombinant human mutant C4BPs. Overall, amino acids T43, T45, and K24 individually and A12, M14, R22, and L34 together were important for binding to Por1A strains. Altering D15 (found in man) to N15 (found in rhesus) introduced a glycosylation site that blocked binding to Por1A gonococci. C4BP binding to Por1B strains required K24 and was partially shielded by additional glycosylation in the D15N mutant. Only those recombinant mutant C4BPs that bound to bacteria rescued them from 100% killing by rhesus serum, thereby providing a functional correlate for the binding studies and highlighting C4BP function in gonococcal serum resistance.     

Experimental Toxoplasmosis in Chimpanzees

Two chimpanzees were given by mouth large numbers of viable oocysts of Toxoplasma gondii obtained from the faeces of experimentally infected cats. Before the experiment the first chimpanzee had a positive dye test reaction (1:250), an indication that it had undergone an earlier infection of toxoplasmosis; the serum antibody titres remained unchanged, no evidence of illness was found, and oocysts did not appear in its faeces during the subsequent six weeks. The second chimpanzee showed a negative dye test reaction before infection, and this converted to positive on the 7th day, rose to a peak on the 35th day, and remained high for six months. This animal appeared unwell during the first week, and on the 7th day its blood proved infective to mice; on the 40th day the lymph nodes became enlarged and biopsy specimens of a node and muscle in the 11th week were also infective to mice. No oocysts were passed in the faeces. The presumed cycle in the chimpanzee and in man and the relationships between Toxoplasma and Isospora are discussed.     

Morphological comparisons of the bovine piroplasm, Babesia divergens, in cattle and jird (Meriones unguiculatus) erythrocytes

In comparative studies of Babesia divergens in jirds and splenectomized calves several differences in the appearance of the parasite were found. Pyriform pairs of the parasite grew larger in jirds than in calves and also were larger than those of the original isolate when calves were infected after multiple jird passage. The parasites usually occupied a central intraerythrocytic position in jirds whereas in cattle they mainly occurred peripherally. The majority of pairs formed an obtuse angle relative to each other in both host species. The main difference in morphological types was found to be the rarity of single pyriforms in jirds and this, together with other small differences, was attributed to a faster replication rate of B. divergens in this host. Intraerythrocytic death of B. divergens was observed in both jirds and calves indicating similar defence mechanisms against primary infections in the 2 host species.     

Differences among primates in defence against infection: sensitivity of polymorphonuclear leukocytes to fMet-Leu-Phe

The sensitivity of polymorphonuclear leukocytes (PMN) to N-formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) for chemotaxis and for lysosomal enzyme release was examined using the PMN of four primate species, human (H. sapiens), chimpanzee (P. troglodytes), rhesus monkey (M. mulatta), and cotton-headed tamarin (S. (O) oedipus). The 50 per cent effective concentrations (EC50) of fMet-Leu-Phe for chemotaxis were 2.5 X 10(-9) M in human, 10(-9) M in chimpanzee, 8 X 10(-8) M in rhesus monkey, and 3.3 X 10(-6) M in tamarin. The EC50 values of fMet-Leu-Phe for myeloperoxidase (MPO) release were 10(-8) M in human, 4 X 10(-8) M in chimpanzee, 4 X 10(-8) M in rhesus monkey, and 10(-6) M in tamarin and those for beta-glucuronidase release were 4 X 10(-9) M, 6.4 X 10(-8) M, 1.8 X 10(-7) M, and 1.6 X 10(-6) M, respectively. Thus, the sensitivity to fMet-Leu-Phe for chemotaxis was in the order: chimpanzee congruent to human greater than rhesus monkey greater than tamarin, and that for the release of lysosomal enzymes, MPO and beta-glucuronidase, was in the order: human greater than chimpanzee greater than rhesus monkey greater than tamarin. These results appear to indicate that the sensitivity to fMet-Leu-Phe increases in the order of evolution of primates toward the human, and suggest that the sensitivity of PMN in the defence function against infection also increases in the same order.     

Simian immunodeficiency virus from mandrill (Mandrillus sphinx) SIVmnd experimentally infects human and nonhuman primate cells.

This study set out to characterize the features of experimental infection by simian immunodeficiency virus in mandrill (SIVmnd) (Mandrillus sphinx), cynomolgus macaque (Macaca fascicularis), rhesus macaque (Macaca mulatta), chimpanzee (Pan troglodytes), African green monkey (Cercopithecus pygerythrus), baboon (Papio cynocephalus) and human cells. Purified cells were exposed to a primary isolate of SIVmnd grown in the infected mandrill peripheral blood mononuclear cells, and viral p27 gag antigen was quantitated by antigen capture ELISA. Human cells have been found to be infected by SIVmnd. SIVmnd infection in cynomolgus macaque, rhesus macaque, baboon, mandrill and human cells were more effective than in vervet and chimpanzee cells. In addition, the lymphocytic cell lines SupT1, CEMx174 and Molt4 clone 8 were consistently infected by SIVmnd, whereas U937, a monocytic cell line, was not.     

Growth rates and phylogeny in primates

There is sufficient evidence to indicate that man grows for a longer period of time than chimpanzee who in turn has a greater duration of growth than rhesus monkey. The problem of this paper was to determine if there was a concomitant decrease in a rate of growth. Using the relative growth rate of Fisher ('21), it appears that for most of their period of growth, the rate of change is the same. Immediately after birth, when we have no data for children, rhesus monkey grows significantly faster than chimpanzee. By a year and a half their rates are the same, and neither species shows a sex difference. From seven years (age of youngest children) until children start through puberty, there is no sex difference in Homo sapiens, and the human rate does not differ from the chimpanzee rate. Because of the resemblance between the primate curve for rate and that for dairy cattle, it is postulated that this curve is more mammalian than primate and that during phylogeny the primates have merely increased the duration of time when growth is possible. Man does show one new feature, the puberal growth spurt, which is not found in the non-human data considered. The implications of these conclusions for primate phylogeny and for growth are discussed.     

Evidence of similar organization of the chromosomes carrying the major histocompatibility complex in man and other primates

The chromosome localization and gene synteny of the major histocompatibility complex (MHC) of the great apes and rhesus monkey were investigated using somatic cell hybrids. The presence of the MHC antigens was determined either with a microadsorption technique employing primate alloantisera, or with a radioimmune assay. The enzymes phosphoglucomutase 3 (PGM3), glyoxalase 1 (GLO1), mitochondrial superoxide dismutase (SOD2), and soluble maleic enzyme (ME1) were assayed in those hybrids where electrophoretic separations could be achieved. A chromosome homologous to the human No. 6 was found in the chimpanzee, gorilla, orangutan and rhesus monkey, and its genomic organization is similar to that of man.     

Human factor H interacts selectively with Neisseria gonorrhoeae and results in species-specific complement evasion

Complement forms a key arm of innate immune defenses against gonococcal infection. Sialylation of gonococcal lipo-oligosaccharide, or expression of porin 1A (Por1A) protein, enables Neisseria gonorrhoeae to bind the alternative pathway complement inhibitor, factor H (fH), and evade killing by human complement. Using recombinant fH fragment-murine Fc fusion proteins, we localized two N. gonorrhoeae Por1A-binding regions in fH: one in complement control protein domain 6, the other in complement control proteins 18-20. The latter is similar to that reported previously for sialylated Por1B gonococci. Upon incubation with human serum, Por1A and sialylated Por1B strains bound full-length human fH (HufH) and fH-related protein 1. In addition, Por1A strains bound fH-like protein 1 weakly. Only HufH, but not fH from other primates, bound directly to gonococci. Consistent with direct HufH binding, unsialylated Por1A gonococci resisted killing only by human complement, but not complement from other primates, rodents or lagomorphs; adding HufH to these heterologous sera restored serum resistance. Lipo-oligosaccharide sialylation of N. gonorrhoeae resulted in classical pathway regulation as evidenced by decreased C4 binding in human, chimpanzee, and rhesus serum but was accompanied by serum resistance only in human and chimpanzee serum. Direct-binding specificity of HufH only to gonococci that prevents serum killing is restricted to humans and may in part explain species-specific restriction of natural gonococcal infection. Our findings may help to improve animal models for gonorrhea while also having implications in the choice of complement sources to evaluate neisserial vaccine candidates.     

Alpha1,4-fucosyltransferase activity: a significant function in the primate lineage has appeared twice independently

In the animal kingdom the enzymes that catalyze the formation of alpha1,4 fucosylated-glycoconjugates are known only in apes (chimpanzee) and humans. They are encoded by FUT3 and FUT5 genes, two members of the Lewis FUT5-FUT3-FUT6 gene cluster, which had originated by duplications of an alpha3 ancestor gene. In order to explore more precisely the emergence of the alpha1,4 fucosylation, new Lewis-like fucosyltransferase genes were studied in species belonging to the three main primate groups. Two Lewis-like genes were found in brown and ruffed lemurs (prosimians) as well as in squirrel monkey (New World monkey). In the latter, one gene encodes an enzyme which transfers fucose only in alpha1,3 linkage, whereas the other is a pseudogene. Three genes homologous to chimpanzee and human Lewis genes were identified in rhesus macaque (Old World monkey), and only one encodes an alpha3/4-fucosyltransferase. The ability of new primate enzymes to transfer fucose in alpha1,3 or alpha1,3/4 linkage confirms that the amino acid R or W in the acceptor-binding motif "HH(R/W)(D/E)" is required for the type 1/type 2 acceptor specificity. Expression of rhesus macaque genes proved that fucose transfer in alpha1,4 linkage is not restricted to the hominoid family and may be extended to other Old World monkeys. Moreover, the presence of only one enzyme supporting the alpha1,4 fucosylation in rhesus macaque versus two enzymes in hominoids suggests that this function occurred twice independently during primate evolution.     

Comparison of research cost: man--primate animal--other animal models

The costs of research in human subjects are compared to those in primate animals and in other animal models on the basis of data available from a U.S. institution. The cost of experimentation in a chimpanzee is 3.59% of the per diem cost of clinical research in man. The cost for the dog is 37.1% of that of the chimpanzee, and the mouse costs 2.02% of the cost of the dog.     

Melioidosis in imported non-human primates

In 1969, five cases of melioidosis in three separate outbreaks were diagnosed in nonhuman primates in the United States. In the first outbreak, two stump-tailed macaque monkeys (Macaca arctoides) developed signs of the disease approximately 6 months after purchase. A third animal, a chimpanzee (Pan troglodytes), probably acquired its infection from one of these monkeys. Two other unrelated cases involving a pig-tailed monkey (Macaca nemestrina) and a rhesus monkey (Macaca mulatta) were diagnosed. These monkeys had been imported 3 years and 6 months, respectively, prior to the recognized onset of their disease. These cases represent the first known occurrences of spontaneous melioidosis in nonhuman primates in the United States.