Mononuclear phagocyte receptors in rhesus monkeys (Macaca mulatta) and their role in hemolytic disease of the newborn

Hemolytic disease of the newborn does not develop in rhesus monkeys because placentally-transferred maternal antibodies do not induce immune clearance of the newborn's erythrocytes. In an in vitro RBC adherence assay, rhesus peripheral blood monocytes did not bind newborn's RBC which had been coated in utero or in vitro with maternal antibodies. Nevertheless, rhesus phagocytes possess receptors that are specific for the Fc portion of IgC and for the C3b. Using purified human IgG subclasses as inhibitors of RBC adherence, rhesus Fc receptors preferentially bind IgG1 and IgG3. Thus, it may be that maternal antibodies are non-opsonic because they belong to IgG subclasses that do not bind effectively to rhesus Fc receptors. Also, RBC adherence appears to be controlled by the level of antibody coating which in turn is determined by avidity of the antibodies and by the number of RBC membrane determinants. The failure of maternal antibodies to opsonize the newborn's RBC and thus cause hemolytic disease is very likely due to the low avidity of antibodies and to the weak expression of blood group determinants on the membranes of these RBC.     

Response of colostrum-deprived cynomolgus monkeys to intragastric challenge exposure with simian rotavirus strain SA11.

The infectivity and pathogenic potential of a cell culture-adapted simian rotavirus was evaluated in colostrum-deprived newborn and infant cynomolgus macaques (Macaca fascicularis). Intragastric challenge exposure with the simian rotavirus strain SA11 on postpartum day 2 induced diarrhea in 5 of 5 colostrum-deprived newborn monkeys. Compared with sham-inoculated controls, 3 of the 5 inoculated monkeys also manifested reduced body weight gain during the initial 5 days after challenge exposure. Rotavirus was detected in feces of 3 challenge-exposed monkeys for up to 2 days after inoculation. Evaluation of antibody response after rotavirus inoculation was obscured by high but variable prechallenge-exposure serum titers of rotavirus-specific antibody. Preexisting serum titer of neutralizing antibody in newborn monkeys was not predictive of clinical response to inoculation with rotavirus SA11. Two 90-day-old infant monkeys with low serum neutralizing antibody titer did not have diarrhea, reduced weight gain, or antibody response after oral inoculation with rotavirus SA11. Results of these challenge-exposure studies in newborn cynomolgus monkeys were consistent with a heterologous host-rotavirus model and indicate that neonatal serum antibody of maternal origin may not be associated with resistance to rotavirus-induced disease.     

Development and functional characterization of monoclonal antibodies recognizing chicken lymphocytes with natural killer cell activity.

We have developed two monoclonal antibodies which detect cell surface antigens present on chicken lymphocytes mediating natural killer (NK) cell activity against the avian tumor cell target. The monoclonal antibodies, K-14 and K-108, stained 17 and 6% of splenic lymphocytes, and 11 and 14% of peripheral blood lymphocytes (PBL), respectively, and fewer than 5% of thymic and bursal lymphocytes. Neither of these monoclonal antibodies stained adherent macrophages or the MC29-virus transformed monocytic cell line. Both monoclonal antibodies significantly inhibited NK cell activity in a standard 4 h 51Cr-release cytotoxicity assay using the LSCC-RP9 tumor cell line as target cells at an effector to target ratio of 50:1. Pretreatment of splenocytes with either monoclonal antibody in the presence of rabbit complement (C) resulted in a significant reduction in NK cell activity. However, the monoclonal antibody K-1 which detects normal chicken macrophages did not interfere with NK cell activity. The monoclonal antibody K-108 significantly blocked Fc receptor-mediated rosette formation of sheep red blood cells coated with IgG antibodies (EA) by 56% while the monoclonal antibody K-14 did not show a significant blocking. These results indicate that the monoclonal antibodies K-108 and K-14 identify different epitopes present on the surface of chicken splenic lymphocytes which mediate spontaneous NK cytotoxicity.     

Variations in the immune response to herpesvirus saimiri in squirrel and rhesus monkeys

Humoral and cell-mediated immunity (CMI) to herpesvirus saimiri (HVS), an oncogenic lymphotropic herpesvirus, was studied in squirrel and rhesus monkeys. Natural antibody to HVS was found in five of six squirrel monkeys but there was no evidence of specific CMI directed against HVS. Rhesus monkeys did not show natural antibody or CMI against HVS antigens. Immunization with HVS, however, produced both antibody and specific CMI in the rhesus monkeys, but no CMI developed in the squirrel monkeys. These findings are important in the development of animal models for the treatment of tumors associated with lymphotropic herpesviruses.     

怀孕后期感染PRRS病毒母猪所产新生仔猪的免疫反应

将PRRS病毒BJ－4株感染怀孕后期（约90天）的抗体阴性和阳性母猪，待自然分娩后，观察新生仔猪的免疫应答。结果显示，接种PRRS病毒BJ－4的母猪没有表现出明显的临床症状，没有出现流产死产。新生仔猪浦被子前血清中PRRS病毒核酸TR－PCR检测和ELISA抗体阴性，哺乳后特异性抗体出现，5－6周母源抗体逐渐下降；20日龄猪瘟疫苗免疫后疫苗抗体维持时间短，仔猪在40日龄后进入野毒感染的危险期。RT－nested PCR检测血清中PRRS病毒核酸和易感仔猪病毒特异性抗体监测的结果提示仔猪群内可能存在水平传播。流式细胞术检测外周血淋巴细胞亚群发现CD3^ 细胞减少，CD4^ 细胞显著下降，CD8^ ，CD4^ CD8^ 和SLA－DR^ 表达细胞升高。以上结果表明在感染后病毒能够长期持续性存在，猪场内新生仔猪母源抗体逐渐下降后，通过水平传播受到感染，感染后免疫应答受到不利影响。     

Time dependent decreases of maternal canine virus antibodies in newborn pups

Levels of passively transferred maternal antibodies to three canine viruses, rabies virus (RV), canine distemper virus (CDV) and infectious canine hepatitis (ICH) virus, in serum specimens from 14 fetal pups and in serial serum specimens collected up to 45 days after whelping from 14 neonate pups were compared with levels of antibodies to these viruses in milk and sera collected concurrently from their respective dams. Radioimmunoassays using RV-, CDV- and ICH virus-specific antigens showed that sera from all fetal pups had detectable levels of antibodies to all three canine viruses and ICH neutralising antibodies were detected in sera from 10 of the 14 fetal pups. As the time after whelping increased, titres of RV-, CDV- and ICH virus antibodies measured by radioimmunoassay and ICH virus neutralising antibody tests in serially collected specimens of milk from dams rapidly decreased, while titres of the antibodies in serum specimens from newborn pups in their litters steadily decreased. Individual fetal and newborn pups with a high titre of antibody to one virus also had high titres to the other two viruses, although a wide range of titres was observed among pups in each of the litters studied. Markedly higher titres of antibody to all three viruses were observed in serially collected specimens of sera from dams than in sera from fetal and newborn pups in their litters. Results show that maternal RV, CDV and ICH virus antibodies are transferred from dams to pups in utero and by nursing. Levels of these maternal virus-specific antibodies in newborn pup sera decreased at similar rates as time after whelping increased.     

Cloning, expression and characterization of monkey (Macaca fascicularis) CD137

CD137 plays an important role as a co-stimulatory molecule in activated T cells. Agonistic CD137 specific antibodies have been investigated as therapeutic agents to promote tumor-specific immune responses by direct activation of T cells. As part of the pre-clinical pharmacological evaluation of cynomolgus monkeys, monkey CD137 was cloned and characterized. The deduced amino acid sequence encoded a full-length gene of 254 amino acids 95% identical to human CD137. Sequence variants identified in monkey CD137 include four splice variants lacking the transmembrane domain. These variants were detectable in human including two previously unreported variants. Two missense single nucleotide polymorphisms were detected present in 42 and 50% of 36 monkeys tested. In both monkey and human, mRNA expression of full-length CD137 and splice variants were significantly increased in peripheral blood mononuclear cells (PBMCs) upon stimulation by anti-CD3 antibodies. Recombinant monkey CD137 protein was bound with high affinity by an agonistic anti-human CD137 antibody but not by an anti-mouse CD137 antibody. In summary, compared to human, monkey CD137 showed distinct extracellular domain amino acid sequence and sequence polymorphisms. Thus, antibodies directed against epitopes in this extracellular domain could have differences in pharmacologic activity between cynomolgus monkeys and human or across individual cynomolgus monkeys.     

Flow cytometric analysis on cross-reactivity of human-specific CD monoclonal antibodies with splenocytes of Aotus nancymaae, a non-human primate model for biomedical research

The reactivity of 204 monoclonal antibodies (mAb) out of 377 commercially available antibodies collected by the animal homologue group of the HLAD8 was analyzed by single colour flow cytometry. Most of these mAb were originally developed against human cell surface molecules. Fifty-eight mAb (28%) showed reactivity with spleen cells of Aotus nancymaae, a non-human primate animal model in biomedical research. Out of these 58 mAb, 22 also showed reactivity with mononuclear cells derived from rhesus macaques and cynomolgus monkeys indicating that the epitopes recognized are evolutionary conserved between human, Old and New World monkeys. This novel panel of A. nancymaae reactive mAb will increase the potential to explore complex host-pathogen interactions in non-human primate animal models, particularly in malaria vaccine research.     

Colostral Transfer of Rinderpest Neutralizing Antibody to Offspring of Våccinated Dams

The transfer of maternal antibodies to Friesian and buffalo calves born of dams vaccinated against rinderpest was through colostrum only. Colostral antibody titers at the time of parturition were higher than the serum titer. Two hours after suckling, a high level of rinderpest neutralizing antibodies was detected in the sera of newborn animals. The half-life of maternal antibodies in buffalo and Friesian calves was found to be approximately 33 and 29 days respectively. By the age of 7-8 months, 60 per cent of buffalo calves and 80 per cent of Friesian calves had no detectable levels of rinderpest neutralizing antibody.     

Antibody responses in protein-energy restricted beef cows and their cold stressed progeny.

Antibody titers were measured in serum and colostral whey of pregnant beef cows immunized with tetanus toxoid and chicken red blood cells while being fed diets either restricted or nonrestricted in protein and/or metabolizable energy during the last 150 days of gestation. Serum antibody titers were also measured in the colostrum-fed, cold and noncold stressed progeny that were actively immunized with dinitrophenol conjugated to keyhole limpet hemocyanin. In general, there were no major or sustained differences in humoral immune responses to injection of tetanus toxoid or chicken red blood cells between cows fed diets that were adequate or restricted in protein or metabolizable energy. In the few cases where serum antibody titers to tetanus toxoid or chicken red blood cells differed (P less than 0.05) between adequately fed or restricted cows, the differences were no greater than twofold. Anti-chicken red blood cell titers were uniformly low (P less than 0.05) by a magnitude of two to threefold in colostral whey of cows restricted in protein and/or metabolizable energy when compared to titers in cows fed adequate amounts of protein and metabolizable energy. With one exception, neither maternal dietary restriction nor cold exposure had a major effect on the ability of the calves to absorb antitetanus toxoid and chicken red blood cell antibodies from colostrum. The humoral immune responses of all calves to injection of keyhole limpet hemocyanin and dinitrophenol were similar in magnitude.     

A congenital persistent swine fever infection. II. Immune response to swine fever virus and unrelated antigens

After the disappearance of maternal antibodies, no antibodies were detected in five pigs that were congenitally infected with the Bergen strain of swine fever virus. The pigs lived for 2–11 months. One pig showed low levels of precipitating antibody during the last month of its life. The pigs had a normal immune response to sheep red blood cells and to pig parvovirus. These observations suggest the presence of immunological tolerance to swine fever virus in these pigs.Cell mediated immunity, measured by phytohaemagglutinin lymphocyte stimulation, appeared to be normal.     

Placental transfer of immunoglobulins in cattle infected with Schistosoma mattheei

Although the epitheliochorial placenta of ruminants does not allow passage of immunoglobulins from dam to foetus specific antibodies have been detected at birth in calves born to Schistosoma mattheei-infected cows. The present study determined the prevalence of calves born with specific antibodies for S. mattheei and the origin of these antibodies. For the determination of the prevalence, 100 calves born to infected mothers in an endemic area (Zambia) were examined, 24 were seropositive. To study the origin of these antibodies placentomes of 40 naturally S. mattheei-infected cows were examined for the presence of schistosome eggs and lesions which could explain foetal priming and/or leakage of maternal antibodies and/or antigen into the foetus. Tissue damage and schistosome eggs were observed on the maternal as well as the foetal side of the placentomes. In order to determine the specific nature of the antibody response, antibody profiles against soluble adult worm antigen preparation (SWAP) of S. mattheei were compared by Western blot between dams and their newborn calves (n = 8). The specific recognition profiles were identical for the seropositive calves and their dams on SWAP mattheei. Identical recognition profiles between dams and calves were also observed when sera were analysed on Escherichia coli, a pathogen of which the foetus should be free, and would indicate passive antibody transfer from the dam. In conclusion, the present study shows that S. mattheei could induce placentome lesions and that eggs can cross the placenta. Consequently, foeti can come into contact with S. mattheei antigens in utero, and might also contain maternal antibodies from leakage through placentome lesions. As such, the infection status of the mother could have far reaching effects on the immunological status of her offspring and modify their reaction upon infection.     

Occurrence of IgE in foals: evidence for transfer of maternal IgE by the colostrum and late onset of endogenous IgE production in the horse

IgE is the key antibody involved in type I allergies. Allergen mediated crosslinking of IgE bound to high affinity Fc-receptors on mast cells and basophils stimulates cellular degranulation and release of inflammatory mediators and cytokines. In this report, we demonstrate that IgE antibodies can be transferred from the mother to offspring in horses via the colostrum. We found a clear correlation between the IgE concentration in colostrum and the total IgE concentration in foal sera on day 2 after birth (r_sp = 0.83). Maternal IgE was detected in foal sera by ELISA and on peripheral blood leukocytes of foals by flow cytometry. Both serum and cell membrane-bound IgE were undetectable in newborn foals before colostrum uptake and peaked on days 2–5 after birth. Cell-bound IgE became undetectable at 2 months after birth. Serum IgE disappeared from the circulation within the first 3–4 months of age. These kinetics suggest that the IgE antibodies which are detectable in foals during the first 4 months after birth are of maternal origin only. The endogenous IgE production was found to begin at 9–11 months of age, when IgE could be detected on peripheral blood leukocytes and in foal sera again. After 18 months of life, the total IgE concentrations in foal sera were comparable to those detected in their dams. The late onset of endogenous IgE production offers an explanation for observations that IgE mediated allergies are generally not observed in horses before puberty. The roles of the passively transferred maternal IgE in newborn foals are not yet known, but could be manifold, ranging from passive immunity and induction of immunoregulatory functions to determinative influences of maternal IgE on the antibody repertoire in the offspring.     

Pharmacokinetics and cardiopulmonary effects of fentanyl in isoflurane-anesthetized rhesus monkeys (Macaca mulatta)

OBJECTIVE: To determine pharmacokinetics and selected cardiopulmonary effects of fentanyl in isoflurane-anesthetized rhesus monkeys. ANIMALS: 6 adult male rhesus monkeys. PROCEDURE: Fentanyl (8 mg/kg of body weight, IV) was administered to 6 monkeys anesthetized with isoflurane. End-tidal isoflurane concentration and esophageal temperature were kept constant, and ventilation was mechanically assisted. Heart rate, rhythm, aortic blood pressure, and blood pH, gas, and fentanyl concentrations were determined before and for 8 hours after administration of fentanyl. Pharmacokinetics of fentanyl were derived by use of noncompartmental methods based on statistical moment theory. RESULTS: Heart rate and mean arterial pressure decreased transiently following fentanyl administration. Maximal decreases were observed 5 to 15 minutes after administration. Arterial pH, Paco2, and Pao2 ranged from 7.46 +/- 0.04 to 751 +/- 0.05 units, 29.2 +/- 3 to 34.6 +/- 4.4 mm Hg, and 412.6 +/- 105.3 to 482.9 +/- 71.2 mm Hg, respectively. The clearance, volume of distribution area, volume of distribution steady state, mean residence time, area under the curve, elimination rate constant, and half-life were 32.5 +/- 2.48 ml/kg/min, 9.04 +/- 1.91 L/kg, 70 +/- 1.2 L/kg, 218.5 +/- 35.5 min, 0.247 +/- 0.019 mg/ml/min, 0.004 + 0.001/min, and 192.0 +/- 33.5 min, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Transient but potentially clinically important decreases in heart rate and mean arterial pressure were observed following fentanyl administration. Distribution and clearance data were similar to those reported for dogs and humans.     

猕猴的类人ABO血型检测研究

猕猴红细胞上类人ABO血型检定受抗原结构差异、抗原性弱和人源ABO抗血清中种属抗体等干扰,本研究的目的为建立医学实验动物模型而正确检定猕猴类人ABO血型。制备猕猴专用ABO抗血清,建立改良吸收放散技术。结果为单克隆ABO抗体不凝集全部猴红细胞,普通人源ABO抗血清因种属抗体而凝集所有红细胞。采用猴专用ABO抗血清及改良吸收放散技术,从30只猴中检测出3只A型,9只B型,3只AB型。猕猴红细胞上有类人ABO抗原,但很弱。单克隆及人源ABO抗血清都不能检测出,必须用专用ABO抗血清及改良吸收放散技术才能检测。     

SIV-associated lymphomas in rhesus monkeys (Macaca mulatta) in comparison with HIV-associated lymphomas

A retrospective study was performed to characterize malignant lymphomas of 16 Simian immunodeficiency virus (SIV)-infected rhesus monkeys (Macaca mulatta), 2-9 years of age, on the basis of clinical data, histologic and immunophenotypic results, and cell death indices compiled with the TdT-mediated X-duTP nick end labeling method. We particularly focused on providing immunohistochemical evidence of expression products of EBNA2, Bc12, c-Myc, P21, P53, and Bc16. Results were compared with data from the literature on human HIV-associated lymphomas. According to the updated Kiel classification, the lymphomas were classified as 11 centroblastic lymphomas, three immunoblastic lymphomas, one Burkitt-like lymphoma, and one immunocytoma. Using antibodies to CD20, the B-cell origin of tumor cells was demonstrated. SIV antigen was not demonstrated in the tumor cells. Infection with rhesus lymphocryptovirus was present in 94% of the monkeys. Lymphomas revealed expression of Bc12 in 15/16 (94%), c-Myc in 14/16 (88%), P21 in 10/ 16 (63%), P53 in 12/16 (75%), and Bc16 in 1/16 (6%) monkeys. This study provided evidence that the expression of these gene products, which are thought to play an important role in cell proliferation and apoptosis in HIV- and non-HIV-associated lymphomas, are also involved in the pathogenesis of lymphomas in SIV-infected rhesus monkeys. A tentative relationship between the described gene products and the cell death indices was established for the expression of Bc12. The present primate model represents a suitable animal model for studying the pathogenesis of AIDS-associated lymphomas.     

Maternal immunity enhances systemic recall immune responses upon oral immunization of piglets with F4 fimbriae

F4 enterotoxigenic Escherichia coli (ETEC) cause diarrhoea and mortality in piglets leading to severe economic losses. Oral immunization of piglets with F4 fimbriae induces a protective intestinal immune response evidenced by an F4-specific serum and intestinal IgA response. However, successful oral immunization of pigs with F4 fimbriae in the presence of maternal immunity has not been demonstrated yet. In the present study we aimed to evaluate the effect of maternal immunity on the induction of a systemic immune response upon oral immunization of piglets. Whereas F4-specific IgG and IgA could be induced by oral immunization of pigs without maternal antibodies and by intramuscular immunization of pigs with maternal antibodies, no such response was seen in the orally immunized animals with maternal antibodies. Since maternal antibodies can mask an antibody response, we also looked by ELIspot assays for circulating F4-specific antibody secreting cells (ASCs). Enumerating the F4-specific ASCs within the circulating peripheral blood mononuclear cells, and the number of F4-specific IgA ASCs within the circulating IgA⁺ B-cells revealed an F4-specific immune response in the orally immunized animals with maternal antibodies. Interestingly, results suggest a more robust IgA booster response by oral immunization of pigs with than without maternal antibodies. These results demonstrate that oral immunization of piglets with F4-specific maternal antibodies is feasible and that these maternal antibodies seem to enhance the secondary systemic immune response. Furthermore, our ELIspot assay on enriched IgA⁺ B-cells could be used as a screening procedure to optimize mucosal immunization protocols in pigs with maternal immunity.     

Priming for local and systemic antibody memory responses to bovine respiratory syncytial virus: effect of amount of virus, virus replication, route of administration and maternal antibodies

We studied the conditions under which calves can be primed for mucosal and serum antibody memory responses against bovine respiratory syncytial virus (BRSV), and the relationship between such responses and protection against the virus. Calves were primed via the respiratory tract with a low or high amount of live virus, with killed virus, or intramuscularly with live virus. Calves were challenged via the respiratory tract. Priming with live virus via the respiratory tract induced primary antibody responses in serum and on the mucosae, which were identical after the low and the high amount of virus. These responses were suppressed by maternal antibodies. Intramuscular priming of seronegative calves induced serum IgG1 and sometimes serum IgM and IgG2 responses, but no responses were detected on the mucosae. Sera of calves primed by the intramuscular or the respiratory route recognized the same viral proteins. No responses were observed after priming with killed virus, or after intramuscular priming of calves with maternal antibodies. After challenge, mucosal and serum antibody memory responses developed in calves that had been primed via the respiratory tract with live virus, whether they had maternal antibodies or not. One colostrum-fed calf showed a mucosal memory response, although serum responses were still suppressed by maternal antibodies. None of the calves thus primed shed virus after challenge. Intramuscular priming also primed for mucosal and serum memory responses after challenge, which however started perhaps slightly later and were not associated with protection against virus shedding. Priming with killed virus, or with live virus intramuscularly in the presence of maternal antibodies proved least effective in inducing memory and protection against virus shedding. Thus, protection against virus shedding was afforded by priming with live virus via the respiratory tract, both in calves with an without maternal antibodies. Protection was associated with a strong and rapid mucosal antibody memory response, but the reverse was not necessarily true. Protection against virus excretion had no relationship to titers of serum neutralizing or serum IgG1 or nasal IgA antibodies at the time of challenge.     

Enumeration of lymphocyte subsets in peripheral blood of rhesus monkeys prior to and following monocyte removal using a modified indirect avidin-biotin immunoperoxidase technique

A modified avidin-biotin immunoperoxidase technique has been used to enumerate B lymphocytes, T inducer/helper (TH) and T cytotoxic/suppressor (TS) cells in the peripheral blood of normal and immunosuppressed rhesus monkeys (Macaca mulatta) prior to and following adherent-cell depletion. The levels of each of the B, TH and TS cells detected in the normal monkeys using monoclonal antibodies which recognized specific surface antigens on human lymphocytes were comparable to the levels reported in human peripheral blood using direct immunofluorescence, immunoperoxidase or flow cytometry techniques. Adherent cell depletion did not result in a significant loss of any of the lymphocyte subpopulations examined. The technique is reproducible and sensitive in detecting differences between normal and immunosuppressed animals, and would prove to be useful in studies pertaining to chemical and drug immunomodulation.     

免疫剂量和母源抗体对禽流感重组鸡痘病毒活载体疫苗免疫效力的影响

利用表达 H 5亚型禽流感病毒 (AIV)血凝素基因的重组鸡痘病毒 (r FPV- HA)以不同剂量免疫 1日龄 SPF鸡、有或无母源抗体 (FPV、AIV H5)的商品鸡 ,并于免疫后 2 1d利用同亚型 AIV通过肌肉注射进行致死性攻击 ,通过检测免疫后 HI抗体应答、比较攻毒后发病率和死亡率评价免疫剂量和母源抗体对 r FPV- HA免疫效力的影响。结果发现 ,免疫后 2 1d,15 %～ 2 0 %的 SPF鸡和无母源抗体商品鸡可检出 HI抗体 ,而含母源抗体商品鸡检测不到 HI抗体。利用H5亚型 AIV致死性攻击后 ,10 3～ 10 6 PFU的 r FPV- HA可保护 95 %～ 10 0 %的 SPF鸡和无母源抗体商品鸡抵御强毒攻击 ,使之免于发病和死亡 ;而不同剂量 r FPV- HA接种的含母源抗体商品鸡有 80 %～ 90 %发病和死亡。结果表明 ,在较宽的免疫剂量范围内 ,r FPV- HA对 SPF鸡和无母源抗体商品鸡可提供良好的保护 ,显示出一定的应用前景 ;母源抗体影响 r FPV- HA诱导的免疫应答 ,且提高免疫剂量亦不能克服其干扰作用 ,这提示在实际应用中需优化免疫程序 ,避免母源抗体干扰。