An adenovirus-simian immunodeficiency virus env vaccine elicits humoral, cellular, and mucosal immune responses in rhesus macaques and decreases viral burden following vaginal challenge

Six female rhesus macaques were immunized orally and intranasally at 0 weeks and intratracheally at 12 weeks with an adenovirus type 5 host range mutant (Ad5hr)-simian immunodeficiency virus SIVsm env recombinant and at 24 and 36 weeks with native SIVmac251 gp120 in Syntex adjuvant. Four macaques received the Ad5hr vector and adjuvant alone; two additional controls were naive. In vivo replication of the Ad5hr wild-type and recombinant vectors occurred with detection of Ad5 DNA in stool samples and/or nasal secretions in all macaques and increases in Ad5 neutralizing antibody in 9 of 10 macaques following Ad administrations. SIV-specific neutralizing antibodies appeared after the second recombinant immunization and rose to titers > 10,000 following the second subunit boost. Immunoglobulin G (IgG) and IgA antibodies able to bind gp120 developed in nasal and rectal secretions, and SIV-specific IgGs were also observed in vaginal secretions and saliva. T-cell proliferative responses to SIV gp140 and T-helper epitopes were sporadically detected in all immunized macaques. Following vaginal challenge with SIVmac251, transient or persistent infection resulted in both immunized and control monkeys. The mean viral burden in persistently infected immunized macaques was significantly decreased in the primary infection period compared to that of control macaques. These results establish in vivo use of the Ad5hr vector, which overcomes the host range restriction of human Ads for rhesus macaques, thereby providing a new model for evaluation of Ad-based vaccines. In addition, they show that a vaccine regimen using the Ad5hr-SIV env recombinant and gp120 subunit induces strong humoral, cellular, and mucosal immunity in rhesus macaques. The reduced viral burden achieved solely with an env-based vaccine supports further development of Ad-based vaccines comprising additional viral components for immune therapy and AIDS vaccine development.     

Temporal analyses of virus replication, immune responses, and efficacy in rhesus macaques immunized with a live, attenuated simian immunodeficiency virus vaccine

Despite evidence that live, attenuated simian immunodeficiency virus (SIV) vaccines can elicit potent protection against pathogenic SIV infection, detailed information on the replication kinetics of attenuated SIV in vivo is lacking. In this study, we measured SIV RNA in the plasma of 16 adult rhesus macaques immunized with a live, attenuated strain of SIV (SIVmac239Deltanef). To evaluate the relationship between replication of the vaccine virus and the onset of protection, four animals per group were challenged with pathogenic SIVmac251 at either 5, 10, 15, or 25 weeks after immunization. SIVmac239Deltanef replicated efficiently in the immunized macaques in the first few weeks after inoculation. SIV RNA was detected in the plasma of all animals by day 7 after inoculation, and peak levels of viremia (10(5) to 10(7) RNA copies/ml) occurred by 7 to 12 days. Following challenge, SIVmac251 was detected in all of the four animals challenged at 5 weeks, in two of four challenged at 10 weeks, in none of four challenged at 15 weeks, and one of four challenged at 25 weeks. One animal immunized with SIVmac239Deltanef and challenged at 10 weeks had evidence of disease progression in the absence of detectable SIVmac251. Although complete protection was not achieved at 5 weeks, a transient reduction in viremia (approximately 100-fold) occurred in the immunized macaques early after challenge compared to the nonimmunized controls. Two weeks after challenge, SIV RNA was also reduced in the lymph nodes of all immunized macaques compared with control animals. Taken together, these results indicate that host responses capable of reducing the viral load in plasma and lymph nodes were induced as early as 5 weeks after immunization with SIVmac239Deltanef, while more potent protection developed between 10 and 15 weeks. In further experiments, we found that resistance to SIVmac251 infection did not correlate with the presence of antibodies to SIV gp130 and p27 antigens and was achieved in the absence of significant neutralizing activity against the primary SIVmac251 challenge stock.     

Rapid turnover of T lymphocytes in SIV-infected rhesus macaques

Studies of lymphocyte turnover in animal models have implications for understanding the mechanism of cell killing and the extent of lymphocyte regeneration in human immunodeficiency virus infection. Quantitative analyses of the sequential changes in bromodeoxyuridine labeling of CD4 and CD8 T lymphocytes not only revealed the normal proliferation and death rates of these cell populations in uninfected macaques, but also showed a substantial increase in these rates associated with simian immunodeficiency virus (SIV) infection. Faster labeling and delabeling in memory and na?ve T lymphocyte subpopulations as well as in NK (natural killer) and B cells were also observed in infected macaques, suggesting a state of generalized activation induced by SIV.     

Diverse host responses and outcomes following simian immunodeficiency virus SIVmac239 infection in sooty mangabeys and rhesus macaques

Sooty mangabeys naturally infected with simian immunodeficiency virus (SIV) do not develop immunodeficiency despite the presence of viral loads of 10(5) to 10(7) RNA copies/ml. To investigate the basis of apathogenic SIV infection in sooty mangabeys, three sooty mangabeys and three rhesus macaques were inoculated intravenously with SIVmac239 and evaluated longitudinally for 1 year. SIVmac239 infection of sooty mangabeys resulted in 2- to 4-log-lower viral loads than in macaques and did not reproduce the high viral loads observed in natural SIVsmm infection. During acute SIV infection, polyclonal cytotoxic T-lymphocyte (CTL) activity coincident with decline in peak plasma viremia was observed in both macaques and mangabeys; 8 to 20 weeks later, CTL activity declined in the macaques but was sustained and broadly directed in the mangabeys. Neutralizing antibodies to SIVmac239 were detected in the macaques but not the mangabeys. Differences in expression of CD38 on CD8(+) T lymphocytes or in the percentage of naive phenotype T cells expressing CD45RA and CD62L-selection did not correlate with development of AIDS in rhesus macaques. In macaques, the proportion of CD4(+) T lymphocytes expressing CD25 declined during SIV infection, while in mangabeys, CD25-expressing CD4(+) T lymphocytes increased. Longitudinal evaluation of cytokine secretion by flow cytometric analysis of unstimulated lymphocytes revealed elevation of interleukin-2 and gamma interferon in a macaque and only interleukin-10 in a concurrently infected mangabey during acute SIV infection. Differences in host responses following experimental SIVmac239 infection may be associated with the divergent outcome in sooty mangabeys and rhesus macaques.     

DQ-haplotype analysis in rhesus macaques: implications for the evolution of these genes

The DQA1 and DQB1 alleles of 258 rhesus monkeys (Macaca mulatta) of different origin were typed by PCR-RFLP. Five novel MamuDQA1 and five novel -DQB1 alleles were detected and 15 Mamu-DQA1-DQB1 haplotypes were identified. Haplotype analysis confirmed the conservation of the DQA1*01-DQB1 *06 haplotypes in evolution. The most conspicuous finding was the tight linkage between the Mamu-DQA1 and -DQB1 alleles. Almost in every case the Mamu-DQA1 allele was linked to only one particular Mamu-DQB1 allele. Although there also are constraints in the formation of DQ haplotypes in humans, such tight linkages are not observed. These findings support the hypothesis of some kind of co-evolution between DQA1 and DQB1 alleles and may reflect a stronger force of natural selection in macaques than in humans.     

Hypnosis as a modulator of cellular immune dysregulation during acute stress.

To assess the influence of a hypnotic intervention on cellular immune function during a commonplace stressful event, the authors selected 33 medical and dental students on the basis of hypnotic susceptibility. Initial blood samples were obtained during a lower stress period, and a second sample was drawn 3 days before the first major exam of the term. Half of the participants were randomly assigned to hypnotic-relaxation training in the interval between samples. Participants in the hypnotic group were, on average, protected from the stress-related decrements that were observed in control participants' proliferative responses to 2 mitogens, percentages of CD3+ and CD4+ T-lymphocytes, and interleukin 1 production by peripheral blood leukocytes. More frequent hypnotic-relaxation practice was associated with higher percentages of CD3+ and CD4+ T-lymphocytes. These data provide encouraging evidence that interventions may reduce the immunological dysregulation associated with acute stressors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of encapsulated single chain antibodies for induction of anti-idiotypic humoral and cellular immune responses

The use of biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres as a cancer vaccine delivery system for induction of anti-idiotypic responses has been investigated using a single chain antibody scFv-pDL10, which recognizes the human ovarian cancer antigen CA125. Immunization of mice with scFv-pDL10 encapsulated in PLGA microspheres resulted in enhanced humoral and cellular immune responses when compared to scFv-pDL10 alone. Induced anti-idiotypic antibodies (Ab2) which mimic the original antigen CA125 compete with CA125 for the epitope. A cellular response (T2 induction) was also observed. These results raise the possibility of anti-idiotypic antibody induction by a single chain antibody, encapsulated in biodegradeble microspheres, as a potential vaccine for ovarian carcinoma.     

Effect of rat placental culture supernatants on cellular and humoral immune responses

PROBLEM: To evaluate the effect of rat placental culture supernatants (PS) on spontaneous, mitogen- and alloantigen-induced lymphoproliferation, antibody synthesis regulation, and symmetric/asymmetric antibody ratio. METHOD OF STUDY: The effect of PS was determined: (a) on cell proliferation of murine hybridoma cells and on spontaneous or ConA-induced proliferation of murine and rat splenocytes by thymidine incorporation; (b) on rat or mouse cell-mediated cytotoxicity (CMC) by 51Cr release; and (c) on antibody synthesis by enzyme-linked immunoadsorbent assay (ELISA). RESULTS: With 20% PS, hybridoma cell inhibition was 37% and that of splenocytes up to 60%, whereas it was 75 and 43%, respectively, in the presence of ConA. Despite marked cell death, hybridoma proliferation index increased significantly. There was a drop in total antidinitrophenylated (DNP) immunoglobulin G1 (IgG1) antibody production and an increase in asymmetric antibody percentage, correlating with placental supernatant concentration. CONCLUSIONS: Rat placental culture supernatants inhibit cell proliferation in all cases, diminish total antibody production, and increase the percentage of asymmetric antibodies by the hybridoma, and they increase antibody production by rat splenocytes.     

Antibody responses to capsular polysaccharide backbone and O-acetate side groups of Streptococcus pneumoniae type 9V in humans and rhesus macaques

Streptococcus pneumoniae is responsible for high rates of pneumococcal bacteremia, meningitis, pneumonia, and acute otitis media worldwide. Protection from disease is conferred by antibodies specific for the polysaccharide (Ps) capsule of the bacteria. Of the four types of group 9 pneumococci, types 9N and 9V cause the most disease, and both types are included in the polyvalent pneumococcal vaccine. The type 9V capsule consists of repeating pentasaccharide units linearly arranged, with an average of 1 to 2 mol of O-acetate side chains per mol of repeat units, added in a complex pattern in which not all repeat units are alike. alpha-GlcA residues may be O-acetylated in the 2 (17%) or 3 (25%) position and beta-ManNAc residues may be O-acetylated in the 4 (6%) or 6 (55%) position. Under certain conditions, the O-acetate side chains are subject to oxidation, which results in subsequent de-O-acetylation of a significant number of the repeat units. This de-O-acetylation could adversely affect the efficacy of a vaccine containing the 9V Ps. A study was undertaken to compare the relative contributions of O-acetate and Ps backbone epitopes in the immune response to S. pneumoniae 9V type-specific Ps. In both an infant rhesus monkey model and humans, antibodies against the non-O-acetylated 9V backbone as well as against O-acetylated 9V Ps were detected. Functional (opsonophagocytic) activity was observed in antisera in which the predominant species of antibody recognized de-O-acetylated 9V Ps. We concluded that the O-acetate side groups, while recognized, are not essential to the ability of the 9V Ps to induce functional antibody responses.     

Heart rate responses to social interactions in free-moving rhesus macaques (Macaca mulatta): A pilot study.

Heart rate telemetry was explored as a means to access animal emotion during social interactions under naturalistic conditions. Heart rates of 2 middle-ranking adult females living in a large group of rhesus macaques (Macaca mulatta) were recorded along with their behavior. Heart rate changes during 2 types of interactions were investigated, while controlling for the effects of posture and activity. The risk of aggression associated with the approach of a dominant individual was expected to provoke anxiety in the approachee. This prediction was supported by the heart rate increase after such an approach. No increase was found when the approacher was a kin or a subordinate individual. The tension-reduction function of allogrooming was also supported. Heart rate decelerated faster during the receipt of grooming than in matched control periods. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Humoral and cellular immune responses of dogs immunized with a nucleic acid vaccine encoding human carcinoembryonic antigen

A nucleic acid vaccine encoding human carcinoembryonic antigen (CEA) was administered to 10 juvenile dogs, 10-15 weeks of age, by four parenteral routes. The routes tested were intramuscular injection using a needle and syringe, intramuscular injection using the Biojector needleless injection device, intradermal injection or intravenous injection. All groups received 150 micrograms of plasmid DNA on weeks 0, 4, 7 and 13. All dogs were bled weekly for 17 weeks and tested for antibody against human CEA. Dogs given plasmid intramuscularly either by needle and syringe or Biojector showed significant antibody responses by week 9 which peaked by week 15. Dogs receiving plasmid intravenously showed slight, unsustained increases in antibody titers while dogs receiving plasmid intradermally had significant titers, but at levels approximately one log less than those induced by intramuscular injection. The five dogs immunized by intramuscular delivery of plasmid DNA were examined for cellular immune responses to human CEA by lymphoblast transformation (LBT) assay. All five showed significant CEA-specific lymphoproliferation when compared with unvaccinated dogs. Physical examination, clinical chemistry, hematology and histopathology examinations revealed no abnormalities associated with nucleic acid immunization.     

骨髓间充质干细胞静脉输注对猕猴细胞免疫功能的影响

目的 评价猕猴间充质干细胞( MSC)静脉异体输注后对细胞免疫功能的影响。方法分离培养MSC;不做其他处理,将异体MSC静脉输注给受者猴,通过定期监测外周血象、混合淋巴细胞反应( MLR)、T细胞亚群来判断MSC输注后受者细胞免疫功能的变化。结果成功培养了猕猴的MSC。异体MSC输注后,受者无明显毒性反应、排异表现及血象变化。可以在一定时间内（2周左右）抑制受者T细胞在MLR中的增殖活性,受者猴A2、A3及A4输注MSC的数量分别为4.0×105/kg、1.0×106/kg、2.0×106/kg,在输注后第14天时,MLR的相对反应值(RR)与输注前比较均明显降低,分别从(46.0±2.6)％、( 40.9±2.3)％、(48.3±2.0)％降至(40.4±1.73)％、(33.0±2.1)％、(39.0±1.0)％(F=1O.19,P=0.023;F=2.593,P= 0.013;F= 28.431,P=0.003),输注后第30天时RR均恢复到输注前水平;统计结果显示,抑制程度(△RR)与输注MSC数量呈正相关(F=27.413,P=0.038)。A4是输注MSC数量最多的受者,输注后第14天开始,外周血CD3+、CD3+ CD4+、CD3+CD8+细胞的百分比与输注前相比有所降低,在输注后第30天左右恢复至输注前水平。结论单纯体内输注异体MSC,可以在一定时间内抑制受者T细胞的免疫活性;免疫抑制程度与输注MSC数量呈正相关。MSC特殊的免疫学特性使其具有深远的临床应用价值。     

Comparative efficacy of experimental anthrax vaccine candidates against inhalation anthrax in rhesus macaques

The authors examined the efficacy of Bacillus anthracis protective antigen (PA) combined with adjuvants as vaccines against an aerosol challenge of virulent anthrax spores in rhesus macaques. Adjuvants tested included i) aluminum hydroxide (Alhydrogel), ii) saponin QS-21 and iii) monophosphoryl lipid A (MPL) in squalene/lecithin/Tween 80 emulsion (SLT). Animals were immunized once with either 50 micrograms of recombinant PA plus adjuvant, or with Anthrax Vaccine Adsorbed (AVA), the licensed human anthrax vaccine. The serological response to PA was measured by enzyme linked immunosorbent assay. Lymphocyte proliferation and serum neutralization of in vitro lethal toxin cytotoxicity were also assayed. In all vaccine groups, anti-PA IgM and IgG titers peaked at 2 weeks and 4-5 weeks postimmunization, respectively. Five weeks postimmunization, animals in all vaccine groups demonstrated PA-specific lymphocyte proliferation and sera that neutralized in vitro cytotoxicity. Six weeks after immunization, the animals were challenged by aerosol with approximately 93 LD50 of virulent anthrax spores. Animals were bled daily for 1 week to monitor bacteremia, and deaths were recorded. Anti-PA ELISA titers in all groups of immunized animals were substantially increased 2 weeks after challenge. One dose of each vaccine provided significant protection (> 90%) against inhalation anthrax in the rhesus macaques.     

The evolution of intergroup bias: Perceptions and attitudes in rhesus macaques.

Social psychologists have learned a great deal about the nature of intergroup conflict and the attitudinal and cognitive processes that enable it. Less is known about where these processes come from in the first place. In particular, do our strategies for dealing with other groups emerge in the absence of human-specific experiences? One profitable way to answer this question has involved administering tests that are conceptual equivalents of those used with adult humans in other species, thereby exploring the continuity or discontinuity of psychological processes. We examined intergroup preferences in a nonhuman species, the rhesus macaque (Macaca mulatta). We found the first evidence that a nonhuman species automatically distinguishes the faces of members of its own social group from those in other groups and displays greater vigilance toward outgroup members (Experiments 1–3). In addition, we observed that macaques spontaneously associate novel objects with specific social groups and display greater vigilance to objects associated with outgroup members (Experiments 4–5). Finally, we developed a looking time procedure—the Looking Time Implicit Association Test, which resembles the Implicit Association Test (Greenwald & Banaji, 1995)—and we discovered that macaques, like humans, automatically evaluate ingroup members positively and outgroup members negatively (Experiments 6–7). These field studies represent the first controlled experiments to examine the presence of intergroup attitudes in a nonhuman species. As such, these studies suggest that the architecture of the mind that enables the formation of these biases may be rooted in phylogenetically ancient mechanisms. (PsycINFO Database Record (c) 2011 APA, all rights reserved)