Progress and challenges in therapies for AIDS in nonhuman primate models

Efforts to develop animal models for human immunodeficiency virus type-1 (HIV-1) vaccine testing have focused on lentivirus infection of nonhuman primates. A long-term goal of this primate research is to utilize the models to understand the mechanisms of pathogenesis leading to AIDS. Because the time to disease is compressed relative to HIV infection in humans, therapeutic strategies and compounds can be tested in nonhuman primate models in a shorter time frame and under more controlled conditions than are possible in many clinical studies. Recent interventive studies in primates using antiviral drugs or passive immune globulin (IgG) have demonstrated that multiple log reductions in plasma virus can be achieved and sustained, with accompanying health benefits. Information gained about timing and dosage may be of utility in designing clinical studies. The development of reliable and predictable animal models for effective therapies and vaccines against AIDS remains a critical priority for primate research.     

毒素战剂的生防疫苗简

毒素战剂是重要的生物战剂之一,其最大的威胁来自它的高毒性和缺乏有效的防治手段。在毒素战剂中,肉毒毒素、志贺毒素、蓖麻毒素、相思子毒素等属于致死性生物战剂,葡萄球菌肠毒素B属于失能性生物战剂。生防疫苗作为毒素战剂的一种重要的有效预防手段,一直备受关注,但目前绝大部分毒素战剂的疫苗都还在研制中,随着分子生物学技术的快速发展,几种重要毒素战剂的重组疫苗研究已获得重要突破。我们重点介绍肉毒毒素、志贺毒素、蓖麻毒素、相思子毒素、葡萄球菌肠毒素B等毒素战剂生防疫苗的研究与发展。     

Preclinical AIDS vaccine research: survey of SIV,SHIV, and HIV challenge studies in vaccinated nonhuman primates

This current supplementary and systematic survey of 237 preclinical AIDS vaccine challenge/protection studies in nonhuman primates enumerates and broadly describes the recent status of different vaccine strategies in macaque and chimpanzee experimental models. Published studies since the previous survey were compiled and categorized by their vaccine types, challenge parameters, and challenge results. These models have supportively verified that some prophylactic vaccine approaches, though rarely preventing infection (which is observed in these models with some passively administered antibody-based vaccines), can control to some degree primate lentivirus replication and disease development, and this is encouraging because it places more potentially effective immunogens on the precipice for early clinical studies. Many of these promising approaches may benefit from more testing in mucosal challenge models, and resources will be needed to follow more of these partially protected vaccinees for longer periods.     

Antibodies for biodefense

Potential bioweapons are biological agents (bacteria, viruses and toxins) at risk of intentional dissemination. Biodefense, defined as development of therapeutics and vaccines against these agents, has seen an increase, particularly in the US, following the 2001 anthrax attack. This review focuses on recombinant antibodies and polyclonal antibodies for biodefense that have been accepted for clinical use. These antibodies aim to protect against primary potential bioweapons or category A agents as defined by the Centers for Disease Control and Prevention (Bacillus anthracis, Yersinia pestis, Francisella tularensis, botulinum neurotoxins, smallpox virus and certain others causing viral hemorrhagic fevers) and certain category B agents. Potential for prophylactic use is presented, as well as frequent use of oligoclonal antibodies or synergistic effect with other molecules. Capacities and limitations of antibodies for use in biodefense are discussed, and are generally applicable to the field of infectious diseases.Key words: antibody, anthrax, plague, smallpox, botulism, tularemia, brucellosis, hemorrhagic, ricin, SEB     

Generation of transgenic monkeys with human inherited genetic disease

Modeling human diseases using nonhuman primates including chimpanzee, rhesus, cynomolgus, marmoset and squirrel monkeys has been reported in the past decades. Due to the high similarity between nonhuman primates and humans, including genome constitution, cognitive behavioral functions, anatomical structure, metabolic, reproductive, and brain functions; nonhuman primates have played an important role in understanding physiological functions of the human body, clarifying the underlying mechanism of human diseases, and the development of novel treatments for human diseases. However, nonhuman primate research has been restricted to cognitive, behavioral, biochemical and pharmacological approaches of human diseases due to the limitation of gene transfer technology in nonhuman primates. The recent advancement in transgenic technology that has led to the generation of the first transgenic monkey in 2001 and a transgenic monkey model of Huntington’s disease (HD) in 2008 has changed that focus. The creation of transgenic HD monkeys that replicate key pathological features of human HD patients further suggests the crucial role of nonhuman primates in the future development of biomedicine. These successes have opened the door to genetic manipulation in nonhuman primates and a new era in modeling human inherited genetic disorders. We focused on the procedures in creating transgenic Huntington’s disease monkeys, but our work can be applied to transgenesis in other nonhuman primate species.     

In vitro manipulation of nonhuman primate gametes for embryo production and embryo transfer.

Since nonhuman primates are closely related to humans and share many physical similarities, they are important for use in research areas such as human infectious diseases, reproduction, physiology, endocrinology, metabolism, neurology and longevity. To develop and maintain these animals, we must establish techniques for in vitro manipulation of spermatozoa and eggs. For a decade my research group has been conducting basic research to establish embryo manipulation techniques and to clarify the reproductive phenomena in nonhuman primates. This article summarizes the past research on in vitro manipulation of nonhuman primate gametes, from collection of reproductive cells and in vitro fertilization to the birth of offspring after embryo transfer, as well as the current status of these research areas. The studies summarized here will directly lead to the development of standard techniques for practical and comprehensive use in nonhuman primates.     

Use of primates in research: a global overview

We assessed the use of nonhuman primates and nonhuman primate biological material in research by reviewing studies published in 2001 in peer-reviewed journals. The number and species of primates used, the origin of the animals, the type of study, the area of research of the investigation, and the location at which the research was performed were tabulated. Additionally, factors related to the animals that may have affected the outcome of the experiments were recorded. A total of 2,937 articles involving 4,411 studies that employed nonhuman primates or nonhuman primate biological material were identified and analyzed. More than 41,000 animals were represented in the studies published in 2001. In the 14% of studies for which re-use could be determined, 69% involved animals that had been used in previous experiments. Published studies most commonly used nonhuman primates or nonhuman primate biological material from the species Chlorocebus aethiops (19%), Macaca mulatta (18%), M. fascicularis (9%), and Papio spp. (6%). Of these studies, 54% were classified as in vitro studies, 14% as noninvasive, 30% as chronic, and 1% were considered acute. Nonhuman primates were primarily used in research areas in which they appear to be the most appropriate models for humans. The most common areas of research were microbiology (including HIV/AIDS (26%)), neuroscience (19%), and biochemistry/chemistry (12%). Most (84%) of the primate research published in 2001 was conducted in North America, Europe, and Japan. The animals and conditions under which they were housed and used were rarely described. Although it is estimated that nonhuman primates account for an extremely small fraction of all animals used in research, their special status makes it important to report the many husbandry and environmental factors that influence the research results generated. This analysis has identified that editors rarely require authors to provide comprehensive information concerning the subjects (e.g., their origin), treatment conditions, and experimental procedures utilized in the studies they publish. The present analysis addresses the use of primates for research, including the effects of a shortage of suitable nonhuman primate subjects in many research areas.     

Risk of occupationally acquired illnesses from biological threat agents in unvaccinated laboratory workers

Many vaccines for bioterrorism agents are investigational and therefore not available (outside of research protocol use) to all at-risk laboratory workers who have begun working with these agents as a result of increased interest in biodefense research. Illness surveillance data archived from the U.S. offensive biological warfare program (from 1943 to 1969) were reviewed to assess the impact of safety measures on disease prevention (including biosafety cabinets [BSCs]) before and after vaccine availability. Most laboratory-acquired infections from agents with higher infective doses (e.g., anthrax, glanders, and plague) were prevented with personal protective measures and safety training alone. Safety measures (including BSCs) without vaccination failed to sufficiently prevent illness from agents with lower infective doses in this high-risk research setting. Infections continued with tularemia (average 15/year), Venezuelan equine encephalitis (1.9/year), and Q fever (3.4/year) but decreased dramatically once vaccinations became available (average of 1, 0.6, and 0 infections per year, respectively). While laboratory-acquired infections are not expected to occur frequently in the current lower-risk biodefense research setting because of further improvements in biosafety equipment and changes in biosafety policies, the data help to define the inherent risks of working with the specific agents of bioterrorism. The data support the idea that research with these agents should be restricted to laboratories with experience in handling highly hazardous agents and where appropriate safety training and precautions can be implemented.     

增强DNA疫苗免疫应答的新进展

DNA疫苗为编码抗原蛋白的真核表达载体,注入体内后在原位表达所编码的抗原并诱导免疫应答,在预防感染、治疗自身免疫性疾病、过敏性疾病和肿瘤等疫病中有着很好的应用前景。但与灭活疫苗相比,其免疫效价还比较低。有多种策略能够增强或调节DNA疫苗诱导的免疫应答,其中,作为外源基因载体的质粒的组成及插入的有关基因均可直接或间接地影响免疫反应的效果,在构建DNA疫苗质粒时,加入细胞因子、融合信号、泛素等基因以及ISS序列,另外还可以通过设计一些对抗原提成细胞有影响的分子共注射,以及加入转移分子,都可以明显增强DNA疫苗的免疫效果,从而有利于研制更有效的DNA疫苗。     

Aotus monkeys: their great value for anti-malaria vaccines and drug testing

Non-human primates represent a valuable resource for testing potential vaccines candidates and drugs for human use. Malaria remains one of the greatest burdens for the humanity represented by approximately 500 million new clinical cases per year worldwide and at least two million deaths caused annually. Additional control measures such as vaccines and new anti-malarial compounds are therefore urgently needed. Safety and protective efficacy studies in animal models are critical steps for vaccines and drugs development and primate models are probably the most appropriate for this purpose. Although Aotus genus provides several species susceptible to both Plasmodium falciparum and Plasmodium vivax, having different susceptibility to malaria, Aotus lemurinus griseimembra represents the best current malaria primate model because of its high susceptibility to infection by blood forms and sporozoites of both species of Plasmodium. Although the ultimate validation of this model depends upon human trials, over the past two decades these monkeys have proved very useful to test multiple malaria vaccine candidates prior to trials in humans. A good correlation between the B- and T-cell epitopes recognised by humans and by immunised monkeys has been documented, and cross reactivity between reagents for human and Aotus cytokines and lymphocyte markers have been identified and are facilitating the selection of vaccine candidates for clinical trials. Aotus also represents a good model for the screening of anti-malarial drugs and the understanding of malaria pathogenesis as well. In view of the decreasing availability of these primates, breeding programs and biomedical research facilities must be improved in countries of primate origin.     

Nonhuman primate transgenesis: progress and prospects

The nonhuman primate is used extensively in biomedical research owing to its close similarities to human physiology and human disease pathophysiology. Recently, several groups have initiated efforts to genetically manipulate nonhuman primates to address complex questions concerning primate-specific development and physiological adaptation. Primates pose unique challenges to transgenesis and, although this field is still in its infancy, the potential for obtaining new insights into primate physiology and gene function is unprecedented. This review focuses on the methods and potential applications of genetically altered nonhuman primates in biomedical research.     

Antibodies for biodefense

Potential bioweapons are biological agents (bacteria, viruses, and toxins) at risk of intentional dissemination. Biodefense, defined as development of therapeutics and vaccines against these agents, has seen an increase, particularly in the US following the 2001 anthrax attack. This review focuses on recombinant antibodies and polyclonal antibodies for biodefense that have been accepted for clinical use. These antibodies aim to protect against primary potential bioweapons, or category A agents as defined by the Centers for Disease Control and Prevention (Bacillus anthracis, Yersinia pestis, Francisella tularensis, botulinum neurotoxins, smallpox virus, and certain others causing viral hemorrhagic fevers) and certain category B agents. Potential for prophylactic use is presented, as well as frequent use of oligoclonal antibodies or synergistic effect with other molecules. Capacities and limitations of antibodies for use in biodefense are discussed, and are generally applicable to the field of infectious diseases.     

炭疽疫苗及治疗药物筛选和评价模型研究进展

炭疽疫苗和治疗药物的研究是近年来国际上研究热点之一,由于对它们的有效性研究不能在人体进行,因此实验模型的选择就特别重要.目前常用的细胞模型主要包括CHO细胞和J774A.1细胞.动物模型种类较多,包括小鼠、大鼠、豚鼠、兔和猴等都被作为炭疽的动物模型加以研究.由于模型选择的差异,实验结果常出现较大差异,甚至得到相反的结果.回顾了以往在细胞和动物模型上进行的炭疽实验,分析选择炭疽研究模型的原则和依据.同时,为探讨不同模型之间产生实验结果差异的原因,简要介绍了炭疽杆菌的致病机理,以及炭疽疫苗和治疗药物的研究进展.     

Nonhuman primate infections after organ transplantation

Nonhuman primates, primarily rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), and baboons (Papio spp.), have been used extensively in research models of solid organ transplantation, mainly because the nonhuman primate (NHP) immune system closely resembles that of the human. Nonhuman primates are also frequently the model of choice for preclinical testing of new immunosuppressive strategies. But the management of post-transplant nonhuman primates is complex, because it often involves multiple immunosuppressive agents, many of which are new and have unknown effects. Additionally, the resulting immunosuppression carries a risk of infectious complications, which are challenging to diagnose. Last, because of the natural tendency of animals to hide signs of weakness, infectious complications may not be obvious until the animal becomes severely ill. For these reasons the diagnosis of infectious complications is difficult among post-transplant NHPs. Because most nonhuman primate studies in organ transplantation are quite small, there are only a few published reports concerning infections after transplantation in nonhuman primates. Based on our survey of these reports, the incidence of infection in NHP transplant models is 14%. The majority of reports suggest that many of these infections are due to reactivation of viruses endemic to the primate species, such as cytomegalovirus (CMV), polyomavirus, and Epstein-Barr virus (EBV)-related infections. In this review, we address the epidemiology, pathogenesis, role of prophylaxis, clinical presentation, and treatment of infectious complications after solid organ transplantation in nonhuman primates.     

Anthrax vaccine design: strategies to achieve comprehensive protection against spore,bacillus, and toxin

The successful use of Bacillus anthracis as a lethal biological weapon has prompted renewed research interest in the development of more effective vaccines against anthrax. The disease consists of three critical components: spore, bacillus, and toxin, elimination of any of which confers at least partial protection against anthrax. Current remedies rely on postexposure antibiotics to eliminate bacilli and pre- and postexposure vaccination to target primarily toxins. Vaccines effective against toxin have been licensed for human use, but need improvement. Vaccines against bacilli have recently been developed by us and others. Whether effective vaccines will be developed against spores is still an open question. An ideal vaccine would confer simultaneous protection against spores, bacilli, and toxins. One step towards this goal is our dually active vaccine, designed to destroy both bacilli and toxin. Existing and potential strategies towards potent and effective anthrax vaccines are discussed in this review.     

Towards an AIDS vaccine: the role of nonhuman primates

Over the last 10 years, about 20 human immunodeficiency virus (HIV) vaccine candidates have been tried in humans, with disappointing results as gauged by limited immune responses or protection against infection. These difficulties suggest that a new strategy is needed to test systematically new vaccine candidates. That opportunity is now afforded by nonhuman primate models with SIV, which have been shown to provide an excellent mirror of HIV infection in humans. The recent introduction of SHIVs, chimeric viruses that carry the HIV envelope and are able to infect and cause AIDS in monkeys, also has added an important additional research tool. These models can be used to address a series of questions, including the following: (1) Can protection be provided by partial immunity or is sterilizing immunity required? (2) What are the immune parameters that best predict protection against a potentially pathogenic challenge? (3) What role does mucosal immunity play and can it be induced by practical modes of immunization? (4) Can an attenuated virus be selected that is both protective and safe? An orderly strategy for the evaluation of vaccine candidates could be adopted that would involve several phases: (a) the selection of a limited set of challenge models, ranging from very severe to mild and requiring consideration of primate species, age, route of infection, and challenge viruses; (b) the assessment of candidate vaccines using comparable virus challenges; and (c) accelerated testing in humans of any candidate vaccines that have met a 'proof of efficacy' in primates.     

Eye-tracking with nonhuman primates is now more accessible than ever before

Human and nonhuman primates rely almost exclusively on vision for social communication. Therefore, tracking eye movements and examining visual scan paths can provide a wealth of information about many aspects of primate social information processing. Although eye-tracking techniques have been utilized with humans for some time, similar studies in nonhuman primates have been less frequent over recent decades. This has largely been owing to the need for invasive manipulations, such as the surgical implantation of devices to limit head movement, which may not be possible in some laboratories or at some universities, or may not be congruent with some experimental aims (i.e., longitudinal studies). It is important for all nonhuman primate researchers interested in visual information processing or operant behavior to realize that such invasive procedures are no longer necessary. Here, we briefly describe new methods for fully noninvasive video eye-tracking with adult rhesus monkeys (Macaca mulatta). We also describe training protocols that require only ～30 days to accomplish and quality control measures that promote reliable data collection. It is our hope that this brief overview will reacquaint nonhuman primate researchers with the benefits of eye-tracking and promote expanded use of this powerful methodology.     

灵长类比较基因组学的研究进展

随着人类和黑猩猩全基因组测序工作宣布完成,以及其他灵长类基因组测序工作的逐步开展,目前已经积累了大量的灵长类基因组数据,一个崭新的研究领域——灵长类比较基因组学应运而生。该文主要通过对人类和其他非人灵长类系统关系和基因组结构的比较,从系统进化、基因组结构和基因表达调控等方面评述该领域的研究进展,阐述人类、黑猩猩与其他非人灵长类之间的主要生物学差异,揭示人类进化的生物学机制。     

An overview of biohazards associated with nonhuman primates

Because of their close phylogenetic relationship, human and nonhuman primates share susceptibility to many pathogens which do not affect lower animals. This similarity, which makes them invaluable models for studying human infectious diseases, also makes primate animals potentially dangerous to work with. The biohazards inherent in the use of nonhuman primates in biomedical research are zoonoses, injuries, and infectious agents introduced by study protocols. This review addresses the various kinds of parasites, fungi, rickettsiae, spirochetes, and viral agents found naturally occurring, or experimentally induced, in nonhuman primates with reference to measures for preventing spread among the animals or to personnel.