Evaluation of recombinant Kunjin replicon SIV vaccines for protective efficacy in macaques

Persistent gag-specific T cell immunity would be a useful component of an effective HIV vaccine. The Flavivirus Kunjin replicon was previously engineered to persistently express HIV gag and was shown to induce protective responses in mice. We evaluated Kunjin replicon virus-like-particles expressing SIVgag-pol in pigtail macaques. Kunjin-specific antibodies were induced, but no SIV-specific T cell immunity were detected. Following SIVmac251 challenge, there was no difference in SIV viremia or retention of CD4 T cells between Kunjin-SIVgag-pol vaccine immunized animals and controls. An amnestic SIV gag-specific CD8 T cell response associated with control of viremia was observed in 1 of 6 immunized animals. Refinements of this vector system and optimization of the immunization doses, routes, and schedules are required prior to clinical trials.     

Delivery of immunotherapy with peptide-pulsed blood in macaques

Simple and effective delivery methods for cellular immunotherapies are needed. We assessed ex vivo pulsing of overlapping SIV Gag 15mer peptides onto either whole blood or PBMC in 15 randomly assigned SIV-infected macaques. Both delivery methods were safe and immunogenic, stimulating high levels of broad and polyfunctional Gag-specific CD4 and CD8 T cells. Delivery of overlapping Gag peptides via either whole blood or PBMC is suitable for clinical evaluation.     

实验猕猴B病毒抗体检测结果分析

目的 研究实验猕猴B病毒抗体阳性情况。方法 选取安徽省实验猕猴中心400只猕猴,各采集静脉血5 mL,3 000 r/min离心10 min后,抽取上层血清,采用酶联免疫吸附试验与免疫酶试验检测血清B病毒抗体,观察B病毒抗体阳性率。结果 400份有效样本中,B病毒抗体阳性率为36.50%;雌性猕猴B病毒抗体阳性率为36.74%,雄性为为36.22%,两者差异无统计学意义（χ²=0.012,P=0.913）。幼年猕猴B病毒抗体阳性率为30.68%,青年猕猴B病毒抗体阳性率为32.34%,成年猕猴B病毒抗体阳性率为66.67%,差异有统计学意义（χ²=26.200,P=0.000）。结论 实验猕猴B病毒抗体阳性率处于较高水平,雌性猕猴B病毒抗体阳性率高于雄性猕猴,成年猕猴B病毒抗体阳性率较高。因此,需加强实验猕猴的管理,以减少B病毒感染,生产出安全性更高的实验猕猴。     

Protection of non-human primates against glanders with a gold nanoparticle glycoconjugate vaccine

The Gram-negative Burkholderia mallei is a zoonotic pathogen and the causative agent of glanders disease. Because the bacteria maintain the potential to be used as a biothreat agent, vaccine strategies are required for human glanders prophylaxis. A rhesus macaque (Macaca mulatta) model of pneumonic (inhalational) glanders was established and the protective properties of a nanoparticle glycoconjugate vaccine composed of Burkholderia thailandensis LPS conjugated to FliC was evaluated. An aerosol challenge dose of ∼1 × 10⁴ CFU B. mallei produced mortality in 50% of naïve animals (n = 2/4), 2–3 days post-exposure. Although survival benefit was not observed by vaccination with a glycoconjugate glanders vaccine (p = 0.42), serum LPS-specific IgG titers were significantly higher on day 80 in 3 vaccinated animals who survived compared with 3 vaccinated animals who died. Furthermore, B. mallei was isolated from multiple organs of both non-vaccinated survivors, but not from any organs of 3 vaccinated survivors at 30 days post-challenge. Taken together, this is the first time a candidate vaccine has been evaluated in a non-human primate aerosol model of glanders and represents the initial step for consideration in pre-clinical studies.     

Virus replication and disease progression inversely correlate with SIV tat evolution in morphine-dependent and SIV/SHIV-infected Indian rhesus macaques

We analyzed the association between evolution of the 5' exon of tat and disease progression in an SIV/SHIV macaque model of opiate dependence and AIDS. Cloned tat sequences were obtained by RT-PCR amplification of 3 plasma viruses (recovered at different times) from 6 morphine-dependent and 2 control Indian rhesus macaques inoculated with SHIV(KU-1B) SHIV(89.6P) and SIV/17E-Fr. Approximately ten clones were sequenced for each animal per time point for use in phylogenetic analyses. We found a strong, significant inverse correlation between disease progression and tat diversity in plasma by 20 weeks post-infection. The morphine-dependent macaques developed 2 distinct disease patterns - rapid progressor (Group A) and slow progressor (Group B) - whereas control animals developed into slow progressor only (Group C). The three animals in Group A exhibited approximately 40% (P = 0.01) and approximately 50% (P = 0.028) less diversity than Group B and C animals, respectively, over the 20 weeks. Furthermore, the Group A macaques showed a prominent reemergence of the wild-type SV17E tat sequence used in the inoculum that coincided with disease progression. This suggests that the virus from the original infection represented the most pathogenic form among all animals in these cohorts throughout the first 20 weeks of infection. We were unable to support or rule out a role for immune pressure on tat evolution based on the spectrum of sequence changes in the data set. Thus, in the short duration of this study, the Tat-specific immune pressure cannot explain the different disease outcomes of the six morphine animals nor of the two controls. Our results also suggest that in vivo morphine dependence can contribute to the pathogenesis of SIV/SHIV infection and that it may do so in conjunction with the evolution of viral proteins, such as Tat.     

Prevention of pneumonic plague in mice, rats, guinea pigs and non-human primates with clinical grade rV10, rV10-2 or F1-V vaccines

Yersinia pestis causes plague, a disease with high mortality in humans that can be transmitted by fleabite or aerosol. A US Food and Drug Administration (FDA)-licensed plague vaccine is currently not available. Vaccine developers have focused on two subunits of Y. pestis: LcrV, a protein at the tip of type III secretion needles, and F1, the fraction 1 pilus antigen. F1-V, a hybrid generated via translational fusion of both antigens, is being developed for licensure as a plague vaccine. The rV10 vaccine is a non-toxigenic variant of LcrV lacking residues 271-300. Here we developed Current Good Manufacturing Practice (cGMP) protocols for rV10. Comparison of clinical grade rV10 with F1-V did not reveal significant differences in plague protection in mice, guinea pigs or cynomolgus macaques. We also developed cGMP protocols for rV10-2, a variant of rV10 with an altered affinity tag. Immunization with rV10-2 adsorbed to aluminum hydroxide elicited antibodies against LcrV and conferred pneumonic plague protection in mice, rats, guinea pigs, cynomolgus macaques and African Green monkeys. The data support further development of rV10-2 for FDA Investigational New Drug (IND) authorization review and clinical testing.     

Lack of acute alcohol effects on estradiol and luteinizing hormone in female macaque monkey

The effects of alcohol (1.5, 2.5, 3.5 g/kg) on 17-β estradiol and LH were evaluated in adult female Macaque monkeys. Integrated plasma samples were collected prior to and following nasogastric intubation of alcohol or isocaloric sucrose control solutions. Samples were collected at 30 minute intervals over 240 minutes. Each alcohol dose and control was studied at menstruation, the peri-ovulatory and mid-luteal periods and the premenstruum. After low, moderate and high doses of alcohol, blood alcohol levels (BAL) averaged 140, 260 and 344 mg/dl at the peak of the ascending BAL curve. Despite high blood alcohol levels, there was no evidence of alcohol dose-related suppression of LH or 17-β estradiol at any phase of the menstrual cycle. These data are consistent with our findings in human females that acute alcohol intoxication did not suppress LH or estradiol. The apparent resiliency of human and Macaque females to acute alcohol effects on reproductive hormones contrasts sharply with data obtained in males that alcohol significantly suppresses testosterone in all species studied.     

In vivo inactivation of Nef ITAM motif of chimeric simian/human immunodeficiency virus SHIVsbg-YE correlates with absence of increased virulence in Chinese rhesus macaques

SHIVsbg, expressing Vpu, Tat, Rev, and Env proteins of HIV-1 Lai, was shown to be infectious for rhesus macaques. In this study, we mutated SHIVsbg Nef amino acids 17-18 from RQ to YE, conferring to SHIVsbg-YE the ability to replicate in vitro in unstimulated macaque PBMC. Juvenile macaques inoculated intravenously or orally with SHIVsbg-YE developed persistent infection. All macaques lost weight during the first 17 weeks but recovered afterward. All animals developed a strong HIV-specific humoral immune response. Viruses isolated 2 years postinoculation lost the ability to replicate in unstimulated macaque PBMC. Point mutations or 33-bp-wide deletions in the nef ITAM motif were responsible for this phenotype and correlated with clinical improvement of the infected macaques. These data demonstrate that the ITAM domain is inactivated in animals developing an acute antiviral immune response and may be detrimental to viral replication, perhaps by interfering with other well-conserved functions of SIV Nef protein.