[Sleep quality and sleep disturbances in Chinese pregnant women: a multicenter cross-sectional study]

Objective: This study aims to investigate the sleep quality of pregnant women in Xuhui District, Shanghai, and the related factors of sleep disturbances during pregnancy. Methods: From February 2019 to February 2021, we used online integrated sleep questionnaire (including PSQI, BQ, ESS, AIS) in Shanghai Jiao Tong University School of Medicine Affiliated Sixth People's Hospital, The International Peace Maternity and Child Health Hospitals of China Welfare Institution, and Shanghai Eighth People's Hospital, to investigate the sleep quality across pregnancy. We also collected maternal physical examination results, childbearing history, sociodemographic, and other clinical data. The prevalences and related factors of various sleep disturbances in pregnant women were analyzed, including insufficient/excessive nighttime sleep, low sleep efficiency, difficulty falling asleep, poor sleep quality, insomnia, daytime sleepiness, and high risk of sleep-disordered breathing (SDB). Results: This study includes 1 898 cases in the first trimester (T1), 3 099 cases in the second trimester (T2), and 1 539 cases in the third trimester (T3). Poor sleep quality (38.6%), daytime sleepiness (mild 41.9%, moderate 17.7%, severe 2.1%), and suspicious insomnia (32.3%) are most prevalent among women in T1 (P<0.01). In comparison, short sleep time (2.7%), long sleep time (8.6%), difficulty falling asleep (12.2%), poor sleep efficiency (35.4%), very poor sleep quality (6.7%), clinical insomnia (21.8%), and high-risk SDB (6.4%) are most prevalent among women in T3 (P<0.05). During pregnancy, late gestation (OR=1.016, 95%CI: 1.006-1.025) and multiple induced/drug abortions (OR=1.329, 95%CI: 1.043-1.692) are risk factors for poor sleep quality (PSQI>5), while multiple full-term deliveries (OR=0.800, 95%CI: 0.675-0.949) is its protective factor. Advanced maternal age (OR=0.976, 95%CI: 0.956-0.997), multiple full-term deliveries (OR=0.808, 95%CI: 0.680-0.959), late gestation (OR=0.983, 95%CI: 0.974-0.992) and hypertension (OR=0.572, 95%CI: 0.401-0.814) are protective factors for daytime sleepiness (ESS>6). The high-risk pregnancy category (OR=9.312, 95%CI: 1.156-74.978) is a risk factor for insomnia (AIS≥4), while multiple full-term deliveries (OR=0.815, 95%CI: 0.691-0.961) is its protective factor. High BMI (OR=1.334, 95%CI: 1.270-1.402) and hypertension (OR=4.427, 95%CI: 2.539-7.719) are risk factors for high-risk SDB in pregnant women. Conclusions: The prevalences of various sleep disturbances are high throughout pregnancy. Noticeably, symptoms of maternal SDB develop along with pregnancy. Different types of sleep disturbances are associated with different factors. Women of high-risk pregnancy category, in late gestation, with high BMI, hypertension, a history of induced/drug abortion, or without a history of full-term delivery can be at high risk of sleep disturbances during pregnancy.

Application of Quantitative Analysis of Diatoms in Lung Tissue for the Diagnosis of Drowning of Experimental Animals

Abstract

Objective To discuss the application value of diatom examination in lung tissue for the forensic diagnosis of drowning. Methods The experimental animals were divided randomly into drowning, postmortem submergence and dying on land group. Diatoms in lung tissue and drowning fluid were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy diatom examination method. The ratios of content of diatoms in lung tissue and drowning fluid （C_L/C_D ratio） were recorded. Results The C_L/C_D ratios of experimental rabbits in the drowning group （5.82±3.50） were much higher than that of postmortem submergence group （0.47±0.35）; the C_L/C_D ratios of different parts of the lung lobes of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）; in seawater, brackish water, river fresh water and lake fresh water, the C_L/C_D ratios of experimental pigs in the drowning group were higher than that of postmortem submergence group （P<0.05）. In animal experiments, all the cases with C_L/C_D ratio >1.6 were from drowning group. Conclusion C_L/C_D ratio is an indicator with good application prospects in the diagnosis of drowning.

Hepatitis C virus cure with direct acting antivirals: Clinical, economic, societal and patient value for China

About 10 million people in China are infected with hepatitis C virus (HCV), with the seroprevalence of anti-HCV in the general population estimated at 0.6%. Delaying effective treatment of chronic hepatitis C (CHC) is associated with liver disease progression, cirrhosis, hepatocellular carcinoma, and liver-related mortality. The extrahepatic manifestations of CHC further add to the disease burden of patients. Managing CHC-related advanced liver diseases and systemic manifestations are costly for both the healthcare system and society. Loss of work productivity due to reduced well-being and quality of life in CHC patients further compounds the economic burden of the disease. Traditionally, pegylated-interferon plus ribavirin (PR) was the standard of care. However, a substantial number of patients are ineligible for PR treatment, and only 40%-75% achieved sustained virologic response. Furthermore, PR is associated with impairment of patient-reported outcomes (PROs), high rates of adverse events, and poor adherence. With the advent of direct acting antivirals (DAAs), the treatment of CHC patients has been revolutionized. DAAs have broader eligible patient populations, higher efficacy, better PRO profiles, fewer adverse events, and better adherence rates, thereby making it possible to cure a large proportion of all CHC patients. This article aims to provide a comprehensive evaluation on the value of effective, curative hepatitis C treatment from the clinical, economic, societal, and patient experience perspectives, with a focus on recent data from China, supplemented with other Asian and international experiences where China data are not available.

[Effects and underlying mechanism of berberine on renal tubulointerstitial injury in diabetic rats]

Objective: To investigate the effect of Berberine on renal tubulointerstitial injury and its potential mechanism in rats with type 2 diabetes mellitus (T2DM). Methods: Thirty Sprague-Dawley rats were randomly divided into 3 groups: normal control rats (NC group), diabetic rats without drug treatment (DM group), diabetic rats treated with Berberine (BBR group) for 8 weeks. At the end of the study, blood and urine samples were collected for biochemical examination, and tubulointerstitial fibrosis was quantified by Hematoxylin and Eosin (HE) and Masson staining. The expressions of E-cadherin (E-cad), α-smooth muscle actin (α-SMA), nuclear factor-κB (NF-κB) and monocyte chemoattractant protein 1 (MCP-1) were detected by immunohistochemistry analysis, real-time polymerase chain reaction (RT-PCR) and Western blot analysis. Results: 24 h urinary microalbumin (mAlb)[(170.5±58.1) vs (253.7±53.0) mg]and urinary N-acetyl-glucosaminidase (NAG)[(33.5±7.2) vs (49.5±9.3)U/L]in diabetic rats were significantly decreased by BBR treatment(both P<0.05). The apparent renal tubulointerstitial injury was found in the DM group, which was ameliorated by BBR treatment. The expression of α-SMA, NF-κB and MCP-1 were significantly decreased, accompanied by increased expression of E-cad in BBR-treated DM rats (all P<0.05). Conclusion: BBR could ameliorate renal tubulointerstitial injury in diabetic rats, the mechanism of which may be associated with the amelioration of epithelial-mesenchymal transition (EMT) through suppressing the expression of the NF-κB and MCP-1.

[Research Progress on Determination of Drowning Site]

The bodies found in water are one of the most common types in forensic practice. The discovery site of the body is often not the drowning site. However, the determination of drowning site is vital for the identification of victim. Inorganic particles and planktons, such as granular impurities, diatoms and bacteria, are valuable markers for the diagnosis of drowning. By comparing the granular impurities and planktons in tissues and suspicious drowning mediums, the drowning site can be concluded based on their similarity of types and distribution, which has practical applied value. In this paper, the research progress on determination of drowning site is summarized to provide reference for the peers.

[Ultrastructural alteration of extraocular muscle proprioceptor in congenital idiopathic nystagmus]

Objective: To explore the ultrastructural alteration of extraocular muscle proprioceptor in congenital idiopathic nystagmus (CIN). Methods: Case-control study. Ten extraocular muscle samples were collected from five CIN children who underwent nystagmus surgeries in Beijing Children's Hospital from March 2015 to March 2016. Another ten extraocular muscle specimens were collected from five strabismus children in surgery at the same period as normal contrast. There were 3 male patients and 2 female patients of CIN with age of 61-147 months (median age: 91 months). The ultrastructure of extraocular muscle proprioceptors was compared between these two groups by transmission electron microscope. Results: Twenty-three proprioceptors were found in extraocular muscle specimens of CIN children, whereas thirty-three proprioceptors were detected in strabismus children. The ultrastructure of extraocular muscle proprioceptor of CIN altered greatly comparing with that of the control. Fourteen extraocular muscle proprioceptors of CIN were discovered much smaller and vacuolated not only at inner capsules but also at the space between inner and outer capsules with lipofuscins and myeloid bodies in the intrafusal muscle fibers. Sensory nerve fibers degenerated greatly with a lot of lipofuscins and myeloid bodies in these sensory nerve fibers. Demyelination also appeared in some severe cases. Nine extraocular muscle proprioceptors of CIN showed significant dissolving degeneration of myofibrils and proliferation of collagen fibrils. The normal structures could not be distinguished in these proprioceptors. And these structural disorders also appeared in extrafusal muscle fibers and nerve endings. Conclusion: The ultrastructure of extraocular muscle proprioceptor in CIN turned much smaller and had significantly structural disorder.(Chin J Ophthalmol, 2017, 53: 136-139).

[Using the concept of universal health coverage to promote the health system reform in China]

The paper is systematically explained the definition, contents of universal health coverage (UHC). Universal health coverage calls for all people to have access to quality health services they need without facing undue financial burden. The relationship between five main attributes, i.e., quality, efficiency, equity, accountability and resilience, and their 15 action plans has been explained. The nature of UHC is belonged to the State and government. The core function is commitment with equality. The whole-of-system method is used to promoting the health system reform. In China, the universal health coverage has been reached to the preliminary achievements, which include universal coverage of social medical insurance, basic medical services, basic public health services, and the provision of essential medicines. China has completed millennium development goals (MDG) and is being stepped to the sustainable development goals (SDG).

Total hip replacement for developmental dysplasia of hip and postoperative nursing

This study was designed to determine the clinical effect of total hip replacement for the treatment of developmental dysplasia of the hip (DDH) and analyze the postoperative nursing. Sixty patients (78 hips) aged 18-75 years (average 58.6±2.31 years) who received total hip replacement for treatment of DDH at the Zhengzhou People’s Hospital, Henan, China, from April 2013 to June 2016 were selected as research subjects. Twenty-four patients were male (30 hips) and 36 were female (48 hips). Of the 60 patients, according to Crowe typing, 24 were type I (30 hips), 26 were type II (34 hips), 6 were type III (8 hips) and 4 were type IV (6 hips). According to the Harris hip score system, the score of all hips was 39.46±3.56 points average (18-56 points) before treatment and resulted as 89.60±4.25 points (79-98 points) at the last follow-up, showing a statistically significant difference (P < 0.05). Complications such as wound infection, dislocation, fracture of femoral shaft, femoral nerve and injury of sciatic nerve were not found after treatment. A total of 48 cases (58 hips) obtained excellent curative results (93.33% recovery), 8 cases (14 hips) good (92.31% recovery), and 4 cases (6 hips) medium. Total hip replacement proved to be effective in treating DDH and secondary osteoarthritis. Moreover, soft tissue release and an optimum degree recovery of anatomic form and physiological function of the diseased hip is an important basis for reconstructing the acetabulum and stabilizing acetabulum prosthesis.

[Meta-analysis of anti-GP210 antibody and anti-SP100 antibody detection for diagnosis of primary biliary cirrhosis]

OBJECTIVE

To conduct a systematic review of studies assessing the association of anti-GP210 antibody and anti-SP100 antibody with diagnosis of primary biliary cirrhosis (PBC) using meta-analysis.

METHODS

Five research literature databases, including the Cochrane Library, MEDLINE, VIP, CNKI and WanFang, were searched for studies of anti-GP210 antibody and anti-SP100 antibody in diagnosis of PBC. Meta-disc statistical software was used for analysis.

RESULTS

The meta-analysis included a total of 25 studies on anti-GP210 antibody and 21 studies on anti-SP100 antibody. The diagnostic odds ratio, sensitivity, and specificity of anti-GP210 antibody for diagnosis of PBC were 24.854 (11.957-51.660), 0.272 (0.257-0.288), and 0.985 (0.982-0.988), respectively, and for anti-SP100 antibody they were 9.133 (4.739-17.600), 0.231 (0.213-0.249), and 0.977 (0.973-0.981), respectively.

CONCLUSIONS

Both anti-GP210 antibody and anti-SP100 antibody show high specificity but low sensitivity in diagnosis of PBC.

Adenovirus-mediated delivery of soluble ST2 attenuates ovalbumin-induced allergic asthma in mice

Allergic asthma is associated with excessive T helper type 2 (Th2) cells activation and airway hyperreactivity (AHR), implicated in the context of significant morbidity and mortality. Soluble ST2, a member of the interleukin (IL)-1 receptor family, has been shown to play a critical role in modulation of inflammatory disorders, yet the function of soluble ST2 in allergic inflammation remains unclear. In this study, we examined the possibility of regulating ovalbumin (OVA)-challenged airway inflammation by recombinant adenovirus-mediated sST2-Fc (Ad-sST2-Fc) gene transfer. Single intranasal administration of Ad-sST2-Fc before allergen challenge in OVA-immunized mice profoundly reduced serum immunoglobulin (Ig)E secretion, eosinophil infiltration and concentrations of IL-4, IL-5 and IL-13 in bronchoalveolar lavage fluid compared with administration of a control Ad vector. Histopathological examination of the lungs revealed that sST2-Fc over-expression markedly suppressed allergen-induced peribronchial inflammation and disruption of the alveolar architecture. Moreover, the beneficial effect of sST2-Fc in allergic lung inflammation is related to blocking the IL-33/ST2L signalling. Taken together, these results suggested that administration of Ad-sST2-Fc gene transfer may have therapeutic potential for the immunomodulatory treatment of OVA-mediated allergic pulmonary diseases.

Adenovirus-mediated overexpression of soluble ST2 provides a protective effect on lipopolysaccharide-induced acute lung injury in mice

Acute lung injury is characterized by a diffuse inflammatory parenchymal process, implicated in the context of significant morbidity and mortality. Previously, we have reported that soluble ST2 (sST2), a member of the Toll-interleukin (IL)-1 receptor (TIR) superfamily, represses proinflammatory cytokine production of macrophage exposed to lipopolysaccharide (LPS). In this study, we examined the possibility of modulating LPS-induced murine inflammatory pulmonary damage by recombinant adenovirus-mediated sST2-Fc (Ad-sST2-Fc) gene transfer. Single intranasal administration of Ad-sST2-Fc led to a profound decrease in LPS-induced bronchoalveolar lavage leucocyte exudation and lung tissue myeloperoxidase activity (reflecting phagocyte infiltration). Histological examination revealed alveolitis with inflammatory cell infiltration and alveolar haemorrhage in the alveolar airspace was less severe in Ad-sST2-Fc-treated mice when compared with control groups. In addition, high levels of sST2-Fc in vivo reduced the transcription of tumour necrosis factor-α, IL-6 and Toll-like receptor-4 gene remarkably, and suppressed the nuclear translocation of nuclear factor-κB in lung tissues in response to LPS challenge. Taken together, these results suggested that administration of Ad-sST2-Fc gene transfer may have therapeutic potential for the immunomodulatory treatment of LPS-mediated inflammatory lung injury.

Hyperbaric oxygen preconditioning protects against traumatic brain injury at high altitude

BACKGROUND

Recent studies have shown that preconditioning with hyperbaric oxygen (HBO) can reduce ischemic and hemorrhagic brain injury. We investigated effects of HBO preconditioning on traumatic brain injury (TBI) at high altitude and examined the role of matrix metalloproteinase-9 (MMP-9) in such protection.

METHODS

Rats were randomly divided into 3 groups: HBO preconditioning group (HBOP; n = 13), high-altitude group (HA; n = 13), and high-altitude sham operation group (HASO; n = 13). All groups were subjected to head trauma by weight-drop device, except for HASO group. HBOP rats received 5 sessions of HBO preconditioning (2.5 ATA, 100% oxygen, 1 h daily) and then were kept in hypobaric chamber at 0.6 ATA (to simulate pressure at 4000m altitude) for 3 days before operation. HA rats received control pretreatment (1 ATA, room air, 1 h daily), then followed the same procedures as HBOP group. HASO rats were subjected to skull opening only without brain injury. Twenty-four hours after TBI, 7 rats from each group were examined for neurological function and brain water content; 6 rats from each group were killed for analysis by H&E staining and immunohistochemistry.

RESULTS

Neurological outcome in HBOP group (0.71 +/- 0.49) was better than HA group (1.57 +/- 0.53; p < 0.05). Preconditioning with HBO significantly reduced percentage of brain water content (86.24 +/- 0.52 vs. 84.60 +/- 0.37; p < 0.01). Brain morphology and structure seen by light microscopy was diminished in HA group, while fewer pathological injuries occurred in HBOP group. Compared to HA group, pretreatment with HBO significantly reduced the number of MMP-9-positive cells (92.25 +/- 8.85 vs. 74.42 +/- 6.27; p < 0.01).

CONCLUSIONS

HBO preconditioning attenuates TBI in rats at high altitude. Decline in MMP-9 expression may contribute to HBO preconditioning-induced protection of brain tissue against TBI.

Generation of a velogenic Newcastle disease virus from cDNA and expression of the green fluorescent protein

Newcastle disease virus (NDV) is a pathogen that is important in the poultry industry worldwide. Specifically, the virulent (velogenic) NDV is a particular threat because it has now occurred frequently worldwide. The outbreaks caused by highly virulent NDV in waterfowl and especially in goose flocks, have led to greater concern in recent years as aquatic birds were previously resistant to most virulent NDV strains from chickens. The molecular determinants of host tropism, virulence and emergence of NDV isolated from diseased goose flocks are poorly understood. In the present study, we rescued a highly virulent NDV isolated from a goose using the reverse genetics approach. Infectious virus was successfully generated by cotransfection of a full-length cDNA clone of the NDV strain ZJ1 with helper plasmids. The recombinant NDV was indistinguishable from the parental wild-type virus with respect to its growth kinetics in cell culture as well as its biological properties. A recombinant NDV expressing green fluorescent protein (GFP) was generated, and GFP was subsequently detected in cells and various organs from the infected chickens.

Ribavirin monotherapy for hepatitis C virus-associated membranous nephropathy

Glomerular diseases associated with hepatitis C virus (HCV) infection are increasingly being recognized. Antiviral therapy with interferon-alpha (IFN-alpha) and ribavirin eradicate viral activity in a significant proportion of patients with chronic active hepatitis, often with amelioration of extrahepatic manifestations, including glomerular pathology. Unfortunately, adverse effects often preclude the use of IFN-alpha. We describe a patient with refractory nephrotic syndrome secondary to HCV-associated membranous nephropathy who sustained a complete remission following the initiation of ribavirin monotherapy. The existing literature on the association between these two disorders and therapy with ribavirin is reviewed.

Mosaics of gene variations in the Interleukin-10 gene promoter affect interleukin-10 production depending on the stimulation used

Interleukin-10 (IL-10), a cytokine involved in many aspects of the immune response shows interindividual variations in their expression. However, genetic variations of the 5'-flanking region of the IL-10 gene (PIL-10) are poorly characterised with respect to different stimuli. New extended haplo- and genotypes are identified present at differing frequencies in three geographically separated populations. Their influence on IL-10 expression have been assessed in vitro after stimulation of leukocytes with lipopolysaccharide (LPS), dibutyryl-cAMP or following immortalisation with Epstein-Barr virus (lymphoblastoid cell line (LCL)). Interindividual differences of IL-10 production were found to be related to single-nucleotide polymorphisms (SNP) haplotype -6752/-6208 in LCLs (P<0.02), and for haplotypes comprising SNPs -6752/-6208/-3538 after LPS stimulation (P<0.03). Carriers of the IL10.G microsatellite with 22, 24 or 26 dinucleotide repeats linked with the -1087G SNP, exhibited the highest levels of IL-10 expression. Contrasting IL-10 secretion patterns were found for IL10.R microsatellite alleles characterised by 15 dinucleotide repeats: after LPS stimulation this allele was associated with high IL-10 production (P<0.007), but with low IL-10 levels in LCLs (P< 0.038). Thus, the effects of mosaics of genetic elements in the PIL-10 on the capacity of leukocytes to produce IL-10 depend on the agent inducing IL-10 expression.

DNA prime/protein boost vaccine strategy in neonatal macaques against simian human immunodeficiency virus

Newborn macaques were vaccinated against a chimeric simian human immunodeficiency (SHIV) virus, SHIV-vpu+, by DNA priming and boosting with homologous HIV-1 gp160. Following SHIV-vpu+ challenge, containment of infection was observed in 4 of 15 animals given DNA priming/protein boost vaccination and in three of four animals given gp160 boosts only. Rechallenge with homologous virus of six animals that contained the first challenge virus resulted in rapid viral clearance or low viral loads. Upon additional rechallenge with heterologous, pathogenic SHIV89.6P, four of these six animals maintained normal CD4+ T-cell counts with no or limited SHIV89.6P infection. Our data suggest that humoral and cellular immune mechanisms may have contributed to the containment of SHIV89.6P; however, viral interference with SHIV-vpu+ could also have played a role. Our results indicate that immunogenicity and efficacy of candidate AIDS vaccines are not affected when vaccination is initiated during infancy as compared with later in life.

Viral dynamics of early HIV infection in neonatal macaques after oral exposure to HIV-2287: an animal model with implications for maternal-neonatal HIV transmission

A model of vertical HIV transmission was developed using oral HIV-2(287) exposure of newborn Macaca nemestrina. The minimal Animal Infectious Dose for this oral route was found to be 10-fold higher than that for atraumatic viral transmission across other mucosal membranes (vaginal/rectal) of juvenile macaques. However, once infection was established, viral replication was rapid and plasma viremia could be detected by reverse-transcriptase polymerase chain reaction and viral co-culture within 1 week following exposure. No animal was resistant to infection and all macaques initially exposed to a subinfectious viral inoculum were subsequently infected by re-exposure of mucosal membranes. Higher viral load during primary infection correlated with a more rapid CD4 depletion; however, all HIV-2(287)-infected animals developed CD4 depletion during the observation period. This animal model can now be used to study early viral replication in the presence and absence of anti-retroviral agents to help identify conditions to reduce vertical HIV transmission in human newborns.

Conserved CXCR4 usage and enhanced replicative capacity of HIV-2/287, an isolate highly pathogenic in Macaca nemestrina

OBJECTIVE

To investigate viral properties that contribute to the pathogenic potential of HIV-2 in macaques.

DESIGN

We compared HIV-2/287, a virus highly pathogenic in Macaca nemestrina, with its non-pathogenic progenitor HIV-2 EHO, for coreceptor usage and ability to infect human and macaque peripheral blood mononuclear cells (PBMC).

METHODS

Coreceptor usage was determined in GHOST cells expressing known coreceptors, and in PBMC with coreceptor-specific inhibitors. Infectivity in PBMC was determined by virus titration and p27 antigen production. Early and late products of reverse transcription were measured by PCR with primers specific for the long terminal repeat (LTR), or the gag region, respectively.

RESULTS

Both viruses preferentially infect HOS-CD4 cells expressing CXCR4. Inhibition by CXCR4-specific peptide TW70 and monoclonal antibody 12G5 indicated that both viruses use predominantly CXCR4 to infect macaque and human PBMC. HIV-2/287 showed greater infectivity than HIV-2 EHO in macaque cells, but the situation was reversed in human cells. Kinetic analysis of reverse transcription products revealed no restriction in reverse transcription following HIV-2 EHO infection of macaque PBMC. However, comparison of the level of newly initiated HIV-2 EHO DNA in macaque and human PBMC indicated that there is an early restriction, prior to the initiation of reverse transcription.

CONCLUSIONS

Results indicate that the adaptation of HIV-2 EHO in M. nemestrina to a highly pathogenic virus HIV-2/287 is not correlated with a shift in or an expansion of coreceptor usage, but with the acquisition of an ability to overcome restrictions for growth in macaque PBMC.

N-linked glycosylation in the V3 region of HIV type 1 surface antigen modulates coreceptor usage in viral infection

The V3 hypervariable region of HIV-1 surface protein has been identified as a major determinant for viral tropism and coreceptor usage. However, the role of the highly conserved N-linked glycan at the V3 loop remains controversial. To further examine its role in viral infection, we introduced a conservative amino acid substitution (asparagine to glutamine) in the V3-proximal glycosylation motif (Asn-X-Ser/Thr) in the surface glycoprotein of a CXCR4-using virus (BRU), a CCR5-using virus (SF162), and a dual-tropic virus (89.6). The effect of the mutation was determined by complementation assays, and by infectivity on CEMx174 and U373-MAGI cells expressing either CXCR4 or CCR5. The mutation resulted in decreased CXCR4 usage by SHIV89.6, but increased usage by BRU. Similarly, it abrogated CCR5 usage by SHIV89.6, but had no effect on SF162. This effect was not dependent on the specific amino acid substitution used, because a threonine-toalanine mutation in the same motif in 89.6 Env yielded identical results as the asparagine-to-glutamine mutation. These findings support the notion that multiple factors, including glycosylation at V3, contribute to coreceptor usage and that the particular effects exerted by the N-linked glycan itself appear to be isolate dependent.

Evidence for early local viral replication and local production of antiviral immunity upon mucosal simian-human immunodeficiency virus SHIV(89.6) infection in Macaca nemestrina

Transmission of human immunodeficiency virus type 1 (HIV-1) is largely a result of heterosexual exposure, leading many investigators to evaluate mucosal vaccines for protection against intravaginal (i.vag.) transmission in macaque models of AIDS. Relatively little is known, however, about the dynamics of viral replication and the ensuing immune response following mucosal infection. We have utilized a simian-human immunodeficiency virus (SHIV) to study the differences in viremia, CD4 T-cell percentages, and mucosal and systemic anti-SHIV humoral and cellular immune responses during primary infection of animals infected either intravenously (i.v.) or i.vag. Positive viral cocultures, peripheral blood mononuclear cell viral load peaks, and CD4 cell declines were delayed by 1 week in the i.vag. inoculated animals compared to the animals infected i.v., demonstrating delayed viral spreading to the periphery. In contrast, mucosal anti-SHIV antibody levels were greater in magnitude and arose more rapidly and mucosal CD8(+) T-cell responses were enhanced in the i.vag. group animals, whereas both the magnitudes and times of onset of systemic immune responses for the animals in the two groups did not differ. These observations demonstrate that compartmentalization of viral replication and induction of local antiviral immunity occur in the genital tract early after i.vag. but not i.v. inoculation. Induction of mucosal immunity to target this local, contained replication should be a goal in HIV vaccine development.

Characterization of a maternal-fetal HIV transmission model using pregnant macaques infected with HIV-2(287)

To study mechanisms involved in mother-to-fetus transmission of human immunodeficiency virus (HIV) in utero, we have developed a chronically catheterized pregnant macaque model that permits simultaneous and sequential determination of virus in maternal and fetal blood and amniotic fluid during pregnancy. In this report, we have characterized this model using three groups of pregnant macaques designed to sample: (1) maternal blood, fetal blood, and amniotic fluid (n = 6); (2) maternal blood and amniotic fluid (n = 6); or (3) maternal blood only (n = 2). After inoculation with the highly pathogenic HIV-2(287), all pregnant macaques developed brief but intense viremias followed by precipitous CD4+ T-cell declines within 2-3 weeks. While all the infants born to dams of the three groups were HIV positive, the degree of infection and outcome of HIV infection varied. All infants were shown to be HIV-RNA-positive by reverse transcriptase-polymerase chain reaction (RT-PCR). However, HIV-infected cells were detected only in the blood of those born to dams enrolled in groups 1 and 2: most of these infants progressed to CD4+ T-cell depletion. The infants in group 3 exhibited HIV-RNA in plasma, although neither HIV-infected cells nor CD4+ T-cell depletion was detectable. However, all infants developed HIV-2-specific antibody at various levels by 2 months of age. Together, the data suggest that, while the degree of instrumentation may modulate intensity of virus transmission to fetus, the highly pathogenic HIV-2(287) exhibited a high frequency of virus transmission from the mother to fetus.

[GC-MS analysis of essential oils from rhizomes of Atractylodes lancea (Thunb.) DC. and A. chinensis (DC.) Koidz]

OBJECTIVE

To analyze the constituents from the rhizomes of Atractylodes lancea and A. chinensis in essential oils.

METHOD

GC-MS method was used.

RESULT

32 and 29 compounds were identified respectively.

CONCLUSION

The main constituents in the essential oils from the rhizome of A. chinensis are beta-eudesmol or a mixture of beta-eudesmol and atractylone, whereas from that of A. lancea are hinesol, a mixture of beta-eudesmol and atractylone, and atractylone.

Derivation and characterization of a highly pathogenic isolate of human immunodeficiency virus type 2 that causes rapid CD4+ cell depletion in Macaca nemestrina

With few exceptions, humans are the only species known to develop acquired immunodeficiency syndrome (AIDS) after human immunodeficiency virus (HIV) infection. We report here that an isolate of HIV type 2, EHO, readily established persistent infection in 100% of Macaca nemestrina in three consecutive transmission studies. Of the eight infected animals, five showed persistently high virus load and six developed AIDS-like diseases or CD4+ cell depletion within 4 years of infection. The pathology and clinical signs closely parallel those of HIV-1 infection of humans, including lymphadenopathy, anemia, CD4+ cell depletion, and opportunistic infections. A cell-free virus stock was established from the lymph nodes of an animal that developed AIDS-like diseases. This virus, HIV-2/287, was highly pathogenic in M. nemestrina, causing CD4+ cell depletion within 2-8 weeks postinfection. While both HIV-2 EHO and HIV-2/287 use predominantly CXCR4, the latter shows greatly enhanced replicative capacity in macaque peripheral blood mononuclear cells (PBMCs). The establishment of a human immunodeficiency virus that causes rapid and reproducible CD4 cell depletion in macaques could facilitate the study of HIV pathogenesis and the development of effective vaccines and therapy against AIDS.

Rapid shift from virally infected cells to germinal center-retained virus after HIV-2 infection of macaques

Lymphoid tissues are the primary target during the initial virus dissemination that occurs in HIV-1-infected individuals. Recent advances in antiretroviral therapy and techniques to monitor virus load in humans have demonstrated that the early stages of viral infection and host response are major determinants of the outcome of individual infections. Relatively little is known about immunopathogenic events occurring during the acute phase of HIV infection. We analyzed viral dissemination within lymphoid tissues by in situ hybridization and by combined immunohistochemistry/in situ hybridization during the acute infection phase (12 hours to 28 days) in pig-tailed macaques (Macaca nemestrina), challenged intravenously with a virulent strain of HIV-2, HIV-2(287). Two stages in viral dissemination were clearly evident within the first 28 days after HIV-2(287) infection. First, a massive increase in individual HIV-2-infected cells, mostly CD3+ T lymphocytes and a smaller percentage of macrophages and interdigitating dendritic cells, was identified within lymph nodes which peaked on the 10th day after HIV-2 infection. A shift of HIV-2 distribution was demonstrable between day 10 and day 14 after HIV-2 infection. Coincident with a marked reduction in individual HIV-2 RNA+ cells by day 14 postinfection, there was a dramatic increase in germinal center-associated HIV-2 RNA. High concentrations of HIV-2 RNA persisted in germinal centers in all animals by days 21 and 28 postinfection. Thus, HIV-2 appears to go through an initial, highly disseminated cellular phase followed by localization in the follicular dendritic cell network with relatively few infected cells. In this nonhuman primate model of HIV-associated immunopathogenesis, using a virus derived from a human pathogen, we identified a significant shift in the pattern of HIV-2 localization within a narrow time frame (day 10 to day 14). This shift in virus localization and behavior indicates that there may be a discrete but remarkably narrow window for therapeutic interventions that interrupt this stage in the natural course of HIV infection. Reproducibility and the accelerated time course of disease development make this model an excellent candidate for such intervention studies.

Role of immune responses against the envelope and the core antigens of simian immunodeficiency virus SIVmne in protection against homologous cloned and uncloned virus challenge in Macaques

We previously showed that envelope (gp160)-based vaccines, used in a live recombinant virus priming and subunit protein boosting regimen, protected macaques against intravenous and intrarectal challenges with the homologous simian immunodeficiency virus SIVmne clone E11S. However, the breadth of protection appears to be limited, since the vaccines were only partially effective against intravenous challenge by the uncloned SIVmne. To examine factors that could affect the breadth and the efficacy of this immunization approach, we studied (i) the effect of priming by recombinant vaccinia virus; (ii) the role of surface antigen gp130; and (iii) the role of core antigens (Gag and Pol) in eliciting protective immunity. Results indicate that (i) priming with recombinant vaccinia virus was more effective than subunit antigen in eliciting protective responses; (ii) while both gp130 and gp160 elicited similar levels of SIV-specific antibodies, gp130 was not as effective as gp160 in protection, indicating a possible role for the transmembrane protein in presenting functionally important epitopes; and (iii) although animals immunized with core antigens failed to generate any neutralizing antibody and were infected upon challenge, their virus load was 50- to 100-fold lower than that of the controls, suggesting the importance of cellular immunity or other core-specific immune responses in controlling acute infection. Complete protection against intravenous infection by the pathogenic uncloned SIVmne was achieved by immunization with both the envelope and the core antigens. These results indicate that immune responses to both antigens may contribute to protection and thus argue for the inclusion of multiple antigens in recombinant vaccine designs.

Thrombotic microangiopathy in the HIV-2-infected macaque

Thrombotic microangiopathy (TMA) has been increasingly reported in human immunodeficiency virus (HIV)-infected humans over the past decade. The pathogenesis is unknown. We prospectively analyzed the renal pathology and function of 27 pigtailed macaques (Macaca nemestrina), infected intravenously with a virulent HIV-2 strain, HIV-2(287), in addition to that of four uninfected control macaques. Necropsies were performed between 12 hours and 28 days after infection. HIV-2 antigen was detectable in peripheral blood mononuclear cell (PBMC) cocultures in all animals after 10 days of HIV-2 infection; a rapid decline in CD4(+) PBMC (<350/microliter) was seen in five of six animals 21 days and 28 days after infection. No macaque developed features of clinical AIDS. Typical lesions of human HIV-associated nephropathy were undetectable. Six of the 27 HIV-2-infected macaques demonstrated both histological TMA lesions (thrombi in glomerular capillary loops and small arteries, mesangiolysis) and ultrastructural lesions (mesangiolysis, subendothelial lucency, platelet thrombi in glomerular capillary lumina). Extrarenal thrombi were detected in the gastrointestinal and adrenal microvasculature of macaques that had developed renal TMA. None of the control animals demonstrated features of renal TMA at necropsy. In a retrospective analysis of kidneys obtained from 39 additional macaques infected with HIV-2(287), seven cases demonstrated TMA. In situ hybridization showed no detectable HIV-2 RNA in kidney sections of 65/66 HIV-2-infected macaques, including all 13 TMA cases. Expression of the chemokine receptor CXCR4, the putative coreceptor for HIV-2(287), was absent in intrinsic renal cells in all HIV-2-infected macaques. The HIV-2-infected macaque may be a useful model of human HIV-associated TMA. Our data do not support a role of direct HIV-2 infection of intrinsic renal cells as an underlying mechanism.

Immunization against SIVmne in macaques using multigenic DNA vaccines

All structural and regulatory genes of SIVmne were cloned into mammalian expression vectors to optimize expression in vitro and immunogenicity in mice. Macaca fascicularis were immunized four times with plasmid DNA (n = 4), or two DNA priming inoculations followed by two boosts of recombinant gp160 plus Gag-Pol particles (n = 4). Following intrarectal challenge with SIVmne, all macaques became infected. Three monkeys immunized with DNA alone maintained low plasma virus loads by 1 year post-challenge; the fourth exhibited high virus loads and significant CD4+ cell decline. Two of the DNA plus boost and three control macaques had high virus loads and associated CD4+ cell decline. Both vaccine protocols elicited antibodies and comparable helper T-cell proliferative responses to gp160. Cytokine mRNA levels in activated peripheral blood mononuclear cells (PBMC) taken at time of challenge suggested a dominant T helper (Th) 1 state in three DNA-immunized and one protein-boosted macaque, which correlated with low virus loads and high CD4+ cell counts post-challenge.

Neutralizing antibody-independent containment of immunodeficiency virus challenges by DNA priming and recombinant pox virus booster immunizations

Eight different protocols were compared for their ability to raise protection against immunodeficiency virus challenges in rhesus macaques. The most promising containment of challenge infections was achieved by intradermal DNA priming followed by recombinant fowl pox virus booster immunizations. This containment did not require neutralizing antibody and was active for a series of challenges ending with a highly virulent virus with a primary isolate envelope heterologous to the immunizing strain.

Protection of macaques against intrarectal infection by a combination immunization regimen with recombinant simian immunodeficiency virus SIVmne gp160 vaccines

We previously reported that immunization with recombinant simian immunodeficiency virus SIVmne envelope (gp160) vaccines protected macaques against intravenous challenge by the cloned homologous virus E11S but that this protection was only partially effective against the uncloned virus, SIVmne. In the present study, we examine the protective efficacy of this immunization regimen against infection by a mucosal route. We found that the same gp160-based vaccines were highly effective against intrarectal infection not only with the E11S clone but also with the uncloned SIVmne. Protection against mucosal infection is therefore achievable by parenteral immunization with recombinant envelope vaccines. Protection appears to correlate with high levels of SIV-specific antibodies and, in animals protected against the uncloned virus, the presence of serum-neutralizing activities. To understand the basis for the differential efficacies against the uncloned virus by the intravenous versus the intrarectal routes, we examined viral sequences recovered from the peripheral blood mononuclear cells of animals early after infection by both routes. We previously showed that the majority (85%) of the uncloned SIVmne challenge stock contained V1 sequences homologous to the molecular clone from which the vaccines were made (E11S type), with the remainder (15%) containing multiple conserved changes (the variant types). In contrast to intravenously infected animals, from which either E11S-type or the variant type V1 sequences could be recovered in significant proportions, animals infected intrarectally had predominantly E11S-type sequences. Preferential transmission or amplification of the E11S-type viruses may therefore account in part for the enhanced efficacy of the recombinant gp160 vaccines against the uncloned virus challenge by the intrarectal route compared with the intravenous route.

Protection from pathogenic SIV challenge using multigenic DNA vaccines

To assess DNA immunization as a strategy for protecting against HIV infection in humans, we utilized SIVmne infection of Macaca fascicularis as a vaccine challenge model with moderate pathogenic potential. We compared the efficacy of DNA immunization alone and in combination with subunit protein boosts. All of the structural and regulatory genes of SIVmne clone 8 were cloned into mammalian expression vectors under the control of the CMV IE-1 promoter. Eight M. fascicularis were immunized twice with 3 mg of plasmid DNA divided between two sites; intramuscular and intradermal. Four primed macaques received a further two DNA immunizations at weeks 16-36, while the second group of four were boosted with 250 microg recombinant gp160 plus 250 microg recombinant Gag-Pol particles formulated in MF-59 adjuvant. Half of the controls received four immunizations of vector DNA; half received two vector DNA and two adjuvant immunizations. As expected, humoral immune responses were stronger in the macaques receiving subunit boosts, but responses were sustained in both groups. Significant neutralizing antibody titers to SIVmne were detected in one of the subunit-boosted animals and in none of the DNA-only animals prior to challenge. T-cell proliferative responses to gp160 and to Gag were detected in all immunized animals after three immunizations, and these responses increased after four immunizations. Cytokine profiles in PHA-stimulated PBMC taken on the day of challenge showed trends toward Thl responses in 2/4 macaques in the DNA vaccinated group and in 1/4 of the DNA plus subunit vaccinated macaques; Th2 responses in 3/4 DNA plus subunit-immunized macaques; and Th0 responses in 4/4 controls. In bulk CTL culture, SIV specific lysis was low or undetectable, even after four immunizations. However, stable SIV Gag-Pol- and env-specific T-cell clones (CD3+ CD8+) were isolated after only two DNA immunizations, and Gag-Pol- and Nef-specific CTL lines were isolated on the day of challenge. All animals were challenged at week 38 with SIVmne uncloned stock by the intrarectal route. Based on antibody anamnestic responses (western, ELISA, and neutralizing antibodies) and virus detection methods (co-culture of PBMC and LNMC, nested set PCR- of DNA from PBMC and LNMC, and plasma QC-PCR), there were major differences between the groups in the challenge outcome. Surprisingly, sustained low virus loads were observed only in the DNA group, suggesting that four immunizations with DNA only elicited more effective immune responses than two DNA primes combined with two protein boosts. Multigenic DNA vaccines such as these, bearing all structural and regulatory genes, show significant promise and may be a safe alternative to live-attenuated vaccines.

Limited breadth of the protective immunity elicited by simian immunodeficiency virus SIVmne gp160 vaccines in a combination immunization regimen

We previously reported that immunization with recombinant simian immunodeficiency virus SIVmne envelope (gp160) vaccines protected macaques against an intravenous challenge by the cloned homologous virus, E11S. In this study, we confirmed this observation and found that the vaccines were effective not only against virus grown on human T-cell lines but also against virus grown on macaque peripheral blood mononuclear cells (PBMC). The breadth of protection, however, was limited. In three experiments, 3 of 10 animals challenged with the parental uncloned SIVmne were completely protected. Of the remaining animals, three were transiently virus positive and four were persistently positive after challenge, as were 10 nonimmunized control animals. Protection was not correlated with levels of serum-neutralizing antibodies against the homologous SIVmne or a related virus, SIVmac251. To gain further insight into the protective mechanism, we analyzed nucleotide sequences in the envelope region of the uncloned challenge virus and compared them with those present in the PBMC of infected animals. The majority (85%) of the uncloned challenge virus was homologous to the molecular clone from which the vaccines were made (E11S type). The remaining 15% contained conserved changes in the V1 region (variant types). Control animals infected with this uncloned virus had different proportions of the two genotypes, whereas three of four immunized but persistently infected animals had >99% of the variant types early after infection. These results indicate that the protective immunity elicited by recombinant gp160 vaccines is restricted primarily to the homologous virus and suggest the possibility that immune responses directed to the V1 region of the envelope protein play a role in protection.

Studies of the neutralizing activity and avidity of anti-human immunodeficiency virus type 1 Env antibody elicited by DNA priming and protein boosting

DNA vaccination is an effective means of eliciting strong antibody responses to a number of viral antigens. However, DNA immunization alone has not generated persistent, high-titer antibody and neutralizing antibody responses to human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env). We have previously reported that DNA-primed anti-Env antibody responses can be augmented by boosting with Env-expressing recombinant vaccinia viruses. We report here that recombinant Env protein provides a more effective boost of DNA-initiated antibody responses. In rabbits primed with Env-expressing plasmids, protein boosting increased titer, persistence, neutralizing activity, and avidity of anti-Env responses. While titers increased rapidly after boosting, avidity and neutralizing activity matured more slowly over a 6-month period following protein boosting. DNA priming and protein immunization with HIV-1 HXB-2 Env elicited neutralizing antibody for T cell line-adapted, but not primary isolate, viruses. The most effective neutralizing antibody responses were observed after priming with plasmids which expressed noninfectious virus-like particles. In contrast to immunizations with HIV-1 Env, DNA immunizations with the influenza virus hemagglutinin glycoprotein did not require a protein boost to achieve high-titer antibody with good avidity and persistence.

Genetic variation in a human immunodeficiency virus type 2 live-virus Macaca nemestrina vaccine model

Four pigtailed macaques were inoculated with an infectious, apathogenic human immunodeficiency virus type 2 (HIV-2) molecular clone (HIV-2KR) and subsequently challenged with a highly pathogenic strain, HIV-2287, together with two naive control animals. After challenge, two animals inoculated with a high dose of the immunizing strain were protected from CD4 decline and immunodeficiency. To examine the role of genetic heterogeneity in protection, fragments of the env gene were amplified from peripheral blood mononuclear cell DNA and plasma RNA of challenged animals by PCR, examined by using a heteroduplex tracking assay (HTA), and sequenced. By HTA, variation was detected principally within the V1 and V2 regions of envelope. Extent of variation in viral DNA clones as assessed by HTA correlated with inoculum size, as did the degree of variation in sequences of clones derived from viral DNA. Conversely, a rapid reduction in the number of plasma viral RNA variants was noted by HTA at 8 weeks postinfection in protected animals; this reduction was not present in naive or unprotected macaques. Sequences derived from plasma viral RNA were found to be more closely related than corresponding viral DNA sequences, and protection correlated with a significant reduction in variation in plasma RNA sequences in animals given the identical inocula of HIV-2287. Nonsynonymous mutations were significantly less prevalent in the protected animals. An additional potential glycosylation site was predicted to be present in the V2 region in all but one clone, and amino acid signatures related to protection were identified in viral DNA and RNA clones within both the V1 and V2 regions. Examination of the role of viral variation in this HIV-2 live-virus vaccine model may provide valuable insights into immunopathogenesis.

Candidate vaccines protect macaques against primate immunodeficiency viruses

The preclinical evaluation of the efficacy of potential vaccines against AIDS requires challenge models. The experimental infection of macaques with simian immunodeficiency virus, human immunodeficiency virus type 2 (HIV-2) or chimeric viruses have proven to be most valuable. The progress made using simian models to assess the efficacy and identify the correlates or mechanism of protection by whole inactivated virus, live attenuated virus or recombinant sub-unit vaccines is reviewed. It is possible to conclude from these studies that an effective AIDS vaccine is feasible. Furthermore, it is likely that these different vaccine approaches protect through distinct mechanisms. These results provide a scientific basis for the development and selection of suitable candidate human AIDS vaccines for testing in humans.

Sequence diversity of SIV(Mne) Nef in vivo and in vitro

We have compared nef gene sequences isolated by PCR from peripheral blood lymphocyte DNA of macaques which had been inoculated with either biologically or molecularly cloned SIV(Mne). Two samples from each animal obtained either early after infection (week 2-8) or after significant CD4+ depletion (week 21-137) were analyzed. Three substitutions in the predicted Nef amino acid sequence were seen in all animals at the late time point, and two more in all but one. Two of the common exchanges are located about 40 residues apart in the Nef core sequence, but are in proximity on the tertiary structure as judged by computer modelling using the structure of the HIV Nef core protein as a guide. Most recurring in vivo changes replaced a residue found in the cloned Nef sequence with one present in a consensus derived by aligning the Nef sequences of the SIVsm/HIV-2 groups. Animals inoculated with virus already containing the "late version" nef gene developed a more aggressive disease. The macaque adapted (MA)nef conferred a threefold higher infectivity to the cloned virus, but had no effects on CD4 downregulation. Propagation of virus with MAnef in tissue culture resulted in the rapid emergence of variants with newly attenuated nef. These findings suggest that the selective pressure on nef in vivo and in vitro are different.

A minimally replicative HIV-2 live-virus vaccine protects M. nemestrina from disease after HIV-2(287) challenge

M. nemestrina immunized with an apathogenic HIV-2 molecular clone (HIV-2KR) were protected from CD4 decline and disease upon challenge with HIV-2(287), after any immunizing virus could be detected. Higher but not lower inocula of HIV-2KR were protective against intravenous inoculation of either 10(5) or 10(1) TCID50 of HIV-2(287). Protected animals displayed substantial reductions in PBMC proviral burden (1-3 logs), viral titers (1-2 logs), and plasma viral RNA (2-4 logs) compared to unprotected or naive animals as early as 1 week postinfection. Plasma viral RNA became undetectable after 24 weeks in protected animals, but remained high in unprotected animals. No viral RNA was present in the spleen of the protected animal necropsied more than a year after challenge (though viral DNA was still present). No neutralizing responses could be demonstrated, but CTL activity was detected sooner and at higher levels after challenge in protected than in unprotected macaques. In this novel HIV-2 vaccine model, protection was clearly dose-dependent, and clearance of challenge virus RNA from the plasma did not require detectable ongoing replication of the immunizing virus at the time of challenge.

Early postinfection antiviral treatment reduces viral load and prevents CD4+ cell decline in HIV type 2-infected macaques

Reports of significant reductions in plasma viral load by anti-HIV drugs have raised the possibility that antiviral therapy, if initiated sufficiently early, may result in sustained control of infection and prolonged clinical benefits. We evaluated the effects of intervention coincident with infection using an antiviral nucleoside, d4T, in Macaca nemestrina infected with a highly pathogenic isolate of HIV-2 (HIV-2[287]). Infection with this virus reproducibly results in high viremia and rapid CD4+ cell depletion, allowing a sensitive measurement of the treatment effect on viral load and clinical outcome. Compared to the control group, d4T-treated macaques showed significantly lower (2-3 log10) plasma- and cell-associated viral load. No CD4+ cell decline was observed in the treatment group while on therapy with d4T whereas CD4+ cells of control macaques declined from a preinfection mean of 32% of PBMCs to below 10%. Notably, when d4T treatment was withdrawn after 16 weeks, five of the six macaques continued to control viral load and have maintained normal CD4+ cell level for more than a year. These results demonstrate that early antiviral intervention, even of a limited duration, may constitute an important strategy against lentiviral-induced disease.

Plasma viremia in macaques infected with simian immunodeficiency virus: plasma viral load early in infection predicts survival

A reliable method for the quantitation of plasma viremia in nonhuman primates infected with simian immunodeficiency virus (SIV) and related viruses is described. This method is based on an established quantitative-competitive PCR format and includes a truncated control for internal assay calibration. Optimization of assay conditions has significantly improved amplification specificity, and interassay variability is comparable to that of commercially available assays for human immunodeficiency virus (HIV) quantitation. This procedure was used to monitor viral loads in a group of Macaca mulatta animals that were infected with SIVsmE660 for over 2 years. Highly diverse profiles of plasma viremia were observed among animals, and high viral loads were associated with more rapid disease progression. Spearman rank correlation analyses were done for survival versus three parameters of viral load: plasma viremia, p27 core antigen, and frequency of infected peripheral blood mononuclear cells. Plasma viremia had the strongest overall correlation and was significantly (P < 0.05 to P < 0.01) associated with survival at 10 of the 13 time points examined. Plasma viremia did not correlate with survival during the primary viremia phase; however, the strength of this correlation increased with time postinfection and, remarkably, viremia levels as early as week 6 postinfection were highly predictive (P < 0.01) of relative survival. These findings are consistent with the available clinical data concerning viral load correlates early in HIV infection, and they provide further support for the view that disease outcome in lentiviral infection may be largely determined by events that occur shortly after infection.

Detection of simian immunodeficiency virus (SIV)-specific CD8+ T cells in macaques protected from SIV challenge by prior SIV subunit vaccination

Vaccines for lentiviruses would ideally induce in the host complete resistance to infection of host cells. However, such sterilizing immunity may be neither readily achievable nor absolutely necessary to provide protection from exposure to the immunodeficiency viruses. To examine the nature of protective immunity to simian immunodeficiency virus (SIV), we studied three macaques that had been immunized with a recombinant vaccinia virus-based SIV subunit vaccine regimen and exhibited protection from a challenge with cell-free SIV (MNE) as determined by viral cultures, serology, and PCR for viral genomes. Peripheral blood mononuclear cells were obtained from the protected macaques and analyzed for CD8+ cytotoxic T-lymphocyte (CTL) responses to SIV proteins. CTL reactive to SIV proteins not included in the subunit vaccine, and thus to which these animals had not been exposed prior to challenge, were detected postchallenge in the vaccine-protected animals and persisted for up to 1 year. These CTL, as reflected by studies of cytolytic lines and derived T-cell clones, were CD8+, did not recognize allogeneic targets, and recognized the SIV proteins in the context of class I major histocompatibility complex molecules. The frequency of precursor CD8+ CTL reactive to SIV proteins was determined by limiting-dilution analysis and demonstrated that the responses elicited following challenge of protected animals to SIV proteins not present in the vaccine were quantitatively similar to those of animals persistently infected with SIV. The presence of these CD8+ CTL responses to SIV proteins present only in the challenge virus suggests that infection of some host cells occurred postchallenge. These results suggest that the development of a low level of SIV infection following exposure of vaccinated hosts to SIV does not preclude protection from lethal SIV disease by vaccine-induced immunity.