Bovine alpha-2-HS-glycoprotein functions as a booster antigen for efficiently stimulating humoral immune responses to CCR5 and SIVmac239 envelope glycoprotein

The presence of anti-CCR5 and anti-HIV-1 envelope glycoprotein (ENV) gp41 antibodies (Abs) at sites of HIV-1 exposure was effective in preventing its transmission to HIV-1-exposed seronegative (ESN) subjects. Here, we design an immunogen that can induce Abs against CCR5 and SIVmac239 ENV simultaneously and show that bovine alpha-2-HS-glycoprotein (bAHSG) functions as a booster antigen for efficiently stimulating humoral immune responses to CCR5 and ENV. Initially, we generated a rhesus CCR5-derived cyclopeptide (cDDR5) conjugated with a recombinant trimeric SIVmac239 Env. When inguinally administered to rhesus macaques, the immunogen simultaneously induced both anti-CCR5 and anti-ENV Abs in sera, and the purified serum IgG fraction exerted an inhibitory effect on SIVmac239 infection in vitro. When further boosted with bAHSG, the responses of both Abs were significantly enhanced. To examine the cross-reactivity of bAHSG, it was administered to naïve cynomolgus macaques. The results showed a statistically significant increase in IgG response against cynomolgus CCR5 and SIVmac239 ENV, and the induction of neutralizing activity against SIVmac239. These findings suggest that bAHSG is useful for immune strategies aimed at generating Abs against CCR5 and ENV simultaneously to confer HIV-protective immunity.     

人类免疫缺陷病毒解剖学病毒储存库与检测方法的研究进展

由于人类免疫缺陷病毒(human immunodeficiency virus,HIV)储存库的存在,获得性免疫缺陷综合征(acquired immunodeficiency syndrome,AIDS)患者即便接受高效抗反转录病毒治疗也无法完全清除体内的潜伏病毒.本文就HIV在人体内可能存在的解剖学储存库、病毒储存库...     

Nonhuman primates and the acquired immunodeficiency syndrome: a union of necessity

Because of the close phylogenetic relationship, nonhuman primates are highly susceptible to human pathogens, including infection of chimpanzees by the human immunodeficiency virus (HIV), the causative agent of AIDS. This, and the existence of a highly related simian virus, SIV, which causes an AIDS-like disease in macaques, emphasizes the continued importance of using nonhuman primates as model systems for identifying and developing prophylaxis and therapy for infectious agents and, in particular, for fighting the pandemic AIDS.     

Rates of amino acid change in the envelope protein correlate with pathogenicity of primate lentiviruses

A spectrum of pathogenicity has been observed for primate lentiviruses in their natural hosts. For example, human immunodeficiency virus type 1 (HIV-1) is a potent etiologic agent for AIDS in man, whereas there is no evidence to date which indicates that simian immunodeficiency virus from African green monkeys (SIVAGM) causes immunodeficiency in AGM. We measured the relative rates of amino acid change, as the ratio of the number of nonsynonymous to synonymous (silent) nucleotide substitutions, for six primate lentiviruses evolving in their respective hosts. These rates for the external envelope glycoprotein (gp120) and gag coding sequences are 2–3 times higher for pathogenic HIV-1 and SIV..ac (macaque) than for minimally pathogenic SIVAGM and SIVsn,m (sooty mangabey), and intermediate for HIV-2. We speculate that the increased rates of nonsynonymous changes in gp120 and gag coding sequences are due to viral escape from immune surveillance and are indicative of higher immunogenicity of these proteins in their hosts. Based on these results and available experimental data, we conclude that there is a positive correlation between lentiviral pathogenicity and immunogenicity of the Env and Gag proteins in a given host. This hypothesis is consistent with recent data suggesting that immune system activation or autoimmunity induced by viral antigens may be important in the pathogenesis of AIDS.Correspondence to: E.G. Shpaer     

Host gene evolution traces the evolutionary history of ancient primate lentiviruses

Simian immunodeficiency viruses (SIVs) have infected primate species long before  human immunodeficiency virus has infected humans. Dozens of species-specific lentiviruses are found in African primate species, including two strains that have repeatedly jumped into human populations within the past century. Traditional phylogenetic approaches have grossly underestimated the age of these primate lentiviruses. Instead, here we review how selective pressures imposed by these viruses have fundamentally altered the evolutionary trajectory of hosts genes and, even in cases where there now remains no trace of the viruses themselves, these evolutionary signatures can reveal the types of viruses that were once present. Examination of selection by ancient viruses on the adaptive evolution of host genes has been used to derive minimum age estimates for modern primate lentiviruses. This type of data suggests that ancestors of modern SIV existed in simian primates more than 10 Ma. Moreover, examples of host resistance and viral adaptation have implications not only for estimating the age and host range of ancient primate lentiviruses, but also the pathogenic potential of their modern counterparts.     

On transient effects in the HIV/AIDS epidemic

During the initially exponential spread of the human immunodeficiency virus (HIV—the causative agent of AIDS) the growth rate of the number of AIDS cases decreases from plus infinity to the growth rate of HIV infections. A sensitivity analysis shows that for all reasonable values of the parameters of the HIV epidemic (incubation period, initial doubling time, etc.) the effect of this positive transient becomes negligible when the annual number of AIDS cases reaches a few dozen. Necessary and sufficient conditions are given for the growth rate of the number of AIDS cases to be monotonically decreasing during the positive transient. A mildly pathological density function for the incubation period of AIDS provides an example of a growth rate of AIDS that does not decrease monotonically, even though HIV is spreading exponentially. A negative transient occurs when the growth rate of HIV begins to decrease. In this context a somewhat surprising result emerges under the assumption that the growth rate of HIV is non-increasing: the growth rate of AIDS is at all times larger than the growth rate of HIV. A logistic HIV epidemic illustrates this result, and implications for the growth of the HIV epidemic in the United States and Europe are discussed. In particular, it is shown that the positive transient must have passed by 1982 in the United States and by 1986 or 1987 for the five European countries with the largest caseloads.     

AIDS in Africa: distinguishing fact and fiction

The data widely purporting to show the existence and heterosexual transmission in Africa of a new syndrome caused by a retrovirus which induces immune deficiency are critically evaluated. It is concluded that both acquired immune deficiency (AID) and the symptoms and diseases which constitute the clinical syndrome (S) are of long standing in Africa, affect both sexes equally and are caused directly and indirectly by factors other than human immunodeficiency virus (HIV). Seropositivity to HIV in Africans usually represents no more than cross-reactivity caused by an abundance of antibodies induced by the numerous infectious and parasitic diseases which are endemic in Africa. The apparently high prevalence of AIDS and HIV seropositives is therefore not surprising and is not proof of heterosexual transmission of either HIV or AIDS.E. Papadopulos-Eleopulos is with the Department of Medical Physics, The Royal Perth Hospital, Perth 6000, Western Australia, Australia; V.F. Turner is with the Department of Emergency Medicine, The Royal Perth Hospital, Perth 6000, Western Australia, Australia, J.M. Papadimitriou is with the Department of Pathology, University of Western Australia, Perth, Western Australia. H. Bialy is with Bio/Technology, 65 Becker St, New York, NY 10012, USA.     

女性艾滋病患者的抗反转录病毒治疗与人类免疫缺陷病毒母婴阻断

自从对感染人类免疫缺陷病毒(HIV)的妊娠妇女实施抗反转录病毒治疗(ART)以预防母婴垂直传播以来,HIV母婴阻断成功率明显上升。而部分抗病毒药物,如依非韦伦和替诺福韦,也逐渐被证实用于妊娠期妇女对胎儿是安全的,这增加了HIV母婴阻断药物的选择范围。     

融合表达小鼠IgG2b-Fc可增强人类免疫缺陷病毒1型Gag DNA疫苗的免疫原性

为阐明小鼠IgG2b-Fc对DNA疫苗免疫原性的增强作用,首先构建表达人类免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)CN54Gag基因的DNA疫苗及表达Gag与小鼠IgG2b-Fc融合基因的DNA疫苗,限制性酶切和DNA测序结果表明这两个疫苗均构建成功,蛋白免疫印迹结果也显示其正确表达。然后,利用上述DNA疫苗接种C57BL/6小鼠,比较两个DNA疫苗所诱导的特异性体液免疫反应和特异性细胞免疫反应。结果显示,融合表达小鼠IgG2b-Fc对特异性细胞免疫和体液免疫反应均有增强作用,但只有对特异性体液免疫反应的增强作用有统计学意义。     

Major histocompatibility complex class I-restricted cytotoxic T lymphocyte responses during primary simian immunodeficiency virus infection in Burmese rhesus macaques

Major histocompatibility complex class I (MHC-I)-restricted CD8(+) cytotoxic T lymphocyte (CTL) responses are crucial for the control of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication. In particular, Gag-specific CTL responses have been shown to exert strong suppressive pressure on HIV/SIV replication. Additionally, association of Vif-specific CTL frequencies with in vitro anti-SIV efficacy has been suggested recently. Host MHC-I genotypes could affect the immunodominance patterns of these potent CTL responses. Here, Gag- and Vif-specific CTL responses during primary SIVmac239 infection were examined in three groups of Burmese rhesus macaques, each group having a different MHC-I haplotype. The first group of four macaques, which possessed the MHC-I haplotype 90-010-Ie, did not show Gag- or Vif-specific CTL responses. However, Nef-specific CTL responses were elicited, suggesting that primary SIV infection does not induce predominant CTL responses specific for Gag/Vif epitopes restricted by 90-010-Ie-derived MHC-I molecules. In contrast, Gag- and Vif-specific CTL responses were induced in the second group of two 89-075-Iw-positive animals and the third group of two 91-010-Is-positive animals. Considering the potential of prophylactic vaccination to affect CTL immunodominance post-viral exposure, these groups of macaques would be useful for evaluation of vaccine antigen-specific CTL efficacy against SIV infection.     

Neurotoxicity caused by didanosine on cultured dorsal root ganglion neurons

The purpose of the present study was to investigate whether didanosine (ddI) directly causes morphological and ultrastructural abnormalities of dorsal root ganglion (DRG) neurons in vitro. Dissociated DRG cells and organotypic DRG explants from embryonic 15-day-old Wistar rats were cultured for 3 days and then exposed to ddI (1 μg/ml, 5 μg/ml, 10 μg/ml, and 20 μg/ml) for another 3 days and 6 days, respectively. Neurons cultured continuously in medium served as normal controls. The diameter of the neuronal cell body and neurite length were measured in dissociated DRG cell cultures. Neuronal ultrastructural changes were observed in both culture models. ddI induced dose-dependent decreases in neurite number, length of the longest neurite in each neuron, and total neurite length per neuron in dissociated DRG cell cultures with 3 days treatment. There were no morphological changes seen in organotypic DRG cultures even with longer exposure time (6 days). But ddI induced ultrastructural changes in both culture models. Ultrastructural abnormalities included loss of cristae in mitochondria, clustering of microtubules and neurofilaments, accumulation of glycogen-like granules, and emergence of large dense particles between neurites or microtubules. Lysosome-like large particles emerged inconstantly in neurites. ddI induced a neurite retraction or neurite loss in a dose-dependent manner in dissociated DRG neurons, suggesting that ddI may partially contribute to developing peripheral neuropathy. Cytoskeletal rearrangement and ultrastructural abnormalities caused by ddI in both culture models may have a key role in neurite degeneration.     

Recombination in AIDS viruses

Recombination contributes to the generation of genetic diversity in human immunodeficiency viruses (HIV) but can only occur between viruses replicating within the same cell. Since individuals have not been found to be simultaneously coinfected with multiple divergent strains of HIV-1 or HIV-2, recombination events have been thought to be restricted to the rather closely related members of the quasispecies that evolves during the course of HIV infection. Here we describe examples of both HIV-1 and HIV-2 genomes that appear to be hybrids of genetically quite divergent viruses. Phylogenetic analyses were used to examine the evolutionary relationships among multiple HIV strains. Evolutionary trees derived from different genomic regions were consistent with respect to most of the viruses investigated. However, some strains of HIV-1 and HIV-2 exhibited significantly discordant branching orders indicative of genetic exchanges during their evolutionary histories. The crossover points of these putative recombination events were mapped by examining the distribution of phylogenetically informative sites supporting alternative tree topologies. A similar example of a recombinant simian immunodeficiency virus identified in West African green monkeys has also been described recently. These results indicate that coinfection with highly divergent viral strains can occur in HIV-infected humans and SIV-infected primates and could lead to the generation of hybrid genomes with significantly altered biological properties. Thus, future characterization of primate lentiviruses should include careful phylogenetic investigation of possible genomic mosaicism.Correspondence to: P.M. Sharp     

抗人类免疫缺陷病毒1型感染的双特异性抗体的构建及其功能研究

靶向人类免疫缺陷病毒（human immunodeficiency virus，HIV）流行毒株的广谱中和抗体（broadly neutralizing antibody, bNAb）单一疗法最终会导致机体出现病毒逃逸突变，然而基于广谱中和抗体开发的双特异性或多特异性抗体则表现出较好的中和效力和广谱性。根据已公布的单链可变区基因抗体序列，经密码子优化后合成一种由单基因编码的双特异性抗体iMab-PGT151，经双酶切和测序对重组质粒进行了验证。酶联免疫吸附试验检测双特异性抗体的结合特异性，检测U87细胞裂解液中的荧光素酶活性以定量分析双特异性抗体对HIV-1假病毒的中和作用；间接免疫荧光染色法检测双特异性抗体iMab-PGT151对人喉癌上皮细胞的反应性；酶联免疫吸附试验检测该抗体对心磷脂的结合能力，验证其自体反应性。结果显示，构建的双特异抗体iMab-PGT151能够成功表达，可分别结合亲本抗体的各个配体，具有双特异性，能100%中和20株假病毒，IC50值为0.084 μg/mL。与亲本抗体相比，该抗体具有更强的中和效力和广谱度，无自体反应性，具有临床适用性。所构建的双特异性抗体iMab-PGT151将可能成为预防和治疗HIV-1感染的有效候选药物之一。     

猴免疫缺陷病毒（SIV）猴模型的建立

应用ＳＩＶｍａｃ毒株感染中国恒河猴１３只,感染剂量为病毒液的１０－１～２×１０－５;感染食蟹猴４只,感染剂量为１０－２。感染后２周出现各种症状和体征如皮疹,浅表淋巴结肿大,脾肿大,血象白细胞总数下降,出现异常淋巴细胞和中性白细胞。感染后期Ｔ４下降,Ｔ４、Ｔ８比例倒置等。从外周血淋巴细胞和血浆分离病毒阳性,血清抗体上升。淋巴结组织切片呈规律性改变,即淋巴滤泡增生－滤泡耗竭－淋巴组织耗竭或逐渐恢复。感染后２．５个月有急性死亡病例,以后呈散在死亡例,尸检还发现机遇性感染如肺寄生虫,肺、肝巨细胞病毒感染等。     

Dynamics of Simian immunodeficiency virus-specific cytotoxic T-cell responses in tissues

Although the dynamics of human immunodeficiency virus and Simian immunodeficiency virus (SIV)-specific cytotoxic T cells (CTLs) have been well documented in the blood, little is known regarding CTL development in other tissues. In this study, seven Mamu-A*01+ macaques were inoculated with SIVmac. Two macaques were killed at 21 days of infection, and SIV gag p11C tetramer responses were measured in the blood, axillary and mesenteric lymph nodes, spleen, bone marrow, and thymus. Three with clinical signs of disease were killed and similarly examined. Four macaques were followed throughout disease progression, and intestinal biopsies and blood were examined at regular time points after inoculation. In animals followed prospectively, peak early tetramer responses were detected in the blood (3.9-19% of CD3+ CD8+ T cells) between day 14-21 post-inoculation (p.i.). After day 49, tetramer responses in the blood diminished and remained relatively stable through day 200, ranging from 0.7-6.5% of CD3+ CD8+ T cells. In contrast, tetramer-positive T cells increased in the intestine in later stages of infection (100-200 days p.i.) in all four infected animals (peak values from 5.3 to 28.8%). Percentages of tetramer-positive cells were consistently higher in the intestine than in the blood in all four animals after day 100. In animals with acquired immunodeficiency syndrome, percentages of CTL in tissues were variable, but were consistently higher in the intestine and spleen compared with blood. These data suggest that while high CTL responses develop at a similar rate, and magnitude in both peripheral and mucosal lymphoid tissues in primary SIV infection, mucosal CTL responses may predominate later in the course of the disease.     

Frequency of the major histocompatibility complex Mamu‐A*01 allele in experimental rhesus macaques in China

Background In Indian rhesus macaques, the major histocompatibility complex Mamu gene, especially the Mamu‐A*01 allele, plays an important role in simian immunodeficiency virus susceptibility and disease progression. The Mamu‐A*01 allele is one of the protective genes mostly being studied in simian acquired immunodeficiency syndrome. Methods PCR was used to amplify the Mamu‐A*01 allele in 130 Chinese‐origin rhesus macaques. Identification of the allele was then confirmed by sequencing and IFN‐γ ELISPOT assay. Results The Mamu‐A*01 allele was detected in 3.85% (5 of 130) of the experimental Chinese‐origin rhesus macaques. The sequence homology reached 99.1% in comparison with Indian rhesus macaques. A significantly large number of spots were observed in Mamu‐A*01‐positive monkeys when analyzed by ELISPOT with Gag181‐189 epitope stimulation. Conclusions Our study suggests that Mamu‐A*01‐positive Chinese‐origin rhesus monkeys are suitable for use in AIDS studies.     

HIV/AIDS患者机会性感染与 CD4+ T淋巴细胞间的关联性

目的研究人免疫缺陷病毒(HIV)感染者及艾滋病(AIDS)患者发生机会性感染的概率与自身CD_4~+T淋巴细胞之间的关系,为HIV患者机会性感染的防治提供参考。方法以2016年6月至2017年6月我院400例HIV患者为研究对象,回顾性分析不同CD_4~+T淋巴细胞计数HIV患者发生机会性感染的情况。结果 400例HIV患者发生机会性感染178例,总感染率为44.5%。CD_4~+T淋巴细胞计数≤50个/μL的患者机会性感染发生率(86.67%)最高,与其他各组比较差异有统计学意义(P0.05)。随着CD_4~+T淋巴细胞计数的减少,HIV患者机会性感染率升高。178例机会性感染者中,单一感染82例,2部位感染52例,3部位感染28例,4部位以上感染16例。感染病原体检测显示,细菌感染84例(47.19%),结核杆菌感染36例(20.22%),病毒感染30例(16.85%,包括巨细胞病毒感染18例、单纯疱疹病毒感染12例),真菌感染77例(43.25%,包括假丝酵母感染35例,肺孢子菌感染20例,马尔尼菲青霉菌感染12例,新型隐球菌感染10例),未明确病原体性质34例(19.10%),复合感染多见。结论 CD_4~+T淋巴细胞水平与HIV患者继发机会性感染的概率关系密切。HIV患者CD_4~+T淋巴细胞水平的监测对其继发机会性感染的防控具有重要临床意义。     

HIV and Latino migrant workers in the USA

Abstract

Migrant workers from Latin America are an essential source of economic development in the US agricultural industry. A majority of migrants are from Mexico and are undocumented and they represent a vulnerable and marginalized group in American society. There is a growing concern for HIV disease in the migrant community. The HIV prevalence rate among migrants is higher than the average rates in USA and in countries of Latin America. There are many behavioural, social, cultural, and health care risk factors and barriers that place migrants at increased risk for HIV infection. Many migrant workers contract HIV while working and living in the USA, which has contributed to rising HIV infection rates in Mexico. In order to prevent an increasing epidemic of HIV disease in Latino migrant workers, there is an urgent call for new and improved health care policies at the international, federal, state, and local levels.