CCL3L1 dose and HIV-1 susceptibility

Several genetic factors influence HIV-1 susceptibility or AIDS disease progression. A recent study reported on what could be a particularly important genetic determinant for HIV-1 susceptibility and disease progression: copy number of a chemokine gene termed CCL3L1. Individuals with low copy numbers of the gene, relative to their ethnic background, were associated with markedly enhanced HIV-1/AIDS susceptibility. These findings define an important new genetic determinant of HIV-1 susceptibility and further emphasize the importance of the chemokine system, either as elements that inhibit HIV-1 infection or that modulate antiviral immune responses.     

Antibody reactivity to HIV-1 Vpu in HIV-1/AIDS patients on highly active antiretroviral therapy

Human immunodeficiency virus type 1 (HIV-1) Vpu protein promotes both extracellular release of viral particles and degradation of CD4 in the endoplasmic reticulum. The correlation of anti-Vpu antibody (Ab) reactivity to Vpu and AIDS disease progression was studied in 162 HIV-1/AIDS patients after they had received highly active antiretroviral therapy (HAART) for 1 year. Anti-Vpu Ab reactivity was analyzed by Western blot using a recombinant Vpu protein. Results showed that at baseline (prior to initiation of HAART), 31.5% of patients (51/162) had anti-Vpu Ab. The proportion of anti-Vpu Ab in patients with CD4 counts > or =500, 200-500 and <200/mm(3) were 40.6, 34.7 and 14.3%, respectively (chi(2) test, p < 0.05). In addition, decreasing levels of anti-Vpu Ab reactivity were significantly correlated with increasing levels of HIV-1 viral load. After receiving HAART for 1 year, 7 of 111 anti-Vpu Ab-negative patients (6.3%) seroconverted (- --> + group) and 8 of 51 anti-Vpu Ab-positive (15.7%) patients became negative (+ --> - group). Among 104 anti-Vpu Ab-negative patients, 40 were selected for analysis of the VPU gene. All of them had an intact VPU gene. Patients were further divided into four groups according to their anti-Vpu Ab serostatus and anti-HIV-1 Ab was measured. The results showed that only the anti-Vpu Ab seroconverted group (- --> +) had increased serum levels of anti-HIV-1 Abs after 1 year of HAART, while the other three groups (+ --> +, - --> - and + --> -) had decreased serum levels of anti-HIV-1 Abs after 1 year of HAART (p < 0.05). In conclusion, the presence of anti-Vpu Ab is associated with improved prognosis following HIV-1 infection, and seroconversion of anti-Vpu Ab in patients on HAART indicates significant recovery of immunity.     

Potential role of immune modulation in the effective long-term control of HIV-1 infection

Recent advances in HIV-1 pathogenesis, and in defining virological and immunological responses to highly active antiretroviral therapy (HAART), along with the identification of the numerous drawbacks of HAART, have clearly demonstrated that the eradication of the virus is not a feasible therapeutic goal, and that there is an urgent need to develop other approaches to fight HIV-1 infection. Novel therapeutic approaches of immune modulation have recently been evaluated in pilot clinical trials. First, treating primary HIV-1 infection with cyclosporin A (CsA) coupled with HAART to target massive immune activation extends the benefits achieved with HAART during primary HIV-1 infection and might contribute to the establishment of a more favourable immunological set-point affecting the ultimate pattern and rate of disease progression. Second, treating chronic HIV-1 infection in patients with long-term suppression of virus replication induced by HAART, with the addition of mycophenolate mofetil (MMF) reduces the pool of activated CD4+ T lymphocytes able to support productive HIV-1 infection, and might have an indirect impact on the pool of resting, latently infected CD4+ T cells, contributing to its depletion in vivo. The important question is clearly whether these results will have an impact on the clinical management of patients with HIV-1 infection, determining the precise therapeutic function of drugs like CsA and MMF, thus investigating the effects of these drugs on residual viral replication and the decay of the latent reservoir, on long-term immunological benefit, and, ultimately, on clinical benefit.     

Cyclosporin A in combination with HAART in primary HIV-1 infection

HAART is the cornerstone of HIV therapy, and has significantly reduced morbidity and mortality associated with HIV disease. The institution of HAART during the primary HIV-1 infection has a more profound influence on the ultimate pattern and rate of disease progression than therapy commenced later on. However, it also well demonstrated that HAART alone is not able to eradicate the virus, unless over a life-long period of time. There is therefore the need to develop alternative strategies aimed at modulating the immune responses in order to achieve the long-term control of HIV even once HAART is discontinued. Among immunomodulant agents, cyclosporin A in combination with HAART might play a role in the treatment of people with primary HIV-1 infection.     

A prospective on drug abuse-associated epigenetics and HIV-1 replication

Drugs of abuse serve as cofactors to susceptibility to HIV infection and disease progression. Although clinical reports indicate association between HIV/AIDS and drug use, the molecular mechanism of infection susceptibility and disease progression remains unclear. Drugs such as cocaine exert their addictive effects in part by epigenetic mechanisms. Given that epigenetic modifications play an important role in HIV-1 life cycle, it is essential to unravel whether drug abuse-associated epigenetic changes may contribute to HIV/AIDS. In this article we will provide a prospective on the impact of epigenetic mechanisms on HIV-1 life cycle.     

Advance in treatment strategy and immune reconstruction against HIV-1 infection

HIV-1 can be considered an infection of the immune system, resulting in progressive and ultimately profound immune suppression. The availability of highly active antiretroviral therapy (HAART) has resulted in dramatic changes in the disease course in persons fortunate enough to have access to these medications, but long-term therapy is limited by the development of resistance as well as toxicities of the potent medication regimens. Emerging data indicate that individuals who have non-progressive clinical course control HIV-1 immunologically. This has bolstered hope that the immune response might be effectively augmented in persons with HIV infection. Recent data indicating that immediate treatment of acute infection leads to augmentation of antiviral immune responses have provided evidence that the immune system might be enhanced in certain situations. Therefore, investigation in the reconstitution of anti-HIV immune response in patients under HAART should provide encouragement for continuing to explore methods to obtain meaningful and durable immune enhancement as an adjunct to HAART in HIV-1 infection.     

AIDS and HIV-1 Infection: Clinical Entities in Geriatric Dentistry1

The number of AIDS cases in individuals 50 years of age or older in the United States is reported to exceed 9000. Contaminated blood and blood transfusions are major contributors to HIV-1 infection in this age group. Sexual transmission and infection through intravenous drug abuse are also potential avenues of HIV-1 transmission in the older population. AIDS presents with a variety of clinical manifestations, including dementia, frequently seen in non-HIV-1-infected older people. Neurological deficiencies associated with AIDS are very common and may lead to misdiagnosis in the elderly. The observed incubation period of HIV-1 infection is longer than previously estimated, increasing the risk of older individuals exposed to HIV-1 in the past to develop AIDS. Oral manifestations may present as one of the early clinical signs of AIDS. Little is known concerning AIDS in the geriatric population. It demands consideration by dental professionals treating older individuals belonging to one of the exposure categories of the disease.     

Meaning of DNA detection during the follow-up of HIV-1 infected patients: a brief review

A growing body of evidence indicates that proviral DNA load quantitation is an important parameter in establishing the dynamics of HIV infection. Proviral DNA load can be determined during the follow-up of infected individuals to evaluate reservoir status in addition to viral replication. Hence, the study of viral reservoirs, represented by HIV-1 latently infected cells, including resting memory CD4+ T cells, monocytes and macrophages, by which HIV-1 can be reactivated, opens new perspectives in the assessment and the comprehension of HIV-1 infection. However, the identification of viral reservoirs, that can store both wild and drug resistance viruses, is one of the most important steps in developing treatment strategies because it is now clear that viral reservoirs not only prevent sterilizing immunity but also represent a major obstacle to curing the infection with the potent antiretroviral drugs currently in use. Even if only careful evaluation of virological and immunological markers is necessary to fully characterize the course of HIV-1 infection and to provide a more complete laboratory-based assessment of disease progression, the availability of a new standardized assay such as DNA proviral load will be important to assess the true extent of virological suppression in treated patients and to verify the efficacy of new immune-based therapies aimed at purging HIV-1 DNA reservoirs. Several studies demonstrate, in fact, that HIV-1 cellular DNA load may be an indicator of spread of infection whereas the plasma RNA load is indicates active infection. This article will review the importance of monitoring HIV-1 proviral load DNA during the follow-up of HIV-1 infected subjects, suggesting that additional information complementing HIV RNA load could provide crucial information to monitor viral replication and the effectiveness of HAART therapy.     

Host genetic factors in susceptibility to HIV-1 infection and progression to AIDS

HIV-1 infection has rapidly spread worldwide and has become the leading cause of mortality in infectious diseases. The duration for development of AIDS (AIDS progression) is highly variable among HIV-1 infected individuals, ranging from 2–3 years to no signs of AIDS development in the entire lifetime. Several factors regulate the rate at which HIV-1 infection progresses to AIDS. Host genetic factors play an important role in the outcome of such complex or multifactor diseases as AIDS and are also known to regulate the rate of disease progression. This review focuses on the major host genes reported to affect the progression to AIDS in HIV-1 infected individuals.     

Genetic basis of HIV-1 resistance and susceptibility: an approach to understand correlation between human genes and HIV-1 infection

HIV infection is the serious medical and public health issue of present generation. By 2005, it has already infected a cumulative total of more than sixty million people worldwide and the number of HIV positive cases are rising day by day. India is currently estimated to have about 5.1 million infected persons with HIV-1 or AIDS (second only to South Africa) and this number could increase to 24 million in the next ten years. This pandemic situation of the AIDS stimulated a plethora of longitudinal cohort studies which are designed to document medical heterogeneity as well as to mitigate the factors that regulate the HIV-1 infection, disease progression and the immune defenses. In recent years these genetic studies have led to the discovery of various MHC and non MHC encoded genes, which directly or indirectly influence the susceptibility and resistance to HIV infection and AIDS. These genes and their mutated forms and their products which play a major role in determining the susceptibility or resistance to HIV-1 infection and AIDS. These genes have been categorized into MHC or non MHC encoded genes. The MHC encoded genes which determine HIV resistance or susceptibility are HLA-B57, HLA-B58, HLA-B27, HLA-Bw4 and HLA-A11 in Southeast Asians. On the other hand, non MHC encoded genes are CCR5, CCR2, RANTES, CXCL12, CXCR6, CCL3L1, Interleukin-10 (IL-10), and interferon gamma. The site specific mutations in these genes determine the susceptibility or resistance to HIV-1 infection and AIDS. In future the study of host genes in relation to HIV-1 infection may provide the researchers to develop newer chemotherapeutic approaches to prevent or cure HIV-1 infection effectively.     

Analysis of the replication kinetics in primary culture of isolates of HIV-1 from infected patients in various stages of the disease]

The authors have studied the replicative kinetics and the induction of cytopathic effects of HIV-1 in primary co-cultures from infected subjects at various stages of the disease. Cultures from subjects with ARC or AIDS yielded HIV-1 replication more precociously and at higher levels compared to those from asymptomatic subjects; cytopathic effect "in vitro" were observed more frequently and earlier in cell cultures from ARC/AIDS subjects. Presented data indicate that the clinical and immunological deterioration during HIV-1 infection is related to viral replicative activity and suggest that the study of HIV-1 replicative kinetics in primary co-cultures may be helpful in predicting who will progress to AIDS.     

Genetic determinants of pediatric HIV-1 infection: vertical transmission and disease progression among children.

It is very likely that perinatal human immunodeficiency virus type 1 (HIV-1) infection is influenced by a combination of virologic and host factors. A greater understanding of the role played by various risk factors for HIV-1 infection is crucial for the design of new preventive and therapeutic strategies. In recent years, a number of studies have suggested that host genetic factors are important determinants of both the susceptibility to perinatal HIV-1 infection and the subsequent pathogenesis of acquired immunodeficiency syndrome (AIDS). Control of HIV-1 infection involves the processing of specific viral peptides and their presentation to cells of the immune system by highly polymorphic human leukocyte antigen (HLA) alleles. The contribution of multiple HLA class I and II alleles in modulating pediatric HIV/AIDS outcomes has now been confirmed by several independent groups. Penetration of HIV-1 into cells is mediated by interaction between CD4 and chemokine receptors that serve as entry coreceptors. Genetic polymorphisms in chemokine ligand and chemokine receptor genes have recently been associated both with mother-to-child HIV-1 transmission and disease progression in children. These observations suggest a key role for genetic factors in pediatric HIV-1 infection. This article describes the current state of knowledge regarding host genetic influences on pediatric HIV-1 infection and discusses the role of these genes in HIV/AIDS pathogenesis.     

Updates on CRISPR-based gene editing in HIV-1/AIDS therapy

Although tremendous efforts have been made to prevent and treat HIV-1 infection, HIV-1/AIDS remains a major threat to global human health. The combination antiretroviral therapy (cART), although able to suppress HIV-1 replication, cannot eliminate the proviral DNA integrated into the human genome and thus requires lifelong treatment that may lead to various side effects. In recent years, clustered regularly interspaced short palindromic repeat (CRISPR)-associated nuclease 9 (Cas9) related gene-editing systems have been developed and designed as effective ways to treat HIV-1 infection. However, new gene-targeting tools derived from or functioning like CRISPR/Cas9, including base editor, prime editing, SHERLOCK, DETECTR, PAC-MAN, ABACAS, pfAGO, have been developed and optimized for pathogens detection and diseases correction. Here, we summarize recent studies on HIV-1/AIDS gene therapy and provide more gene-editing targets based on studies relating to the molecular mechanism of HIV-1 infection. We also identify the strategies and potential applications of these new gene-editing technologies for HIV-1/AIDS treatment in the future. Moreover, we discuss the caveats and problems that should be addressed before the clinical use of these versatile CRISPR-based gene targeting tools. Finally, we offer alternative solutions to improve the practice of gene targeting in HIV-1/AIDS gene therapy.     

High level HIV-1 DNA concentrations in brain tissues differentiate patients with post-HAART AIDS dementia complex or cardiovascular disease from those with AIDS

Highly active antiretroviral treatment (HAART) has had a significant impact on survival of individuals with acquired immunodeficiency syndrome (AIDS); however, with the longer life-span of patients with AIDS, there is increasing prevalence of AIDS dementia complex (ADC) and other non-AIDS-defining illness, and cardiovascular diseases (CVD) are also common. The influence of these varied disease processes on HIV-1 DNA concentration in brain tissues has not been thoroughly assessed in the post-HAART era. The purpose of the current study is to clarify the impacts of ADC and other complications of HIV disease on the viral load in the brains in AIDS patients with post-HARRT. We examined autopsy specimens from the brains of thirteen patients who died from complications of AIDS with quantitative polymerase chain reaction (QPCR). All but one patient had received HAART prior to death since 1995. Two patients died with severe CVD, multiple cerebrovascular atherosclerosis (CVA) throughout the brain and five patients died with ADC. Six patients had no ADC/CVA. A QPCR was used to measure the presence of HIV-1 DNA in six brain tissues (meninges, frontal grey matter, frontal white matter, temporal subcortex, cerebellum and basal ganglia). In the post-HARRT era, for non-ADC/CVA patients, HIV-1 DNA concentration in brain tissues was statistically higher than that in patients with ADC. In a new finding, two patients who suffered from severe CVD, especially CVA, also had high concentrations of HIV-1 in brain compartments not showing ADC related changes. To our knowledge, this is the first report of a relationship between the CVA and HIV-1 viral burden in brain. The current observations suggest that HAART-resistant HIV reservoirs may survive within ADC lesions of the brain as well as the macrophage rich atherosclerosis, which needs to be confirmed by more AIDS cases with CVA. Supported by the National Institutes of Health (Grant Nos. NIH ZMH1 BRB-S and UOI CA66259-09 TDC), National Science Foundation (Grant No. NSF DMI-0349669), abd Science & Technology Development Program of Shandong Province (Grant No. 2007GG30002003).     

用两步MS-PCR结合ELISA检测HIV-1逆转录酶基因的耐药性突变

高效抗逆转录病毒治疗法（HAART）的推广使用有效地抑制了HIV-1病毒的传播和艾滋病（AIDS）的发病率、死亡率。近年来,HIV-1逆转录酶基因突变所导致的耐药性成为了HAART的治疗失败的主要原因,耐药性突变的检测对于指导病人用药以及新药开发具有重要意义。本工作发展了一种检测HIV-1逆转录酶基因耐药性突变的新方法。采用两步MS-PCR方法检测HIV-1 B亚型野生型和耐药突变型逆转录酶基因突变,检测点包括M41L、K70R、K103N、Y181C和T215,并在两步MS-PCR基础上,设计比野生型引物长的突变型引物,结合微孔板杂交ELISA呈色技术检测各点突变。结果显示,简化的两步MS-PCR能保持灵敏度和特异性高的优点,ELISA的阳性结果与阴性结果的比值（P/N）达到要求,两步MS-PCR结合ELISA方法灵敏度高,操作简单、结果直观、成本低、相对耗时短且能进行高通量检测,其无论在HIV-1耐药性突变及其它的点突变检测中具有较好的临床应用前景。     

Excision of HIV-1 proviral DNA by recombinant cell permeable tre-recombinase

Over the previous years, comprehensive studies on antiretroviral drugs resulted in the successful introduction of highly active antiretroviral therapy (HAART) into clinical practice for treatment of HIV/AIDS. However, there is still need for new therapeutic approaches, since HAART cannot eradicate HIV-1 from the infected organism and, unfortunately, can be associated with long-term toxicity and the development of drug resistance. In contrast, novel gene therapy strategies may have the potential to reverse the infection by eradicating HIV-1. For example, expression of long terminal repeat (LTR)-specific recombinase (Tre-recombinase) has been shown to result in chromosomal excision of proviral DNA and, in consequence, in the eradication of HIV-1 from infected cell cultures. However, the delivery of Tre-recombinase currently depends on the genetic manipulation of target cells, a process that is complicating such therapeutic approaches and, thus, might be undesirable in a clinical setting. In this report we demonstrate that E.coli expressed Tre-recombinases, tagged either with the protein transduction domain (PTD) from the HIV-1 Tat trans-activator or the translocation motif (TLM) of the Hepatitis B virus PreS2 protein, were able to translocate efficiently into cells and showed significant recombination activity on HIV-1 LTR sequences. Tre activity was observed using episomal and stable integrated reporter constructs in transfected HeLa cells. Furthermore, the TLM-tagged enzyme was able to excise the full-length proviral DNA from chromosomal integration sites of HIV-1-infected HeLa and CEM-SS cells. The presented data confirm Tre-recombinase activity on integrated HIV-1 and provide the basis for the non-genetic transient application of engineered recombinases, which may be a valuable component of future HIV eradication strategies.     

The effect of HAART on humoral immune response in primary HIV-1 infected patients

The effect of Highly Active Antiretroviral Therapy (HAART) on binding and neutralizing antibody responses to human immunodeficiency virus type-1 (HIV-1) during primary and chronic infection was investigated. Seven patients HAART treated during primary infection, six HAART treated during chronic infection and five patients treated only with ZVD (Zidovudine) were analysed. HAART inhibited the development of anti env antibodies during primary infection. Administering HAART during primary infection usually did not substantially affect the development of weak neutralizing antibody responses against autologous virus. However, we demonstrated that very early treatment, during seroconversion, induce in some cases, a strong neutralizing antibodies against autologous virus. These results may be relevant for understanding how HAART may elicit a strong protective responses and may be useful in developing new strategies designed to achieve a long term control of the HIV infection.     

Neuropathogenesis of HIV-1 infection. Outstanding questions

Significant progress in understanding and treating acquired immunodeficiency syndrome (AIDS) has been made over the last 5 years. Current multi drug therapies prolong patients' lives and reduce the incidence of neurobehavioural symptoms. However, the impact of therapy on human immunodeficiency virus type one (HIV-1), the causative agent of AIDS, in the brain, is unknown. Some patients develop dementia in spite of the multi drug therapies and others develop subtle neurobehavioural changes that diminish the quality of their prolonged lives. Thus, HIV-1 infection of the central nervous system remains an important clinical concern. Although much is known about neuropathology of HIV-1 infection, major questions about neuropathogenesis remain. How does HIV-1 reach the brain? Is it present in neurons and glial cells? What is the biological and therapeutic significance of neurotropism of HIV-1? What causes neuronal damage and loss? And, is CNS a resevoir of HIV-1? More research in vivo and in situ in humans and in animals, is needed to answer these outstanding questions. Specific experiments addressing these questions are proposed.     

Discordance between frequency of human immunodeficiency virus type 1 (HIV-1)-specific gamma interferon-producing CD4(+) T cells and HIV-1-specific lymphoproliferation in HIV-1-infected subjects with active viral replication

One hallmark of uncontrolled, chronic human immunodeficiency virus type 1 (HIV-1) infection is the absence of strong HIV-1-specific, CD4(+) T-cell-proliferative responses, yet the mechanism underlying this T helper (Th)-cell defect remains controversial. To better understand the impact of HIV-1 replication on Th-cell function, we compared the frequency of CD4(+) Th-cell responses based on production of gamma interferon to lymphoproliferative responses directed against HIV-1 proteins in HIV-1-infected subjects with active in vivo viral replication versus those on suppressed highly active antiretroviral therapy (HAART). No statistically significant differences in the frequencies of cytokine-secreting, HIV-1-specific CD4(+) T cells between the donor groups were found, despite differences in viral load and treatment status. However, HIV-1-specific lymphoproliferative responses were significantly greater in the subjects with HAART suppression than in subjects with active viral replication. Similar levels of HIV-1 RNA were measured in T-cell cultures stimulated with HIV-1 antigens regardless of donor in vivo viral loads, but only HIV-1-specific CD4(+) T cells from subjects with HAART suppression proliferated in vitro, suggesting that HIV-1 replication in vitro does not preclude HIV-1-specific lymphoproliferation. This study demonstrates a discordance between the frequency and proliferative capacity of HIV-1-specific CD4(+) T cells in subjects with ongoing in vivo viral replication and suggests that in vivo HIV-1 replication contributes to the observed defect in HIV-1-specific CD4(+) T-cell proliferation.