Acquired Immunodeficiency Syndrome Therapy Research Articles

Retinal detachment and mortality in patients with cytomegalovirus retinitis: A multicenter study in taiwan.

To characterize patients with cytomegalovirus (CMV) retinitis and identify risk factors for retinal detachment (RD) and mortality in this Taiwanese patient population. This retrospective study included patients diagnosed with CMV retinitis between 2007 and 2019. The diagnosis was confirmed through aqueous polymerase chain reaction (PCR). Relevant data were collected from the Chang Gung Research Database. Univariate Cox regression was performed to identify the associations of RD and mortality risks with various patient characteristics, including demographic features, comorbidities, laboratory results, and medication use patterns. In total, 32 patients with CMV retinitis were included. Among these patients, 78.1% had an immunocompromised status, including 56.3% with high-dose systemic steroid use, 21.9% with HIV infection, 12.5% with hematologic malignancy, and 9.4% with renal transplantation. Approximately 21.9% of patients had RD 2.4 ± 2.1 months after CMV retinitis diagnosis, and 34.4% died within 6.2 [4.2, 38.2] months after diagnosis. Patients with RD had a statistically significant, but likely not clinically significant, later initiation of anti-CMV medications compared to their non-RD counterparts (8 [5, 23] days vs. 2 [1,11] days, p = 0.039). Mortality was significantly associated with older age (hazard ratio [HR]: 1.06; 95% confidence interval [CI]: 1.02-1.10), hematologic malignancy (HR: 5.92; 95% CI: 1.44-24.37), and positivity for CMV on blood PCR (HR: 4.93; 95% CI: 1.49-16.35). Our study suggests that older age, hematologic malignancy, and positivity for CMV on blood PCR are risk factors for mortality in patients with CMV retinitis. What is known Cytomegalovirus (CMV) retinitis is the predominant sight-threatening opportunistic ocular infection in patients with acquired immunodeficiency syndrome (AIDS). What is new In the era of highly active antiretroviral therapy for AIDS, the majority of CMV retinitis patients are those receiving immunomodulatory therapy for underlying diseases. Older age, hematologic malignancy, and positive blood polymerase chain reaction for CMV are potential risk factors for mortality in patients with CMV retinitis.

Improvement of epilepsy secondary to acquired immunodeficiency syndrome with intestinal microbiota preparations: a case report

Abstract Background Epilepsy secondary to acquired immunodeficiency syndrome (AIDS) can be challenging to manage. The potential interactions between antiretroviral drugs and antiepileptic drugs may result in the failure of both treatments. Therefore, it is crucial to develop more effective strategies to enhance the clinical outcomes of patients. Case presentation We report a case of epilepsy secondary to AIDS. After administration of Bacteroides Fragilis 839 (BF839), the secondary generalized tonic-clonic seizures disappeared, the frequency of complex partial seizures decreased by 70%, and the duration of each episode was shortened. Additionally, long-term diarrhea associated with antiretroviral therapy for AIDS resolved, and the syphilis serofast reaction turned negative. No serious adverse reactions were observed during the three-year follow up. Conclusions This case report suggests that the specific gut microbiota preparation could possibly improve refractory epilepsy in HIV patients while also potentially alleviating adverse reactions to antiretroviral drugs and concurrent syphilis infection. Our case may provide a new perspective for the treatment of HIV infection/AIDS.

The Use of Zidovudine Pharmacophore in Multi-Target-Directed Ligands for AIDS Therapy

The concept of polypharmacology embraces multiple drugs combined in a therapeutic regimen (drug combination or cocktail), fixed dose combinations (FDCs), and a single drug that binds to different targets (multi-target drug). A polypharmacology approach is widely applied in the treatment of acquired immunodeficiency syndrome (AIDS), providing life-saving therapies for millions of people living with HIV. Despite the success in viral load suppression and patient survival of combined antiretroviral therapy (cART), the development of new drugs has become imperative, owing to the emergence of resistant strains and poor adherence to cART. 3'-azido-2',3'-dideoxythymidine, also known as azidothymidine or zidovudine (AZT), is a widely applied starting scaffold in the search for new compounds, due to its good antiretroviral activity. Through the medicinal chemistry tool of molecular hybridization, AZT has been included in the structure of several compounds allowing for the development of multi-target-directed ligands (MTDLs) as antiretrovirals. This review aims to systematically explore and critically discuss AZT-based compounds as potential MTDLs for the treatment of AIDS. The review findings allowed us to conclude that: (i) AZT hybrids are still worth exploring, as they may provide highly active compounds targeting different steps of the HIV-1 replication cycle; (ii) AZT is a good starting point for the preparation of co-drugs with enhanced cell permeability.

The Challenge of a "Functional Cure" for AIDS by Gene Modified HSCT Therapy.

Acquired immunodeficiency syndrome (AIDS), an infectious disease which is difficult to be cured, is regularly and effectively treated with anti-retroviral therapy in clinic. When considering about the defects of antiretroviral therapy (ART), patients need a new way to cure AIDS. With the development of genetic engineering technology and humanized mouse models, a new way has been found to achieve a "functional cure" for AIDS. One/some specific gene(s), such as CCR5 and CXCR4, can be knocked out to produce HIV-resisting cells, so as to achieve the purpose of curing AIDS. To find a safe and effective therapy for AIDS, treatment strategy and technical scheme should be improved and optimized in many aspects. Moreover, different stages of works have been done in laboratory and in clinic based on this gene mutation strategy. However, a great deal of challenge has emerged while great progress has been made. Safety considerations and effectiveness of gene modified stem cell in clinic are major obstacles of the application of this strategy.

The immune pathogenesis of immune reconstitution inflammatory syndrome associated with highly active antiretroviral therapy in AIDS.

The present study investigated the immunological pathogenesis of immune reconstitution inflammatory syndrome (IRIS) in acquired immunodeficiency syndrome (AIDS) patients undergoing highly active antiretroviral therapy (HAART). A total of 238 patients with AIDS who received initial HAART were included in this prospective cohort study. Blood samples were collected immediately, at baseline, at week 12, and at week 24 after initial HAART and at the onset of IRIS. Lymphocyte subsets, Th1 and Th2 cytokines, and interleukin (IL)-7 levels were measured by flow cytometry or ELISA. Among the 238 patients with AIDS who received HAART, 47 patients developed IRIS. The percentages of CD4(+) and CD8(+) naive, memory, and activated cells exhibited no significant differences between AIDS patients with and without IRIS 24 weeks after initial HAART. The percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells was lower in IRIS patients than in non-IRIS patients before HAART, 12 weeks after HAART, 24 weeks after HAART, and at the onset of IRIS. IL-2 and interferon (IFN)-γ levels were significantly higher at week 4 and at the onset of IRIS in IRIS patients than in non-IRIS patients. In contrast, IL-4 and IL-10 levels were significantly lower at week 4 and at the onset of IRIS in IRIS patients than in non-IRIS patients. Plasma IL-7 decreased gradually with the progression of HAART. The level of IL-7 was higher in IRIS patients than in non-IRIS patients at all follow-up time points. An imbalance of Th1/Th2 cytokines, a consistently low CD(+)CD25(+)Fox3(+) percentage, and a high IL-7 level may be crucial in the pathogenesis of IRIS in AIDS patients who had received HAART.

A Mathematical Study of Combined Use of Anti-HIV Drugs and a Mutagen

The multidrug therapy for acquired immunodeficiency syndrome (AIDS) is efficacious in suppressing viral load, but it is an inappropriate treatment for AIDS patients suffering from side effects of anti-human immunodeficiency virus (HIV) drugs or who have developed resistance against these drugs. To cure these patients, alternative AIDS therapy is necessary. In a previous study 1, we discussed the availability of an alternative AIDS treatment that plunges viral activities into chaos by inducing excessive mutations by mutagenic activity in the HIV RNA genome and established a theoretical basis for its successful use in treatment. However concurrently mathematical analyses revealed treatment is only successful when the virulence of a virus was relatively low. In this study, we develop a new treatment to tackle HIV that has high virus virulence by examining the combined effects of a mutagenic agent and existing anti-HIV drugs. The drugs used include a reverse transcriptase inhibitor and a protease inhibitor. We prove that a therapy combining drug treatments with a mutagen is superior for its capacity to handle HIV with high virulence and its shorter treatment duration.

RES and brain targeting stavudine-loaded solid lipid nanoparticles for AIDS therapy

Cells of the reticuloendothelial system (RES, e.g., macrophages) play an important role in the immunopathogenesis of Acquired Immunodeficiency Syndrome (AIDS). The objective of the present study was to investigate the possibility of specifically targeting antiviral drugs Stavudine to RES (like Liver, Spleen etc.) and brain using solid lipid nanoparticles (SLNs) as colloidal drug carriers. Various lipids like stearic acid, cetyl palmitate, glyceryl behenate and phospholipid in combination have been used and effect of lipid on properties of SLNs has been investigated. The SLNs of Stavudine were prepared by double emulsion solvent evaporation method.The diameter of SLNs was determined and found in range of 175 ± 6.027 to 393 ± 2.309 nm depending on the type of lipid used. Percentage drug entrapment was found to be influenced by the concentration and type of lipid used, which was found in the range of 18.1 to 65.2%. The drug release behavior was studied by dialysis bag method and the release pattern of drug was found to follow Higuchi model. Results of stability evaluation showed a relatively long-term stability after storage at 4°C for 1 month. Stavudine-loaded SLNs were successfully prepared, optimized and effectively targeted to RES and brain. SLNs of Stavudine have been shown to be taken up by brain 11 fold greater as compared to pure Stavudine. This finding is more important since Human Immunodeficiency Syndrome (HIV) infect the central nervous system.

The Suv39H1 methyltransferase inhibitor chaetocin causes induction of integrated HIV-1 without producing a T cell response

Latent HIV-1 (human immunodeficiency virus-1) provirus is unaffected by current AIDS (acquired immunodeficiency syndrome) therapies. We show here that chaetocin, an SUV39H1 histone methyltransferase inhibitor, causes 25-fold induction of latent HIV-1 expression, while producing minimal toxicity and without causing T cell activation. Induction is associated with loss of histone H3 lysine 9 (H3K9) trimethylation at the long terminal repeat (LTR) promoter, and a corresponding increase in H3K9 acetylation. The effect of chaetocin is amplified synergistically in combination with histone deacetylase (HDAC) inhibitors. These results indicate that chaetocin may provide a therapy to purge cells of latent HIV-1, possibly in combination with other chromatin remodeling drugs.

Rationalising fixed dose combinations for tuberculosis and acquired immunodeficiency syndrome therapy

Poorly managed healthcare can be directly attributed to extensive drug regimens. Numerous chronic illnesses and epidemics such as HIV/AIDS and tuberculosis require elaborate drug regimens for efficacious therapeutic outcomes. Various drug delivery systems have been developed to simplify their regimental drug therapy. However, more effective and innovative drug delivery technologies are required to increase patient compliance and provide controlled drug delivery. This review article attempts to provide a concise incursion into the use of fixed dose combinations as a strategy for drug delivery and describes the opportunities and challenges for the treatment of conditions that require chronic suppressive regimental drug therapy.

Radiotherapy for patients with the human immunodeficiency virus: Are special precautions necessary?

Shortly after the onset of the acquired immunodeficiency syndrome (AIDS) epidemic in the 1980s, reports of radiation-associated toxicity in patients with the human immunodeficiency virus (HIV) and AIDS began to appear in the medical literature. Although the majority of reports have focused on AIDS-defining malignancies such as Kaposi sarcoma, greater-than-expected toxicity after a course of radiotherapy or chemoradiotherapy has also been documented in cancers not generally classified as being related to HIV. With improved antiretroviral therapies, HIV patients are living longer and have the potential to develop a variety of HIV-associated and nonassociated malignancies that require treatment, including radiotherapy. This review reports the published data regarding the interactions of HIV, AIDS, and antiretroviral therapy with radiotherapy and implications for the management of malignancies in patients with HIV.

Electromagnetic interference in the permeability of saquinavir across the blood–brain barrier using nanoparticulate carriers

Transport of antiretroviral agents across the blood–brain barrier (BBB) is of key importance to the treatment for the acquired immunodeficiency syndrome (AIDS). In this study, impact of exposure to electromagnetic field (EMF) on the permeability of saquinavir (SQV) across BBB was investigated. The in vitro BBB model was based on human brain-microvascular endothelial cells (HBMEC), and the concentration of SQV in receiver chamber of the transport system was evaluated. Polybutylcyanoacrylate (PBCA), methylmethacrylate-sulfopropylmethacrylate (MMA-SPM), and solid lipid nanoparticle (SLN) were employed as carriers for the delivery systems. Cytotoxicity of SLN decreased as content of cacao butter increased. Power of 5 mV was apposite for the study on HBMEC without obvious apoptosis. Square wave produced greater permeability than sine and triangle waves. The carrier order on permeability of SQV across HBMEC monolayer under exposure to EMF was SLN > PBCA > MMA-SPM. Also, a larger frequency, modulation or depth of amplitude modulation (AM), or modulation or deviation of frequency modulation (FM) yielded a greater permeability. Besides, enhancement of permeability by AM wave was more significant than that by FM wave. Transport behavior of SQV across BBB was strongly influenced by the combination of nanoparticulate PBCA, MMA-SPM, and SLN with EMF exposure. This combination would be beneficial to the clinical application to the therapy of AIDS and other brain-related diseases.

Current perspectives on cytokines for anti-retroviral therapy in AIDS related B-cell lymphomas.

The development of high-grade B-cell lymphoma in Acquired Immunodeficiency Syndrome (AIDS) patients is a relatively late manifestation induced by Human Immunodeficiency Virus-1 (HIV) infection and is considered to be an AIDS-defining condition. Multiple, ongoing molecular and cytogenetic aberrations appear necessary for the development of AIDS-related lymphoma. Studying a panel of human B-cell lines derived from patients with Burkitt's lymphoma (BL) and AIDS-associated Burkitt's lymphoma (AIDS-BL) we had described constitutive expression and secretion of large amounts of Interleukin-16 (IL-16), Macrophage Inflammatory Protein-1alpha (MIP-1alpha), Macrophage Inflammatory Protein-1beta (MIP-1beta), Interleukin-12 (IL-12), Interleukin-10 (IL-10), and Interleukin-7 (IL-7). Some of these cytokines like IL-16, MIP-1beta, MIP-1alpha and Regulated upon activation normal T expressed and secreted (RANTES) are shown to have inhibitory effect on HIV replication. Interestingly, we identified a novel transcription factor family, Macrophage Inflammatory Protein-1alpha Nuclear Protein (MNP), which is suggested as a potential target for anti-retroviral therapy based on the implication of its role and involvement as a key regulator of MIP-1alpha. It is apparent, that HIV induces the production of a cascade of cytokines and cytokine receptors. Some of these molecules serve to increase the infection and replication of HIV per se, and some others serve to induce a state of B-cell growth, activation, and differentiation. This review attempts to delineate the complex mechanisms of viral, B-cell, oncogene, cytokine/cytokine receptor and transcription factor interactions that are involved in AIDS associated lymphomagenesis. Unfolding the relationship between cytokines and the underlying mechanisms of the disease will not only help in understanding the pathophysiology but also will facilitate focusing on the development of new diagnostic and therapeutic strategies.

Effect of electrical stimulation on HIV-1-infected HeLa cells cultured on an electrode surface.

Acquired immunodeficiency syndrome (AIDS) is a disease caused by infection with the human immunodeficiency virus (HIV). Although drug therapy for AIDS is available, problems such as side effects associated with drug therapy and the appearance of resistant HIV strains have arisen. Therefore, therapies based on new principles other than drug treatment are required. In the present study, the effect of electrical stimulation on HIV-1(LAI) chronically infected HeLa (P6 HeLa/HIV-1(LAI)) cells cultured on an electrode surface was examined. The results indicated that sensitivity to electrical stimulation was much higher in P6 HeLa/HIV-1(LAI) cells than in uninfected P6 HeLa cells. When electrical stimulation was applied at 1.0 V (vs. Ag/AgCl) for 20 min, the proportion of damage to cell membrane among P6 HeLa/HIV-1(LAI) cells, as evaluated by Trypan blue staining, was approximately 4 times higher than that for uninfected P6 HeLa cells. Furthermore, in comparison with uninfected P6 HeLa cells, the proliferation of P6 HeLa/HIV-1(LAI) cells was significantly suppressed after electrical stimulation. This technique was proven to selectively kill P6 HeLa/HIV-1(LAI) cells, when compared with uninfected control cells.

Lentivirus infections and mechanisms of disease resistance in chimpanzees.

One year after the human immunodeficiency virus (HIV) was pinpointed as the etiological agent of the acquired immunodeficiency syndrome (AIDS) in humans, chimpanzees were identified as one of the few living species also capable of sustaining persistent HIV-1 infection. During the mid to late 1980s, as the AIDS epidemic spread globally in humans, the chimpanzee was eagerly looked to for answers concerning effective AIDS therapies and a possible HIV vaccine. Although from the complicated inter-relationship of the AIDS virus with the human immune system, neither an effective vaccine nor a therapy has emerged, one remarkable observation has been that, unlike humans, chimpanzees are relatively resistant to the development of AIDS. In the meantime, HIV-1 vaccine and therapy research has moved on to the SHIV/SIVmac rhesus model as an alternative AIDS model for which disease intervention studies can be better performed, and chimpanzees are rarely studied anymore. However, pertinent questions about the mechanisms of resistance to AIDS in this species beg to be answered. After more than twenty years, the spotlight has recently been turned once again on to the chimpanzee, in the intense search for the origin of the AIDS epidemic. Here we review the history of HIV-1 infection in this species as well as the observations that have led to some of the current leading hypotheses regarding the resistance to AIDS in naturally infected African primates.

Presumed Choroidal Atypical Tuberculosis Superinfected with Cytomegalovirus Retinitis in an Acquired Immunodeficiency Syndrome Patient: A Case Report

Background: To report an unusual case of multifocal choroidopathy with uveitis and cytomegalovirus (CMV) retinitis in a patient with acquired immunodeficiency syndrome (AIDS) after initially presenting with pulmonary tuberculosis ( Mycobacterium kansasii). Case: Slit-lamp biomicroscopy and indirect ophthalmoscopic examination were done. Vitreous biopsy, pars plana vitrectomy, and retinal biopsy were performed. Computer tomography scan, magnetic resonance imaging and biopsy of the brain were also carried out. Observations: Multiple yellowish-white, round, slightly elevated subretinal pigment epithelium lesions were noted in areas devoid of the atrophic retina of previous CMV infection. Anterior uveitis and vitritis were also noted. Vitreous, retina, and brain biopsy did not offer any clue for diagnosis. The visual acuity improved later, along with recovered immunity under the anti-tuberculosis medications and the cocktail therapy for AIDS. Conclusions: Combined CMV retinitis and atypical tuberculosis chorioretinitis, although rare, can develop in the patients with AIDS. Systemic dissemination of atypical tuberculosis infection should be responsible for the choroidopathy in this patient.

Spontaneous reports on drug-induced pancreatitis in Denmark from 1968 to 1999.

To present an update on drug-induced pancreatitis reported to the Danish Committee on Adverse Drug Reactions. Retrospective study of spontaneous case reports to the Danish reporting system on adverse drug reactions. All cases of suspected drug-induced pancreatitis reported to the Danish Committee on Adverse Drug Reactions from 1968 to 1999 were analysed. Three cases were excluded leaving 47 cases for analysis. Drug-induced pancreatitis made up 0. 1% of all the reports to the committee from 1968 to 1999. The proportion seemed to increase and was 0.3% during the last 8 years. The 47 cases corresponded to 0.1% of the number of patients discharged due to pancreatic disease (without cancers) per year in Denmark. Serious courses were frequent as indicated by death and hospitalisation being reported in 4 (9%) and 32 (68%) cases, respectively. Death occurred after valproate (two cases), clomipramine (one case) and azathioprine (one case). Definite relationship was stated for mesalazine (three cases), azathioprine (two cases) and simvastatin (one case) on the basis of re-challenge. A possible or probable causality was considered for a further 30 drugs including 5-acetylsalicylic acid agents, angiotensin-converting enzyme inhibitors, estrogen preparations, didanosine, valproate, codeine, antiviral agents used in acquired immunodeficiency syndrome therapy, various lipid-reducing agents, interferon, paracetamol, griseofulvin, ticlopine, allopurinol, lithium and the MMR (measles" mumps/rubella) vaccination. Drug-induced pancreatitis is rarely reported. The incidence may be increasing and the course is often serious. This is the first report on definite simvastatin-induced pancreatitis. Further studies on the pancreotoxic potential of drugs are warranted.

Coevolution and subsite decomposition for the design of resistance-evading HIV-1 protease inhibitors

Drug resistance sharply limits the effectiveness of human immunodeficiency virus (HIV) protease inhibitors in acquired immunodeficiency syndrome therapy. In previous work, we presented methods for design of resistance-evading inhibitors using a computational coevolution technique. Here, we report subsite decomposition experiments that examine the relative importance and roles of each subsite in HIV protease, and the constraints on robust inhibitor design that are imposed by possible resistance mutations in each subsite. The results identify several structural features of robust resistance-evading inhibitors for use in drug design, and show their basis in the constraints imposed by the range of allowable mutation in the protease. In particular, the results identify the P3 and P3′ sites as being particularly sensitive to protease mutation: inhibitors designed to fill the S3 and S3′ sites of the wild-type protease will be susceptible to viral resistance, but inhibitors with side-chains smaller than a phenylalanine residue at P3 and P3′, preferably medium-sized amino acids in the range from valine to leucine and isoleucine residues, will be more robust in the face of protease resistance mutation.

Treatment of acquired immunodeficiency syndrome-related lymphoma with a standard chemotherapy regimen.

Sixty patients with poor-prognosis malignant lymphoma associated with acquired immunodeficiency syndrome (AIDS) were treated with a standard chemotherapy regimen: cyclophosphamide 600 mg/m2 i.v., day 1; vincristine 1.4 mg/m2 i.v., day 1; epirubicin 70 mg/m2 i.v., day 1; and bleomycin 10 mg/m2 i.v., on day 14. Granulocyte colony-stimulating factor, 5 microg/kg/day, was administered subcutaneously on days 4-14 to ameliorate severe myelosuppression. All patients were in an advanced stage of AIDS with <200 absolute CD4+ cells/mm3 and the presence of adverse prognostic factors related to lymphoma, such as high or high-intermediate clinical risk, multiple extranodal involvement, presence of bulky disease, and high levels of beta 2 microglobulin. Complete response (CR) was achieved by 33 patients (54%); no partial response was observed, and 27 cases were considered failures. All 27 died secondary to tumor progression without any response to salvage chemotherapy. Twenty patients in CR died of opportunistic infections related to AIDS. Actuarial 5-year survival shows that time to treatment failure for the 13 patients who remain in CR is 3.1 years. However, disease-free survival was 14.5 months. Overall survival for the entire group was 13.6 months. Side effects secondary to chemotherapy were frequent and severe, but no death related to treatment was observed. Infection-related granulocytopenia was observed in 27 cycles (8%). This study indicates that standard chemotherapy could be useful in patients with AIDS-associated lymphoma because CR rate, duration of remission, and survival were similar to those with other intensive, but more toxic, regimens. Until a new and better therapy for AIDS is found, treatment of patients with AIDS-related lymphoma will be regarded as palliative, and less toxic regimens will be considered. The use of a standard regimen appears to be an adequate therapeutic approach in this group of patients.

Intracellular Immunization of Rhesus CD34+ Hematopoietic Progenitor Cells With a Hairpin Ribozyme Protects T Cells and Macrophages From Simian Immunodeficiency Virus Infection

Evaluation of candidate genes for stem cell gene therapy for acquired immunodeficiency syndrome (AIDS) has been limited by the difficulty of supporting in vitro T-cell differentiation of genetically modified hematopoietic progenitor cells. Using a novel thymic stromal culture technique, we evaluated the ability of a hairpin ribozyme specific for simian immunodeficiency virus (SIV) and human immunodeficiency virus type 2 (HIV-2) to inhibit viral replication in T lymphocytes derived from transduced CD34+ progenitor cells. Retroviral transduction of rhesus macaque CD34+ progenitor cells with a retroviral vector (p9456t) encoding the SIV-specific ribozyme and the selectable marker neomycin phosphotransferase in the presence of bone marrow stroma and in the absence of exogenous cytokines resulted in efficient transduction of both colony-forming units and long-term culture-initiating cells, with transduction efficiencies ranging between 21% and 56%. After transduction, CD34+ cells were cultured on rhesus thymic stromal culture (to support in vitro differentiation of T cells) or in the presence of cytokines (to support differentiation of macrophage-like cells). After expansion and selection with the neomycin analog G418, cells derived from transduced progenitor cells were challenged with SIV. CD4+ T cells derived from CD34+ hematopoietic cells transduced with the ribozyme vector p9456t were highly resistant to challenge with SIV, exhibiting up to a 500-fold decrease in SIV replication, even after high multiplicities of infection. Macrophages derived from CD34+ cells transduced with the 9456 ribozyme exhibited a comparable level of inhibition of SIV replication. These results show that a hairpin ribozyme introduced into CD34+ hematopoietic progenitor cells can retain the ability to inhibit AIDS virus replication after T-cell differentiation and support the feasibility of intracellular immunization of hematopoietic stem cells against infection with HIV and SIV. Protection of multiple hematopoietic lineages with the SIV-specific ribozyme should permit analysis of stem cell gene therapy for AIDS in the SIV/macaque model.

Intracellular Immunization of Rhesus CD34+ Hematopoietic Progenitor Cells With a Hairpin Ribozyme Protects T Cells and Macrophages From Simian Immunodeficiency Virus Infection

AbstractEvaluation of candidate genes for stem cell gene therapy for acquired immunodeficiency syndrome (AIDS) has been limited by the difficulty of supporting in vitro T-cell differentiation of genetically modified hematopoietic progenitor cells. Using a novel thymic stromal culture technique, we evaluated the ability of a hairpin ribozyme specific for simian immunodeficiency virus (SIV) and human immunodeficiency virus type 2 (HIV-2) to inhibit viral replication in T lymphocytes derived from transduced CD34+ progenitor cells. Retroviral transduction of rhesus macaque CD34+ progenitor cells with a retroviral vector (p9456t) encoding the SIV-specific ribozyme and the selectable marker neomycin phosphotransferase in the presence of bone marrow stroma and in the absence of exogenous cytokines resulted in efficient transduction of both colony-forming units and long-term culture-initiating cells, with transduction efficiencies ranging between 21% and 56%. After transduction, CD34+ cells were cultured on rhesus thymic stromal culture (to support in vitro differentiation of T cells) or in the presence of cytokines (to support differentiation of macrophage-like cells). After expansion and selection with the neomycin analog G418, cells derived from transduced progenitor cells were challenged with SIV. CD4+ T cells derived from CD34+ hematopoietic cells transduced with the ribozyme vector p9456t were highly resistant to challenge with SIV, exhibiting up to a 500-fold decrease in SIV replication, even after high multiplicities of infection. Macrophages derived from CD34+ cells transduced with the 9456 ribozyme exhibited a comparable level of inhibition of SIV replication. These results show that a hairpin ribozyme introduced into CD34+ hematopoietic progenitor cells can retain the ability to inhibit AIDS virus replication after T-cell differentiation and support the feasibility of intracellular immunization of hematopoietic stem cells against infection with HIV and SIV. Protection of multiple hematopoietic lineages with the SIV-specific ribozyme should permit analysis of stem cell gene therapy for AIDS in the SIV/macaque model.