1
|
Tada T, Dcosta BM, Minnee J, Landau NR. Vectored Immunoprophylaxis and Treatment of SARS-CoV-2 Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523649. [PMID: 36711584 PMCID: PMC9882093 DOI: 10.1101/2023.01.11.523649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Vectored immunoprophylaxis was first developed as a means to establish engineered immunity to HIV through the use of an adeno-associated viral vector expressing a broadly neutralizing antibody. We have applied this concept to establish long-term prophylaxis against SARS-CoV-2 by adeno-associated and lentiviral vectors expressing a high affinity ACE2 decoy receptor. Administration of decoy-expressing AAV vectors based on AAV2.retro and AAV6.2 by intranasal instillation or intramuscular injection protected mice against high-titered SARS-CoV-2 infection. AAV and lentiviral vectored immunoprophylaxis was durable and active against recent SARS-CoV-2 Omicron subvariants. The AAV vectors were also effective when administered up to 24 hours post-infection. Vectored immunoprophylaxis could be of value for immunocompromised individuals for whom vaccination is not practical and as a means to rapidly establish protection from infection. Unlike monoclonal antibody therapy, the approach is expected to remain active despite continued evolution viral variants.
Collapse
|
2
|
Mahmood I. A Single Animal Species-Based Prediction of Human Clearance and First-in-Human Dose of Monoclonal Antibodies: Beyond Monkey. Antibodies (Basel) 2021; 10:antib10030035. [PMID: 34562983 PMCID: PMC8477747 DOI: 10.3390/antib10030035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
These days, there is a lot of emphasis on the prediction of human clearance (CL) from a single species for monoclonal antibodies (mabs). Many studies indicate that monkey is the most suitable species for the prediction of human clearance for mabs. However, it is not well established if rodents (mouse or rat) can also be used to predict human CL for mabs. The objectives of this study were to predict and compare human CL as well as first-in-human dose of mabs from mouse or rat, ormonkey. Four methods were used for the prediction of human CL of mabs. These methods were: use of four allometric exponents (0.75, 0.80, 0.85, and 0.90), a minimal physiologically based pharmacokinetics method (mPBPK), lymph flow rate, and liver blood flow rate. Based on the predicted CL, first-in-human dose of mabs was projected using either exponent 1.0 (linear scaling) or exponent 0.85, and human-equivalent dose (HED) from each of these species. The results of the study indicated that rat or mouse could provide a reasonably accurate prediction of human CL as well as first-in-human dose of mabs. When exponent 0.85 was used for CL prediction, there were 78%, 95%, and 92% observations within a 2-fold prediction error for mouse, rat, and monkey, respectively. Predicted human dose fell within the observed human dose range (administered to humans) for 10 out of 13 mabs for mouse, 11 out of 12 mabs for rat, and 12 out of 15 mabs for monkey. Overall, the clearance and first-in-human dose of mabs were predicted reasonably well by all three species (a single species). On average, monkey may be the best species for the prediction of human clearance and human dose but mouse or rat especially; rat can be a very useful species for conducting the aforementioned studies.
Collapse
Affiliation(s)
- Iftekhar Mahmood
- Mahmood Clinical Pharmacology Consultancy, LLC., Rockville, MD 20850, USA
| |
Collapse
|
3
|
Falkenhagen A, Joshi S. Genetic Strategies for HIV Treatment and Prevention. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 13:514-533. [PMID: 30388625 PMCID: PMC6205348 DOI: 10.1016/j.omtn.2018.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 08/28/2018] [Accepted: 09/02/2018] [Indexed: 01/02/2023]
Abstract
Conventional HIV gene therapy approaches are based on engineering HIV target cells that are non-permissive to viral replication. However, expansion of gene-modified HIV target cells has been limited in patients. Alternative genetic strategies focus on generating gene-modified producer cells that secrete antiviral proteins (AVPs). The secreted AVPs interfere with HIV entry, and, therefore, they extend the protection against infection to unmodified HIV target cells. Since any cell type can potentially secrete AVPs, hematopoietic and non-hematopoietic cell lineages can function as producer cells. Secretion of AVPs from non-hematopoietic cells opens the possibility of using a genetic approach for HIV prevention. Another strategy aims at modifying cytotoxic T cells to selectively target and eliminate infected cells. This review provides an overview of the different genetic approaches for HIV treatment and prevention.
Collapse
Affiliation(s)
- Alexander Falkenhagen
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Sadhna Joshi
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
4
|
Falkenhagen A, Joshi S. HIV Entry and Its Inhibition by Bifunctional Antiviral Proteins. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 13:347-364. [PMID: 30340139 PMCID: PMC6197789 DOI: 10.1016/j.omtn.2018.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 12/14/2022]
Abstract
HIV entry is a highly specific and time-sensitive process that can be divided into receptor binding, coreceptor binding, and membrane fusion. Bifunctional antiviral proteins (bAVPs) exploit the multi-step nature of the HIV entry process by binding to two different extracellular targets. They are generated by expressing a fusion protein containing two entry inhibitors with a flexible linker. The resulting fusion proteins exhibit exceptional neutralization potency and broad cross-clade inhibition. In this review, we summarize the HIV entry process and provide an overview of the design, antiviral potency, and methods of delivery of bAVPs. Additionally, we discuss the advantages and limitations of bAVPs for HIV prevention and treatment.
Collapse
Affiliation(s)
- Alexander Falkenhagen
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada
| | - Sadhna Joshi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3E2, Canada.
| |
Collapse
|
5
|
Malecki M, Saetre B. HIV Apheresis Tags (HIVAT) Aided Elimination of Viremia. MOLECULAR AND CELLULAR THERAPIES 2018; 6:6. [PMID: 30931130 PMCID: PMC6438618 DOI: 10.26781/2052-8426-2018-06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
INTRODUCTION HIV viremia is the essential element for progression of an initial HIV infection into AIDS and death. The currently approved management relies primarily on chemotherapy repressing the HIV replication in the infected CD4+ cells, although with severe systemic adverse effects. The problem is that it does not physically eliminate viruses, which then not only keep infecting healthy cells of these patients, but also promote infections of other people. SPECIFIC AIM An overall objective of our work is biomolecular engineering of virus apheresis tags (VAT) that eliminate viremias without adverse effects. The specific aim of this project was biomolecular engineering of Human Immunodeficiency Virus Apheresis Tags (HIVAT): CD4-Au-Fe3O4, CD4-SiO2-Fe3O4, anti-gp120-Au-Fe3O4, and anti-gp120-SiO2-Fe3O4. HEALTHY DONORS AND PATIENTS Per the Institutional Review Board's approval and in compliance with Declaration of Helsinki, healthy donors and patients were presented with Patient Bill of Rights and provided Patient Informed Consent, while all the procedures were pursued by the licensed physicians. MATERIALS AND METHODS CD4, gp120, gp41, gp160, anti-gp120, p24 were transgenomically expressed. Superparamagnetic core-shell particles (SPM-CSP) were synthesized. SPM-CSP were used as the nucleation centers for assembling the expressed molecules upon them to create virus apheresis tags (VAT). VAT were injected into the blood or lymph acquired from the HIV+ and HBV+ patients followed by apheresis at 0.47 - 9.4 T. VAT efficacy in eliminating viremia was determined through immunoblots, NMR and q-RT-PCR. RESULTS Treatment of blood or lymph of the HIV+ patients' with VAT followed by virus apheresis resulted in rapid elimination of the HIV viremia. Efficacy of apheresis was contingent upon the gravity of viremia versus doses and regimens of VAT. Importantly, administration of VAT also effectively improved levels of non-infected CD4+ lymphocytes. DISCUSSION / CONCLUSIONS Herein, we present the proof of concept for a new, effective treatment with virus apheresis tags (VAT), specifically Human Immunodeficiency Virus Apheresis Tags (HIVAT), of the HIV+ patients' blood and lymph, which is eliminating the HIV viremia.It can be easily adapted as treatments of viremias perpetrated by other deadly viruses, which we vigorously pursue.
Collapse
Affiliation(s)
- Marek Malecki
- Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA
| | - Bianka Saetre
- Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA
| |
Collapse
|
6
|
Malecki M, Saetre B. HIV Apheresis Tags (HIVAT) Aided Elimination of Viremia. MOLECULAR AND CELLULAR THERAPIES 2018; 6:6. [PMID: 30931130 PMCID: PMC6438618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
INTRODUCTION HIV viremia is the essential element for progression of an initial HIV infection into AIDS and death. The currently approved management relies primarily on chemotherapy repressing the HIV replication in the infected CD4+ cells, although with severe systemic adverse effects. The problem is that it does not physically eliminate viruses, which then not only keep infecting healthy cells of these patients, but also promote infections of other people. SPECIFIC AIM An overall objective of our work is biomolecular engineering of virus apheresis tags (VAT) that eliminate viremias without adverse effects. The specific aim of this project was biomolecular engineering of Human Immunodeficiency Virus Apheresis Tags (HIVAT): CD4-Au-Fe3O4, CD4-SiO2-Fe3O4, anti-gp120-Au-Fe3O4, and anti-gp120-SiO2-Fe3O4. HEALTHY DONORS AND PATIENTS Per the Institutional Review Board's approval and in compliance with Declaration of Helsinki, healthy donors and patients were presented with Patient Bill of Rights and provided Patient Informed Consent, while all the procedures were pursued by the licensed physicians. MATERIALS AND METHODS CD4, gp120, gp41, gp160, anti-gp120, p24 were transgenomically expressed. Superparamagnetic core-shell particles (SPM-CSP) were synthesized. SPM-CSP were used as the nucleation centers for assembling the expressed molecules upon them to create virus apheresis tags (VAT). VAT were injected into the blood or lymph acquired from the HIV+ and HBV+ patients followed by apheresis at 0.47 - 9.4 T. VAT efficacy in eliminating viremia was determined through immunoblots, NMR and q-RT-PCR. RESULTS Treatment of blood or lymph of the HIV+ patients' with VAT followed by virus apheresis resulted in rapid elimination of the HIV viremia. Efficacy of apheresis was contingent upon the gravity of viremia versus doses and regimens of VAT. Importantly, administration of VAT also effectively improved levels of non-infected CD4+ lymphocytes. DISCUSSION / CONCLUSIONS Herein, we present the proof of concept for a new, effective treatment with virus apheresis tags (VAT), specifically Human Immunodeficiency Virus Apheresis Tags (HIVAT), of the HIV+ patients' blood and lymph, which is eliminating the HIV viremia.It can be easily adapted as treatments of viremias perpetrated by other deadly viruses, which we vigorously pursue.
Collapse
Affiliation(s)
- Marek Malecki
- Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA
| | - Bianka Saetre
- Phoenix Biomolecular Engineering Foundation, San Francisco, CA, USA
| |
Collapse
|
7
|
Malecki M, Saetre B. HIV Universal Vaccine. MOLECULAR AND CELLULAR THERAPIES 2018; 6:5. [PMID: 30815266 PMCID: PMC6388684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
BACKGROUND For many deadly viruses, there are no preventive and / or therapeutic vaccines approved by health authorities World-wide (e.g., HIV, Ebola, Dengue, and many others). Although, for some viruses, prophylactic vaccines are very effective (e.g., HBV, and many others).In this realm, we design, manufacture, test, and streamline into the clinics novel viral universal vaccines (VUV). VUV have such unique features, that medical vaccination or natural infection induced immunity against some viruses (e.g., HBV) upon the VUV's administration to the infected with other, different viruses patients, is redirected against these other, newly infecting viruses (e.g., HIV). SPECIFIC AIM The specific aim of this work was biomolecular engineering of the HIV universal vaccine comprising the two main functional domains: CD4 or anti-gp120 - as the HIV tagging domain and HBsAg - as the immune response eliciting domain, so that upon its administration the HBV medical immunization or natural infection induced immunity would be redirected, accelerated, and amplified to fight the HIV infection. HEALTHY DONORS AND PATIENTS Per the Institutional Review Board approval and in compliance with the Declaration of Helsinki, all healthy donors and patients were presented with the Patients' Bill of Rights and provided Patient Informed Consent. All the procedures were pursued by the licensed medical doctors. METHODS & RESULTS We have biomolecularly engineered HIV universal vaccine (HIVUV) comprising human CD4 or anti-gp120 and HBsAg of HBV. By immunoblotting and magnetic activated molecular sorting, we have demonstrated high specificity of this vaccine in binding HIV. By flow cytometry and nuclear magnetic resonance, we have demonstrated high efficacy of these vaccines to engage HBV immunized patients' immune system against HIV. Administration of HIVUV to blood or lymph of the HIV+ patients resulted in rapid reduction of the HIV viremia down to undetectable. It also resulted in protection of populations of CD4+ cells against HIV caused decline. CONCLUSIONS We have demonstrated the proof of concept for high efficacy of VUV, specifically HIVUV, in annihilating HIV. Nevertheless, the same compositions, processes, and methods, for persons skilled in biotechnology, pharmacogenomics, and molecular medicine, are adaptable for other deadly viral infections, which we vigorously pursue.
Collapse
Affiliation(s)
- Marek Malecki
- Phoenix Biomolecular Engineering Foundation (PBMEF), San Francisco, CA,
USA
| | - Bianka Saetre
- Phoenix Biomolecular Engineering Foundation (PBMEF), San Francisco, CA,
USA
| |
Collapse
|
8
|
Malecki M, Saetre B. HIV Universal Vaccine. MOLECULAR AND CELLULAR THERAPIES 2018; 6:5. [PMID: 30815266 PMCID: PMC6388684 DOI: 10.26781/2052-8426-2018-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND For many deadly viruses, there are no preventive and / or therapeutic vaccines approved by health authorities World-wide (e.g., HIV, Ebola, Dengue, and many others). Although, for some viruses, prophylactic vaccines are very effective (e.g., HBV, and many others).In this realm, we design, manufacture, test, and streamline into the clinics novel viral universal vaccines (VUV). VUV have such unique features, that medical vaccination or natural infection induced immunity against some viruses (e.g., HBV) upon the VUV's administration to the infected with other, different viruses patients, is redirected against these other, newly infecting viruses (e.g., HIV). SPECIFIC AIM The specific aim of this work was biomolecular engineering of the HIV universal vaccine comprising the two main functional domains: CD4 or anti-gp120 - as the HIV tagging domain and HBsAg - as the immune response eliciting domain, so that upon its administration the HBV medical immunization or natural infection induced immunity would be redirected, accelerated, and amplified to fight the HIV infection. HEALTHY DONORS AND PATIENTS Per the Institutional Review Board approval and in compliance with the Declaration of Helsinki, all healthy donors and patients were presented with the Patients' Bill of Rights and provided Patient Informed Consent. All the procedures were pursued by the licensed medical doctors. METHODS & RESULTS We have biomolecularly engineered HIV universal vaccine (HIVUV) comprising human CD4 or anti-gp120 and HBsAg of HBV. By immunoblotting and magnetic activated molecular sorting, we have demonstrated high specificity of this vaccine in binding HIV. By flow cytometry and nuclear magnetic resonance, we have demonstrated high efficacy of these vaccines to engage HBV immunized patients' immune system against HIV. Administration of HIVUV to blood or lymph of the HIV+ patients resulted in rapid reduction of the HIV viremia down to undetectable. It also resulted in protection of populations of CD4+ cells against HIV caused decline. CONCLUSIONS We have demonstrated the proof of concept for high efficacy of VUV, specifically HIVUV, in annihilating HIV. Nevertheless, the same compositions, processes, and methods, for persons skilled in biotechnology, pharmacogenomics, and molecular medicine, are adaptable for other deadly viral infections, which we vigorously pursue.
Collapse
Affiliation(s)
- Marek Malecki
- Phoenix Biomolecular Engineering Foundation (PBMEF), San Francisco, CA,
USA
| | - Bianka Saetre
- Phoenix Biomolecular Engineering Foundation (PBMEF), San Francisco, CA,
USA
| |
Collapse
|
9
|
Falkenhagen A, Joshi S. Further Characterization of the Bifunctional HIV Entry Inhibitor sCD4-FI T45. MOLECULAR THERAPY-NUCLEIC ACIDS 2017. [PMID: 28624214 PMCID: PMC5432676 DOI: 10.1016/j.omtn.2017.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
HIV entry into target cells is a highly sequential and time-sensitive process. In recent years, potent HIV Env-targeting antibodies, such as VRC01, have been identified. However, antibodies bind only to a single epitope, and mutations that confer resistance to antibody-mediated inhibition of HIV entry have been detected. In contrast, HIV cannot escape from binding to soluble CD4 (sCD4) without a fitness disadvantage. sCD4 has the unique ability to induce conformational changes within the HIV envelope glycoproteins (Env) that allow fusion inhibitors to bind. We have previously linked sCD4 to the fusion inhibitor FIT45 (sCD4-FIT45) and examined delivery of the bifunctional entry inhibitor via gene therapy. Here, we extend our studies and analyze the ability of sCD4-FIT45 to inhibit HIV Env-mediated cell fusion and HIV entry of several primary isolates. sCD4-FIT45 inhibited both cell fusion and HIV entry with remarkable antiviral activity. The mean 50% inhibitory concentrations (IC50) for sCD4-FIT45 were <0.2 μg/mL in both assays. Importantly, inhibition by sCD4-FIT45 was more potent than by VRC01, sCD4, or the previously described bifunctional protein sCD4-scFv17b. In contrast to sCD4, sCD4-FIT45 as well as VRC01 and sCD4-scFv17b did not mediate cell fusion between HIV Env+ and CD4−CCR5+ cells. The results presented here provide further evidence for the testing of sCD4-FIT45 and development of bifunctional proteins based on the sCD4-fusion inhibitor architecture.
Collapse
Affiliation(s)
- Alexander Falkenhagen
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 150 College Street, Rm. 210, Toronto, ON M5S 3E2, Canada
| | - Sadhna Joshi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, 150 College Street, Rm. 210, Toronto, ON M5S 3E2, Canada; Department of Molecular Genetics, University of Toronto, 150 College Street, Rm. 210, Toronto, ON M5S 3E2, Canada.
| |
Collapse
|
10
|
HIV-1 Entry, Inhibitors, and Resistance. Viruses 2010; 2:1069-1105. [PMID: 21994672 PMCID: PMC3187606 DOI: 10.3390/v2051069] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 04/16/2010] [Accepted: 04/18/2010] [Indexed: 02/07/2023] Open
Abstract
Entry inhibitors represent a new class of antiretroviral agents for the treatment of infection with HIV-1. While resistance to other HIV drug classes has been well described, resistance to this new class is still ill defined despite considerable clinical use. Several potential mechanisms have been proposed: tropism switching (utilization of CXCR4 instead of CCR5 for entry), increased affinity for the coreceptor, increased rate of virus entry into host cells, and utilization of inhibitor-bound receptor for entry. In this review we will address the development of attachment, fusion, and coreceptor entry inhibitors and explore recent studies describing potential mechanisms of resistance.
Collapse
|
11
|
Choudhry V, Zhang MY, Dimitrova D, Prabakaran P, Dimitrov AS, Fouts TR, Dimitrov DS. Antibody-based inhibitors of HIV infection. Expert Opin Biol Ther 2007; 6:523-31. [PMID: 16610981 DOI: 10.1517/14712598.6.5.523] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The demand for new treatment options against HIV is becoming increasingly desperate as the side effects and the expansion and spread of drug-resistant virus within the infected population limit the clinical benefits provided by available anti-HIV drugs. Preparations of polyclonal antibodies have a long history of proven clinical utility against some viruses; however, they have enjoyed very limited success against HIV. Recent clinical trials and in vitro experiments suggest that monoclonal antibodies against HIV may have promise clinically. These antibodies and antibody-based reagents target either the viral envelope glycoprotein, the receptor (CD4) or coreceptor (CCR5) molecules, or transition-state structures that appear during viral entry. The challenge is whether an antibody-based therapy can be identified (with or without their small molecule brethren) that presents long-term clinical efficacy, low toxicity and minimal risk of clinical failure from viral resistance.
Collapse
Affiliation(s)
- Vidita Choudhry
- NCI-Frederick, Protein Interactions Group, CCRNP, CCR, NIH, P.O. Box B, Frederick, MD 21702-1201, USA.
| | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
HIV virus particles interact with several receptors on cell surfaces. Two receptors, CD4 and a co-receptor act sequentially to trigger fusion of viral and cellular membranes and confer virus entry into cells. For HIV-1, the chemokine receptor CCR5 is the predominant co-receptor exploited for transmission and replication in vivo. Variants that switch to use CXCR4 and perhaps other co-receptors evolve in some infected individuals and have altered tropism and pathogenic properties. Other cell surface receptors including mannose binding protein on macrophages and DC-SIGN on dendritic cells also interact with gp120 on virus particles but do not actively promote fusion and virus entry. These receptors may tether virus particles to cells enabling interactions with suboptimal concentrations of CD4 and/or co-receptors. Alternatively such receptors may transport cell surface trapped virions into lymph nodes before transmitting them to susceptible cells. Therapeutic strategies that prevent HIV from interacting with receptors are currently being developed. This review describes how the interaction and use of different cellular receptors influences HIV tropism and pathogenesis in vivo.
Collapse
Affiliation(s)
- P R Clapham
- Center for AIDS Research, Program in Molecular Medicine, Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | | |
Collapse
|
13
|
Abstract
Delivery of pharmacological doses of proteins to people has raised concerns of inducing immune responses, especially when the protein is provided in multiple doses over an extended period of time. Immune responses could impact the therapeutic exposure and efficacy of the protein itself. In addition, there have been fears of anaphylaxis or autoimmunity. This review summarizes the available literature regarding the measurement and evaluation of immune responses observed during clinical assessment of recombinant human proteins. Immune responses have ranged from none at all to inactivation and/or accelerated clearance. Presence of antibodies does not necessarily impact therapeutic viability. While responses are related to frequency and route of delivery, there is no clear relationship that enables one to predict the clinical experience.
Collapse
Affiliation(s)
- S Porter
- Cerus Corporation, 2411 Stanwell Drive, Concord, California 94520, USA.
| |
Collapse
|
14
|
Shearer WT. POTENTIAL IMMUNE-BASED INTERVENTIONS TO REDUCE HIV-1 VERTICAL TRANSMISSION. Immunol Allergy Clin North Am 1998. [DOI: 10.1016/s0889-8561(05)70012-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
15
|
Abstract
Advances in knowledge of the pathogenesis of HIV infection, coupled with the arrival of new antiviral agents and results from clinical trials, have moved clinicians closer to effective therapy of HIV infection. Despite these advances, many important issues remain unresolved. The precise clinical roles of new agents such as 3TC and the protease inhibitors have yet to be defined. Methods for monitoring efficacy of therapy continue to be developed, and the results of current and planned clinical trials to address the role of three-drug combinations in initial and subsequent treatment regimens are awaited. With the increasing array of available drugs and monitoring assays, clinicians will have an increased ability to provide effective, individualized therapy. Results of upcoming clinical trials must be carefully evaluated with regard to the patient populations studied, duration of follow-up, and statistical methods employed in developing more rational approaches to the care of patients with HIV disease.
Collapse
Affiliation(s)
- S C Threlkeld
- Infectious Disease Unit, Massachusetts General Hospital, Boston, USA
| | | |
Collapse
|
16
|
Abstract
The prototypic immunoadhesin is an antibody-like molecule that fuses the Fc region of an immunoglobulin and the ligand-binding region of a receptor or adhesion molecule. In this article, we review some important structural and functional principles of immunoadhesins. In addition, we highlight some unique advantages of immunoadhesins as experimental tools in biology, as well as some of their exciting potential applications in medicine.
Collapse
Affiliation(s)
- S M Chamow
- Department of Recovery Sciences, Genentech, South San Francisco, CA 94080-4990, USA.
| | | |
Collapse
|
17
|
Carter P, Ridgway J, Zhu Z. Toward the production of bispecific antibody fragments for clinical applications. JOURNAL OF HEMATOTHERAPY 1995; 4:463-70. [PMID: 8581386 DOI: 10.1089/scd.1.1995.4.463] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The clinical potential of bispecific antibodies (BsAb) has been hindered by the difficulty of obtaining clinical grade material, together with the immunogenicity of rodent-derived BsAb in patients. The supply issue is being directly addressed by recombinant methods for BsAb fragment production reviewed here. The immunogenicity issue will likely be overcome by the use of humanized or human antibodies. Currently, three technologies appear suitable for the production of BsAb fragments for clinical applications: BsF(ab')2 assembled from Fab' fragments expressed in Escherichia coli, BsF(ab')2 assembled using leucine zippers, and diabodies.
Collapse
Affiliation(s)
- P Carter
- Department of Molecular Oncology, Genentech Inc., South San Francisco, CA 94080, USA
| | | | | |
Collapse
|
18
|
Shearer WT, Duliege AM, Kline MW, Hammill H, Minkoff H, Ammann AJ, Chen S, Izu A, Mordenti J. Transport of recombinant human CD4-immunoglobulin G across the human placenta: pharmacokinetics and safety in six mother-infant pairs in AIDS clinical trial group protocol 146. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1995; 2:281-5. [PMID: 7664172 PMCID: PMC170146 DOI: 10.1128/cdli.2.3.281-285.1995] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recombinant CD4-immunoglobulin G (rCD4-IgG) is a 98-kDa human immunoglobulin-like protein that is produced by fusing the gp120 binding domain of CD4 to the Fc portion of the human IgG1 heavy chain. This hybrid molecule was given to human immunodeficiency virus (HIV)-infected pregnant women at the onset of labor by intravenous bolus at 1 mg/kg of body weight (group A; n = 3) and 1 week prior to and at the onset of labor by the same route and at the same dose (group B; n = 3). In addition to pharmacokinetic studies, safety in the mothers and infants was determined through routine chemistries, hematology, and urinalysis; immunologic and HIV infection statuses in the infants were assessed through lymphocyte cultures, p24 antigen level determination, culture of HIV from plasma, PCR, lymphocyte subset enumeration, quantitative immunoglobulin analysis, and lymphocyte proliferation. Thirty minutes after the rCD4-IgG injection, concentrations in maternal serum were 12 to 23 micrograms/ml. These concentrations declined slowly, with initial and terminal half-lives (mean +/- standard deviation) of 9.95 +/- 3.23 and 47.6 +/- 22.3 h, respectively. Infants were born 2.6 to 46.5 h after rCD4-IgG administration; concentrations of rCD4-IgG in cord blood ranged from 28 to 107 ng/ml. The half-life of rCD4-IgG in infants ranged from 5 to 29 h. These data demonstrate that the transfer of rCD4-IgG from the mother to the fetus is rapid and that newborns do not appear to have any difficulty eliminating rCD4-IgG. No safety concerns in mothers or infants were encountered. Although the study did not address the question of efficacy, none of the infants was HIV type 1 infected 36 months later. In summary, these findings document that bifunctional immune molecules can be transported across the placenta, and this general approach may be used in the future to block vertical transmission of HIV type 1.
Collapse
Affiliation(s)
- W T Shearer
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Norkin LC. Virus receptors: implications for pathogenesis and the design of antiviral agents. Clin Microbiol Rev 1995; 8:293-315. [PMID: 7621403 PMCID: PMC172860 DOI: 10.1128/cmr.8.2.293] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A virus initiates infection by attaching to its specific receptor on the surface of a susceptible host cell. This prepares the way for the virus to enter the cell. Consequently, the expression of the receptor on specific cells and tissues of the host is a major determinant of the route of entry of the virus into the host and of the patterns of virus spread and pathogenesis in the host. This review emphasizes the virus-receptor interactions of human immunodeficiency virus, the rhinoviruses, the herpesviruses, and the coronaviruses. These interactions are often found to be complex and dynamic, involving multiple sites or factors on both the virus and the host cell. Also, the receptor may play an important role in virus entry per se in addition to its role in virus binding. In the cases of human immunodeficiency virus and the rhinoviruses, ingenious approaches to therapeutic strategies based on inhibiting virus attachment and entry are under development and in clinical trials.
Collapse
Affiliation(s)
- L C Norkin
- Department of Microbiology, University of Massachusetts, Amherst 01003, USA
| |
Collapse
|
20
|
Morgan RA, Baler-Bitterlich G, Ragheb JA, Wong-Staal F, Gallo RC, Anderson WF. Further evaluation of soluble CD4 as an anti-HIV type 1 gene therapy: demonstration of protection of primary human peripheral blood lymphocytes from infection by HIV type 1. AIDS Res Hum Retroviruses 1994; 10:1507-15. [PMID: 7888205 DOI: 10.1089/aid.1994.10.1507] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We previously reported on the construction of retroviral vectors that produce a secreted form of the HIV-1 receptor, T cell antigen CD4 (Morgan et al., AIDS Res Hum Retroviruses 1990;6:183-191). In this article we test the ability of these sCD4-expressing retroviral vectors to protect human T-cell lines or primary T cells from HIV-1 infection. To demonstrate that protection from HIV-1 infection is mediated by the soluble nature of this protein, two coculture protection experiments were conducted. In these experiments, sCD4-expressing retroviral vectors were used to engineer mouse NIH 3T3 cells. In one coculture experiment the human SupT1 cell line was added directly to the culture of sCD4-producing NIH 3T3 cells, and in another experiment the two cell types were separated physically by a semipermeable membrane. In both coculture configurations, the T cell line was protected from HIV-1 challenge as measured by syncytium formation and indirect immunofluorescent assays. In addition, the SupT1 line was directly engineered with sCD4-expressing retroviral vectors and shown to be protected from HIV-1 challenge. As a prelude to further preclinical studies, we tested the ability of retroviral vectors to transduce primary human peripheral blood lymphocytes (PBLs). Conditions used to stimulate T cell growth resulted in significant shifts in the CD4/CD8 cell in favor of CD8 cells. Retroviral-mediated gene transfer under these conditions resulted in low levels of gene transfer (< 5%).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- R A Morgan
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
| | | | | | | | | | | |
Collapse
|
21
|
Flasher D, Konopka K, Chamow SM, Dazin P, Ashkenazi A, Pretzer E, Düzgünes N. Liposome targeting to human immunodeficiency virus type 1-infected cells via recombinant soluble CD4 and CD4 immunoadhesin (CD4-IgG). BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1194:185-96. [PMID: 8075135 DOI: 10.1016/0005-2736(94)90219-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
HIV-infected cells producing virions express the viral envelope glycoprotein gp120/gp41 on their surface. We examined whether liposomes coupled to recombinant soluble CD4 (sCD4, the ectodomain of CD4 which binds gp120 with high affinity) could specifically bind to HIV-infected cells. sCD4 was chemically coupled by 2 different methods to liposomes containing rhodamine-phosphatidylethanolamine in their membrane as a fluorescent marker. In one method, sCD4 was thiolated with N-succinimidyl acetylthioacetate (SATA) and coupled to liposomes via a maleimide-derivatised phospholipid. In the other method, the oligosaccharides on sCD4 were coupled to a sulfhydryl-derivatised phospholipid, utilizing the bifunctional reagent, 4-(4-N-maleimidophenyl)butyric acid hydrazide (MPBH). The association of the liposomes with HIV-1-infected or uninfected cells was examined by flow cytometry. CD4-coupled liposomes associated specifically to chronically infected H9/HTLV-IIIB cells, but not to uninfected H9 cells. CD4-coupled liposomes also associated specifically with monocytic THP-1 cells chronically infected with HIV-1 (THP-1/HIV-1IIIB). Control liposomes without coupled CD4 did not associate significantly with any of the cells, while free sCD4 could competitively inhibit the association of the CD4-coupled liposomes with the infected cells. The chimeric molecule CD4-immunoadhesin (CD4-IgG) could also be used as a ligand to target liposomes with covalently coupled Protein A (which binds the Fc region of the CD4-IgG) to H9/HTLV-IIIB cells. The CD4-liposomes inhibited the infectivity of HIV-1 in A3.01 cells, and also bound rgp120. Our results suggest that liposomes containing antiviral or cytotoxic agents may be targeted specifically to HIV-infected cells.
Collapse
Affiliation(s)
- D Flasher
- Department of Microbiology, School of Dentistry, University of the Pacific, San Francisco, CA 94115-2399
| | | | | | | | | | | | | |
Collapse
|
22
|
|
23
|
Affiliation(s)
- K M Neuzil
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2005
| |
Collapse
|
24
|
Mayaux JF, Bousseau A, Pauwels R, Huet T, Hénin Y, Dereu N, Evers M, Soler F, Poujade C, De Clercq E. Triterpene derivatives that block entry of human immunodeficiency virus type 1 into cells. Proc Natl Acad Sci U S A 1994; 91:3564-8. [PMID: 8170948 PMCID: PMC43620 DOI: 10.1073/pnas.91.9.3564] [Citation(s) in RCA: 126] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A series of triterpene compounds characterized by a stringent structure-activity relationship were identified as potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) replication. Currently studied botulinic derivatives have 50% inhibitory concentrations (IC50) against HIV-1 strain IIIB/LAI in the 10 nM range in several cellular infection assays but are inactive against HIV-2. These compounds did not significantly inhibit the in vitro activities of several purified HIV-1 enzymes. Rather, they appeared to block virus infection at a postbinding, envelope-dependent step involved in the fusion of the virus to the cell membrane.
Collapse
Affiliation(s)
- J F Mayaux
- Rhône Poulenc Rorer S.A., Centre de Recherche de Vitry-Alfortville, Vitry Sur Seine, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
|
26
|
Fletcher CV, Acosta EP. Advances in pharmacotherapy: treatment of HIV infection. J Clin Pharm Ther 1993. [DOI: 10.1111/j.1365-2710.1993.tb00875.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
27
|
Affiliation(s)
- M S Hirsch
- Department of Medicine, Massachusetts General Hospital, Boston, MA 02114
| | | |
Collapse
|
28
|
Abstract
Part I of this article reviewed the targets against which anti-HIV drugs can be directed, problems in assessing active compounds (e.g. resistance development and use of surrogate end-points). and nucleoside analogues effective against HIV reverse transcriptase. Intensive research is currently being undertaken in laboratories and hospitals to design and evaluate new inhibitors of HIV. In this work, combining different drugs is one important approach, both to decrease toxicity and to offset the rate of resistance development, which seems to be a major problem associated with therapy directed against the ever-changing HIV. Therapeutic vaccines and immunomodulators are other modalities being actively evaluated against HIV and AIDS, although this effort has not yet yielded any licensed treatment. It appears likely that new antiviral drugs and immunotherapies will be forthcoming during the next 5 years, that they will be used in a variety of combinations, and that the treatment options available for opportunistic infections will increase. These developments should improve the survival and the quality of life of patients with HIV infection.
Collapse
Affiliation(s)
- E Sandström
- Department of Dermatovenerology, Södersjukhuset, Stockholm, Sweden
| | | |
Collapse
|
29
|
Yeh P, Landais D, Lemaître M, Maury I, Crenne JY, Becquart J, Murry-Brelier A, Boucher F, Montay G, Fleer R. Design of yeast-secreted albumin derivatives for human therapy: biological and antiviral properties of a serum albumin-CD4 genetic conjugate. Proc Natl Acad Sci U S A 1992; 89:1904-8. [PMID: 1542690 PMCID: PMC48562 DOI: 10.1073/pnas.89.5.1904] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Due to its remarkably long half-life, together with its wide in vivo distribution and its lack of enzymatic or immunological functions, human serum albumin (HSA) represents an optimal carrier for therapeutic peptides/proteins aimed at interacting with cellular or molecular components of the vascular and interstitial compartments. As an example, we designed a genetically engineered HSA-CD4 hybrid aimed at specifically blocking the entry of the human immunodeficiency virus into CD4+ cells. In contrast with CD4, HSA-CD4 is correctly processed and efficiently secreted by Kluyveromyces yeasts. In addition, its CD4 moiety exhibits binding and antiviral in vitro properties similar to those of soluble CD4. Finally, the elimination half-life of HSA-CD4 in a rabbit experimental model is comparable to that of control HSA and 140-fold higher than that of soluble CD4. These results indicate that the genetic fusion of bioactive peptides to HSA is a plausible approach toward the design and recovery of secreted therapeutic HSA derivatives with appropriate pharmacokinetic properties.
Collapse
Affiliation(s)
- P Yeh
- Rhône-Poulenc Rorer, Centre de Recherche de Vitry-Alfortville, Vitry, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Connolly KJ, Hammer SM. Antiretroviral therapy: strategies beyond single-agent reverse transcriptase inhibition. Antimicrob Agents Chemother 1992; 36:509-20. [PMID: 1377897 PMCID: PMC190549 DOI: 10.1128/aac.36.3.509] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- K J Connolly
- Department of Medicine, New England Deaconess Hospital, Boston, Massachusetts
| | | |
Collapse
|