2006 — 2010 |
Nussenzweig, Michel C |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Human Antibody Tolerance in Normal and Sle @ Baylor Research Institute
During B cell development in the bone marrow (BM) random immunoglobulin (Ig) gene rearrangement[unreadable] generates a highly diverse antibody repertoire, including B cells that express autoreactive antibodies.[unreadable] Experiments with transgenic mice indicate that three mechanisms - receptor editing, deletion and anergy -[unreadable] account for silencing of self-reactive B cells and ensure self-tolerance. We have recently shown that the[unreadable] majority of antibodies expressed by developing B cells in the BM of healthy human donors recognize selfantigens,[unreadable] but self-reactive antibodies are lost from the repertoire at two checkpoints: at the immature B cell[unreadable] stage in the BM and in the periphery before maturation into naive immunocompetent B cells. Autoantibodies[unreadable] can also be generated by random somatic hypermutation of Ig genes during active immune responses, but[unreadable] the frequencies at which such autoantibodies are generated, how they are regulated and the role of B cell[unreadable] tolerance checkpoints during antigen-mediated B cell differentiation into memory and plasma cells are not[unreadable] known. The finding that large numbers of autoantibodies are produced under physiologic circumstances[unreadable] suggests that even small changes in the efficiency of autoantibody regulation at any stage during B cell[unreadable] development and differentiation would lead to increased susceptibility to autoimmunity. A hallmark of the[unreadable] systemic autoimmune disease lupus erythematosus (SLE) is the production of autoantibodies making this[unreadable] disease a useful model to study B cell tolerance checkpoints. Our preliminary data show that early[unreadable] checkpoints in B cell tolerance are abnormal in SLE, and that B cells emerging from the bone marrow of[unreadable] such patients are not adequately filtered to remove autoreactivity. The long-range goal of the proposed[unreadable] research project is (I) to define B cell tolerance checkpoints in healthy humans, (II) to determine where B cell[unreadable] tolerance is broken in SLE and (III) how B cell tolerance checkpoints are affected by therapy in patients with[unreadable] SLE.
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0.901 |
2013 — 2017 |
Nussenzweig, Michel C |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Animal Services @ California Institute of Technology
Four critical aspects of the proposed research include mouse models: testing Abs designed for improved potency, breadth and/or effector function in a novel in vivo mouse model to assess viral entry, evaluating designed immunogens in human VH germline knock-in mice, determining the basis for HIV resistance using HIV-infected humanized NOD/SCID yc-/- mice, and testing AAV models in humanized NOD/SCID yc-/- mice. First, Dr. Nussenzweig and Dr. Ravetch will develop an in vivo assay to assess the ability of broadly neutralizing antibodies to prevent viral entry in mice bearing human Fc receptors (Aim 1 of Project 1 and Aim 2 of Project 2). HIV neutralization is currently assayed in vitro using TZM-bl cells. This system is based on HIV gpl60 pseudotype viruses that carry a transcriptional activator that induces luciferase. Although the TZM-bl assay provides vital information on neutralizing activity in vitro, it fails to inform about innate effector mechanisms that are likely to be essential for neutralizing activity in vivo. The new proposed in vivo viral entry assay, using HIVr^(flox)Luc mice carrying the ROSA-stop-FloxLuciferase gene and the human CD4 and CCR5 genes, will be used by Dr. Nussenzweig, Dr. Ravetch, and Dr. Bjorkman to assess the impact of antibody specificity and effector function on neutralizing activity in vivo. In addition, we will work with our collaborator Dr. Alexander Ploss who is the head of the Rockefeller University, Memorial Sloan-Kettering Cancer and Weill Cornell Medical College humanized mouse user interest group (HuMIG), to produce humanized mice for experiments proposed in Aim 2 of Project 1 and Aim 3 of Project 2. This will require that we maintain a colony of NOD/SCID yc-/- mice to produce chimeric mice reconstituted with human CD34+ stem cells. The core will perform the human CD34+ stem cell transfers to produce humanized mice for testing bNAbs and defining the basis for HIV resistance (Nussenzweig) and for AAV experiments (Ravetch). Core C will maintain and breed the HIVr^(flox)Luc mice, FcR transgenic mice, and NOD/SCID yc-/- mice and will perform the breeding experiments required to produce hFcR/HIVr^(flox)Luc mice that carry human Fc receptors for the experiments proposed by Dr. Nussenzweig and Dr. Ravetch. Core C will also maintain the human VH germline knock-in mice that will be used in Project 1, Aim 3 to test potential immunogens designed by Dr. Bjorkman in Project 3, Aim 4. In addition Core C will distribute HIVr^(flox)Luc mice to other interested investigators in accordance with our Data Sharing plan and NIH policy.
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0.916 |
2013 — 2017 |
Bjorkman, Pamela J Nussenzweig, Michel C Ravetch, Jeffrey Victor |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Development Structure and Function of Broadly Neutralizing Anti-Hiv Antibodies @ California Institute of Technology
DESCRIPTION (provided by applicant): This P01 Program Project application seeks to develop insights into mechanisms by which antibodies (Abs) protect against HIV infection to facilitate design of improved Abs and effective immunogens. Development of effective vaccines or delivered Abs to control infection will require understanding of Ab interactions with antigen and with Ab receptors that mediate effector functions. Using knowledge of what Env mutations arise in response to HIV infection in humanized mice allows structural/bioinformatic analyses of which features promote Ab evasion, required information for designing broadly neutralizing antibodies (bNAbs) that are insensitive to common routes of viral evasion. This knowledge will allow optimization of the breadth/potency of bNAbs for passive delivery (both by injection and gene therapy reverse vaccination) and is required for effective immunogen design for vaccines, thus our project is relevant to both traditional and reverse vaccine strategies to combat HIV. To accomplish these goals and to establish basic principles underlying Ab-mediated protection, we will combine the expertise of the Nussenzweig, Ravetch, and Bjorkman laboratories in characterization of HIV bNAbs and humanized mouse models of HIV infection, antibody effector function evaluation and improvement, and the structural biology of Ab-HIV and Ab-receptor interactions. Our proposal comprises three separate, but inter-related and inter-dependent collaborative projects, with the following aims: (1) Test designed bNAbs in a humanized mouse model of HIV infection, sequence resistant HIV strains, evaluate bNAbs for ability to control established HIV infection in humanized mice, and evaluate novel immunogens in a mouse model; (2) Investigate the contributions of Fc effector function to HIV bNAbs in vitro and in vivo, including in a new in vivo mouse model for HIV entry and an AAV-based reverse immunization model in humanized mice; (3) Determine structural correlates of broad/potent neutralization and improved effector functions by solving crystal structures of designed and natural bNAbs complexed with HIV Env proteins and Fc receptors; design and test immunogens for eliciting bNAbs. These projects will be supported by an administrative core and three scientific cores comprising a cell/biochemical automation core to perform automated in vitro HIV neutralization and plate-binding assays, a protein expression core to express and purify recombinant proteins required for functional and structural studies, and an animal services core to generate/maintain mice required for in vivo experiments. RELEVANCE: HIV/AIDS remains a global epidemic with an urgent need for a vaccine and/or new therapies. Our project goals are to discover the mechanisms by which anti-HIV antibodies can prevent or treat infection (through Fab-mediated neutralization and Fc-mediated effector functions) and how HIV can escape through mutation, critical knowledge required for improving natural bNAbs as therapeutics and designing immunogens to elicit bNAbs. Project 1 - Human Antibodies to HIV Project Leader (PL): Nussenzweig, Michel DESCRIPTION (provided by applicant): The vast majority of HIV infected individuals develop antibodies to the virus. In most cases the antibodies only target the autologous strain, but some individuals develop neutralizing serologic responses to a broad range of different viral isolates. These responses are of interest because passive transfer of monoclonal antibodies with broad neutralizing activity to humanized mice or monkeys prevents infection. On the basis of these observations it has been proposed that a vaccine that elicits broadly neutralizing antibodies would be protective against HIV. However, little is known about the nature of the broadly neutralizing response. Only a small number of patients have been studied to date, and the majority of these patients are selected because their serologic activity focuses on the CD4 binding site of the viral envelope spike. The long-term goals of this proposal are to characterize new broadly neutralizing antibodies in terms of their functions in vivo and to understand how HIV-1 develops resistance to these antibodies in vivo. To accomplish these goals we propose three specific aims. First, we will develop an in vivo assay to assess the ability of broadly antibodies to prevent viral entry in mice. HIV neutralization is currently assayed in vitro using TZM-bl cells. The new mouse model will be used to examine the relative efficacy of different monoclonal antibodies and the contribution of innate effector mechanisms to blocking HIV entry in vivo. Second, we will define the basis for development of resistance to broadly neutralizing antibodies in HIV infected humanized mice. We will use the information for structure based rational design approaches to iteratively enhance antibody breadth and potency. The ultimate goal of this part of the proposal is to determine which of the large group of currently available antibodies might be most useful for passive vaccine and immunogen design approaches. Finally, we will evaluate potential immunogens designed using structural and other data in knock-in mice containing human germline antibody precursor genes. Taken together, these experiments should help inform future clinical studies in which neutralizing antibodies might be considered for use in passive therapy or prevention studies and which of their targets would be most useful for immunization strategies. RELEVANCE: Although there is still no vaccine for HIV, a small number of infected individuals develop antibodies that can prevent the infection. The proposed research aims to develop an understanding of these antibodies with the long term goal of being able to elicit them de novo as a component of a vaccine to be used in un-infected individuals.
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0.916 |
2019 — 2021 |
Bjorkman, Pamela J Nussenzweig, Michel C |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Developing Immunogens to Elicit Broadly Neutralizing Anti-Hiv-1 Antibodies @ California Institute of Technology
UNAIDS has documented millions of new HIV-1 infections every year, thus a vaccine for HIV-1 is highly desirable. To date, despite numerous efforts, no immunization regimen reproducibly elicits broadly neutralizing antibodies (bNAbs) against HIV-1. Recently available native-like HIV-1 envelope spike (Env) trimers elicit antibodies that neutralize autologous tier-2 viruses but these antibodies have only limited potency and breadth. The observations that inferred germline (iGL) antibody precursors of bNAbs do not generally bind HIV-1 Env proteins or neutralizing HIV-1 suggested that rationally designed iGL-targeting Env immunogens would be required to initiate bNAb responses. Drs. Bjorkman and Nussenzweig propose a highly collaborative project to apply this approach to target epitopes of two classes of HIV-1 bNAbs: a class related to PGT121 that binds to the base of the V3 variable loop and interacts with the N332gp120 glycan (V3/N332 bNAbs), and IOMA-like bNAbs, a new class of CD4-mimetic CD4 binding site (CD4bs) bNAbs derived from the VH1-2 germline gene segment. The V3/N332 and IOMA classes were chosen because (i) V3/N332 Abs are among the most potent of bNAbs and are commonly found in HIV-infected individuals who develop bNAbs, (ii) IOMA's relatively low number of somatic hypermutations and its normal-length CDRL3 suggest it may be more easily elicited than VRC01-class VH1-2?derived CD4bs bNAbs that are heavily somatically mutated and contain rare 5-residue CDRL3s, and (iii) immunogen design will be facilitated the crystal structure of a natively-glycosylated Env trimer bound to the V3/N332 bNAb 10-1074 and to IOMA. The Bjorkman lab will create immunogens to target iGLs and shepherd bNAb maturation, while the Nussenzweig lab develops immunization schemes to elicit bNAbs using the designed immunogens. The Nussenzweig lab specific aims are: (1) Develop and simplify immunization protocols that elicit bNAbs to V3/N332 in iGL knock-in mice, (2) Adapt immunization protocols developed for V3/N332 bNAbs in knock-in mice to wild type and AlivaMab mice that carry un-rearranged human antibody loci, (3) Develop an immunization protocol to elicit IOMA-like antibodies, and (4) Determine the frequency of IOMA and V3/N332 bNAb precursors in the naïve B cell repertoire of un-infected human donors. The Bjorkman lab specific aims are: (1) Solve structures of iGL?immunogen complexes to aid in structure-based immunogen design, (2) Use structure-based design and library screening to identify Env trimers that bind V3/N332 iGLs with high affinity, (3) Use structural information to guide construction of a yeast display library to find rare variants that bind IOMA iGL, (4) Combine results to create Env trimer immunogens that bind iGLs of both bNAbs and work with Dr. Nussenzweig to evaluate double and single immunogens in mice. These efforts will be supported by Core A (Automated cell/biochemical assays) and Core B (Protein Expression). The proposed experiments will produce candidate immunogens testing in macaques by collaborator Dr. Malcolm Martin and for vaccine trials in humans.
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0.916 |
2019 — 2021 |
Nussenzweig, Michel C |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Activation of Hiv-1 Specific B Cell Precursors Using Novel Vaccine Approaches @ Fred Hutchinson Cancer Research Center
Project Summary According to the World Health Organization, approximately 36 million people worldwide were living with HIV-1 at the end of 2015 and 1.1 million people died from this disease during the same year. Vaccination is the most effective strategy to prevent infectious diseases, and successful vaccines are usually protective because they elicit antibodies that neutralize the pathogen (1). Although there is no protective vaccine against HIV-1, broadly neutralizing antibodies (bNAbs) isolated from infected patients are protective in animal models of infection even at relatively low concentrations. These antibodies are potent neutralizers that recognize conserved features of the virus envelope spike (Env) that are shared among diverse strains of the virus, and it is generally agreed that a vaccine that elicits bNAbs would be protective against HIV-1 infection. However, with the exception of llamas and genetically engineered mice, bNAbs have not been elicited by vaccination (2). The experiments in genetically engineered knock-in mice showed that bNAb development required germline-targeting Env-antigens that were specifically designed to activate B cells expressing the germline precursor antibodies that correspond to bNAbs (3-5). In addition, singular antigens were not sufficient, and bNAb development required a sequence of specific immunogens delivered in order (5-8). However, the immunization schemes devised in knock-in mice could not be extended to wild type (wt) mice or other animals in part because of lack of understanding of the relationship between germline antigen affinity and bNAb precursor B cell frequency in initiating a productive immune response in the presence of competing polyclonal B cells. The objects of the proposed research are to: 1. define the precise relationship between precursor B cell frequency and affinity to cognate antigen, in recruiting bNAb precursors into the germinal center; 2. test the idea that pre-expansion of specific precursors using anti-idiotypic antibodies will facilitate the development of anti-CD4bs antibodies. The relationship between affinity and precursor B cell frequency will be defined in adoptive transfer experiments using antigens provided by Drs. Stamatatos and McGuire. New vaccination approaches using anti-idiotypic antibodies to expand bNAb precursor frequency before vaccination will be tested in three different mouse models with variable levels of polyclonality: I) In HC only knock-in mice which have the lowest level of polyclonality due to variable mouse light chains II) adoptive transfer of variable numbers of knock-in B cells expressing a single Env-specific BCR into wt mice and III) fully polyclonal mice expressing human germline Ig genes. The information obtained by these experiments will advance our understanding of how to approach the problem of how to develop a protective vaccine against HIV-1.
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0.916 |
2021 |
Bjorkman, Pamela J Nussenzweig, Michel C |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Enhancement of the Hiv Antibody Database Tool For Open Science @ California Institute of Technology
Project Summary The goal of our P01 HIVRAD Project is to advance our germline-targeting approach to HIV-1 vaccine design by cycles of immunogen design and testing in transgenic mice and macaques. The experiments proposed in this P01 grant will produce candidate immunogens for testing in macaques by collaborator Dr. Malcolm Martin and for vaccine trials in humans. One innovative aspect of the project is its integrated approach to structure determination and immunogen design, selection, and evaluation - the same people solving structures are also involved with immunogen design and screening, allowing a rapid and informed cycle of iterative improvements of immunogens. As part of this integrated approach, the Bjorkman lab has developed the software package HIV Antibody Database, which was designed to enable frictionless access to, comparisons of, and analyses of broadly neutralizing anti-HIV antibody sequences, structures, and neutralization data. This program includes a data analysis tool to identify HIV-1 Env sequence features responsible for neutralization/binding potency variability across strains. This innovative tool has allowed us to determine key interactions at Ab/Env interfaces using a combination of structural and bioinformatics analyses. We propose to enhance the HIV Antibody Database tool by improving its robustness and sustainability by integrating publicly available data streams, adopting standard formats for input and output of structural data, optimizing performance, and integrating another program developed by the Bjorkman lab, Variant Database, which can query a viral mutational landscape. Variant Database can quickly search SARS-CoV-2 genome datasets with over a million sequences. Thus, it can be used to detect emerging mutation patterns that might be overlooked in conventional phylogenetic analyses. We propose to generalize Variant Database to analyze different virus taxa, including HIV-1. Variant Database will be enhanced to be more robust and sustainable, and this version will be integrated with HIV Antibody Database.
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0.916 |