Document text
Principal Investigator: Jenna Guthmiller
Organization: UNIVERSITY OF COLORADO DENVER
Fiscal Year: 2024
Award: $436,669
Funding agency: National Institute of Allergy and Infectious Diseases
PROJECT SUMMARY
Influenza viruses remain a major global threat to human health, which is exacerbated by the lack of an effective
vaccine. Humoral immunity does not target all parts of the virus evenly, a phenomenon known as
immunodominance. Following seasonal vaccination, humans preferentially generate antibody responses against
evolving epitopes of the hemagglutinin (HA) head domain rather than against broadly protective epitopes of the
conserved stalk domain. In the absence of preexisting immunity against the HA head, as occurred with the 2009
pandemic H1N1 virus, humans can preferentially recall memory B cells against the stalk domain. However, naïve
B cells against novel epitopes of the HA head are induced, populate the memory B cell pool, and are
preferentially recalled following exposure to an antigenically similar virus. Therefore, immunodominance of the
head domain and the preferential recruitment of naïve B cells against new epitopes remains a major obstacle for
the generation of a broadly protective influenza vaccine. In order to generate broadly protective humoral
immunity, a vaccine needs to be designed that induces robust and durable antibody responses against the stalk
domain but prevents the recruitment of naïve B cells against neoepitopes.
Immunodominance is in part dictated by which B cells can acquire antigen and efficiently present antigen to CD4
T cells. B cell avidity, the simultaneous binding of both binding-sites of an antibody with its epitope and the cross-
linking of multiple B cell receptors on a B cells, plays a critical role in which B cell specificities are selected. B
cells against the head domain have an avidity advantage, as these epitopes are more accessible than those of
the stalk domain. We hypothesize that reducing B cell avidity for head epitopes will reduce competition for
antigen, limit the induction of anti-head B cells, and preferentially select for B cells against the stalk domain.
Using combinatorial mutagenesis and yeast-display, we will generate and select for a library of stable HAs with
diverse head epitopes but an identical stalk domain, which we refer to as scrambled HA (Aim 1). By titrating the
diversity of scrambled HAs, we will determine the effect of increasing head epitope diversity on which B and T
follicular helper cell specificities are induced. We will perform these experiments in naïve and H1N1 immune
mice to mimic immune histories in infants and adults, respectively (Aim 2). Moreover, we will immunize human
ex vivo lymph node organoids generated from individuals of diverse immune histories to determine if our
approach recalls memory B cells against the stalk domain (Aim 3). Together, this study will generate a vaccine
that shifts immunodominance towards the stalk domain, which will be proven using multiple models of preexisting
immunity. Although this proposal focuses on shifting immunodominance of anti-influenza humoral immunity, the
approach taken provides a proof-of-concept that can be applied to other rapidly evolving pathogens for which
immunodominance is a key barrier for successful vaccine generation, including HIV and coronaviruses.
Terms: <2019 novel corona virus><2019 novel coronavirus><2019-nCoV><21+ years old><AIDS Virus><Acquired Immune Deficiency Syndrome Virus><Acquired Immunodeficiency Syndrome Virus><Adult><Adult Human><Affinity><Antibodies><Antibody Binding Sites><Antibody Response><Antigen Presentation><Antigen Variation><Antigenic Determinants><Antigenic Variability><Antigenic Variation><Antigens><Avidity><B blood cells><B cell><B cell receptor><B cells><B-Cell Antigen Receptor><B-Cells><B-Lymphocytes><B-cell><Binding><Binding Determinants><Binding Sites><Blood Serum><CD4 Cells><CD4 Positive T Lymphocytes><CD4 T cells><CD4 helper T cell><CD4 lymphocyte><CD4+ T-Lymphocyte><CD4-Positive Lymphocytes><COVID-19 virus><COVID19 virus><Clinical Treatment Moab><CoV-2><CoV2><Combining Site><Coronaviridae><Coronavirus><EBOV><Ebola virus><Ebola-like Viruses><Epitopes><Exposure to><Flavivirus><Frequencies><Generations><Genetic Alteration><Genetic Change><Genetic defect><Genetics-Mutagenesis><Group B Arbovirus><H1N1><H1N1 Virus><HIV><Hantavirus><Head><Health><Helper Cells><Helper T-Cells><Helper T-Lymphocytes><Helper-Inducer T-Cells><Helper-Inducer T-Lymphocyte><Hemagglutinin><History><Human><Human Immunodeficiency Viruses><Humoral Immunities><Immune><Immune system><Immunes><Immunity><Immunize><Immunochemical Immunologic><Immunologic><Immunological><Immunologically><Immunologics><Individual><Inducer Cells><Inducer T-Lymphocytes><Infant><Influenza A Virus, H1N1 Subtype><Influenza Vaccines><Influenza Virus><Knowledge><LAV-HTLV-III><Laboratories><Libraries><Lymph Node Reticuloendothelial System><Lymph node proper><Lymphadenopathy-Associated Virus><Lymphatic nodes><Memory B Cell><Memory B-Lymphocyte><Mice><Mice Mammals><Modeling><Modern Man><Molecular Interaction><Monoclonal Antibodies><Murine><Mus><Mutagenesis><Mutagenesis Molecular Biology><Mutate><Mutation><Organoids><Orthoflavivirus><Parasites><Paratopes><Plasmodium><Play><Population><Postdoc><Postdoctoral Fellow><Pre-Clinical Model><Preclinical Models><Reactive Site><Recording of previous events><Research><Research Associate><Role><SARS corona virus 2><SARS-CO-V2><SARS-COVID-2><SARS-CoV-2><SARS-CoV2><SARS-associated corona virus 2><SARS-associated coronavirus 2><SARS-coronavirus-2><SARS-related corona virus 2><SARS-related coronavirus 2><SARSCoV2><Seasons><Serum><Severe Acute Respiratory Coronavirus 2><Severe Acute Respiratory Distress Syndrome CoV 2><Severe Acute Respiratory Distress Syndrome Corona Virus 2><Severe Acute Respiratory Distress Syndrome Coronavirus 2><Severe Acute Respiratory Syndrome CoV 2><Severe Acute Respiratory Syndrome-associated coronavirus 2><Severe Acute Respiratory Syndrome-related coronavirus 2><Severe acute respiratory syndrome associated corona virus 2><Severe acute respiratory syndrome coronavirus 2><Severe acute respiratory syndrome related corona virus 2><Shapes><Site><Specificity><T cell response><T4 Cells><T4 Lymphocytes><Testing><Titrations><Vaccination><Vaccine Antigen><Vaccine Design><Vaccines><Variant><Variation><Virus><Virus-HIV><Work><Wuhan coronavirus><Yeasts><adulthood><anti-flu><anti-influenza><antibody combining site><antibody-based immunity><antiflu><combinatorial><corona virus><coronavirus disease 2019 virus><coronavirus disease-19 virus><crosslink><design><designing><emerging pathogen><evaluate vaccines><experiment><experimental research><experimental study><experiments><flu vaccine><flu virus vaccine><genome mutation><hCoV19><histories><immunogen><improved><influenza virus vaccine><influenzavirus><lymph gland><lymph nodes><lymphnodes><mAbs><memory recall><monoclonal Abs><monoclonal antibody production><nCoV2><neo-antigen><neo-epitopes><neoantigens><neoepitopes><new pathogen><novel><novel pathogen><pandemic><pandemic disease><pathogen><post-doc><post-doctoral><post-doctoral trainee><prevent><preventing><rational design><recruit><research associates><response><seasonal flu><seasonal influenza><social role><translational immunology><vaccine against flu><vaccine against influenza><vaccine candidate><vaccine efficacy><vaccine evaluation><vaccine screening><vaccine testing>