As a NIAID clinician, my main focus has been on the diagnosis, evaluation and management of individuals with defined and undefined primary immunodeficiencies (PIDs) with a particular focus on those with hyper IgE syndromes. STAT3 mutated Hyper IgE syndrome (STAT3 DN; Job’s syndrome) is associated with eczematous dermatitis, recurrent boils, recurrent sinopulmonary infections, and multiple connective tissues, skeletal and vascular abnormalities. This is a rare primary immune deficiency, and our center allows us to study the largest cohort in the US, and likely in the world.  We currently follow more than 100 individuals with STAT3 DN and provide clinical care to many when well and during acute illnesses.  Through laboratory collaborations over the years, we have sought to understand STAT3’s role on human immunity, airway infection susceptibility and wound and vascular remodeling. Although our understanding of the pathogenesis of STAT3 has increased in recent years, there are still many unresolved questions regarding the pathogenesis of the varied features and the optimal therapies, including the role of hematopoietic stem cell transplantation and gene editing. 

1. Elicitation and maturation of VRC01-class antibodies in transgenic mouse models, which allows a germline human IGHV1-2*02 segment to undergo normal V(D)J recombination and, thereby, leads to the generation of peripheral B cells that express a highly diverse repertoire of VRC01-related receptors. A strong VRC01-class predicted germline precursor binder, eOD-GT8 60mer, was able to elicit and enrich VRC01-class antibodies in this mouse model.

2. Induction of HIV Neutralizing Antibody Lineages in Mice with Diverse Precursor Repertoires with sequential immunization. The serum from the stepwise immunized mice exhibited cross-strain neutralizing activities and the mutation frequency of both the IGHV1-2*02 IgH and VRC01 IgL chains steadily increased.

 3. Glycan Masking Focuses Immune Responses to the HIV-1 CD4-Binding Site and Enhances Elicitation of VRC01-Class Precursor Antibodies. A substantial portion of eOD-GT8-elicited antibodies target non-CD4bs epitopes, potentially limiting its efficacy. To mask irrelevant epitopes, we introduced N-linked glycans into non-CD4bs surfaces of eOD-GT8 and evaluated the mutants in a VRC01-class mouse model. Compared to the parental eOD-GT8, a mutant with five added glycans stimulated significantly higher proportions of CD4bs specific serum responses and CD4bs-specific immunoglobulin G+ B cells including VRC01-class precursors.

4. Antibody Lineages with Vaccine-Induced Antigen-Binding Hotspots Develop Broad HIV Neutralization. The vaccine-mediated elicitation of antibodies (Abs) capable of neutralizing diverse HIV-1 strains has been a long-standing goal. To understand how broadly neutralizing antibodies (bNAbs) develop, we identified, characterized, and tracked five neutralizing Ab lineages targeting the HIV-1-fusion peptide (FP) in vaccinated macaques over time. Genetic and structural analyses revealed two of these lineages to belong to a reproducible class capable of neutralizing up to 59% of 208 diverse viral strains. B cell analysis indicated that each of the five lineages was initiated and expanded by FP-carrier priming, with envelope (Env)-trimer boosts inducing cross-reactive neutralization.

5. Fusion Peptide Priming –Alone or in Cocktail with Env Trimer– Imprints Broad HIV-1-Neutralizing Responses with a Characteristic Early B Cell Signature. To optimize the immunization regimen and shorten the “neutralization-eclipse phase”, we analyzed plasma and antigen-specific B cells from 7 different immunization regimens in 32 macaques with a common boosting module comprising five FP/Trimer immunizations. We found that FP priming to imprint cross-reactive FP-directed HIV-neutralizing responses, with FP-trimer cocktail elicited the earliest cross-strain responses.

6. Fusion Peptide Priming Reduces Immune Responses to HIV-1 Envelope Trimer Base. Soluble ‘SOSIP’-stabilized envelope (Env) trimers are promising HIV-vaccine immunogens. However, they induce high titer responses against the glycan-free trimer base, which is occluded on native virions. To delineate the impact on base responses of priming with immunogens targeting the fusion peptide (FP) site of vulnerability, we quantified the prevalence of trimer-base antibody responses in 49 non-human primates (NHPs) immunized with various SOSIP-stabilized Env trimers and FP-carrier conjugates. We found that trimer-base responses accounted for ~90% of the overall trimer response in animals immunized with trimer only, ~70% in animals immunized with a cocktail of SOSIP-trimer and FP-conjugate, and ~30% in animals primed with FP-conjugate prior to trimer immunization, with neutralization breadth in FP-conjugate-primed animals correlated inversely with trimer-base responses.

The Respiratory Viruses Core (RVC) within the Molecular Immunoengineering Section (MIS) at the Vaccine Research Center is focused on the development and testing of countermeasures for respiratory diseases caused by RNA viruses. Activities in the RVC range from antigen design and preclinical immunogenicity testing to exploratory studies using samples from human clinical trials. We have a long-standing interest in respiratory syncytial virus (RSV), which can cause serious illness, particularly for infants and older adults, and have evaluated immune responses to the prefusion F subunit vaccine, DS-Cav1, in a phase I clinical trial. Clinical samples were assessed for neutralizing activity against RSV, and B cell and T cell responses to vaccination were also determined. We continue to explore adaptive immunity to RSV infection and vaccination in ongoing research projects.

Our work also includes a variety of resurging and emerging viral pathogens, including paramyxoviruses, Zika, SARS-CoV-2, and enterovirus D68 (EV-D68). This often involves assay and model development for proof-of-concept immunogenicity and protection studies. We perform a variety of serological assays and use tools such as multiparameter flow cytometry to evaluate cellular responses and for monoclonal antibody discovery. RVC efforts are closely integrated with that of the MIS, and often support VRC-wide vaccine development efforts.

The Molecular Immunoengineering Section (MIS) at the Vaccine Research Center aims to conceive novel vaccine concepts that elicit broad and potent protective immune responses against influenza virus and provide a mechanistic principle for designing vaccines for other hypervariable pathogens such as coronaviruses and HIV-1. MIS is dedicated to advancing vaccine immunogen design beyond structure-based protein engineering by combining concepts and principles from multiple disciplines, including, but not limited to, immunobiology, biochemistry, biophysics, nanotechnology, and computational biology. The mission of the MIS is to define the fundamental rules behind vaccine-elicited immunity. Our interests span from basic immunology and virology to translational sciences with the goal of advancing vaccine concepts that would radically improve immune responses to vaccines. Our work involves various biochemical, biophysical, structural, immunological, and computational techniques and tools. MIS efforts include development of “supraseasonal” and “pre-pandemic” influenza vaccine candidates, “mosaic” antigen display technology, high-throughput high-definition virus neutralization assay systems, and animal models that recapitulate key aspects of human responses to influenza, such as immunological imprinting, preexisting immunity, antibody specificity and repertoire, immunodominance, and pathogenesis. MIS is also integrated with the VRC’s Influenza Program by serving as the lead of the Vaccine Concepts team. The Influenza Program involves multiple VRC Sections and Programs with the goal of advancing candidate vaccines from bench to clinic.