| 1. |
- Ols, Sebastian, et al.
(författare)
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Route of Vaccine Administration Alters Antigen Trafficking but Not Innate or Adaptive Immunity
- 2020
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Ingår i: CELL REPORTS. - : Elsevier BV. - 2211-1247. ; 30:12
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Tidskriftsartikel (refereegranskat)abstract
- Although intramuscular (i.m.) administration is the most commonly used route for licensed vaccines, subcutaneous (s.c.) delivery is being explored for several new vaccines under development. Here, we use rhesus macaques, physiologically relevant to humans, to identify the anatomical compartments and early immune processes engaged in the response to immunization via the two routes. Administration of fluorescently labeled HIV-1 envelope glycoprotein trimers displayed on liposomes enables visualization of targeted cells and tissues. Both s.c. and i.m. routes induce efficient immune cell infiltration, activation, and antigen uptake, functions that are tightly restricted to the skin and muscle, respectively. Antigen is also transported to different lymph nodes depending on route. However, these early differences do not translate into significant differences in the magnitude or quality of antigen-specific cellular and humoral responses over time. Thus, although some distinct immunological differences are noted, the choice of route may instead be motivated by clinical practicality.
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| 2. |
- Phad, Ganesh E., et al.
(författare)
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Extensive dissemination and intraclonal maturation of HIV Env vaccine-induced B cell responses
- 2020
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 217:2
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Tidskriftsartikel (refereegranskat)abstract
- Well-ordered HIV-1 envelope glycoprotein (Env) trimers are prioritized for clinical evaluation, and there is a need for an improved understanding about how elicited B cell responses evolve following immunization. To accomplish this, we prime-boosted rhesus macaques with Glade C NFL trimers and identified 180 unique Ab lineages from similar to 1,000 single-sorted Envspecific memory B cells. We traced all lineages in high-throughput heavy chain (HC) repertoire (Rep-seq) data generated from multiple immune compartments and time points and expressed several as monoclonal Abs (mAbs). Our results revealed broad dissemination and high levels of somatic hypermutation (SHM) of most lineages, including tier 2 virus neutralizing lineages, following boosting. SHM was highest in the Ab complementarity determining regions (CDRs) but also surprisingly high in the framework regions (FRO, especially FR3. Our results demonstrate the capacity of the immune system to affinity-mature large numbers of Env-specific B cell lineages simultaneously, supporting the use of regimens consisting of repeated boosts to improve each Ab, even those belonging to less expanded lineages.
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| 3. |
- Pushparaj, Pradeepa
(författare)
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Immunoglobulin gene usage and affinity maturation in antiviral antibodies
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The ability of antibodies to block infections makes them highly relevant for successful vaccine development. Through the papers described in this thesis, I attempt to characterize the functional and genetic aspects of antiviral antibodies induced by infection and vaccination. In Paper I, we characterized the distribution and maturation of HIV-1 envelope glycoproteins (Env)-specific antibody lineages post-vaccination in different immune compartments of rhesus macaques. Vaccine-induced Env-specific antibody lineages were disseminated across the periphery, lymph node, spleen, and bone marrow (BM) but not in gut tissue. We observed a consistent increase in the somatic hypermutation (SHM) levels of Env-specific antibody sequences after each boost and the SHM levels strongly correlated with the affinity of members from a potent neutralizing antibody lineage. In Paper II, we set out to understand the role of SHM in a broad, potent, public class of antibodies isolated from a healthcare worker who was previously infected with SARS-CoV2. I selected a potent neutralizing antibody and reverted the heavy chain (HC) to the germline sequence. I then sequentially introduced individual or combinations of SHM so that we could test the functional impact of this. We found a substantial gain of antibody potency and breadth when certain SHM mutations were reintroduced, and we identified two key mutations that largely contributed to the breadth of this lineage. Furthermore, we showed that the mature antibody retained neutralizing activity against potential future viral variants by deep mutational scanning (DMS) experiments. A high-resolution structure of this antibody obtained by cryo-electron microscopy (cryo-EM) confirmed important interactions made by the identified SHMs with the SARS-CoV-2 spike (S). In Papers III and IV, we investigated the effect of immunoglobulin heavy chain variable (IGHV) gene polymorphisms on the function of human SARS-CoV-2 antibodies isolated post-infection. We genotyped a cohort of previously infected healthcare workers and evaluated the neutralization activity of germline-reverted and allele-swapped S-specific IGHV1-69*20-using antibodies from two independent donors carrying this allele. Neutralization was retained when reverting the IGHV region to the germline IGHV1- 69∗20 allele but lost when reverting to other IGHV1-69 alleles demonstrating a strong allele-dependence in these antibodies. A high resolution cryo-EM structure of one of the antibodies revealed significant contacts made by two IGHV1-69*20-germline encoded amino acid residues with the S, illustrating the impact of IGHV polymorphisms on antibody functions. We next focused on the IGHV3-30 group of genes, which are frequently used by S-specific antibodies. By IGHV genotype and haplotype analysis we observed that IGHV3-30-3 gene was deleted in many individuals, and the IGHV3-30 alleles were heterogeneously distributed in our cohort. When the IGHV region of an IGHV3-30-3*01 neutralizing antibody was swapped with IGHV3-30 alleles, the neutralization remained unaffected demonstrating functional redundancy within this gene group, at least for this antibody lineage. The results from my doctoral research provide insight into functional and genetic properties of antibodies induced by viral antigens, which have important clinical relevance both for guided-vaccine design and monoclonal antibody therapeutics, and for our general understanding of antibody responses in the population.
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| 4. |
- Pushparaj, Pradeepa, et al.
(författare)
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Immunoglobulin germline gene polymorphisms influence the function of SARS-CoV-2 neutralizing antibodies
- 2023
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Ingår i: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 56:1, s. 7-206
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Tidskriftsartikel (refereegranskat)abstract
- The human immunoglobulin heavy-chain (IGH) locus is exceptionally polymorphic, with high levels of allelic and structural variation. Thus, germline IGH genotypes are personal, which may influence responses to infection and vaccination. For an improved understanding of inter-individual differences in antibody responses, we isolated SARS-CoV-2 spike-specific monoclonal antibodies from convalescent health care workers, focusing on the IGHV1-69 gene, which has the highest level of allelic variation of all IGHV genes. The IGHV1-69∗20-using CAB-I47 antibody and two similar antibodies isolated from an independent donor were critically dependent on allele usage. Neutralization was retained when reverting the V region to the germline IGHV1-69∗20 allele but lost when reverting to other IGHV1-69 alleles. Structural data confirmed that two germline-encoded polymorphisms, R50 and F55, in the IGHV1-69 gene were required for high-affinity receptor-binding domain interaction. These results demonstrate that polymorphisms in IGH genes can influence the function of SARS-CoV-2 neutralizing antibodies.
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