Project description:Here we applied a systems approach to define human innate immune signatures following MRKAd5/HIV immunization and to analyze the effects of pre-existing Ad5 immunity. We defined the global early immune response to MRKAd5/HIV by profiling the PBMC transcriptomes from seven Ad5Neg individuals pre- and post-vaccination in vivo. Since the Step Study results suggested a deleterious effect of pre-existing Ad5 nAb on vaccine immunogenicity, we examined the vaccine-induced transcriptional responses from two Ad5Med and one Ad5Low individual 50 total samples were analyzed. This includes 5 time points post vaccination with MRKAd5/HIV for 10 independent human subjects. The time points were 0hr, 6hrs, 24hrs, 72hrs, and 168hrs. Seven of the subjects did not have pre-existing neutralizing antibodies to the vaccine vector (Ad5Neg). One subject had low level pre-existing neutralizing antibodies to the vaccine vector (Ad5Low). Two subjects had moderate level pre-existing neutralizing antibodies to the vaccine vector (Ad5Low).
Project description:We sought to determine differences in transcript expression between a cohort of HIV-infected individuals that either developed broadly neutralizing antibodies (bnAb) or did not develop them (control). With the ultimate goal to identify transcripts that are associated with the development of bnAbs that would identify novel pathways that could be targeted in future vaccine strategies to increase the frequency of individuals that develop bnAbs against HIV. Using this approach we identified that Rab11 recycling endosomes, particularly in dysfunctional natural killer cells are associated with the development of HIV-1 bnAbs.
Project description:Broadly HIV-1 neutralizing VRC01-class antibodies target the CD4-binding site of Env. They are derived from VH1-2*02 antibody heavy chains paired with rare light chains expressing five amino acid long CDRL3s. They have been isolated from infected subjects but have not yet been elicited by immunization. Env-derived immunogens capable of binding the germline forms of VRC01 B cell receptors on naïve B cells have been designed and evaluated in knock-in mice. However, the elicited antibodies cannot bypass glycans present on the conserved position N276 of Env, which restricts access to the CD4-binding site. Efforts to guide the appropriate maturation of these antibodies by sequential immunization have not yet been successful. Here, we report on a two-step immunization scheme that led to the maturation of VRC01-like antibodies capable of accommodating the N276 glycan and displaying autologous tier 2 neutralizing activities. Our results are relevant to clinical trials aiming to elicit VRC01 antibodies.
Project description:Many human monoclonal antibodies that neutralize multiple clades of HIV-1 are polyreactive and bind avidly to mammalian autoantigens. Indeed, the generation of neutralizing antibodies to the 2F5 and 4E10 epitopes of HIV-1 gp41 in man may be proscribed by immune tolerance since mice expressing the VH and VL regions of 2F5 have a block in B-cell development characteristic of central tolerance. This developmental blockade implies the presence of tolerizing autoantigens that are mimicked by the membrane-proximal external region of HIV-1 gp41. Here we identify human kynureninase (KYNU) and splicing factor 3b subunit 3 (SF3B3) as the primary conserved, vertebrate self-antigens recognized by the 2F5 and 4E10 antibodies, respectively. 2F5 binds the H4 domain of KYNU which contains the complete 2F5 linear epitope (ELDKWA). 4E10 recognizes a conformational epitope of SF3B3 that is strongly dependent on hydrophobic interactions. Opossums carry a rare KYNU H4 domain that abolishes 2F5 binding, but retain all SF3B3 4E10 epitopes. Immunization of opossums with HIV-1 gp140 induced extraordinary titers of serum antibody to the 2F5 ELDKWA epitope but little or nothing to the 4E10 determinant. Identification of structural motif shared by vertebrates and HIV-1 provides direct evidence that immunological tolerance can impair humoral responses to HIV-1. The invitrogen protoarray that contains >9,400 recombinant human proteins was used to identify self-ligands that are recognized by broadly neutralizing HIV-1 antibodies 2F5 and 4E10. An isotype-matched human myeloma protein (151K, Southern Biotech) was used as control.
Project description:HIV-1 vaccine immunofocusing strategies have the potential to induce broadly reactive nAbs. Here, we engineered a panel of diverse, membrane-resident native HIV-1 trimers vulnerable to two broad targets of neutralizing antibodies (NAbs), the V2 apex and fusion peptide (FP). This dataset contains the raw files used to obtain site-spefific glycan analysis of the membrane-resident HIV-1 trimers
Project description:Tissue-like memory, activated memory and resting memory B cells were sorted by FACS from the individual living with HIV (EC17) who was aviremic and transcriptomes generated using the SmartSeq2 protocol. This was to provide a reference set for each memory B cell subset in the context of HIV. Next, HIV-specific memory B cells from the individual with broadly neutralizing plasma were then also sorted by FACS and single cell transcriptomes generated using the SmartSeq2 protocol. The phenotypes of memory B cells from the individual with broadly neutralizing plasma (T125) were then inferred from the reference set using Glmnet and Celltypist packages.
Project description:A protective HIV-1 vaccine has been hampered by a limited understanding of how B cells acquire neutralizing activity. Our previous vaccines expressing two different HIV-1 envelopes elicited robust antigen specific serum IgG titers in 20 rhesus macaques; yet serum from only two animals neutralized the autologous virus. Here, we used high throughput immunoglobulin receptor and single cell RNA sequencing to characterize the overall expansion, recall, and maturation of antigen specific B cells longitudinally over 90 weeks. Diversification and expansion of many B cell clonotypes occurred broadly in the absence of serum neutralization. However, in one animal that developed neutralization, two neutralizing B cell clonotypes arose from the same immunoglobulin germline and were tracked longitudinally. Early antibody variants with high identity to germline neutralized the autologous virus while later variants acquired somatic hypermutation and increased neutralization potency. The early engagement of precursors capable of neutralization with little to no SHM followed by prolonged affinity maturation allowed the two neutralizing lineages to successfully persist despite many other antigen specific B cells. The findings provide new insight into B cells responding to HIV-1 envelope during heterologous prime and boost immunization in rhesus macaques and the development of selected autologous neutralizing antibody lineages