Biology subjects

Lora, J.

Publications and source records attributed to Lora, J..

5 recordsLinked to original sources

bioRxiv2025

Consistent Induction of Broadly Neutralizing HIV Antibodies by a Novel Two-Step Mechanism Informs Immunogen Design

A major obstacle confronting HIV-1 vaccine and cure research is the lack of an outbred animal model for rapid and consistent induction of broadly neutralizing antibodies (bNAbs). We designed an epitope-focused simian-human immunodeficiency virus (SHIV.5MUT) that elicited broad and potent V3-glycan-targeted antibodies within a year of infection in 14 of 22 macaques compared with 0 of 14 control animals. SHIV.5MUT elicited bNAbs by a novel two-step mechanism, inducing an initial wave of V1-directed antibodies that selected for Envs with shortened, hypoglycosylated V1 loops, which in turn primed V3-glycan bNAb precursors. Rhesus bNAbs were immunogenetically and structurally diverse, closely resembling human V3-glycan bNAbs. Env-bNAb coevolution revealed a diverse repertoire of bNAb precursors and the Env variants that matured them, yielding a molecular blueprint for vaccine design.

immunology↗

bioRxiv2025

Env-antibody coevolution identifies B cell priming as the principal bottleneck to HIV-1 V2 apex broadly neutralizing antibody development

Broadly neutralizing antibodies (bNAbs) are rarely elicited during HIV-1 infection. To identify obstacles to bNAb development, we longitudinally studied 122 rhesus macaques infected by one of 16 different simian-human immunodeficiency viruses (SHIVs). We identified V2 apex as the most common bNAb target and a subset of Envs that preferentially elicited these antibodies. In 10 macaques, we delineated Env-antibody coevolution from B cell priming to bNAb development. Antibody phylogenies revealed permissive developmental pathways guided by evolving Envs that contained few mutations in or near the V2 apex C-strand, which were a sensitive indicator of apex-targeted responses. The absence of such mutations reflected a failure in bNAb priming. These results indicate that efficiency of B cell priming, and not complexities in Env-guided affinity maturation, is the primary obstacle to V2 apex bNAb elicitation in SHIV-infected macaques and identify specific HIV-1 Envs to advance as novel vaccine platforms. One sentence summaryB cell priming is the primary bottleneck to HIV-1 V2 apex bNAb elicitation.

immunology↗

bioRxiv2024

Transient glycan-shield reduction induces CD4-binding site broadly neutralizing antibodies in SHIV-infected macaques

Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 CD4-binding site (CD4bs) occur infrequently in macaques and humans and have not been reproducibly elicited in any outbred animal model. To address this challenge, we first isolated RHA10, an infection-induced rhesus bNAb with 51% breadth. The cryo-EM structure of RHA10 with HIV-1 envelope (Env) resembled prototypic human CD4bs bNAbs with CDR-H3-dominated binding. Env-antibody co-evolution revealed transient elimination of two Env CD4bs-proximal glycans near the time of RHA10-lineage initiation, and these glycan-deficient Envs bound preferentially to early RHA10 intermediates, suggesting glycan deletions in infecting SHIVs could consistently induce CD4bs bNAbs. To test this, we constructed SHIV.CH505.D3 with CD4bs-proximal glycan deletions. Infection of 10 macaques resulted in accelerated CD4bs bNAb responses in 8, compared with 1 of 115 control macaques. Glycan hole-based immunofocusing coupled to Env-Ab co-evolution can consistently induce broad CD4bs responses in macaques and thus serve as a model for HIV vaccine design. HighlightsO_LIOut of 115 wildtype HIV-1 Env bearing SHIV infected macaques, only one macaque (T681) developed CD4bs bNAbs C_LIO_LICD4bs bNAbs in macaque T681 recognized Env similarly to previously described CDR-H3 dominated human CD4bs bNAbs and exhibited comparable breadth and potency C_LIO_LITransient CD4bs-proximal glycan deletions in macaque T681 preceded bNAb induction C_LIO_LIA novel SHIV with CD4bs-proximal glycan holes and enhanced CD4bs antigenicity immunofocused B cell responses to the CD4bs and elicited cross-clade neutralizing responses in 80% of macaques C_LI

microbiology↗

bioRxiv2024

Synthetic bacteria with programmed cell targeting and protein injection suppress tumor growth in vivo

Bacterial living therapeutics (BLTs) hold promise for treating cancer and other human diseases because they can be engineered and transported into the microbiota (e.g., of tumors, gastrointestinal tract) to deliver therapeutic payloads. Current approaches rely on the natural tropism of the bacterial chassis used and trigger the local release of protein cargoes, typically through active extracellular secretion or bacterial lysis. BLTs capable of targeting specific cellular subsets and delivering payloads intracellularly might provide new therapeutic opportunities and improve efficacy while reducing off-target effects. We used synthetic biology to develop BLTs that can deliver defined cargo proteins into the cytoplasm of target cells. We designed a modular synthetic bacterium with programmed adhesion to cells by targeting defined cell surface antigen and armed with an inducible type III secretion system (T3SS) for injection of a protein cargo of interest. As a proof of principle, we programmed synthetic bacteria to recognize the epidermal growth factor receptor (EGFR) and inject the catalytic fragments of the potent adenosine diphosphate-ribosyltransferase toxins ExoA and TccC3. These BLTs demonstrated the ability to trigger robust tumor cell death in vitro. Intratumoral administration of these synthetic bacteria suppressed tumor growth in vivo and prolonged the survival of treated animals when the tumor cells were recognized by the engineered bacteria. These results demonstrate the potential of programming cell targeting and controlled protein injection for the development of effective and specific BLTs. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/590337v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@eb769dorg.highwire.dtl.DTLVardef@b84b39org.highwire.dtl.DTLVardef@152b8b0org.highwire.dtl.DTLVardef@1db4108_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2021

Type I interferon modulates Langerhans cell ADAM17 to promote photosensitivity in lupus

BackgroundThe autoimmune disease lupus erythematosus (lupus) is characterized by photosensitivity, where even ambient ultraviolet radiation (UVR) exposure inflames skin. Beneficial effects of anifrolumab (anti-interferon /breceptor (anti-IFNAR)) on lupus skin disease support a pathogenic role for IFN-I, but mechanistic understanding is limited. We have shown that Langerhans cell (LC) dysfunction contributes to photosensitivity. Healthy LCs act via a disintegrin and metalloprotease 17 (ADAM17) to release epidermal growth factor receptor (EGFR) ligands that limit UVR-induced keratinocyte apoptosis and photosensitivity. However, LC ADAM17 activity is reduced in non-lesional lupus model skin, and data point to reduced LC-mediated protection in human lupus. Here, we asked about the role of the IFN-rich lupus skin environment in LC dysfunction and the implications of this regulation for photosensitivity. MethodsGene expression patterns in non-lesional skin from human lupus and multiple murine models were examined. We used MRL/lpr, B6.Sle1yaa, and imiquimod models of lupus in in vivo studies to assess the role of IFN-I in LC ADAM17 dysfunction and photosensitivity. ResultsWe show a shared IFN-rich environment in non-lesional skin across human and murine model systems, that IFN-I inhibits LC ADAM17 activity, and that anti-IFNAR in lupus models restores LC ADAM17 function and reduces photosensitivity in EGFR and LC ADAM17-dependent manners. Reactive oxygen species (ROS) can mediate ADAM17 activity, and we show reduced LC ROS expression in lupus models that is restored by anti-IFNAR. ConclusionsOur findings suggest that IFN-I promotes photosensitivity by causing LC ADAM17 dysfunction and that anifrolumab ameliorates lupus skin disease at least in part by restoring LC function. This work provides insight into IFN-I-mediated disease mechanisms, LC regulation, and a mechanism of action for anifrolumab in lupus.

immunology↗