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1.
Cell ; 184(11): 2955-2972.e25, 2021 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-34019795

RESUMEN

Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , VIH-1/inmunología , Fragmentos Fab de Inmunoglobulinas/inmunología , Polisacáridos/inmunología , SARS-CoV-2/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Linfocitos B/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , COVID-19/inmunología , Dimerización , Epítopos/inmunología , Glicosilación , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Macaca mulatta , Polisacáridos/química , Receptores de Antígenos de Linfocitos B/química , Virus de la Inmunodeficiencia de los Simios/genética , Vacunas/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
2.
Cell ; 182(4): 812-827.e19, 2020 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-32697968

RESUMEN

A SARS-CoV-2 variant carrying the Spike protein amino acid change D614G has become the most prevalent form in the global pandemic. Dynamic tracking of variant frequencies revealed a recurrent pattern of G614 increase at multiple geographic levels: national, regional, and municipal. The shift occurred even in local epidemics where the original D614 form was well established prior to introduction of the G614 variant. The consistency of this pattern was highly statistically significant, suggesting that the G614 variant may have a fitness advantage. We found that the G614 variant grows to a higher titer as pseudotyped virions. In infected individuals, G614 is associated with lower RT-PCR cycle thresholds, suggestive of higher upper respiratory tract viral loads, but not with increased disease severity. These findings illuminate changes important for a mechanistic understanding of the virus and support continuing surveillance of Spike mutations to aid with development of immunological interventions.


Asunto(s)
Betacoronavirus/genética , Betacoronavirus/patogenicidad , Infecciones por Coronavirus/virología , Neumonía Viral/virología , Glicoproteína de la Espiga del Coronavirus/genética , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/fisiopatología , Monitoreo Epidemiológico , Aptitud Genética , Variación Genética , Sistemas de Información Geográfica , Hospitalización , Humanos , Pandemias , Filogenia , Neumonía Viral/epidemiología , Neumonía Viral/fisiopatología , Sistema Respiratorio/virología , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Carga Viral
3.
Immunity ; 51(4): 724-734.e4, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31586542

RESUMEN

HIV- and SIV-envelope (Env) trimers are both extensively glycosylated, and antibodies identified to date have been unable to fully neutralize SIVmac239. Here, we report the isolation, structure, and glycan interactions of antibody ITS90.03, a monoclonal antibody that completely neutralized the highly neutralization-resistant isolate, SIVmac239. The co-crystal structure of a fully glycosylated SIVmac239-gp120 core in complex with rhesus CD4 and the antigen-binding fragment of ITS90.03 at 2.5-Å resolution revealed that ITS90 recognized an epitope comprised of 45% glycan. SIV-gp120 core, rhesus CD4, and their complex could each be aligned structurally to their human counterparts. The structure revealed that glycans masked most of the SIV Env protein surface, with ITS90 targeting a glycan hole, which is occupied in ∼83% of SIV strains by glycan N238. Overall, the SIV glycan shield appears to functionally resemble its HIV counterpart in coverage of spike, shielding from antibody, and modulation of receptor accessibility.


Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Neutralizantes/química , Infecciones por VIH/inmunología , VIH/fisiología , Polisacáridos/química , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Monoclonales/metabolismo , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Neutralizantes/metabolismo , Antígenos CD4/metabolismo , Células Cultivadas , Cristalización , Cristalografía por Rayos X , Modelos Animales de Enfermedad , Glicosilación , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/metabolismo , Proteína gp120 de Envoltorio del VIH/metabolismo , Humanos , Macaca mulatta , Glicoproteínas de Membrana/metabolismo , Polisacáridos/metabolismo , Unión Proteica , Relación Estructura-Actividad , Proteínas del Envoltorio Viral/metabolismo
4.
Immunity ; 46(6): 1073-1088.e6, 2017 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-28636956

RESUMEN

The development of stabilized recombinant HIV envelope trimers that mimic the virion surface molecule has increased enthusiasm for a neutralizing antibody (nAb)-based HIV vaccine. However, there is limited experience with recombinant trimers as immunogens in nonhuman primates, which are typically used as a model for humans. Here, we tested multiple immunogens and immunization strategies head-to-head to determine their impact on the quantity, quality, and kinetics of autologous tier 2 nAb development. A bilateral, adjuvanted, subcutaneous immunization protocol induced reproducible tier 2 nAb responses after only two immunizations 8 weeks apart, and these were further enhanced by a third immunization with BG505 SOSIP trimer. We identified immunogens that minimized non-neutralizing V3 responses and demonstrated that continuous immunogen delivery could enhance nAb responses. nAb responses were strongly associated with germinal center reactions, as assessed by lymph node fine needle aspiration. This study provides a framework for preclinical and clinical vaccine studies targeting nAb elicitation.


Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Centro Germinal/inmunología , Anticuerpos Anti-VIH/uso terapéutico , Infecciones por VIH/terapia , VIH-1/inmunología , Animales , Células Cultivadas , Epítopos de Linfocito B/química , Epítopos de Linfocito B/inmunología , Centro Germinal/virología , Infecciones por VIH/inmunología , Humanos , Inmunización , Inyecciones Subcutáneas , Primates , Multimerización de Proteína , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología
5.
PLoS Pathog ; 18(6): e1010507, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35714165

RESUMEN

The HIV/SIV envelope glycoprotein (Env) cytoplasmic domain contains a highly conserved Tyr-based trafficking signal that mediates both clathrin-dependent endocytosis and polarized sorting. Despite extensive analysis, the role of these functions in viral infection and pathogenesis is unclear. An SIV molecular clone (SIVmac239) in which this signal is inactivated by deletion of Gly-720 and Tyr-721 (SIVmac239ΔGY), replicates acutely to high levels in pigtail macaques (PTM) but is rapidly controlled. However, we previously reported that rhesus macaques and PTM can progress to AIDS following SIVmac239ΔGY infection in association with novel amino acid changes in the Env cytoplasmic domain. These included an R722G flanking the ΔGY deletion and a nine nucleotide deletion encoding amino acids 734-736 (ΔQTH) that overlaps the rev and tat open reading frames. We show that molecular clones containing these mutations reconstitute signals for both endocytosis and polarized sorting. In one PTM, a novel genotype was selected that generated a new signal for polarized sorting but not endocytosis. This genotype, together with the ΔGY mutation, was conserved in association with high viral loads for several months when introduced into naïve PTMs. For the first time, our findings reveal strong selection pressure for Env endocytosis and particularly for polarized sorting during pathogenic SIV infection in vivo.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Endocitosis , Productos del Gen env/genética , Macaca mulatta/metabolismo , Macaca nemestrina , Síndrome de Inmunodeficiencia Adquirida del Simio/genética , Síndrome de Inmunodeficiencia Adquirida del Simio/patología , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/metabolismo
6.
PLoS Pathog ; 18(11): e1010945, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36395347

RESUMEN

Broadly neutralizing antibodies (bNAbs) have remarkable breadth and potency against most HIV-1 subtypes and are able to prevent HIV-1 infection in animal models. However, bNAbs are extremely difficult to induce by vaccination. Defining the developmental pathways towards neutralization breadth can assist in the design of strategies to elicit protective bNAb responses by vaccination. Here, HIV-1 envelope glycoproteins (Env)-specific IgG+ B cells were isolated at various time points post infection from an HIV-1 infected elite neutralizer to obtain monoclonal antibodies (mAbs). Multiple antibody lineages were isolated targeting distinct epitopes on Env, including the gp120-gp41 interface, CD4-binding site, silent face and V3 region. The mAbs each neutralized a diverse set of HIV-1 strains from different clades indicating that the patient's remarkable serum breadth and potency might have been the result of a polyclonal mixture rather than a single bNAb lineage. High-resolution cryo-electron microscopy structures of the neutralizing mAbs (NAbs) in complex with an Env trimer generated from the same individual revealed that the NAbs used multiple strategies to neutralize the virus; blocking the receptor binding site, binding to HIV-1 Env N-linked glycans, and disassembly of the trimer. These results show that diverse NAbs can complement each other to achieve a broad and potent neutralizing serum response in HIV-1 infected individuals. Hence, the induction of combinations of moderately broad NAbs might be a viable vaccine strategy to protect against a wide range of circulating HIV-1 viruses.


Asunto(s)
Seropositividad para VIH , VIH-1 , Animales , Anticuerpos ampliamente neutralizantes , Microscopía por Crioelectrón , Anticuerpos Monoclonales , Proteína gp120 de Envoltorio del VIH
7.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-33431684

RESUMEN

The HIV-1 gp41 N-heptad repeat (NHR) region of the prehairpin intermediate, which is transiently exposed during HIV-1 viral membrane fusion, is a validated clinical target in humans and is inhibited by the Food and Drug Administration (FDA)-approved drug enfuvirtide. However, vaccine candidates targeting the NHR have yielded only modest neutralization activities in animals; this inhibition has been largely restricted to tier-1 viruses, which are most sensitive to neutralization by sera from HIV-1-infected individuals. Here, we show that the neutralization activity of the well-characterized NHR-targeting antibody D5 is potentiated >5,000-fold in TZM-bl cells expressing FcγRI compared with those without, resulting in neutralization of many tier-2 viruses (which are less susceptible to neutralization by sera from HIV-1-infected individuals and are the target of current antibody-based vaccine efforts). Further, antisera from guinea pigs immunized with the NHR-based vaccine candidate (ccIZN36)3 neutralized tier-2 viruses from multiple clades in an FcγRI-dependent manner. As FcγRI is expressed on macrophages and dendritic cells, which are present at mucosal surfaces and are implicated in the early establishment of HIV-1 infection following sexual transmission, these results may be important in the development of a prophylactic HIV-1 vaccine.


Asunto(s)
Proteína gp41 de Envoltorio del VIH/inmunología , Infecciones por VIH/tratamiento farmacológico , Receptores de IgG/inmunología , Secuencias Repetitivas de Aminoácido/genética , Secuencia de Aminoácidos , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/farmacología , Afinidad de Anticuerpos , Cobayas , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/farmacología , Proteína gp41 de Envoltorio del VIH/genética , Infecciones por VIH/genética , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Seropositividad para VIH/inmunología , VIH-1/efectos de los fármacos , VIH-1/inmunología , VIH-1/patogenicidad , Humanos , Sueros Inmunes/inmunología , Sueros Inmunes/farmacología , Inmunización , Inmunoglobulina G/inmunología , Secuencias Repetitivas de Aminoácido/inmunología , Internalización del Virus/efectos de los fármacos
8.
J Virol ; 96(11): e0023122, 2022 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-35536018

RESUMEN

Despite the worldwide availability of antiretroviral therapy (ART), approximately 150,000 pediatric HIV infections continue to occur annually. ART can dramatically reduce HIV mother-to-child transmission (MTCT), but inconsistent drug access and adherence, as well as primary maternal HIV infection during pregnancy and lactation are major barriers to eliminating vertical HIV transmission. Thus, immunologic strategies to prevent MTCT, such as an HIV vaccine, will be required to attain an HIV-free generation. A primary goal of HIV vaccine research has been to elicit broadly neutralizing antibodies (bnAbs) given the ability of passive bnAb immunization to protect against sensitive strains, yet we previously observed that HIV-transmitting mothers have more plasma neutralization breadth than nontransmitting mothers. Additionally, we have identified infant transmitted/founder (T/F) viruses that escape maternal bnAb responses. In this study, we examine a cohort of postpartum HIV-transmitting women with neutralization breadth to determine if certain maternal bnAb specificities drive the selection of infant T/F viruses. Using HIV pseudoviruses that are resistant to neutralizing antibodies targeting common bnAb epitopes, we mapped the plasma bnAb specificities of this cohort. Significantly more transmitting women with plasma bnAb activity had a mappable plasma bnAb specificity (six of seven, or 85.7%) compared to that of nontransmitting women with plasma bnAb activity (7 of 21, or 33.3%, P = 0.029 by 2-sided Fisher exact test). Our study suggests that having multispecific broad activity and/or uncommon epitope-specific bnAbs in plasma may be associated with protection against the vertical HIV transmission in the setting of maternal bnAb responses. IMPORTANCE As mother to child transmission (MTCT) of HIV plays a major part in the persistence of the HIV/AIDS epidemic and bnAb-based passive and active vaccines are a primary strategy for HIV prevention, research in this field is of great importance. While previous MTCT research has investigated the neutralizing antibody activity of HIV-infected women, this is, to our knowledge, the largest study identifying differences in bnAb specificity of maternal plasma between transmitting and nontransmitting women. Here, we show that among HIV-infected women with broad and potent neutralization activity, more postpartum-transmitting women had a mappable plasma broadly neutralizing antibody (bnAb) specificity, compared to that of nontransmitting women, suggesting that the nontransmitting women more often have multispecific bnAb responses or bnAb responses that target uncommon epitopes. Such responses may be required for protection against vertical HIV transmission in the setting of maternal bnAb responses.


Asunto(s)
Formación de Anticuerpos , Anticuerpos ampliamente neutralizantes , Infecciones por VIH , Seropositividad para VIH , Transmisión Vertical de Enfermedad Infecciosa , Vacunas contra el SIDA , Epítopos , Femenino , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/transmisión , VIH-1 , Humanos , Lactante , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Embarazo
9.
J Virol ; 96(1): e0155221, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-34669426

RESUMEN

The human immunodeficiency virus type 1 (HIV-1) trimeric envelope glycoprotein (Env) is heavily glycosylated, creating a dense glycan shield that protects the underlying peptidic surface from antibody recognition. The absence of conserved glycans, due to missing potential N-linked glycosylation sites (PNGS), can result in strain-specific, autologous neutralizing antibody (NAb) responses. Here, we sought to gain a deeper understanding of the autologous neutralization by introducing holes in the otherwise dense glycan shields of the AMC011 and AMC016 SOSIP trimers. Specifically, when we knocked out the N130 and N289 glycans, which are absent from the well-characterized B41 SOSIP trimer, we observed stronger autologous NAb responses. We also analyzed the highly variable NAb responses induced in rabbits by diverse SOSIP trimers from subtypes A, B, and C. Statistical analysis, using linear regression, revealed that the cumulative area exposed on a trimer by glycan holes correlates with the magnitude of the autologous NAb response. IMPORTANCE Forty years after the first description of HIV-1, the search for a protective vaccine is still ongoing. The sole target for antibodies that can neutralize the virus are the trimeric envelope glycoproteins (Envs) located on the viral surface. The glycoprotein surface is covered with glycans that shield off the underlying protein components from recognition by the immune system. However, the Env trimers of some viral strains have holes in the glycan shield. Immunized animals developed antibodies against such glycan holes. These antibodies are generally strain specific. Here, we sought to gain a deeper understanding of what drives these specific immune responses. First, we show that strain-specific neutralizing antibody responses can be increased by creating artificial holes in the glycan shield. Second, when studying a diverse set of Env trimers with different characteristics, we found that the surface area of the glycan holes contributes prominently to the induction of strain-specific neutralizing antibodies.


Asunto(s)
Infecciones por VIH/inmunología , VIH-1/inmunología , Polisacáridos/metabolismo , Multimerización de Proteína , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/metabolismo , Vacunas contra el SIDA/inmunología , Aminoácidos/química , Aminoácidos/inmunología , Aminoácidos/metabolismo , Animales , Anticuerpos Neutralizantes/inmunología , Formación de Anticuerpos/inmunología , Antígenos Virales/inmunología , Glicosilación , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/metabolismo , Infecciones por VIH/virología , VIH-1/genética , Interacciones Huésped-Patógeno , Humanos , Inmunización , Modelos Moleculares , Conformación Proteica , Multimerización de Proteína/inmunología , Conejos , Eliminación de Secuencia , Relación Estructura-Actividad , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
10.
PLoS Pathog ; 17(8): e1009736, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34432859

RESUMEN

The development of an effective human immunodeficiency virus (HIV-1) vaccine is a high global health priority. Soluble native-like HIV-1 envelope glycoprotein trimers (Env), including those based on the SOSIP design, have shown promise as vaccine candidates by inducing neutralizing antibody responses against the autologous virus in animal models. However, to overcome HIV-1's extreme diversity a vaccine needs to induce broadly neutralizing antibodies (bNAbs). Such bNAbs can protect non-human primates (NHPs) and humans from infection. The prototypic BG505 SOSIP.664 immunogen is based on the BG505 env sequence isolated from an HIV-1-infected infant from Kenya who developed a bNAb response. Studying bNAb development during natural HIV-1 infection can inform vaccine design, however, it is unclear to what extent vaccine-induced antibody responses to Env are comparable to those induced by natural infection. Here, we compared Env antibody responses in BG505 SOSIP-immunized NHPs with those in BG505 SHIV-infected NHPs, by analyzing monoclonal antibodies (mAbs). We observed three major differences between BG505 SOSIP immunization and BG505 SHIV infection. First, SHIV infection resulted in more clonal expansion and less antibody diversity compared to SOSIP immunization, likely because of higher and/or prolonged antigenic stimulation and increased antigen diversity during infection. Second, while we retrieved comparatively fewer neutralizing mAbs (NAbs) from SOSIP-immunized animals, these NAbs targeted more diverse epitopes compared to NAbs from SHIV-infected animals. However, none of the NAbs, either elicited by vaccination or infection, showed any breadth. Finally, SOSIP immunization elicited antibodies against the base of the trimer, while infection did not, consistent with the base being placed onto the virus membrane in the latter setting. Together these data provide new insights into the antibody response against BG505 Env during infection and immunization and limitations that need to be overcome to induce better responses after vaccination.


Asunto(s)
Vacunas contra el SIDA/administración & dosificación , Anticuerpos Neutralizantes/inmunología , Epítopos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/inmunología , Formación de Anticuerpos , Antígenos Virales/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/virología , Humanos , Inmunización , Lactante , Kenia , Primates , Multimerización de Proteína , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunación
11.
J Immunol ; 206(6): 1266-1283, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33536254

RESUMEN

The role of vaccine-induced anti-V2 Abs was tested in three protection experiments in rhesus macaques. In an experiment using immunogens similar to those in the RV144 vaccine trial (Anti-envelope [Env]), nine rhesus macaques were coimmunized with gp16092TH023 DNA and SIV gag and gp120A244 and gp120MN proteins. In two V2-focused experiments (Anti-V2 and Anti-V2 Mucosal), nine macaques in each group were immunized with V1V292TH023 DNA, V1V2A244 and V1V2CasaeA2 proteins, and cyclic V2CaseA2 peptide. DNA and protein immunogens, formulated in Adjuplex, were given at 0, 4, 12, and 20 weeks, followed by intrarectal SHIVBaL.P4 challenges. Peak plasma viral loads (PVL) of 106-107 copies/ml developed in all nine sham controls. Overall, PVL was undetectable in one third of immunized macaques, and two animals tightly controlled the virus with the Anti-V2 Mucosal vaccine strategy. In the Anti-Env study, Abs that captured or neutralized SHIVBaL.P4 inversely correlated with PVL. Conversely, no correlation with PVL was found in the Anti-V2 experiments with nonneutralizing plasma Abs that only captured virus weakly. Titers of Abs against eight V1V2 scaffolds and cyclic V2 peptides were comparable between controllers and noncontrollers as were Ab-dependent cellular cytotoxicity and Ab-dependent cell-mediated virus inhibition activities against SHIV-infected target cells and phagocytosis of gp120-coated beads. The Anti-Env experiment supports the role of vaccine-elicited neutralizing and nonneutralizing Abs in control of PVL. However, the two V2-focused experiments did not support a role for nonneutralizing V2 Abs alone in controlling PVL, as neither Ab-dependent cellular cytotoxicity, Ab-dependent cell-mediated virus inhibition, nor phagocytosis correlated inversely with heterologous SHIVBaL.P4 infection.


Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/prevención & control , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunas contra el SIDA/administración & dosificación , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Modelos Animales de Enfermedad , Femenino , Productos del Gen env/inmunología , Infecciones por VIH/sangre , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Inmunogenicidad Vacunal , Macaca mulatta , Masculino , Fagocitosis/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/sangre , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Carga Viral
12.
J Virol ; 95(15): e0235020, 2021 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-33980592

RESUMEN

HIV-1 infection is initiated by the viral glycoprotein Env, which, after interaction with cellular coreceptors, adopts a transient conformation known as the prehairpin intermediate (PHI). The N-heptad repeat (NHR) is a highly conserved region of gp41 exposed in the PHI; it is the target of the FDA-approved drug enfuvirtide and of neutralizing monoclonal antibodies (mAbs). However, to date, these mAbs have only been weakly effective against tier-1 HIV-1 strains, which are most sensitive to neutralizing antibodies. Here, we engineered and tested 11 IgG variants of D5, an anti-NHR mAb, by recombining previously described mutations in four of D5's six antibody complementarity-determining regions. One variant, D5_AR, demonstrated 6-fold enhancement in the 50% inhibitory dose (ID50) against lentivirus pseudotyped with HXB2 Env. D5_AR exhibited weak cross-clade neutralizing activity against a diverse set of tier-2 HIV-1 viruses, which are less sensitive to neutralizing antibodies than tier-1 viruses and are the target of current antibody-based vaccine efforts. In addition, the neutralization potency of D5_AR IgG was greatly enhanced in target cells expressing FcγRI, with ID50 values of <0.1 µg/ml; this immunoglobulin receptor is expressed on macrophages and dendritic cells, which are implicated in the early stages of HIV-1 infection of mucosal surfaces. D5 and D5_AR have equivalent neutralization potency in IgG, Fab, and single-chain variable-fragment (scFv) formats, indicating that neutralization is not impacted by steric hindrance. Taken together, these results provide support for vaccine strategies that target the PHI by eliciting antibodies against the gp41 NHR and support investigation of anti-NHR mAbs in nonhuman primate passive immunization studies. IMPORTANCE Despite advances in antiretroviral therapy, HIV remains a global epidemic and has claimed more than 32 million lives. Accordingly, developing an effective HIV vaccine remains an urgent public health need. The gp41 N-heptad repeat (NHR) of the HIV-1 prehairpin intermediate (PHI) is highly conserved (>90%) and is inhibited by the FDA-approved drug enfuvirtide, making it an attractive vaccine target. However, to date, anti-NHR antibodies have not been potent. Here, we engineered D5_AR, a more potent variant of the anti-NHR antibody D5, and established its ability to inhibit HIV-1 strains that are more difficult to neutralize and are more representative of circulating strains (tier-2 strains). The neutralizing activity of D5_AR was greatly potentiated in cells expressing FcγRI; FcγRI is expressed on cells that are implicated at the earliest stages of sexual HIV-1 transmission. Taken together, these results bolster efforts to target the gp41 NHR and the PHI for vaccine development.


Asunto(s)
Fármacos Anti-VIH/farmacología , Anticuerpos Monoclonales/farmacología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Proteína gp41 de Envoltorio del VIH/antagonistas & inhibidores , VIH-1/inmunología , Anticuerpos Monoclonales/inmunología , Línea Celular , Enfuvirtida/farmacología , Células HEK293 , Proteína gp41 de Envoltorio del VIH/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Humanos , Dominios Proteicos/inmunología
14.
PLoS Pathog ; 16(3): e1008377, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32163525

RESUMEN

The recombinant Canarypox ALVAC-HIV/gp120/alum vaccine regimen was the first to significantly decrease the risk of HIV acquisition in humans, with equal effectiveness in both males and females. Similarly, an equivalent SIV-based ALVAC vaccine regimen decreased the risk of virus acquisition in Indian rhesus macaques of both sexes following intrarectal exposure to low doses of SIVmac251. Here, we demonstrate that the ALVAC-SIV/gp120/alum vaccine is also efficacious in female Chinese rhesus macaques following intravaginal exposure to low doses of SIVmac251 and we confirm that CD14+ classical monocytes are a strong correlate of decreased risk of virus acquisition. Furthermore, we demonstrate that the frequency of CD14+ cells and/or their gene expression correlates with blood Type 1 CD4+ T helper cells, α4ß7+ plasmablasts, and vaginal cytocidal NKG2A+ cells. To better understand the correlate of protection, we contrasted the ALVAC-SIV vaccine with a NYVAC-based SIV/gp120 regimen that used the identical immunogen. We found that NYVAC-SIV induced higher immune activation via CD4+Ki67+CD38+ and CD4+Ki67+α4ß7+ T cells, higher SIV envelope-specific IFN-γ producing cells, equivalent ADCC, and did not decrease the risk of SIVmac251 acquisition. Using the systems biology approach, we demonstrate that specific expression profiles of plasmablasts, NKG2A+ cells, and monocytes elicited by the ALVAC-based regimen correlated with decreased risk of virus acquisition.


Asunto(s)
Células Asesinas Naturales/inmunología , Monocitos/inmunología , Vacunas contra el SIDAS/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Células TH1/inmunología , Vacunación , Vagina/inmunología , Vacunas Virales/inmunología , Animales , Femenino , Células Asesinas Naturales/patología , Macaca mulatta , Monocitos/patología , Células TH1/patología
15.
J Virol ; 95(2)2020 12 22.
Artículo en Inglés | MEDLINE | ID: mdl-33087466

RESUMEN

The RV144 vaccine trial revealed a correlation between reduced risk of HIV infection and the level of nonneutralizing-antibody (Ab) responses targeting specific epitopes in the second variable domain (V2) of the HIV gp120 envelope (Env) protein, suggesting this region as a target for vaccine development. To favor induction of V2-specific Abs, we developed a vaccine regimen that included priming with DNA expressing an HIV V1V2 trimeric scaffold immunogen followed by booster immunizations with a combination of DNA and protein in rhesus macaques. Priming vaccination with DNA expressing the HIV recombinant subtype CRF01_AE V1V2 scaffold induced higher and broader V2-specific Ab responses than vaccination with DNA expressing CRF01_AE gp145 Env. Abs recognizing the V2 peptide that was reported as a critical target in RV144 developed only after the priming immunization with V1V2 DNA. The V2-specific Abs showed several nonneutralizing Fc-mediated functions, including ADCP and C1q binding. Importantly, robust V2-specific Abs were maintained upon boosting with gp145 DNA and gp120 protein coimmunization. In conclusion, priming with DNA expressing the trimeric V1V2 scaffold alters the hierarchy of humoral immune responses to V2 region epitopes, providing a method for more efficient induction and maintenance of V2-specific Env Abs associated with reduced risk of HIV infection.IMPORTANCE The aim of this work was to design and test a vaccine regimen focusing the immune response on targets associated with infection prevention. We demonstrated that priming with a DNA vaccine expressing only the HIV Env V1V2 region induces Ab responses targeting the critical region in V2 associated with protection. This work shows that V1V2 scaffold DNA priming immunization provides a method to focus immune responses to the desired target region, in the absence of immune interference by other epitopes. This induced immune responses with improved recognition of epitopes important for protective immunity, namely, V2-specific humoral immune responses inversely correlating with HIV risk of infection in the RV144 trial.


Asunto(s)
Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/química , Proteína gp120 de Envoltorio del VIH/inmunología , VIH/inmunología , Inmunización/métodos , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/genética , Animales , Anticuerpos Neutralizantes/inmunología , Epítopos/química , Epítopos/genética , Epítopos/inmunología , Células HEK293 , Antígenos VIH/química , Antígenos VIH/genética , Antígenos VIH/inmunología , Proteína gp120 de Envoltorio del VIH/genética , Humanos , Inmunización Secundaria , Inmunogenicidad Vacunal , Macaca mulatta , Conformación Proteica , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Vacunas de ADN/inmunología
16.
J Virol ; 94(6)2020 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-31852794

RESUMEN

We covalently attached human immunodeficiency virus type 1 (HIV-1) Env SOSIP trimers to iron oxide nanoparticles (IO-NPs) to create a particulate immunogen for neutralizing antibody (NAb) induction. The attached trimers, ∼20 per particle, retained native-like antigenicity, judged by reactivity with NAbs and non-NAbs. Bivalent (BG505 and B41) trimer IO-NPs were made, as were IO-NPs displaying B41 trimers carrying a PADRE T-cell helper epitope (TCHE). We immunized mice with B41 soluble or IO-NP trimers after PADRE peptide priming. After two immunizations, IO-NP presentation and the TCHE tag independently and substantially increased anti-trimer antibody responses, but titer differences waned after two further doses. Notable and unexpected findings were that autologous NAbs to the N289 glycan hole epitope were consistently induced in mice given soluble but not IO-NP trimers. Various recombinant mannose binding lectins (MBLs) and MBLs in sera of both murine and human origin bound to soluble and IO-NP trimers. MBL binding occluded the autologous NAb epitope on the B41 IO-NP trimers, which may contribute to its poor immunogenicity. The exposure of a subset of broadly active NAb epitopes was also impaired by MBL binding, which could have substantial implications for the utility of trimer-bearing nanoparticles in general and perhaps also for soluble Env proteins.IMPORTANCE Recombinant trimeric SOSIP proteins are vaccine components intended to induce neutralizing antibodies (NAbs) that prevent cells from infection by human immunodeficiency virus type 1 (HIV-1). A way to increase the strength of antibody responses to these proteins is to present them on the surface of nanoparticles (NPs). We chemically attached about 20 SOSIP trimers to NPs made of iron oxide (IO). The resulting IO-NP trimers had appropriate properties when we studied them in the laboratory but, unexpectedly, were less able to induce NAbs than nonattached trimers when used to immunize mice. We found that mannose binding lectins, proteins naturally present in the serum of mice and other animals, bound strongly to the soluble and IO-NP trimers, blocking access to antibody epitopes in a way that may impede the development of NAb responses. These findings should influence how trimer-bearing NPs of various designs are made and used.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Epítopos de Linfocito T/inmunología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Nanopartículas de Magnetita , Lectina de Unión a Manosa/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Humanos , Ratones , Multimerización de Proteína/inmunología
17.
J Virol ; 94(6)2020 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-31827000

RESUMEN

Generating durable humoral immunity through vaccination depends upon effective interactions of follicular helper T (Tfh) cells with germinal center (GC) B cells. Th1 polarization of Tfh cells is an important process shaping the success of Tfh-GC B cell interactions by influencing costimulatory and cytokine-dependent Tfh help to B cells. However, the question remains as to whether adjuvant-dependent modulation of Tfh cells enhances HIV-1 vaccine-induced antienvelope (anti-Env) antibody responses. We investigated whether an HIV-1 vaccine platform designed to increase the number of Th1-polarized Tfh cells enhances the magnitude and quality of anti-Env antibodies. Utilizing a novel interferon-induced protein 10 (IP-10)-adjuvanted HIV-1 DNA prime followed by a monophosphoryl lipid A and QS-21 (MPLA+QS-21)-adjuvanted Env protein boost (DIP-10 PALFQ) in macaques, we observed higher anti-Env serum IgG titers with greater cross-clade reactivity, specificity for V1V2, and effector functions than in macaques primed with DNA lacking IP-10 and boosted with MPLA-plus-alum-adjuvanted Env protein (DPALFA) The DIP-10 PALFQ vaccine regimen elicited higher anti-Env IgG1 and lower IgG4 antibody levels in serum, showing for the first time that adjuvants can dramatically impact the IgG subclass profile in macaques. The DIP-10 PALFQ regimen also increased vaginal and rectal IgA antibodies to a greater extent. Within lymph nodes, we observed augmented GC B cell responses and the promotion of Th1 gene expression profiles in GC Tfh cells. The frequency of GC Tfh cells correlated with both the magnitude and avidity of anti-Env serum IgG. Together, these data suggest that adjuvant-induced stimulation of Th1-Tfh cells is an effective strategy for enhancing the magnitude and quality of anti-Env antibody responses.IMPORTANCE The results of the RV144 trial demonstrated that vaccination could prevent HIV transmission in humans and that longevity of anti-Env antibodies may be key to this protection. Efforts to improve upon the prime-boost vaccine regimen used in RV144 have indicated that booster immunizations can increase serum anti-Env antibody titers but only transiently. Poor antibody durability hampers efforts to develop an effective HIV-1 vaccine. This study was designed to identify the specific elements involved in the immunological mechanism necessary to produce robust HIV-1-specific antibodies in rhesus macaques. By clearly defining immune-mediated pathways that improve the magnitude and functionality of the anti-HIV-1 antibody response, we will have the foundation necessary for the rational development of an HIV-1 vaccine.


Asunto(s)
Vacunas contra el SIDA/farmacología , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Inmunización Secundaria , Inmunoglobulina G/inmunología , Células TH1/inmunología , Vacunas contra el SIDA/inmunología , Adyuvantes Inmunológicos/farmacología , Animales , Linfocitos B/inmunología , Linfocitos B/patología , Femenino , Centro Germinal/inmunología , Centro Germinal/patología , Humanos , Lípido A/análogos & derivados , Lípido A/farmacología , Macaca mulatta , Saponinas/farmacología , Células TH1/patología
18.
J Virol ; 94(24)2020 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-32999024

RESUMEN

The induction of broadly neutralizing antibodies (bNAbs) is a major goal in vaccine research. HIV-1-infected individuals that develop exceptionally strong bNAb responses, termed elite neutralizers, can inform vaccine design by providing blueprints for the induction of similar bNAb responses. We describe a new recombinant native-like envelope glycoprotein (Env) SOSIP trimer, termed AMC009, based on the viral founder sequences of an elite neutralizer. The subtype B AMC009 SOSIP protein formed stable native-like trimers that displayed multiple bNAb epitopes. Overall, its structure at 4.3-Å resolution was similar to that of BG505 SOSIP.664. The AMC009 trimer resembled one from a second elite neutralizer, AMC011, in having a dense and complete glycan shield. When tested as immunogens in rabbits, the AMC009 trimers did not induce autologous neutralizing antibody (NAb) responses efficiently while the AMC011 trimers did so very weakly, outcomes that may reflect the completeness of their glycan shields. The AMC011 trimer induced antibodies that occasionally cross-neutralized heterologous tier 2 viruses, sometimes at high titer. Cross-neutralizing antibodies were more frequently elicited by a trivalent combination of AMC008, AMC009, and AMC011 trimers, all derived from subtype B viruses. Each of these three individual trimers could deplete the NAb activity from the rabbit sera. Mapping the polyclonal sera by electron microscopy revealed that antibodies of multiple specificities could bind to sites on both autologous and heterologous trimers. These results advance our understanding of how to use Env trimers in multivalent vaccination regimens and the immunogenicity of trimers derived from elite neutralizers.IMPORTANCE Elite neutralizers, i.e., individuals who developed unusually broad and potent neutralizing antibody responses, might serve as blueprints for HIV-1 vaccine design. Here, we studied the immunogenicity of native-like recombinant envelope glycoprotein (Env) trimers based on viral sequences from elite neutralizers. While immunization with single trimers from elite neutralization did not recapitulate the breadth and potency of neutralization observed in these infected individuals, a combination of three subtype B Env trimers from elite neutralizers resulted in some neutralization breadth within subtype B viruses. These results should guide future efforts to design vaccines to induce broadly neutralizing antibodies.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Antígenos Virales/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Neutralizantes/química , Antígenos Virales/química , Microscopía por Crioelectrón , Epítopos/inmunología , Glicoproteínas , Infecciones por VIH/virología , Inmunización , Conejos , Proteínas Recombinantes/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética
20.
PLoS Pathog ; 15(12): e1008121, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31794588

RESUMEN

The ALVAC-HIV clade B/AE and equivalent SIV-based/gp120 + Alum vaccines successfully decreased the risk of virus acquisition in humans and macaques. Here, we tested the efficacy of HIV clade B/C ALVAC/gp120 vaccine candidates + MF59 or different doses of Aluminum hydroxide (Alum) against SHIV-Cs of varying neutralization sensitivity in macaques. Low doses of Alum induced higher mucosal V2-specific IgA that increased the risk of Tier 2 SHIV-C acquisition. High Alum dosage, in contrast, elicited serum IgG to V2 that correlated with a decreased risk of Tier 1 SHIV-C acquisition. MF59 induced negligible mucosal antibodies to V2 and an inflammatory profile with blood C-reactive Protein (CRP) levels correlating with neutralizing antibody titers. MF59 decreased the risk of Tier 1 SHIV-C acquisition. The relationship between vaccine efficacy and the neutralization profile of the challenge virus appear to be linked to the different immunological spaces created by MF59 and Alum via CXCL10 and IL-1ß, respectively.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Compuestos de Alumbre/farmacología , Anticuerpos Neutralizantes/inmunología , Vacunas contra el SIDAS/química , Vacunas contra el SIDAS/inmunología , Vacunas contra el SIDA/química , Vacunas contra el SIDA/inmunología , Animales , Anticuerpos Antivirales/inmunología , Femenino , Infecciones por VIH , Macaca mulatta , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Vacunas Virales/química , Vacunas Virales/inmunología
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