RESUMEN

Combination monoclonal broadly neutralizing antibodies (bnAbs) are currently being developed for preventing HIV-1 acquisition. Recent work has focused on predicting in vitro neutralization potency of both individual bnAbs and combination regimens against HIV-1 pseudoviruses using Env sequence features. To predict in vitro combination regimen neutralization potency against a given HIV-1 pseudovirus, previous approaches have applied mathematical models to combine individual-bnAb neutralization and have predicted this combined neutralization value; we call this the combine-then-predict (CP) approach. However, prediction performance for some individual bnAbs has exceeded that for the combination, leading to another possibility: combining the individual-bnAb predicted values and using these to predict combination regimen neutralization; we call this the predict-then-combine (PC) approach. We explore both approaches in both simulated data and data from the Los Alamos National Laboratory's Compile, Neutralize, and Tally NAb Panels repository. The CP approach is superior to the PC approach when the neutralization outcome of interest is binary (e.g., neutralization susceptibility, defined as inhibitory 80% concentration < 1 µg/mL). For continuous outcomes, the CP approach performs nearly as well as the PC approach when the individual-bnAb prediction algorithms have strong performance, and is superior to the PC approach when the individual-bnAb prediction algorithms have poor performance. This knowledge may be used when building prediction models for novel antibody combinations in the absence of in vitro neutralization data for the antibody combination; this, in turn, will aid in the evaluation and down-selection of these antibody combinations into prevention efficacy trials.

Asunto(s)

Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , VIH-1/inmunología , VIH-1/efectos de los fármacos , Humanos , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Monoclonales/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Pruebas de Neutralización/métodos

RESUMEN

Stabilized trimers preserving the native-like HIV envelope structure may be key components of a preventive HIV vaccine regimen to induce broadly neutralizing antibodies (bnAbs). We evaluated trimeric BG505 SOSIP.664 gp140 formulated with a novel TLR7/8 signaling adjuvant, 3M-052-AF/Alum, for safety, adjuvant dose-finding, and immunogenicity in a first-in-healthy adult (n = 17), randomized, and placebo-controlled trial (HVTN 137A). The vaccine regimen appeared safe. Robust, trimer-specific antibody, and B cell and CD4+ T cell responses emerged after vaccination. Five vaccinees developed serum autologous tier 2 nAbs (ID50 titer, 1:28-1:8647) after two to three doses targeting C3/V5 and/or V1/V2/V3 Env regions by electron microscopy and mutated pseudovirus-based neutralization analyses. Trimer-specific, B cell-derived monoclonal antibody activities confirmed these results and showed weak heterologous neutralization in the strongest responder. Our findings demonstrate the clinical utility of the 3M-052-AF/Alum adjuvant and support further improvements of trimer-based Env immunogens to focus responses on multiple broad nAb epitopes.

Asunto(s)

Vacunas contra el SIDA , Adyuvantes Inmunológicos , Compuestos de Alumbre , Anticuerpos Neutralizantes , Productos del Gen env del Virus de la Inmunodeficiencia Humana , Humanos , Anticuerpos Neutralizantes/inmunología , Vacunas contra el SIDA/inmunología , Vacunas contra el SIDA/administración & dosificación , Compuestos de Alumbre/administración & dosificación , Adulto , Adyuvantes Inmunológicos/administración & dosificación , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Anticuerpos Anti-VIH/inmunología , Femenino , VIH-1/inmunología , Masculino , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Linfocitos B/inmunología , Adyuvantes de Vacunas , Persona de Mediana Edad , Adulto Joven , Linfocitos T CD4-Positivos/inmunología

RESUMEN

HIV-1 envelope glycoproteins (Envs) of most primary HIV-1 strains exist in closed conformation and infrequently sample open states, limiting access to internal epitopes. Thus, immunogen design aims to mimic the closed Env conformation as preferred target for eliciting broadly neutralizing antibodies (bnAbs). Here we identify incompletely closed Env conformations of 6 out of 13 transmitted/founder (T/F) strains that are sensitive to antibodies that recognize internal epitopes typically exposed on open Envs. A 3.6 Å cryo-electron microscopy structure of unliganded, incompletely closed T/F Envs (1059-SOSIP) reveals protomer motion that increased sampling of states with incompletely closed trimer apex. We reconstruct de novo the post-transmission evolutionary pathway of a second T/F. Evolved viruses exhibit increased Env resistance to cold, soluble CD4 and 19b, all of which correlate with closing of the adapted Env trimer. Lastly, we show that the ultra-broad N6 bnAb efficiently recognizes different Env conformations and exhibits improved antiviral breadth against VRC01-resistant Envs isolated during the first-in-humans antibody-mediated-prevention trial.

Asunto(s)

Anticuerpos Neutralizantes , Microscopía por Crioelectrón , Anticuerpos Anti-VIH , VIH-1 , Conformación Proteica , Productos del Gen env del Virus de la Inmunodeficiencia Humana , VIH-1/inmunología , Humanos , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/metabolismo , Anticuerpos Anti-VIH/inmunología , Anticuerpos Neutralizantes/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Epítopos/inmunología , Epítopos/química , Anticuerpos ampliamente neutralizantes/inmunología , Anticuerpos ampliamente neutralizantes/química , Células HEK293 , Antígenos CD4/metabolismo , Antígenos CD4/inmunología , Antígenos CD4/química , Modelos Moleculares

RESUMEN

The HIV-1 envelope glycoprotein (Env) is the sole neutralizing determinant on the surface of the virus. The Env gp120 and gp41 subunits mediate receptor binding and membrane fusion and are generated from the gp160 precursor by cellular furins. This cleavage event is required for viral entry. One approach to generate HIV-1 neutralizing antibodies following immunization is to express membrane-bound Env anchored on the cell-surface by genetic means using the natural HIV gp41 transmembrane (TM) spanning domain. To simplify the process of Env trimer membrane expression we sought to remove the need for Env precursor cleavage while maintaining native-like conformation following genetic expression. To accomplish these objectives, we selected our previously developed 'native flexibly linked' (NFL) stabilized soluble trimers that are both near-native in conformation and cleavage-independent. We genetically fused the NFL construct to the HIV TM domain by using a short linker or by restoring the native membrane external proximal region, absent in soluble trimers, to express the full HIV Env ectodomain on the plasma membrane. Both forms of cell-surface NFL trimers, without and with the MPER, displayed favorable antigenic profiles by flow cytometry when expressed from plasmid DNA or mRNA. These results were consistent with the presence of well-ordered cell surface native-like trimeric Env, a necessary requirement to generate neutralizing antibodies by vaccination. Inoculation of rabbits with mRNA lipid nanoparticles (LNP) expressing membrane-bound stabilized HIV Env NFL trimers generated tier 2 neutralizing antibody serum titers in immunized animals. Multiple inoculations of mRNA LNPs generated similar neutralizing antibody titers compared to immunizations of matched NFL soluble proteins in adjuvant. Given the recent success of mRNA vaccines to prevent severe COVID, these are important developments for genetic expression of native-like HIV Env trimers in animals and potentially in humans.

Asunto(s)

Vacunas contra el SIDA , Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , Nanopartículas , ARN Mensajero , Productos del Gen env del Virus de la Inmunodeficiencia Humana , Animales , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Anticuerpos Neutralizantes/inmunología , Humanos , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Vacunas contra el SIDA/inmunología , Conejos , ARN Mensajero/inmunología , ARN Mensajero/genética , Lípidos/inmunología , Multimerización de Proteína , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/prevención & control , Femenino , Liposomas

RESUMEN

Eliciting potent and broadly neutralizing antibodies (bnAbs) is a major goal in HIV-1 vaccine development. Here, we describe how germline-targeting immunogen BG505 SOSIP germline trimer 1.1 (GT1.1), generated through structure-based design, engages a diverse range of VRC01-class bnAb precursors. A single immunization with GT1.1 expands CD4 binding site (CD4bs)-specific VRC01-class B cells in knock-in mice and drives VRC01-class maturation. In nonhuman primates (NHPs), GT1.1 primes CD4bs-specific neutralizing serum responses. Selected monoclonal antibodies (mAbs) isolated from GT1.1-immunized NHPs neutralize fully glycosylated BG505 virus. Two mAbs, 12C11 and 21N13, neutralize subsets of diverse heterologous neutralization-resistant viruses. High-resolution structures revealed that 21N13 targets the same conserved residues in the CD4bs as VRC01-class and CH235-class bnAbs despite its low sequence similarity (~40%), whereas mAb 12C11 binds predominantly through its heavy chain complementarity-determining region 3. These preclinical data underpin the ongoing evaluation of GT1.1 in a phase 1 clinical trial in healthy volunteers.

Asunto(s)

Vacunas contra el SIDA , Anticuerpos Neutralizantes , Antígenos CD4 , Anticuerpos Anti-VIH , VIH-1 , Animales , Vacunas contra el SIDA/inmunología , Ratones , Humanos , Anticuerpos Anti-VIH/inmunología , Anticuerpos Neutralizantes/inmunología , VIH-1/inmunología , Antígenos CD4/inmunología , Sitios de Unión/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Vacunación , Anticuerpos Monoclonales/inmunología , Femenino

RESUMEN

HIV envelope immunogen designed to activate germline B cell precursors of CD4 binding site-specific neutralizing antibodies shows promise in monkeys.

Asunto(s)

Anticuerpos Neutralizantes , Antígenos CD4 , Anticuerpos Anti-VIH , Animales , Humanos , Anticuerpos Anti-VIH/inmunología , Anticuerpos Neutralizantes/inmunología , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , VIH-1/inmunología , Infecciones por VIH/inmunología , Vacunas contra el SIDA/inmunología , Sitios de Unión/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , Linfocitos B/inmunología

RESUMEN

Adolescents are a growing population of people living with HIV. The period between weaning and sexual debut presents a low-risk window for HIV acquisition, making early childhood an ideal time for implementing an immunization regimen. Because the elicitation of broadly neutralizing antibodies (bnAbs) is critical for an effective HIV vaccine, our goal was to assess the ability of a bnAb B cell lineage-designed HIV envelope SOSIP (protein stabilized by a disulfide bond between gp120-gp41-named "SOS"-and an isoleucine-to-proline point mutation-named "IP"-at residue 559) to induce precursor CD4 binding site (CD4bs)-targeting bnAbs in early life. Infant rhesus macaques received either a BG505 SOSIP, based on the infant BG505 transmitted/founder virus, or the CD4bs germ line-targeting BG505 SOSIP GT1.1 (n = 5 per group). Although both strategies induced durable, high-magnitude plasma autologous virus neutralization responses, only GT1.1-immunized infants (n = 3 of 5) exhibited VRC01-like CD4bs bnAb precursor development. Thus, a multidose immunization regimen with bnAb lineage-designed SOSIPs shows promise for inducing early B cell responses with the potential to mature into protective HIV bnAbs before sexual debut.

Asunto(s)

Vacunas contra el SIDA , Anticuerpos Anti-VIH , Macaca mulatta , Animales , Anticuerpos Anti-VIH/inmunología , Vacunas contra el SIDA/inmunología , Vacunas contra el SIDA/administración & dosificación , Anticuerpos Neutralizantes/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , Inmunización , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , VIH-1/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Humanos , Células Germinativas/inmunología

RESUMEN

Nucleoside-modified mRNA technology has revolutionized vaccine development with the success of mRNA COVID-19 vaccines. We used modified mRNA technology for the design of envelopes (Env) to induce HIV-1 broadly neutralizing antibodies (bnAbs). However, unlike SARS-CoV-2 neutralizing antibodies that are readily made, HIV-1 bnAb induction is disfavored by the immune system because of the rarity of bnAb B cell precursors and the cross-reactivity of bnAbs targeting certain Env epitopes with host molecules, thus requiring optimized immunogen design. The use of protein nanoparticles (NPs) has been reported to enhance B cell germinal center responses to HIV-1 Env. Here, we report our experience with the expression of Env-ferritin NPs compared with membrane-bound Env gp160 when encoded by modified mRNA. We found that well-folded Env-ferritin NPs were a minority of the protein expressed by an mRNA design and were immunogenic at 20 µg but minimally immunogenic in mice at 1 µg dose in vivo and were not expressed well in draining lymph nodes (LNs) following intramuscular immunization. In contrast, mRNA encoding gp160 was more immunogenic than mRNA encoding Env-NP at 1 µg dose and was expressed well in draining LN following intramuscular immunization. Thus, analysis of mRNA expression in vitro and immunogenicity at low doses in vivo are critical for the evaluation of mRNA designs for optimal immunogenicity of HIV-1 immunogens.IMPORTANCEAn effective HIV-1 vaccine that induces protective antibody responses remains elusive. We have used mRNA technology for designs of HIV-1 immunogens in the forms of membrane-bound full-length envelope gp160 and envelope ferritin nanoparticle. Here, we demonstrated in a mouse model that the membrane-bound form induced a better response than envelope ferritin nanoparticle because of higher in vivo protein expression. The significance of our research is in highlighting the importance of analysis of mRNA design expression and low-dose immunogenicity studies for HIV-1 immunogens before moving to vaccine clinical trials.

Asunto(s)

Ferritinas , VIH-1 , Nanopartículas , Animales , VIH-1/inmunología , VIH-1/genética , Ratones , Ferritinas/inmunología , Ferritinas/genética , Humanos , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , ARN Mensajero/inmunología , ARN Mensajero/genética , Anticuerpos Anti-VIH/inmunología , Femenino , Anticuerpos Neutralizantes/inmunología , Vacunas contra el SIDA/inmunología , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/genética , Ratones Endogámicos BALB C , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Inmunogenicidad Vacunal , Infecciones por VIH/inmunología , Infecciones por VIH/prevención & control , Infecciones por VIH/virología

RESUMEN

Anti-human immunodeficiency virus (HIV) broadly neutralizing antibodies (bNAbs) offer a promising approach for the treatment of HIV-1. The current paradigm for antibody therapy involves passive antibody transfer, requiring regular delivery of bNAbs in treating chronic diseases such as HIV-1. An alternative strategy is to use AAV-mediated gene transfer to enable in vivo production of desirable anti-HIV-1 antibodies. In this study, we investigated two sets of triple combinations of AAV9-vectors encoding different bNAbs: N6, 10E8, 10-1074 (CombiMab1), and VRC07-523, PGDM1400, 10-1074 (CombiMab2). We used CBAxC57Bl and C57BL/6 mouse models to characterize rAAV-induced antibody expression and to evaluate the neutralization capacity of mouse sera against a global panel of HIV-1 viral strains. rAAV9-mediated IgG expression varied between bNAb clones and mouse strains, with C57BL/6 mice exhibiting higher bNAb titers following rAAV delivery. Although CombiMab2 treatment elicited a higher IgG titer than CombiMab1, both combinations resulted in neutralization of all the viral strains from the global HIV-1 panel. Our data highlight the potential of AAV vectors as a long-term option for HIV-1 therapy.

Asunto(s)

Anticuerpos Neutralizantes , Dependovirus , Vectores Genéticos , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Inmunoglobulina G , Ratones Endogámicos C57BL , Animales , Dependovirus/genética , Dependovirus/inmunología , VIH-1/inmunología , VIH-1/genética , Humanos , Ratones , Anticuerpos Anti-VIH/inmunología , Anticuerpos Neutralizantes/inmunología , Vectores Genéticos/genética , Inmunoglobulina G/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/terapia , Femenino , Células HEK293

RESUMEN

Anti-HIV-1 broadly neutralizing antibodies (bNAbs) have the dual potential of mediating virus neutralization and antiviral effector functions through their Fab and Fc domains, respectively. So far, bNAbs with enhanced Fc effector functions in vitro have only been tested in NHPs during chronic simian-HIV (SHIV) infection. Here, we investigate the effects of administering in acute SHIVAD8-EO infection either wild-type (WT) bNAbs or bNAbs carrying the S239D/I332E/A330L (DEL) mutation, which increases binding to FcγRs. Emergence of virus in plasma and lymph nodes (LNs) was delayed by bNAb treatment and occurred earlier in monkeys given DEL bNAbs than in those given WT bNAbs, consistent with faster clearance of DEL bNAbs from plasma. DEL bNAb-treated monkeys had higher levels of circulating virus-specific IFNγ single-producing CD8+ CD69+ T cells than the other groups. In LNs, WT bNAbs were evenly distributed between follicular and extrafollicular areas, but DEL bNAbs predominated in the latter. At week 8 post-challenge, LN monocytes and NK cells from DEL bNAb-treated monkeys upregulated proinflammatory signaling pathways and LN T cells downregulated TNF signaling via NF-κB. Overall, bNAbs with increased affinity to FcγRs shape innate and adaptive cellular immunity, which may be important to consider in future strategies of passive bNAb therapy.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , Macaca mulatta , Receptores de IgG , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Receptores de IgG/inmunología , Receptores de IgG/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , VIH-1/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Monoclonales/inmunología , Ganglios Linfáticos/inmunología , Linfocitos T CD8-positivos/inmunología , Afinidad de Anticuerpos/inmunología , FN-kappa B/metabolismo , FN-kappa B/inmunología , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Células Asesinas Naturales/inmunología , Anticuerpos ampliamente neutralizantes/inmunología

RESUMEN

Human immunodeficiency virus type 1 (HIV-1) vaccine immunogens capable of inducing broadly neutralizing antibodies (bNAbs) remain obscure. HIV-1 evades immune responses through enormous diversity and hides its conserved vulnerable epitopes on the envelope glycoprotein (Env) by displaying an extensive immunodominant glycan shield. In elite HIV-1 viremic controllers, glycan-dependent bNAbs targeting conserved Env epitopes have been isolated and are utilized as vaccine design templates. However, immunological tolerance mechanisms limit the development of these antibodies in the general population. The well characterized bNAbs monoclonal variants frequently exhibit extensive levels of somatic hypermutation, a long third heavy chain complementary determining region, or a short third light chain complementarity determining region, and some exhibit poly-reactivity to autoantigens. This review elaborates on the obstacles to engaging and manipulating the Env glycoprotein as an effective immunogen and describes an alternative reverse vaccinology approach to develop a novel category of bNAb-epitope-derived non-cognate immunogens for HIV-1 vaccine design.

Asunto(s)

Vacunas contra el SIDA , Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , VIH-1/inmunología , Humanos , Vacunas contra el SIDA/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Anti-VIH/inmunología , Polisacáridos/inmunología , Infecciones por VIH/inmunología , Imitación Molecular/inmunología , Epítopos/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Ligandos

RESUMEN

Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope glycoprotein (Env) have the capacity to delay viral rebound when administered to people with HIV-1 (PWH) during anti-retroviral therapy (ART) interruption. To further enhance the performance of bNAbs through their Fc effector functions, in particular NK cell-mediated killing of HIV-1 infected cells, we have produced a panel of glyco-engineered (afucosylated) bNAbs with enhanced affinity for Fc gamma receptor IIIa. These afucosylated anti-HIV-1 bNAbs enhance NK cell activation and degranulation compared to fucosylated counterparts even at low antigen density. NK cells from PWH expressing exhaustion markers PD-1 and TIGIT are activated in a similar fashion by afucosylated bNAbs as NK cell from HIV-1 negative individuals. Killing of HIV-1 infected cells is most effective with afucosylated bNAbs 2G12, N6, PGT151 and PGDM1400, whereas afucosylated PGT121 and non-neutralizing antibody A32 only induce minor NK cell-mediated killing. These data indicate that the approach angle and affinity of Abs influence the capacity to induce antibody-dependent cellular cytotoxicity. Thus, afucosylated bNAbs have the capacity to induce NK cell-mediated killing of infected cells, which warrants further investigation of afucosylated bNAb administration in vivo, aiming for reduction of the viral reservoir and ART free durable control.

Asunto(s)

Anticuerpos ampliamente neutralizantes , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Células Asesinas Naturales , Humanos , VIH-1/inmunología , Células Asesinas Naturales/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/tratamiento farmacológico , Anticuerpos Anti-VIH/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , Anticuerpos Neutralizantes/inmunología , Receptores de IgG/inmunología , Receptores de IgG/metabolismo , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Fucosa

RESUMEN

Despite advancements in antiretroviral therapy (ART) suppressing HIV-1 replication, existing antiviral drugs pose limitations, including lifelong medication, frequent administration, side effects and viral resistance, necessitating novel HIV-1 treatment approaches. CD4, pivotal for HIV-1 entry, poses challenges for drug development due to neutralization and cytotoxicity concerns. Nevertheless, Ibalizumab, the sole approved CD4-specific antibody for HIV-1 treatment, reignites interest in exploring alternative anti-HIV targets, emphasizing CD4's potential value for effective drug development. Here, we explore anti-CD4 nanobodies, particularly Nb457 from a CD4-immunized alpaca. Nb457 displays high potency and broad-spectrum activity against HIV-1, surpassing Ibalizumab's efficacy. Strikingly, engineered trimeric Nb457 nanobodies achieve complete inhibition against live HIV-1, outperforming Ibalizumab and parental Nb457. Structural analysis unveils Nb457-induced CD4 conformational changes impeding viral entry. Notably, Nb457 demonstrates therapeutic efficacy in humanized female mouse models. Our findings highlight anti-CD4 nanobodies as promising HIV-1 therapeutics, with potential implications for advancing clinical treatment against this global health challenge.

Asunto(s)

Antígenos CD4 , Camélidos del Nuevo Mundo , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Anticuerpos de Dominio Único , VIH-1/inmunología , VIH-1/efectos de los fármacos , Anticuerpos de Dominio Único/farmacología , Anticuerpos de Dominio Único/inmunología , Animales , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Camélidos del Nuevo Mundo/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/farmacología , Ratones , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/farmacología , Conformación Proteica , Femenino , Internalización del Virus/efectos de los fármacos , Células HEK293 , Fármacos Anti-VIH/farmacología , Fármacos Anti-VIH/uso terapéutico , Anticuerpos Monoclonales

RESUMEN

Natural Killer (NK) cells have the potential to eliminate HIV-1-infected cells by antibody-dependent cellular cytotoxicity (ADCC). NK cell activation is tightly regulated by the engagement of its inhibitory and activating receptors. The activating receptor CD16 drives ADCC upon binding to the Fc portion of antibodies; NK cell activation is further sustained by the co-engagement of activating receptors NTB-A and 2B4. During HIV-1 infection, Nef and Vpu accessory proteins contribute to ADCC escape by downregulating the ligands of NTB-A and 2B4. HIV-1 also evades ADCC by keeping its envelope glycoproteins (Env) in a "closed" conformation which effectively masks epitopes recognized by non-neutralizing antibodies (nnAbs) which are abundant in the plasma of people living with HIV. To achieve this, the virus uses its accessory proteins Nef and Vpu to downregulate the CD4 receptor, which otherwise interacts with Env and exposes the epitopes recognized by nnAbs. Small CD4-mimetic compounds (CD4mc) have the capacity to expose these epitopes, thus sensitizing infected cells to ADCC. Given the central role of NK cell co-activating receptors NTB-A and 2B4 in Fc-effector functions, we studied their contribution to CD4mc-mediated ADCC. Despite the fact that their ligands are partially downregulated by HIV-1, we found that both co-activating receptors significantly contribute to CD4mc sensitization of HIV-1-infected cells to ADCC.

Asunto(s)

Citotoxicidad Celular Dependiente de Anticuerpos , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Células Asesinas Naturales , Familia de Moléculas Señalizadoras de la Activación Linfocitaria , Humanos , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , VIH-1/inmunología , Células Asesinas Naturales/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/inmunología , Familia de Moléculas Señalizadoras de la Activación Linfocitaria/metabolismo , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Proteínas del Virus de la Inmunodeficiencia Humana/inmunología , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/metabolismo , Proteínas Reguladoras y Accesorias Virales/metabolismo , Proteínas Reguladoras y Accesorias Virales/inmunología , Proteínas Reguladoras y Accesorias Virales/genética , Anticuerpos Neutralizantes/inmunología , Proteínas Viroporinas

RESUMEN

Monoclonal antibodies have widespread applications in disease treatment and antigen detection. They are traditionally produced using mammalian cell expression system, which is not able to satisfy the increasing demand of these proteins at large scale. Baculovirus expression vector system (BEVS) is an attractive alternative platform for the production of biologically active monoclonal antibodies. In this chapter, we demonstrate the production of an HIV-1 broadly neutralizing antibody b12 in BEVS. The processes including transfer vector construction, recombinant baculovirus generation, and antibody production and detection are described.

Asunto(s)

Baculoviridae , Vectores Genéticos , Baculoviridae/genética , Vectores Genéticos/genética , Animales , Humanos , Expresión Génica , VIH-1/genética , VIH-1/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/biosíntesis , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Ensayo de Inmunoadsorción Enzimática , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/genética , Células Sf9

RESUMEN

The magnitude of the HIV-1 epidemic in Nigeria is second only to the subtype C epidemic in South Africa, yet the subtypes prevalent in Nigeria require further characterization. A panel of 50 subtype G and 18 CRF02_AG Nigerian HIV-1 pseudoviruses (PSV) was developed and envelope coreceptor usage, neutralization sensitivity and cross-clade reactivity were characterized. These PSV were neutralized by some antibodies targeting major neutralizing determinants, but potentially important differences were observed in specific sensitivities (eg. to sCD4, MPER and V2/V3 monoclonal antibodies), as well as in properties such as variable loop lengths, number of potential N-linked glycans and charge, demonstrating distinct antigenic characteristics of CRF02_AG and subtype G. There was preferential neutralization of the matched CRF/subtype when PSV from subtype G or CRF02_AG were tested using pooled plasma. These novel Nigerian PSV will be useful to study HIV-1 CRF- or subtype-specific humoral immune responses for subtype G and CRF02_AG.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Pruebas de Neutralización , VIH-1/inmunología , VIH-1/genética , VIH-1/clasificación , Nigeria , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Humanos , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Reacciones Cruzadas/inmunología

RESUMEN

We recently demonstrated that Simian-HIV (SHIV)-infected neonate rhesus macaques (RMs) generated heterologous HIV-1 neutralizing antibodies (NAbs) with broadly-NAb (bNAb) characteristics at a higher frequency compared with their corresponding dam. Here, we characterized genetic diversity in Env sequences from four neonate or adult/dam RM pairs: in two pairs, neonate and dam RMs made heterologous HIV-1 NAbs; in one pair, neither the neonate nor the dam made heterologous HIV-1 NAbs; and in another pair, only the neonate made heterologous HIV-1 NAbs. Phylogenetic and sequence diversity analyses of longitudinal Envs revealed that a higher genetic diversity, within the host and away from the infecting SHIV strain, was correlated with heterologous HIV-1 NAb development. We identified 22 Env variable sites, of which 9 were associated with heterologous HIV-1 NAb development; 3/9 sites had mutations previously linked to HIV-1 Env bNAb development. These data suggested that viral diversity drives heterologous HIV-1 NAb development, and the faster accumulation of viral diversity in neonate RMs may be a potential mechanism underlying bNAb induction in pediatric populations. Moreover, these data may inform candidate Env immunogens to guide precursor B cells to bNAb status via vaccination by the Env-based selection of bNAb lineage members with the appropriate mutations associated with neutralization breadth.

Asunto(s)

Anticuerpos Neutralizantes , Evolución Molecular , VIH-1 , Macaca mulatta , Filogenia , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , VIH-1/genética , VIH-1/inmunología , VIH-1/clasificación , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Variación Genética , Animales Recién Nacidos , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/sangre , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , Infecciones por VIH/virología

RESUMEN

How different classes of the B cell antigen receptor (BCR) sense viral antigens used in vaccination protocols is poorly understood. Here, we study antigen binding and sensing of human Ramos B cells expressing a BCR of either the IgM or IgG1 class with specificity for the CD4-binding-site of the envelope (Env) protein of the HIV-1. Both BCRs carry an identical antigen binding site derived from the broad neutralizing antibody (bnAb) CH31. We find a five times higher expression of the IgG1-BCR in comparison to the IgM-BCR on the surface of transfected Ramos B cells. The two BCR classes also differ from each other in their interaction with cognate HIV Env antigens in that the IgG1-BCR and IgM-BCR bind preferentially to polyvalent and monovalent antigens, respectively. By generating an IgM/IgG1 chimeric BCR, we found that the class-specific BCR expression and antigen-sensing behavior can be transferred with the CH1γ domain from the IgG1-BCR to the IgM-BCR. Thus, the class of CH1 domain has an impact on BCR assembly and expression as well as on antigen sensing.

Asunto(s)

VIH-1 , Inmunoglobulina G , Inmunoglobulina M , Receptores de Antígenos de Linfocitos B , Humanos , Inmunoglobulina M/inmunología , Inmunoglobulina G/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/inmunología , VIH-1/inmunología , VIH-1/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Anticuerpos Anti-VIH/inmunología , Dominios Proteicos , Anticuerpos Neutralizantes/inmunología

RESUMEN

Viral infection generally induces polyclonal neutralizing antibody responses. However, how many lineages of antibody responses can fully represent the neutralization activities in sera has not been well studied. Using the newly designed stable HIV-1 Env trimer as hook, we isolated two distinct broadly neutralizing antibodies (bnAbs) from Chinese rhesus macaques infected with SHIV1157ipd3N4 for 5 years. One lineage of neutralizing antibodies (JT15 and JT16) targeted the V2-apex in the Env trimers, similar to the J038 lineage bnAbs identified in our previous study. The other lineage neutralizing antibody (JT18) targeted the V3 crown region in the Env, which strongly competed with human 447-52D. Each lineage antibody neutralized a different set of viruses. Interestingly, when the two neutralizing antibodies from different lineages isolated from the same macaque were combined, the mixture had a neutralization breath very similar to that from the cognate sera. Our study demonstrated that a minimum of two different neutralizing antibodies can fully recapitulate the serum neutralization breadth. This observation can have important implications in AIDS vaccine design.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , Macaca mulatta , Síndrome de Inmunodeficiencia Adquirida del Simio , Macaca mulatta/inmunología , Animales , VIH-1/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Humanos , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/sangre , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/sangre , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Pruebas de Neutralización

RESUMEN

Development of a safe and effective human immunodeficiency virus (HIV) vaccine is a persistent challenge despite decades of research. Previous strategies utilizing protein subunit and viral vector vaccines were safe but not protective. Current strategies seek to induce broadly neutralizing antibodies, with multiple early phase trials in progress seeking to achieve this through sequential vaccination, mRNA, or updated viral-vectored vaccines. A safe and effective vaccine is critical to ending the HIV epidemic.

Asunto(s)

Vacunas contra el SIDA , Infecciones por VIH , Humanos , Vacunas contra el SIDA/inmunología , Vacunas contra el SIDA/administración & dosificación , Infecciones por VIH/prevención & control , Anticuerpos Neutralizantes/inmunología , VIH-1/inmunología , Anticuerpos Anti-VIH/inmunología , Desarrollo de Vacunas