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Cell Reports Aug 2023Zika virus (ZIKV) is an emerging pathogen that causes devastating congenital defects. The overlapping epidemiology and immunologic cross-reactivity between ZIKV and...
Zika virus (ZIKV) is an emerging pathogen that causes devastating congenital defects. The overlapping epidemiology and immunologic cross-reactivity between ZIKV and dengue virus (DENV) pose complex challenges to vaccine design, given the potential for antibody-dependent enhancement of disease. Therefore, classification of ZIKV-specific antibody targets is of notable value. From a ZIKV-infected rhesus macaque, we identify ZIKV-reactive B cells and isolate potent neutralizing monoclonal antibodies (mAbs) with no cross-reactivity to DENV. We group these mAbs into four distinct antigenic groups targeting ZIKV-specific cross-protomer epitopes on the envelope glycoprotein. Co-crystal structures of representative mAbs in complex with ZIKV envelope glycoprotein reveal envelope-dimer epitope and unique dimer-dimer epitope targeting. All four specificities are serologically identified in convalescent humans following ZIKV infection, and representative mAbs from all four groups protect against ZIKV replication in mice. These results provide key insights into ZIKV-specific antigenicity and have implications for ZIKV vaccine, diagnostic, and therapeutic development.
Topics: Humans; Animals; Mice; Zika Virus; Zika Virus Infection; Antibodies, Neutralizing; Epitopes; Macaca mulatta; Antibodies, Viral; Dengue Virus; Dengue; Antibodies, Monoclonal; Viral Vaccines; Viral Envelope Proteins
PubMed: 37561630
DOI: 10.1016/j.celrep.2023.112942 -
Annual Review of Immunology Jun 2024Elite controllers are a heterogeneous group of people living with HIV who control viral replication without antiretroviral therapy. There is substantial evidence that at... (Review)
Review
Elite controllers are a heterogeneous group of people living with HIV who control viral replication without antiretroviral therapy. There is substantial evidence that at least some elite controllers are infected with replication-competent virus, thus they may serve as a model of a functional cure of HIV. The mechanisms responsible for virologic control have been actively studied. The most objective data support CD8+ T cell-based mechanisms of control, but other immune responses, mediated by antibodies and natural killer cells, may also play a role in controlling viral replication. In this article, we review the evidence for different mechanisms of immune control in these remarkable individuals.
Topics: Humans; HIV Infections; Virus Replication; Killer Cells, Natural; CD8-Positive T-Lymphocytes; HIV-1; Animals
PubMed: 37827174
DOI: 10.1146/annurev-immunol-083122-035233 -
Current Opinion in HIV and AIDS Jul 2023To discuss progress and challenges in the development of antiretroviral regimens that combine broadly neutralizing antibodies (bNAbs) and long-acting (LA) small-molecule... (Review)
Review
PURPOSE OF REVIEW
To discuss progress and challenges in the development of antiretroviral regimens that combine broadly neutralizing antibodies (bNAbs) and long-acting (LA) small-molecule antiretroviral drugs (ARVs).
RECENT FINDINGS
Data are extremely limited, with results from only a single phase 1a clinical trial reported to date. That study, a combination of lenacapavir plus the bNAbs teropavimab and zinlirvimab, maintained viral suppression over 26 weeks in 18 of 20 participants. A second pilot study, ACTG A5357, which tests the safety and virologic efficacy of the combination of LA injectable cabotegravir with the bNAb VRC07-523LS is fully enrolled; results are expected in the second half of 2023.
SUMMARY
The development of regimens that combine bNAbs and LA ARVs has been challenging. Both agents need similar half-lives in order to harmonize dosing schedules. In addition, the need to perform bNAb susceptibility testing to assure activity of the bNAb in order to protect against the risk of developing resistance to the LA ARV has slowed enrollment into trials and poses substantial logistical challenges to widespread adoption of these combinations should they prove safe and effective. Improvements in manufacture that reduce the cost of goods and advances in delivery systems are needed to ensure equitable access to these regimens.
Topics: Humans; HIV Infections; Broadly Neutralizing Antibodies; Pharmaceutical Preparations; Pilot Projects; Antibodies, Neutralizing; HIV-1; Anti-Retroviral Agents; HIV Antibodies
PubMed: 37265259
DOI: 10.1097/COH.0000000000000801 -
Drugs Dec 2023Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) provides a critical intervention toward ending the HIV epidemic and protecting people with reasons to... (Review)
Review
Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) provides a critical intervention toward ending the HIV epidemic and protecting people with reasons to utilize PrEP. PrEP options continue to expand as new administration modalities offer the potential to tailor PrEP use for individual success. We have provided the evidence for new and emerging antiretroviral agents for PrEP (cabotegravir, lenacapavir, dapivirine, and broadly neutralizing antibodies), divided into pharmacology, animal model, and human data, accompanied by a summary and suggested place in therapy. Cabotegravir is a US Food and Drug Administration (FDA)-approved intramuscular injection given every 2 months with a strong body of evidence demonstrating efficacy for HIV PrEP, lenacapavir administered subcutaneously every 6 months is currently under investigation for HIV PrEP, dapivirine vaginal ring is an available PrEP option for women in certain areas of Africa, and broadly neutralizing monoclonal antibodies have been challenged in demonstrating efficacy in phase 1-2 study for HIV PrEP to date. Clinical literature for individual agents is discussed with data from major studies summarized in tables. This review provides a detailed overview of recently available and premier candidate PrEP drugs.
Topics: Animals; Humans; Female; HIV; HIV Infections; Pharmaceutical Preparations; Anti-HIV Agents; Anti-Retroviral Agents; Pre-Exposure Prophylaxis
PubMed: 38079092
DOI: 10.1007/s40265-023-01963-9 -
Nature Communications Oct 2023HIV-1 infection causes severe alterations of gut mucosa, microbiota and immune system, which can be curbed by early antiretroviral therapy. Here, we investigate how...
HIV-1 infection causes severe alterations of gut mucosa, microbiota and immune system, which can be curbed by early antiretroviral therapy. Here, we investigate how treatment timing affects intestinal memory B-cell and plasmablast repertoires of HIV-1-infected humans. We show that only class-switched memory B cells markedly differ between subjects treated during the acute and chronic phases of infection. Intestinal memory B-cell monoclonal antibodies show more prevalent polyreactive and commensal bacteria-reactive clones in late- compared to early-treated individuals. Mirroring this, serum IgA polyreactivity and commensal-reactivity are strongly increased in late-treated individuals and correlate with intestinal permeability and systemic inflammatory markers. Polyreactive blood IgA memory B cells, many of which egressed from the gut, are also substantially enriched in late-treated individuals. Our data establish gut and systemic B-cell polyreactivity to commensal bacteria as hallmarks of chronic HIV-1 infection and suggest that initiating treatment early may limit intestinal B-cell abnormalities compromising HIV-1 humoral response.
Topics: Humans; Memory B Cells; HIV-1; B-Lymphocytes; Bacteria; HIV Infections; Immunoglobulin A; Intestinal Mucosa
PubMed: 37816704
DOI: 10.1038/s41467-023-42027-6 -
Current Opinion in HIV and AIDS Jul 2024Highlighting opportunities/potential for immunotherapy by understanding dynamics of HIV control during pediatric HIV infection with and without antiretroviral therapy... (Review)
Review
PURPOSE OF REVIEW
Highlighting opportunities/potential for immunotherapy by understanding dynamics of HIV control during pediatric HIV infection with and without antiretroviral therapy (ART), as modeled in Simian immunodeficiency virus (SIV) and Simian-human immunodeficiency virus (SHIV)-infected rhesus macaques and observed in clinical trials. This review outlines mode of transmission, pathogenesis of pediatric HIV, unique aspects of the infant immune system, infant macaque models and immunotherapies.
RECENT FINDINGS
During the earliest stages of perinatal HIV infection, the infant immune system is characterized by a unique environment defined by immune tolerance and lack of HIV-specific T cell responses which contribute to disease progression. Moreover, primary lymphoid organs such as the thymus appear to play a distinct role in HIV pathogenesis in children living with HIV (CLWH). Key components of the immune system determine the degree of viral control, targets for strategies to induce viral control, and the response to immunotherapy. The pursuit of highly potent broadly neutralizing antibodies (bNAbs) and T cell vaccines has revolutionized the approach to HIV cure. Administration of HIV-1-specific bNAbs, targeting the highly variable envelope improves humoral immunity, and T cell vaccines induce or improve T cell responses such as the cytotoxic effects of HIV-1-specific CD8+ T cells, both of which are promising options towards virologic control and ART-free remission as evidenced by completed and ongoing clinical trials.
SUMMARY
Understanding early events during HIV infection and disease progression in CLWH serves as a foundation for predicting or targeting later outcomes by harnessing the immune system's natural responses. The developing pediatric immune system offers multiple opportunities for specific long-term immunotherapies capable of improving quality of life during adolescence and adulthood.
Topics: Humans; HIV Infections; Immunotherapy; Animals; Child; Macaca mulatta; Disease Models, Animal; Infant; Simian Immunodeficiency Virus; AIDS Vaccines
PubMed: 38841850
DOI: 10.1097/COH.0000000000000857 -
Antiviral Research Feb 2024Despite the ability to suppress viral replication using anti-retroviral therapy (ART), HIV-1 remains a global public health problem. Curative strategies for HIV-1 have... (Review)
Review
Despite the ability to suppress viral replication using anti-retroviral therapy (ART), HIV-1 remains a global public health problem. Curative strategies for HIV-1 have to target and eradicate latently infected cells across the body, i.e. the viral reservoir. Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope glycoprotein (Env) have the capacity to neutralize virions and bind to infected cells to initiate elimination of these cells. To improve the efficacy of bNAbs in terms of viral suppression and viral reservoir eradication, next generation antibodies (Abs) are being developed that address the current limitations of Ab treatment efficacy; (1) low antigen (Env) density on (reactivated) HIV-1 infected cells, (2) high viral genetic diversity, (3) exhaustion of immune cells and (4) short half-life of Abs. In this review we summarize and discuss preclinical and clinical studies in which anti-HIV-1 Abs demonstrated potent viral control, and describe the development of engineered Abs that could address the limitations described above. Next generation Abs with optimized effector function, avidity, effector cell recruitment and immune cell activation have the potential to contribute to an HIV-1 cure or durable control.
Topics: Humans; Broadly Neutralizing Antibodies; Antibodies, Neutralizing; HIV-1; HIV Antibodies; HIV Infections
PubMed: 38158130
DOI: 10.1016/j.antiviral.2023.105788 -
Nature Medicine Nov 2023Human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies (nAbs) that prevent infection are the main goal of HIV vaccine discovery. But as no nAb-eliciting...
Human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies (nAbs) that prevent infection are the main goal of HIV vaccine discovery. But as no nAb-eliciting vaccines are yet available, only data from HIV-1 neutralizers-persons with HIV-1 who naturally develop broad and potent nAbs-can inform about the dynamics and durability of nAb responses in humans, knowledge which is crucial for the design of future HIV-1 vaccine regimens. To address this, we assessed HIV-1-neutralizing immunoglobulin G (IgG) from 2,354 persons with HIV-1 on or off antiretroviral therapy (ART). Infection with non-clade B viruses, CD4 T cell counts <200 µl, being off ART and a longer time off ART were independent predictors of a more potent and broad neutralization. In longitudinal analyses, we found nAb half-lives of 9.3 and 16.9 years in individuals with no- or low-level viremia, respectively, and 4.0 years in persons who newly initiated ART. Finally, in a potent HIV-1 neutralizer, we identified lower fractions of serum nAbs and of nAb-encoding memory B cells after ART initiation, suggesting that a decreasing neutralizing serum activity after antigen withdrawal is due to lower levels of nAbs. These results collectively show that HIV-1-neutralizing responses can persist for several years, even at low antigen levels, suggesting that an HIV-1 vaccine may elicit a durable nAb response.
Topics: Humans; HIV-1; HIV Infections; HIV Antibodies; Antibodies, Neutralizing; AIDS Vaccines; Virus Replication
PubMed: 37957379
DOI: 10.1038/s41591-023-02582-3 -
Cell Reports Jul 2023Broadly neutralizing antibodies (bNAbs) against HIV can reduce viral transmission in humans, but an effective therapeutic will require unusually high breadth and potency...
Broadly neutralizing antibodies (bNAbs) against HIV can reduce viral transmission in humans, but an effective therapeutic will require unusually high breadth and potency of neutralization. We employ the OSPREY computational protein design software to engineer variants of two apex-directed bNAbs, PGT145 and PG9RSH, resulting in increases in potency of over 100-fold against some viruses. The top designed variants improve neutralization breadth from 39% to 54% at clinically relevant concentrations (IC < 1 μg/mL) and improve median potency (IC) by up to 4-fold over a cross-clade panel of 208 strains. To investigate the mechanisms of improvement, we determine cryoelectron microscopy structures of each variant in complex with the HIV envelope trimer. Surprisingly, we find the largest increases in breadth to be a result of optimizing side-chain interactions with highly variable epitope residues. These results provide insight into mechanisms of neutralization breadth and inform strategies for antibody design and improvement.
Topics: Humans; HIV Infections; HIV Antibodies; Antibodies, Neutralizing; HIV-1; Broadly Neutralizing Antibodies; Cryoelectron Microscopy; HIV Seropositivity; Neutralization Tests
PubMed: 37436900
DOI: 10.1016/j.celrep.2023.112711