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PLoS Pathogens May 2024The human immunodeficiency virus (HIV) envelope protein (Env) mediates viral entry into host cells and is the primary target for the humoral immune response. Env is...
The human immunodeficiency virus (HIV) envelope protein (Env) mediates viral entry into host cells and is the primary target for the humoral immune response. Env is extensively glycosylated, and these glycans shield underlying epitopes from neutralizing antibodies. The glycosylation of Env is influenced by the type of host cell in which the virus is produced. Thus, HIV is distinctly glycosylated by CD4+ T cells, the major target cells, and macrophages. However, the specific differences in glycosylation between viruses produced in these cell types have not been explored at the molecular level. Moreover, it remains unclear whether the production of HIV in CD4+ T cells or macrophages affects the efficiency of viral spread and resistance to neutralization. To address these questions, we employed the simian immunodeficiency virus (SIV) model. Glycan analysis implied higher relative levels of oligomannose-type N-glycans in SIV from CD4+ T cells (T-SIV) compared to SIV from macrophages (M-SIV), and the complex-type N-glycans profiles seem to differ between the two viruses. Notably, M-SIV demonstrated greater infectivity than T-SIV, even when accounting for Env incorporation, suggesting that host cell-dependent factors influence infectivity. Further, M-SIV was more efficiently disseminated by HIV binding cellular lectins. We also evaluated the influence of cell type-dependent differences on SIV's vulnerability to carbohydrate binding agents (CBAs) and neutralizing antibodies. T-SIV demonstrated greater susceptibility to mannose-specific CBAs, possibly due to its elevated expression of oligomannose-type N-glycans. In contrast, M-SIV exhibited higher susceptibility to neutralizing sera in comparison to T-SIV. These findings underscore the importance of host cell-dependent attributes of SIV, such as glycosylation, in shaping both infectivity and the potential effectiveness of intervention strategies.
Topics: Simian Immunodeficiency Virus; Glycosylation; CD4-Positive T-Lymphocytes; Animals; Macrophages; Antibodies, Neutralizing; Simian Acquired Immunodeficiency Syndrome; Humans; Macaca mulatta; Polysaccharides
PubMed: 38805549
DOI: 10.1371/journal.ppat.1012190 -
Nature Communications May 2024Understanding of infection dynamics is important for public health measures against monkeypox virus (MPXV) infection. Herein, samples from multiple body sites and...
Understanding of infection dynamics is important for public health measures against monkeypox virus (MPXV) infection. Herein, samples from multiple body sites and environmental fomites of 77 acute MPXV infections (HIV co-infection: N = 42) were collected every two to three days and used for detection of MPXV DNA, surface protein specific antibodies and neutralizing titers. Skin lesions show 100% positivity rate of MPXV DNA, followed by rectum (88.16%), saliva (83.78%) and oropharynx (78.95%). Positivity rate of oropharynx decreases rapidly after 7 days post symptom onset (d.p.o), while the rectum and saliva maintain a positivity rate similar to skin lesions. Viral dynamics are similar among skin lesions, saliva and oropharynx, with a peak at about 6 d.p.o. In contrast, viral levels in the rectum peak at the beginning of symptom onset and decrease rapidly thereafter. 52.66% of environmental fomite swabs are positive for MPXV DNA, with highest positivity rate (69.89%) from air-conditioning air outlets. High seropositivity against A29L (100%) and H3L (94.74%) are detected, while a correlation between IgG endpoint titers and neutralizing titers is only found for A29L. Most indexes are similar between HIV and Non-HIV participants, while HIV and rectitis are associated with higher viral loads in rectum.
Topics: Humans; Male; Virus Shedding; Antibodies, Viral; Prospective Studies; Adult; Monkeypox virus; Mpox (monkeypox); Saliva; HIV Infections; Antibodies, Neutralizing; Middle Aged; Longitudinal Studies; DNA, Viral; Oropharynx; Coinfection; Viral Load; Fomites
PubMed: 38802350
DOI: 10.1038/s41467-024-48754-8 -
Patterns (New York, N.Y.) May 2024Existing antibody language models are limited by their use of unpaired antibody sequence data. A recently published dataset of ∼1.6 × 10 natively paired human...
Existing antibody language models are limited by their use of unpaired antibody sequence data. A recently published dataset of ∼1.6 × 10 natively paired human antibody sequences offers a unique opportunity to evaluate how antibody language models are improved by training with native pairs. We trained three baseline antibody language models (BALM), using natively paired (BALM-paired), randomly-paired (BALM-shuffled), or unpaired (BALM-unpaired) sequences from this dataset. To address the paucity of paired sequences, we additionally fine-tuned ESM (evolutionary scale modeling)-2 with natively paired antibody sequences (ft-ESM). We provide evidence that training with native pairs allows the model to learn immunologically relevant features that span the light and heavy chains, which cannot be simulated by training with random pairs. We additionally show that training with native pairs improves model performance on a variety of metrics, including the ability of the model to classify antibodies by pathogen specificity.
PubMed: 38800360
DOI: 10.1016/j.patter.2024.100967 -
BioRxiv : the Preprint Server For... May 2024Antibody-dependent cell-mediated cytotoxicity, mediated by natural killer (NK) cells and antibodies, emerged as a secondary correlate of protection in the RV144 HIV...
Antibody-dependent cell-mediated cytotoxicity, mediated by natural killer (NK) cells and antibodies, emerged as a secondary correlate of protection in the RV144 HIV vaccine clinical trial, the only vaccine thus far demonstrating some efficacy in human. Therefore, leveraging NK cells with enhanced cytotoxic effector responses may bolster vaccine induced protection against HIV. Here, we investigated the effect of orally administering indole-3-carbinol (I3C), an aryl hydrocarbon receptor (AHR) agonist, as an adjuvant to an RV144-like vaccine platform in a mouse model. We demonstrate the expansion of KLRG1-expressing NK cells induced by the vaccine together with I3C. This NK cell subset exhibited enhanced vaccine antigen-specific cytotoxic memory-like features. Our study underscores the potential of incorporating I3C as an oral adjuvant to HIV vaccine platforms to enhance antigen-specific (memory-like) cytotoxicity of NK cells against HIV-infected cells. This approach may contribute to enhancing the protective efficacy of HIV preventive vaccines against HIV acquisition.
PubMed: 38798447
DOI: 10.1101/2024.05.11.593683 -
Pharmaceutics Apr 2024Monoclonal antibodies are commonly engineered with an introduction of Met428Leu and Asn434Ser, known as the LS mutation, in the fragment crystallizable region to improve...
Impact of LS Mutation on Pharmacokinetics of Preventive HIV Broadly Neutralizing Monoclonal Antibodies: A Cross-Protocol Analysis of 16 Clinical Trials in People without HIV.
Monoclonal antibodies are commonly engineered with an introduction of Met428Leu and Asn434Ser, known as the LS mutation, in the fragment crystallizable region to improve pharmacokinetic profiles. The LS mutation delays antibody clearance by enhancing binding affinity to the neonatal fragment crystallizable receptor found on endothelial cells. To characterize the LS mutation for monoclonal antibodies targeting HIV, we compared pharmacokinetic parameters between parental versus LS variants for five pairs of anti-HIV immunoglobin G1 monoclonal antibodies (VRC01/LS/VRC07-523LS, 3BNC117/LS, PGDM1400/LS PGT121/LS, 10-1074/LS), analyzing data from 16 clinical trials of 583 participants without HIV. We described serum concentrations of these monoclonal antibodies following intravenous or subcutaneous administration by an open two-compartment disposition, with first-order elimination from the central compartment using non-linear mixed effects pharmacokinetic models. We compared estimated pharmacokinetic parameters using the targeted maximum likelihood estimation method, accounting for participant differences. We observed lower clearance rate, central volume, and peripheral volume of distribution for all LS variants compared to parental monoclonal antibodies. LS monoclonal antibodies showed several improvements in pharmacokinetic parameters, including increases in the elimination half-life by 2.7- to 4.1-fold, the dose-normalized area-under-the-curve by 4.1- to 9.5-fold, and the predicted concentration at 4 weeks post-administration by 3.4- to 7.6-fold. Results suggest a favorable pharmacokinetic profile of LS variants regardless of HIV epitope specificity. Insights support lower dosages and/or less frequent dosing of LS variants to achieve similar levels of antibody exposure in future clinical applications.
PubMed: 38794258
DOI: 10.3390/pharmaceutics16050594 -
Vaccines May 2024Since the emergence of COVID-19, extensive research efforts have been undertaken to accelerate the development of multiple types of vaccines to combat the pandemic.... (Review)
Review
Since the emergence of COVID-19, extensive research efforts have been undertaken to accelerate the development of multiple types of vaccines to combat the pandemic. These include inactivated, recombinant subunit, viral vector, and nucleic acid vaccines. In the development of these diverse vaccines, appropriate methods to assess vaccine immunogenicity are essential in both preclinical and clinical studies. Among the biomarkers used in vaccine evaluation, the neutralizing antibody level serves as a pivotal indicator for assessing vaccine efficacy. Neutralizing antibody detection methods can mainly be classified into three types: the conventional virus neutralization test, pseudovirus neutralization test, and surrogate virus neutralization test. Importantly, standardization of these assays is critical for their application to yield results that are comparable across different laboratories. The development and use of international or regional standards would facilitate assay standardization and facilitate comparisons of the immune responses induced by different vaccines. In this comprehensive review, we discuss the principles, advantages, limitations, and application of different SARS-CoV-2 neutralization assays in vaccine clinical trials. This will provide guidance for the development and evaluation of COVID-19 vaccines.
PubMed: 38793805
DOI: 10.3390/vaccines12050554 -
Viruses May 2024Neutralizing antibodies targeting the spike (S) protein of SARS-CoV-2, elicited either by natural infection or vaccination, are crucial for protection against the virus....
Neutralizing antibodies targeting the spike (S) protein of SARS-CoV-2, elicited either by natural infection or vaccination, are crucial for protection against the virus. Nonetheless, the emergence of viral escape mutants presents ongoing challenges by contributing to breakthrough infections. To define the evolution trajectory of SARS-CoV-2 within the immune population, we co-incubated replication-competent rVSV/SARS-CoV-2/GFP chimeric viruses with sera from COVID-19 convalescents. Our findings revealed that the E484D mutation contributes to increased viral resistant against both convalescent and vaccinated sera, while the L1265R/H1271Y double mutation enhanced viral infectivity in 293T-hACE2 and Vero cells. These findings suggest that under the selective pressure of polyclonal antibodies, SARS-CoV-2 has the potential to accumulate mutations that facilitate either immune evasion or greater infectivity, facilitating its adaption to neutralizing antibody responses. Although the mutations identified in this study currently exhibit low prevalence in the circulating SARS-CoV-2 populations, the continuous and meticulous surveillance of viral mutations remains crucial. Moreover, there is an urgent necessity to develop next-generation antibody therapeutics and vaccines that target diverse, less mutation-prone antigenic sites to ensure more comprehensive and durable immune protection against SARS-CoV-2.
Topics: SARS-CoV-2; Spike Glycoprotein, Coronavirus; Humans; COVID-19; Antibodies, Neutralizing; Antibodies, Viral; Animals; Chlorocebus aethiops; Vero Cells; Mutation; Immune Evasion; HEK293 Cells
PubMed: 38793644
DOI: 10.3390/v16050763 -
Viruses Apr 2024People living with HIV (PLWH) can exhibit impaired immune responses to vaccines. Accumulating evidence indicates that PLWH, particularly those receiving antiretroviral...
People living with HIV (PLWH) can exhibit impaired immune responses to vaccines. Accumulating evidence indicates that PLWH, particularly those receiving antiretroviral therapy, mount strong antibody responses to COVID-19 vaccines, but fewer studies have examined cellular immune responses to the vaccinations. Here, we used an activation-induced marker (AIM) assay to quantify SARS-CoV-2 spike-specific CD4+ and CD8+ T cells generated by two and three doses of COVID-19 vaccines in 50 PLWH receiving antiretroviral therapy, compared to 87 control participants without HIV. In a subset of PLWH, T-cell responses were also assessed after post-vaccine breakthrough infections and/or receipt of a fourth vaccine dose. All participants remained SARS-CoV-2 infection-naive until at least one month after their third vaccine dose. SARS-CoV-2 infection was determined by seroconversion to a Nucleocapsid (N) antigen, which occurred in 21 PLWH and 38 control participants after the third vaccine dose. Multivariable regression analyses were used to investigate the relationships between sociodemographic, health- and vaccine-related variables, vaccine-induced T-cell responses, and breakthrough infection risk. We observed that a third vaccine dose boosted spike-specific CD4+ and CD8+ T-cell frequencies significantly above those measured after the second dose (all < 0.0001). Median T-cell frequencies did not differ between PLWH and controls after the second dose ( > 0.1), but CD8+ T-cell responses were modestly lower in PLWH after the third dose ( = 0.02), an observation that remained significant after adjusting for sociodemographic, health- and vaccine-related variables ( = 0.045). In PLWH who experienced a breakthrough infection, median T-cell frequencies increased even higher than those observed after three vaccine doses ( < 0.03), and CD8+ T-cell responses in this group remained higher even after a fourth vaccine dose ( = 0.03). In multivariable analyses, the only factor associated with an increased breakthrough infection risk was younger age, which is consistent with the rapid increase in SARS-CoV-2 seropositivity that was seen among younger adults in Canada after the initial appearance of the Omicron variant. These results indicate that PLWH receiving antiretroviral therapy mount strong T-cell responses to COVID-19 vaccines that can be enhanced by booster doses or breakthrough infection.
Topics: Humans; Male; HIV Infections; Female; COVID-19 Vaccines; Middle Aged; SARS-CoV-2; COVID-19; CD8-Positive T-Lymphocytes; Adult; CD4-Positive T-Lymphocytes; Spike Glycoprotein, Coronavirus; Antibodies, Viral; Aged; Immunity, Cellular; Breakthrough Infections
PubMed: 38793543
DOI: 10.3390/v16050661 -
Pathogens (Basel, Switzerland) Apr 2024This study aims to screen for IgG antibodies against () in the sera of 155 newly diagnosed Human Immunodeficiency Virus (HIV) positive patients under surveillance in...
This study aims to screen for IgG antibodies against () in the sera of 155 newly diagnosed Human Immunodeficiency Virus (HIV) positive patients under surveillance in Greek Infectious Disease Units. Additionally, risk factors based on patient demographics were examined, and a comparative evaluation of commercially available serological methods was conducted. Three methods were employed to detect IgG antibodies against : Enzyme-Linked Immunosorbent Assay (ELISA), Indirect Immunofluorescence Antibody Test (IFAT), and Western Blot (WB), which was used as a reference here. Forty-nine sera samples were true-positive for IgG antibodies against , resulting in a 31.61% positivity rate, and the immunoassay test statistical reliability analysis resulted in higher IFAT accuracy (90.97%) compared to ELISA (76.26%). Furthermore, statistical analysis of demographic and immunological data included in the study placed female and foreign/non-Greek individuals at 2.24 ( = 0.0009) and 2.34 ( = 0.0006) times higher risk of positive IgG testing compared to their male and Greek counterparts, respectively. Our findings on positivity rates and comparative serology underscore the importance of early and suitable screening measures for newly diagnosed HIV+ patients to mitigate the life-threatening outcomes that may arise from a potential subsequent activation.
PubMed: 38787227
DOI: 10.3390/pathogens13050375 -
JCI Insight Apr 2024Children with perinatally acquired HIV (PHIV) have special vaccination needs, as they make suboptimal immune responses. Here, we evaluated safety and immunogenicity of 2...
Children with perinatally acquired HIV (PHIV) have special vaccination needs, as they make suboptimal immune responses. Here, we evaluated safety and immunogenicity of 2 doses of 4-component group B meningococcal vaccine in antiretroviral therapy-treated children with PHIV and healthy controls (HCs). Assessments included the standard human serum bactericidal antibody (hSBA) assay and measurement of IgG titers against capsular group B Neisseria meningitidis antigens (fHbp, NHBA, NadA). The B cell compartment and vaccine-induced antigen-specific (fHbp+) B cells were investigated by flow cytometry, and gene expression was investigated by multiplexed real-time PCR. A good safety and immunogenicity profile was shown in both groups; however, PHIV demonstrated a reduced immunogenicity compared with HCs. Additionally, PHIV showed a reduced frequency of fHbp+ and an altered B cell subset distribution, with higher fHbp+ frequency in activated memory and tissue-like memory B cells. Gene expression analyses on these cells revealed distinct mechanisms between PHIV and HC seroconverters. Overall, these data suggest that PHIV presents a diverse immune signature following vaccination. The impact of such perturbation on long-term maintenance of vaccine-induced immunity should be further evaluated in vulnerable populations, such as people with PHIV.
Topics: Humans; HIV Infections; Male; Female; Child; Meningococcal Vaccines; Child, Preschool; Meningococcal Infections; Antibodies, Bacterial; B-Lymphocytes; Infectious Disease Transmission, Vertical; Immunogenicity, Vaccine; Immunoglobulin G
PubMed: 38775152
DOI: 10.1172/jci.insight.177182