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Clinical Microbiology and Infection :... Jun 2024Invasive lumbar puncture (LP) is the conventional method for diagnosing neurosyphilis (NS). We investigated a noninvasive alternative method to detect serum Treponema...
Refining a noninvasive prediction model for neurosyphilis diagnosis by using Immunoassay to Detect serum anti-TP0435 (TP17) and TP0574 (TP47) IgG antibodies: Two-center Cross-sectional retrospective study in China.
OBJECTIVES
Invasive lumbar puncture (LP) is the conventional method for diagnosing neurosyphilis (NS). We investigated a noninvasive alternative method to detect serum Treponema pallidum specific antibodies against highly immunogenic antigens TP0171 (TP15), TP0435 (TP17), and TP0574 (TP47) by using luciferase immunosorbent assay (LISA).
METHODS
816 HIV-negative patients suspected of NS from Beijing and Guangzhou cohort were retrospectively selected and tested for serum anti-TP15, TP17, and TP47 IgG antibody. Two diagnostic prediction models were developed using stepwise logistic regression in Beijing cohort, and evaluated in Guangzhou cohort for external validation.
RESULTS
Serum antibodies against TP15, TP17, and TP47 showed moderate capability for NS diagnosis in Beijing cohort and the corresponding AUCs were 0.722 (95% CI: 0.680-0.762), 0.780 (95% CI: 0.741-0.817), and 0.774 (95% CI: 0.734-0.811), respectively. An expanded NS prediction model integrated with anti-TP17 and anti-TP47 antibodies showed better performance than the base NS diagnostic model without anti-TP17 and anti-TP47 antibodies with the AUC of 0.874 (95% CI: 0.841-0.906) vs 0.845 (95% CI: 0.809-0.881) (p = 0.007) in the development cohort, and 0.934 (95% CI: 0.909-0.960) vs 0.877 (95% CI: 0.840-0.914) (p<0.001) in validation cohort, respectively. Decision curve analysis (DCA) revealed that the net benefit of the expanded model exceeded that of the base model when the threshold probability was between 0.10 and 0.95 in both the development and external validation cohorts.
CONCLUSIONS
Serum antibodies against TP17 and TP47 exhibited promising diagnostic capability for NS and significantly enhanced predictive accuracy of model for NS diagnosis. Our study highlights the potential of serum treponemal antibody detection as a noninvasive method for NS diagnosis to substitute invasive LP in NS diagnosis.
PubMed: 38909686
DOI: 10.1016/j.cmi.2024.06.013 -
Medical Microbiology and Immunology Jun 2024Rapid tests allow outpatient, low cost, reliable, screening for chronic HIV infection. However, data regarding their sensitivity on primary infection remain scarce. The...
Rapid tests allow outpatient, low cost, reliable, screening for chronic HIV infection. However, data regarding their sensitivity on primary infection remain scarce. The objective of this study was to assess sensitivity of nine HIV rapid tests for primary HIV-1 infection screening. Seventy-five serum samples from patients during HIV-1 primary infection were included. Primary infection was diagnosed by a positive 4th generation ELISA and HIV-1 RNA positivity confirmed by Western blot patterns associated with HIV-1 primary infection. Early seroconversion was defined as the absence of antibodies on HIV-1 Western blot associated with HIV-1 RNA and p24-antigen positivity. An identical sensitivity (95% CI) of 76.7% (65.2-84.2%) was observed for HIV 1/2 STAT-PAK Assay (STAT-PAK), INSTI™ HIV-1/HIV-2 antibody Test (INSTI), SURE CHECK HIV 1/2 (SURE CHECK) and MULTISURE HIV rapid test (MULTISURE) with visual reading. Sensitivity was 74.7% (63.8-83.1%) for MULTISURE (automatic reading), 77.0% (66.3-85.1%) for FIRST RESPONSE Test VIH 1-2.O CARTE (FIRST RESPONSE), 83.8% (73.8-90.5%) for VIKIA HIV1/2 (VIKIA), 88.0% (78.7-93.6%) for Genie™ Fast HIV 1/2 (Genie Fast), 88.6% (79.0-94.1%) for Hexagon HIV (Hexagon), and 92.8% (83.6-96.3%) for Exacto TEST HIV Pro (Exacto). However, rapid tests performed poorly for the early seroconversion subgroup (n = 14), with sensitivities ranging from 7% (1.3-31.5%) for STAT-PAK, INSTI, SURE CHECK, MULTISURE (automatic reading), to 29% (12-55%) for FIRST RESPONSE, 31% (13-58%) for VIKIA, 43% (21-67%) for Hexagon and 57.1% (32.6-78.6%) for Exacto and Genie Fast. Overall, despite significant discrepancies in sensitivity, HIV rapid tests should be used with caution in the context of a suspected primary infection.
Topics: Humans; HIV Infections; Sensitivity and Specificity; HIV-1; Male; Mass Screening; Female; Adult; HIV Antibodies; Middle Aged; RNA, Viral; Enzyme-Linked Immunosorbent Assay; Young Adult; Blotting, Western; Diagnostic Tests, Routine; HIV Testing
PubMed: 38907945
DOI: 10.1007/s00430-024-00792-1 -
Sante Publique (Vandoeuvre-les-Nancy,... 2024Pakistan has the second highest prevalence of hepatitis C globally. The Musafir study, set up in 2018 in a Parisian suburb to understand the representations of hepatitis...
INTRODUCTION
Pakistan has the second highest prevalence of hepatitis C globally. The Musafir study, set up in 2018 in a Parisian suburb to understand the representations of hepatitis and HIV within the Urdu-speaking, male, migrant community living there, provided an opportunity to think about culturally acceptable health promotion interventions. These included awareness campaigns on hepatitis—which did not cover the question of HIV, considered taboo—, held in a mosque.
PURPOSE OF THE RESEARCH
The aim of this article is to describe the implementation of awareness and testing campaigns within a Pakistani religious and cultural association.
METHOD
A partnership with a Pakistani association that runs a place of worship enabled awareness and testing campaigns for hepatitis and HIV to be carried out, thanks to the involvement of the association’s managers and the imam.
RESULTS
Between February and June 2023, 113 people were tested during the five campaigns that were carried out. The population screened consisted almost exclusively of Urdu-speaking men. Anti-HCV antibodies were found in six people, three of whom had already recovered, and two people tested positive for HBV. No cases of HIV were detected.
CONCLUSIONS
The prevalence of hepatitis C found was 5.3 percent, in line with the prevalence in Pakistan. This experiment highlighted the feasibility conditions of a partnership with a faith-based organization and offers ideas for developing this type of initiative in France.
Topics: Humans; Pakistan; Male; Adult; Hepatitis C; Mass Screening; Middle Aged; Young Adult; Female; Prevalence; HIV Infections; Health Promotion; Adolescent
PubMed: 38906813
DOI: No ID Found -
Frontiers in Immunology 2024The HVTN 105 vaccine clinical trial tested four combinations of two immunogens - the DNA vaccine DNA-HIV-PT123, and the protein vaccine AIDSVAX B/E. All combinations...
SWIFT clustering analysis of intracellular cytokine staining flow cytometry data of the HVTN 105 vaccine trial reveals high frequencies of HIV-specific CD4+ T cell responses and associations with humoral responses.
INTRODUCTION
The HVTN 105 vaccine clinical trial tested four combinations of two immunogens - the DNA vaccine DNA-HIV-PT123, and the protein vaccine AIDSVAX B/E. All combinations induced substantial antibody and CD4+ T cell responses in many participants. We have now re-examined the intracellular cytokine staining flow cytometry data using the high-resolution SWIFT clustering algorithm, which is very effective for enumerating rare populations such as antigen-responsive T cells, and also determined correlations between the antibody and T cell responses.
METHODS
Flow cytometry samples across all the analysis batches were registered using the swiftReg registration tool, which reduces batch variation without compromising biological variation. Registered data were clustered using the SWIFT algorithm, and cluster template competition was used to identify clusters of antigen-responsive T cells and to separate these from constitutive cytokine producing cell clusters.
RESULTS
Registration strongly reduced batch variation among batches analyzed across several months. This in-depth clustering analysis identified a greater proportion of responders than the original analysis. A subset of antigen-responsive clusters producing IL-21 was identified. The cytokine patterns in each vaccine group were related to the type of vaccine - protein antigens tended to induce more cells producing IL-2 but not IFN-γ, whereas DNA vaccines tended to induce more IL-2+ IFN-γ+ CD4 T cells. Several significant correlations were identified between specific antibody responses and antigen-responsive T cell clusters. The best correlations were not necessarily observed with the strongest antibody or T cell responses.
CONCLUSION
In the complex HVTN105 dataset, alternative analysis methods increased sensitivity of the detection of antigen-specific T cells; increased the number of identified vaccine responders; identified a small IL-21-producing T cell population; and demonstrated significant correlations between specific T cell populations and serum antibody responses. Multiple analysis strategies may be valuable for extracting the most information from large, complex studies.
Topics: Humans; AIDS Vaccines; CD4-Positive T-Lymphocytes; Flow Cytometry; Cluster Analysis; HIV Infections; Cytokines; Immunity, Humoral; HIV Antibodies; HIV-1; Vaccines, DNA; Interleukins
PubMed: 38903517
DOI: 10.3389/fimmu.2024.1347926 -
Research Square Mar 2024Broadly neutralizing antibodies (bNAbs) are promising candidates for the treatment and prevention of HIV-1 infection. Despite their critical importance, automatic...
Broadly neutralizing antibodies (bNAbs) are promising candidates for the treatment and prevention of HIV-1 infection. Despite their critical importance, automatic detection of HIV-1 bNAbs from immune repertoire is still lacking. Here, we developed a straightforward computational method for apid utomatic dentification of bAbs ) based on Machine Learning methods. In contrast to other approaches using one-hot encoding amino acid sequences or structural alignment for prediction, RAIN uses a combination of selected sequence-based features for accurate prediction of HIV-1 bNAbs. We demonstrate the performance of our approach on non-biased, experimentally obtained sequenced BCR repertoires from HIV-1 immune donors. RAIN processing leads to the successful identification of novel HIV-1 bNAbs targeting the CD4-binding site of the envelope glycoprotein. In addition, we validate the identified bNAbs using neutralization assay and we solve the structure of one of them in complex with the soluble native-like heterotrimeric envelope glycoprotein by single-particle cryo-electron microscopy (cryo-EM). Overall, we propose a method to facilitate and accelerate HIV-1 bNAbs discovery from non-selected immune repertoires.
PubMed: 38903123
DOI: 10.21203/rs.3.rs-4023897/v1 -
BioRxiv : the Preprint Server For... Jun 2024Broadly neutralizing antibodies targeting the V2 apex of the HIV-1 envelope trimer are among the most common specificities elicited in HIV-1-infected humans and...
UNLABELLED
Broadly neutralizing antibodies targeting the V2 apex of the HIV-1 envelope trimer are among the most common specificities elicited in HIV-1-infected humans and simian-human immunodeficiency virus (SHIV)-infected macaques. To gain insight into the prevalent induction of these antibodies, we isolated and characterized 11 V2 apex-directed neutralizing antibody lineages from SHIV-infected rhesus macaques. Remarkably, all SHIV-induced V2 apex lineages were derived from reading frame two of the rhesus DH3-15*01 gene. Cryo-EM structures of envelope trimers in complex with antibodies from nine rhesus lineages revealed modes of recognition that mimicked three canonical human V2 apex-recognition modes. Notably, amino acids encoded by DH3-15*01 played divergent structural roles, inserting into a hole at the trimer apex, H-bonding to an exposed strand, or forming part of a loop scaffold. Overall, we identify a DH3-15*01-signature for rhesus V2 apex broadly neutralizing antibodies and show that highly selected genetic elements can play multiple roles in antigen recognition.
HIGHLIGHTS
Isolated 11 V2 apex-targeted HIV-neutralizing lineages from 10 SHIV-infected Indian-origin rhesus macaquesCryo-EM structures of Fab-Env complexes for nine rhesus lineages reveal modes of recognition that mimic three modes of human V2 apex antibody recognitionAll SHIV-elicited V2 apex lineages, including two others previously published, derive from the same DH3-15*01 gene utilizing reading frame twoThe DH3-15*01 gene in reading frame two provides a necessary, but not sufficient, signature for V2 apex-directed broadly neutralizing antibodiesStructural roles played by DH3-15*01-encoded amino acids differed substantially in different lineages, even for those with the same recognition modePropose that the anionic, aromatic, and extended character of DH3-15*01 in reading frame two provides a selective advantage for V2 apex recognition compared to B cells derived from other D genes in the naïve rhesus repertoireDemonstrate that highly selected genetic elements can play multiple roles in antigen recognition, providing a structural means to enhance recognition diversity.
PubMed: 38903070
DOI: 10.1101/2024.06.11.598384 -
PloS One 2024Hepatitis B virus (HBV) and hepatitis delta virus (HDV) co-infection has been described as the most severe form of viral hepatitis, and can be co-transmitted from...
BACKGROUND
Hepatitis B virus (HBV) and hepatitis delta virus (HDV) co-infection has been described as the most severe form of viral hepatitis, and can be co-transmitted from mother-to-child. A seroprevalence of 4.0% of HDV infection was reported in pregnant women in Yaoundé, and 11.9% in the general population in Cameroon. Our objective was to describe the rate of HDV infection in HBsAg-positive pregnant women and to determine risk factors associated with mother-to-child transmission of HDV.
MATERIALS AND METHODS
A cross-sectional, descriptive study was conducted from January 2019 to July 2022 among pregnant women attending antenatal contacts in seven health structures in the Centre Region of Cameroon. A consecutive sampling (non-probability sampling) was used to select only pregnant women of age over 21 years, who gave a written informed consent. Following an informed consent, an open-ended questionnaire was used for a Knowledge, Attitude and Practice (KAP) survey of these women, and their blood specimens collected and screened for HBsAg, anti-HIV and anti-HCV antibodies by rapid tests and ELISA. HBsAg-positive samples were further screened for HBeAg, anti-HDV, anti-HBs, and anti HBc antibodies by ELISA, and plasma HDV RNA load measured by RT-qPCR.
RESULTS
Of 1992 pregnant women, a rate of 6.7% of HBsAg (133/1992) with highest rate in the rural areas, and 3.9% of hepatitis vaccination rate were recorded. Of 130, 42 (32.3%) were anti-HDV antibody-positive, and 47.6% had detectable HDV RNA viraemia. Of 44 anti-HDV-positive cases, 2 (4.5%) were co-infected with HBV and HCV, while 5 (11.4%) with HIV and HBV. Multiple pregnancies, the presence of tattoos and/or scarifications were significantly associated with the presence of anti-HDV antibodies. Of note, 80% of women with negative HBeAg and positive anti-HBe serological profile, had plasma HDV RNA load of more than log 3.25 (>10.000 copies/ml).
CONCLUSION
These results show an intermediate rate of HDV infection among pregnant women with high level of HDV RNA viremia, which suggest an increased risk of vertical and horizontal co-transmission of HDV.
Topics: Humans; Female; Pregnancy; Cameroon; Hepatitis D; Adult; Risk Factors; Hepatitis Delta Virus; Cross-Sectional Studies; Pregnancy Complications, Infectious; Prevalence; Infectious Disease Transmission, Vertical; Young Adult; Seroepidemiologic Studies; Hepatitis B Surface Antigens; Hepatitis B; Coinfection
PubMed: 38900729
DOI: 10.1371/journal.pone.0287491 -
BioRxiv : the Preprint Server For... Jun 2024An alternative to lifelong antiretroviral therapy (ART) is needed to achieve durable control of HIV-1. Here we show that adeno-associated virus (AAV)-delivery of two...
An alternative to lifelong antiretroviral therapy (ART) is needed to achieve durable control of HIV-1. Here we show that adeno-associated virus (AAV)-delivery of two rhesus macaque antibodies to the SIV envelope glycoprotein (Env) with potent neutralization and antibody-dependent cellular cytotoxicity can prevent viral rebound in macaques infected with barcoded SIV239M after discontinuing suppressive ART. Following AAV administration, sustained antibody expression with minimal anti-drug antibody responses was achieved in all but one animal. After ART withdrawal, SIV replication rebounded within two weeks in all of the control animals but remained below the threshold of detection in plasma (<15 copies/mL) for more than a year in four of the eight animals that received AAV vectors encoding Env-specific antibodies. Viral sequences from animals with delayed rebound exhibited restricted barcode diversity and antibody escape. Thus, sustained expression of antibodies with potent antiviral activity can afford durable, ART-free containment of pathogenic SIV infection.
PubMed: 38895320
DOI: 10.1101/2024.05.30.593694 -
BioRxiv : the Preprint Server For... Jun 2024The majority of naturally-elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs), because they are unable to recognize the Env...
The majority of naturally-elicited antibodies against the HIV-1 envelope glycoproteins (Env) are non-neutralizing (nnAbs), because they are unable to recognize the Env timer in its native "closed" conformation. Nevertheless, it has been shown that nnAbs have the potential to eliminate HIV-1-infected cells by Antibody-Dependent Cellular Cytotoxicity (ADCC) provided that Env is present on the cell surface in its "open" conformation. This is because most nnAbs recognize epitopes that become accessible only after Env interaction with CD4 and the exposure of epitopes that are normally occluded in the closed trimer. HIV-1 limits this vulnerability by downregulating CD4 from the surface of infected cells, thus preventing a premature encounter of Env with CD4. Small CD4-mimetics (CD4mc) sensitize HIV-1-infected cells to ADCC by opening the Env glycoprotein and exposing CD4-induced (CD4i) epitopes. There are two families of CD4i nnAbs, termed anti-cluster A and anti-CoRBS Abs, which are known to mediate ADCC in the presence of CD4mc. Here, we performed Fab competition experiments and found that anti-gp41 cluster I antibodies comprise a major fraction of the plasma ADCC activity in people living with HIV (PLWH). Moreover, addition of gp41 cluster I antibodies to cluster A and CoRBS antibodies greatly enhanced ADCC mediated cell killing in the presence of a potent indoline CD4mc, CJF-III-288. This cocktail outperformed broadly-neutralizing antibodies and even showed activity against HIV-1 infected monocyte-derived macrophages. Thus, combining CD4i antibodies with different specificities achieves maximal ADCC activity, which may be of utility in HIV cure strategies.
PubMed: 38895270
DOI: 10.1101/2024.06.07.597978 -
BioRxiv : the Preprint Server For... Jun 2024The presence of antibodies against HIV in infected children is associated with a greater capacity to control viremia in the absence of therapy. While the benefits of...
The presence of antibodies against HIV in infected children is associated with a greater capacity to control viremia in the absence of therapy. While the benefits of early antiretroviral treatment (ART) in infants are well documented, early ART may interfere with the development of antibody responses. In contrast to adults, early treated children lack detectable HIV-specific antibodies, suggesting a fundamental difference in HIV pathogenesis. Despite this potential adverse effect, early ART may decrease the size of the latent reservoir established early in infection in infants, which can be beneficial in viral control. Understanding the virologic and immunologic aspects of pediatric HIV is crucial to inform innovative targeted strategies for treating children living with HIV. In this study, we investigate how ART initiation time sets the stage for trade-offs in the latent reservoir establishment and the development of humoral immunity and how these, in turn, affect posttreatment dynamics. We also elucidate the biological function of antibodies in pediatric HIV. We employ mathematical modeling coupled with experimental data from an infant nonhuman primate Simian/Human Immunodeficiency Virus (SHIV) infection model. Infant Rhesus macaques (RMs) were orally challenged with SHIV.C.CH505 375H dCT four weeks after birth and started treatment at different times after infection. In addition to viral load measurements, antibody responses and latent reservoir sizes were measured. We estimate model parameters by fitting viral load measurements to the standard HIV viral dynamics model within a nonlinear fixed effects framework. This approach allows us to capture differences between rhesus macaques (RMs) that develop antibody responses or exhibit high latent reservoir sizes compared to those that do not. We find that neutralizing antibody responses are associated with increased viral clearance and decreased viral infectivity but decreased death rate of infected cells. In addition, the presence of detectable latent reservoir is associated with less robust immune responses. These results demonstrate that both immune response and latent reservoir dynamics are needed to understand post-rebound dynamics and point to the necessity of a comprehensive approach in tailoring personalized medical interventions.
PubMed: 38895223
DOI: 10.1101/2024.06.01.596971