A Rapid Assay for SARS-CoV-2 Neutralizing Antibodies That Is Insensitive to Antiretroviral Drugs

AbstractRationale/Study DesignA major challenge in the development of HIV vaccines is finding immunogens that elicit protection against a broad range of viral strains. Immunity to a narrow range of viral strains may protect infants of HIV-infected women or partners discordant for HIV. We hypothesized that immunization to the relevant viral variants could be achieved by exposure to infectious virus during prophylaxis with antiretroviral drugs. To explore this approach in an animal model, macaques were exposed to live virus (SIVmne or HIV-2287) during prophylaxis with parenteral tenofovir. The humoral and cellular immune responses were quantified. Subsequently, experimental animals were challenged with homologous virus to evaluate protection from infection, and if infection occurred, the course of disease was compared to control animals. Experimental animals uninfected with SIVmne were challenged with heterologous HIV-2287 to assess resistance to retroviral infection.Methodology/Principal FindingsJuvenile Macaca nemestrina (N=8) were given ten weekly intravaginal exposures with either moderately (SIVmne) or highly (HIV-2287) pathogenic virus during tenofovir prophylaxis. Tenofovir protected all 8 experimental animals from infection, while all untreated control animals became infected. Specific non-neutralizing antibodies were elicited in blood and vaginal secretions of experimental animals, but no ELISPOT responses were detected. Six weeks following the cessation of tenofovir, intravaginal challenge with homologous virus infected 2/4 (50%) of the SIVmne-immunized animals and 4/4 (100%) of the HIV-2287-immunized animals. The two SIVmne-infected and 3 (75%) HIV-2287-infected had attenuated disease, suggesting partial protection.Conclusions/SignificanceRepeated exposure to SIVmne or HIV-2287 during antiretroviral prophylaxis blocked infection induced binding antibodies in the blood and mucosa, but not neutralizing antibodies or specific cellular immune responses. Studies to determine whether antibodies are similarly induced in breastfeeding infants and sexual partners discordant for HIV infection and receiving pre-exposure antiretroviral prophylaxis are warranted, including whether these antibodies appear to confer partial or complete protection from infection.

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An Enhanced Synthetic Multiclade DNA Prime Induces Improved Cross-Clade-Reactive Functional Antibodies when Combined with an Adjuvanted Protein Boost in Nonhuman Primates

Journal of Virology ◽

10.1128/jvi.00652-15 ◽

2015 ◽

Vol 89 (18) ◽

pp. 9154-9166 ◽

Cited By ~ 14

Author(s):

Megan C. Wise ◽

Natalie A. Hutnick ◽

Justin Pollara ◽

Devin J. F. Myles ◽

Constance Williams ◽

...

Keyword(s):

T Cell ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Consensus Sequence ◽

Vaccine Trial ◽

T Cell Responses ◽

Antiretroviral Drugs ◽

Cell Responses ◽

Protein Boost ◽

Hiv 1

ABSTRACTThe search for an efficacious human immunodeficiency virus type 1 (HIV-1) vaccine remains a pressing need. The moderate success of the RV144 Thai clinical vaccine trial suggested that vaccine-induced HIV-1-specific antibodies can reduce the risk of HIV-1 infection. We have made several improvements to the DNA platform and have previously shown that improved DNA vaccines alone are capable of inducing both binding and neutralizing antibodies in small-animal models. In this study, we explored how an improved DNA prime and recombinant protein boost would impact HIV-specific vaccine immunogenicity in rhesus macaques (RhM). After DNA immunization with either a single HIV Env consensus sequence or multiple constructs expressing HIV subtype-specific Env consensus sequences, we detected both CD4+and CD8+T-cell responses to all vaccine immunogens. These T-cell responses were further increased after protein boosting to levels exceeding those of DNA-only or protein-only immunization. In addition, we observed antibodies that exhibited robust cross-clade binding and neutralizing and antibody-dependent cellular cytotoxicity (ADCC) activity after immunization with the DNA prime-protein boost regimen, with the multiple-Env formulation inducing a more robust and broader response than the single-Env formulation. The magnitude and functionality of these responses emphasize the strong priming effect improved DNA immunogens can induce, which are further expanded upon protein boost. These results support further study of an improved synthetic DNA prime together with a protein boost for enhancing anti-HIV immune responses.IMPORTANCEEven with effective antiretroviral drugs, HIV remains an enormous global health burden. Vaccine development has been problematic in part due to the high degree of diversity and poor immunogenicity of the HIV Env protein. Studies suggest that a relevant HIV vaccine will likely need to induce broad cellular and humoral responses from a simple vaccine regimen due to the resource-limited setting in which the HIV pandemic is most rampant. DNA vaccination lends itself well to increasing the amount of diversity included in a vaccine due to the ease of manufacturing multiple plasmids and formulating them as a single immunization. By increasing the number of Envs within a formulation, we were able to show an increased breadth of responses as well as improved functionality induced in a nonhuman primate model. This increased breadth could be built upon, leading to better coverage against circulating strains with broader vaccine-induced protection.

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Targeted Immuno-Antiretroviral HIV Therapeutic Approach to Provide Dual Protection and Boosts Cellular Immunity: A Proof-of-Concept Study

10.21203/rs.3.rs-103123/v1 ◽

2020 ◽

Author(s):

Subhra Mandal ◽

Shawnalyn Sunagawa ◽

Pavan Kumar Prathipati ◽

Michael Belshan ◽

Annemarie Shibata ◽

...

Keyword(s):

Monoclonal Antibody ◽

T Cells ◽

Hiv Infection ◽

Binding Affinity ◽

Neutralizing Antibodies ◽

Antiretroviral Drugs ◽

Functional Cure ◽

Sustained Drug Release ◽

Protective Efficiency ◽

Dual Protection

Abstract Background: Human immunodeficiency virus (HIV)-infected active and latent C-C motif chemokine receptor-5 (CCR5) expressing long-lived T-cells are the primary barrier to HIV/AIDS eradication. Broadly neutralizing antibodies and latency-reversing agents are the two most promising strategies emerging to achieve ‘functional cure’ against HIV infection. Antiretrovirals (ARVs) have shown to suppress plasma viral loads to non- detectable levels and other strategies have demonstrated a ‘functional cure’ against HIV infection is achievable. Strategies are effective at inducing direct or immune-mediated cell death of latent HIV+ T-cells but have shown respective limitations. We designed a novel targeted ARVs-loaded nanoformulation that combines a CCR5 monoclonal antibody and antiretroviral drugs (ARV) as a dual protection strategy to promote HIV ‘functional cure’. The modified CCR5 monoclonal antibody (xfR5 mAb) surface-coated dolutegravir (DTG) and tenofovir alafenamide (TAF) loaded nanoformulation (xfR5-D+T NPs)Results: The nanoformulation was uniformly sized <250 nm, with 6.5 times enhanced antigen-binding affinity compared to naïve xfR5 mAb, and provided prolonged DTG and TAF intracellular retention. The multivalent and sustained drug release properties of xfR5-D+T NPs enhance the protective efficiency against HIV by approximately 12, 3, and 5 times compared to naïve xfR5 mAb, D+T NP alone, and xfR5 NPs, respectively. Further, the nanoformulation demonstrated high binding-affinity to CCR5 expressing CD4+ cells, monocytes, and other HIV prone/latent T-cells by 25, 2, and 2 times, respectively. Finally, during short-term pre-exposure prophylaxis, the xfR5-D+T NPs induced a protective immunophenotype, with boosted T-helper (Th), temporary memory (TM), and effector (E) sub-population. Treatment with xfR5-D+T NPs to HIV-infected T-cells induced a defensive/activated immunophenotype with boosted naïve, Th, central memory, TM, EM, E, and activated cytotoxic T-cells population.Conclusion: This dual-action targeted nanoformulation could potentially become a multifactorial solution to achieve a “functional cure.”

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Immunization by exposure to live virus (SIVmne/HIV-2287) during antiretroviral drug prophylaxis may reduce risk of subsequent viral challenge

PLoS ONE ◽

10.1371/journal.pone.0240495 ◽

2021 ◽

Vol 16 (4) ◽

pp. e0240495

Author(s):

Lisa M. Frenkel ◽

LaRene Kuller ◽

Ingrid A. Beck ◽

Che-Chung Tsai ◽

Jaimy P. Joy ◽

...

Keyword(s):

Immune Responses ◽

Neutralizing Antibodies ◽

Antiretroviral Drugs ◽

Macaca Nemestrina ◽

Live Virus ◽

Experimental Animals ◽

Cellular Immune Responses ◽

Antiretroviral Prophylaxis ◽

Homologous Virus ◽

Cellular Immune

Rationale/Study design A major challenge in the development of HIV vaccines is finding immunogens that elicit protection against a broad range of viral strains. Immunity to a narrow range of viral strains may protect infants of HIV-infected women or partners discordant for HIV. We hypothesized that immunization to the relevant viral variants could be achieved by exposure to infectious virus during prophylaxis with antiretroviral drugs. To explore this approach in an animal model, macaques were exposed to live virus (SIVmne or HIV-2287) during prophylaxis with parenteral tenofovir and humoral and cellular immune responses were quantified. Subsequently, experimental animals were challenged with homologous virus to evaluate protection from infection, and if infection occurred, the course of disease was compared to control animals. Experimental animals uninfected with SIVmne were challenged with heterologous HIV-2287 to assess resistance to retroviral infection. Methodology/Principal findings Juvenile female Macaca nemestrina (N = 8) were given ten weekly intravaginal exposures with either moderately (SIVmne) or highly (HIV-2287) pathogenic virus during tenofovir prophylaxis. Tenofovir protected all 8 experimental animals from infection, while all untreated control animals became infected. Specific non-neutralizing antibodies were elicited in blood and vaginal secretions of experimental animals, but no ELISPOT responses were detected. Six weeks following the cessation of tenofovir, intravaginal challenge with homologous virus infected 2/4 (50%) of the SIVmne-immunized animals and 4/4 (100%) of the HIV-2287-immunized animals. The two SIVmne-infected and 3 (75%) HIV-2287-infected had attenuated disease, suggesting partial protection. Conclusions/Significance Repeated exposure to SIVmne or HIV-2287, during antiretroviral prophylaxis that blocked infection, induced binding antibodies in the blood and mucosa, but not neutralizing antibodies or specific cellular immune responses. Studies to determine whether antibodies are similarly induced in breastfeeding infants and sexual partners discordant for HIV infection and receiving pre-exposure antiretroviral prophylaxis are warranted, including whether these antibodies appear to confer partial or complete protection from infection.

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Targeted immuno-antiretroviral HIV therapeutic approach to provide dual protection and boosts cellular immunity: A proof-of-concept study

10.1101/2020.04.20.050849 ◽

2020 ◽

Author(s):

Subhra Mandal ◽

Shawnalyn W. Sunagawa ◽

Pavan Kumar Prathipati ◽

Michael Belshan ◽

Annemarie Shibata ◽

...

Keyword(s):

Monoclonal Antibody ◽

T Cells ◽

Hiv Infection ◽

Binding Affinity ◽

Neutralizing Antibodies ◽

Cytotoxic T Cells ◽

Antiretroviral Drugs ◽

Functional Cure ◽

Sustained Drug Release ◽

Dual Protection

AbstractHuman immunodeficiency virus (HIV)-infected active and latent CCR5 expressing long-lived T-cells are the primary barrier to HIV/AIDS eradication. Broadly neutralizing antibodies and latency-reversing agents are the two most promising strategies emerging to achieve ‘functional cure’ against HIV infection. Antiretrovirals (ARVs) have shown to suppress plasma viral loads to non-detectable levels and above strategies have demonstrated a ‘functional cure’ against HIV infection is achievable. Both the above strategies are effective at inducing direct or immune-mediated cell death of latent HIV+ T-cells but have shown respective limitations. In this study, we designed a novel targeted ARVs-loaded nanoformulation that combines the CCR5 monoclonal antibody and antiretroviral drugs (ARV) as a dual protection strategy to promote HIV ‘functional cure’. The modified CCR5 monoclonal antibody (xfR5 mAb) surface-coated dolutegravir (DTG) and tenofovir alafenamide (TAF) loaded nanoformulation (xfR5-D+T NPs) were uniformly sized <250 nm, with 6.5 times enhanced antigen-binding affinity compared to naïve xfR5 mAb, and provided prolonged DTG and TAF intracellular retention (t1/2). The multivalent and sustained drug release properties of xfR5-D+T NPs enhance the protection efficiency against HIV by approximately 12, 3, and 5 times compared to naïve xfR5 mAb, D+T NP alone, and xfR5 NPs, respectively. Further, the nanoformulation demonstrated high binding-affinity to CCR5 expressing CD4+ cells, monocytes, and other HIV prone/latent T-cells by 25, 2, and 2 times, respectively. Further, the xfR5-D+T NPs during short-term pre-exposure prophylaxis induced a protective immunophenotype, i.e., boosted T-helper (Th), temporary memory (TM), and effector (E) sub-population. Moreover, treatment with xfR5-D+T NPs to HIV-infected T-cells induced a defensive/activated immunophenotype i.e., boosted naïve, Th, boosted central memory, TM, EM, E, and activated cytotoxic T-cells population. Therefore, this dual-action targeted mAb-ARV loaded nanoformulation could potentially become a multifactorial/multilayered solution to achieve a “functional cure.”

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A novel and rapid assay for the detection of neutralizing antibodies against interferon-beta

Multiple Sclerosis Journal ◽

10.1191/1352458503ms889oa ◽

2003 ◽

Vol 9 (1) ◽

pp. 32-35 ◽

Cited By ~ 12

Author(s):

M Kob ◽

J Harvey ◽

F Schautzer ◽

S Kascha ◽

D Bibl ◽

...

Keyword(s):

Whole Blood ◽

Neutralizing Antibodies ◽

Interferon Beta ◽

Negative Influence ◽

Specific Marker ◽

Rapid Assay ◽

Protein Levels ◽

Paired Samples ◽

Viral Culture ◽

The Difference

There is evidence that neutralizing antibodies (NA B) have a negative influence on the clinical and magnetic resonance imaging effects of interferon-beta (IFNb) in multiple sclerosis (MS) patients. The current methods for NA B detectio n are restricted to specialized laboratories because they require a cell culture and sometimes a viral culture. Results are typically obtained after several weeks. Therefore, the development of a simple and rapid assay for the detectio n of NA B was sought. Whole blood samples from 28 NAB-positive patients and 110 NAB-negative patients (52 with IFNb and 58 without IFNb therapy) were incubated with IFNb 976 IU/mL for 24 hours. MxA protein levels-a specific marker of class 1 IFN bioactivity-were measured in paired samples with and without IFNb incubatio n and the difference in MxA levels was calculated. The mean increase of MxA levels after stimulation with IFNb in the NAB-positive group was 8 ng/mL (range 0-44 ng/mL) and in the NA B-negative group was 84 ng/mL (range 0-302 ng/mL). Using an increase of 22.5 ng/mL as cut-off, the specificity of the MxA stimulation assay was 81.2% and the sensitivity was 96.4%. The whole blood MxA stimulation assay is virtually as sensitive as the conventional NA B assay but somewhat less specific. However, this is outweighed by the procedural advantage of the assay, which is simpler, quicker and much less expensive.

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