Gp120 Antibodies Research Articles

Early Prognostic Utility of Gp210 Antibody-Positive Rate in Primary Biliary Cholangitis: A Meta-Analysis.

Background The prevalence of primary biliary cholangitis (PBC), which is an autoimmune liver disease, has increased over time. PBC often leads to severe consequences, such as liver failure and death. Stratification tools using biochemical liver tests are needed to assess and predict the progression of this disease at the time of PBC diagnosis. Methods We searched PubMed, Cochrane Library, Web of Science, and Embase for studies focused on the relationship between positive rates of Gp210 antibodies and poor prognosis of PBC. The primary end point was the number of PBC patients with poor outcome in the Gp210 antibody (+) and Gp210 antibody (−) groups. The secondary end point was the basic serum level of alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin (TBIL), and IgM in the two groups. The age and number of female patients were also measured. Results A total of 5 studies, comprising 737 patients, were included in this analysis. A positive rate of Gp210 antibodies was positively correlated with poor outcomes and with many types of progression in PBC, especially liver failure. Mortality was also higher in the Gp210 antibody (+) group. Furthermore, the serum levels of ALP and IgM were associated with the positive rate of Gp210 antibodies, while the serum levels of ALT and TBIL were not. The age and number of female patients were also not associated with the positive rate of Gp210 antibodies. Conclusion PBC-specific Gp120 antibodies are optimal predictors of PBC prognosis at the time of diagnosis. Some other liver function indicators, such as ALP and IgM, can be used as predictors to complement Gp210 antibodies to establish a stratification tool to predict the prognosis of PBC at the time of diagnosis.

Flexible HIV-1 Biosensor Based on the Au/MoS2 Nanoparticles/Au Nanolayer on the PET Substrate.

An electrochemical flexible biosensor composed of gold (Au), molybdenum disulfide nanoparticles (MoS2 NPs), and Au (Au/MoS2/Au nanolayer) on the polyethylene terephthalate (PET) substrate is developed to detect envelope glycoprotein GP120 (gp120), the surface protein of HIV-1. To fabricate the nanolayer on the PET substrate, Au is sputter coated on the flexible PET substrate and MoS2 NPs are spin coated on Au, which is sputter coated once again with Au. The gp120 antibody is then immobilized on this flexible electrode through cysteamine (Cys) modified on the surface of the Au/MoS2/Au nanolayer. Fabrication of the biosensor is verified by atomic force microscopy, scanning electron microscopy, and cyclic voltammetry. A flexibility test is done using a micro-fatigue tester. Detection of the gp120 is measured by square wave voltammetry. The results indicate that the prepared biosensor detects 0.1 pg/mL of gp120, which is comparable with previously reported gp120 biosensors prepared even without flexibility. Therefore, the proposed biosensor supports the development of a nanomaterial-based flexible sensing platform for highly sensitive biosensors with flexibility for wearable device application.

Anti tissue transglutaminase antibody in idiopathic autoimmune haemolytic anemia

BackgroundIn idiopathic autoimmune haemolytic anaemia (AIHA haemolytic antibodies are directed to every type of red cellsWestern blot studies have shown antibody positivity towards red cell anion channel complex which also includes band 4.2 a protein with similarities to tissue trans glutaminase. ObjectiveEvaluation of AIHA for anti tissue transglutaminase antibody (Anti tTG). Materials & methodsTwenty three AIHA patients were tested along with routine hamatogical work up, for a series of auto antibodies and red cell eluates and serum from the patents were tested against solubilised group O red cell ghosts on western blot. Other ancillary investigations were done to rule out complications and secondary causes of haemolysis. Results11/23 patients (48%) were positive for anti tTG, Four, 3 and 8,7 patients were positive for anti thyroid, anti b2 glycoprotein, lupus anticoagulant and ANA respectively. One patient with anti tTG had biopsy proven celiac disease. Three patient developed DVT and all of them were lupus anticoagulant as well as b2 gp-1 antibody positive.17 had become Coombs test negative on treatment while 21/23 had positive western blot test. Discussion & conclusionThere is strong association of anti tTG antibody with idiopathic AIHA. Aetiological association of this finding needs exploration.

HIV-1 Envelope Recognition by Polyreactive and Cross-Reactive Intestinal B Cells

SummaryMucosal immune responses to HIV-1 involve the recognition of the viral envelope glycoprotein (gp)160 by tissue-resident B cells and subsequent secretion of antibodies. To characterize the B cells “sensing” HIV-1 in the gut of infected individuals, we probed monoclonal antibodies produced from single intestinal B cells binding to recombinant gp140 trimers. A large fraction of mucosal B cell antibodies were polyreactive and showed only low affinity to HIV-1 envelope glycoproteins, particularly the gp41 moiety. A few high-affinity gp140 antibodies were isolated but lacked neutralizing, potent ADCC, and transcytosis-blocking capacities. Instead, they displayed cross-reactivity with defined self-antigens. Specifically, intestinal HIV-1 gp41 antibodies targeting the heptad repeat 2 region (HR2) cluster II cross-reacted with the p38α mitogen-activated protein kinase 14 (MAPK14). Hence, physiologic polyreactivity of intestinal B cells and molecular mimicry-based self-reactivity of HIV-1 antibodies are two independent phenomena, possibly diverting and/or impairing mucosal humoral immunity to HIV-1.

HIV-1 inhibitory properties of eCD4-Igmim2 determined using an Env-mediated membrane fusion assay.

Human Immunodeficiency Virus-1 (HIV-1) entry is dependent on the envelope glycoprotein (Env) that is present on the virion and facilitates fusion between the envelope and the cellular membrane. The protein consists of two subunits, gp120 and gp41, with the former required for binding the CD4 receptor and either the CXCR4 or CCR5 coreceptor, and the latter for mediating fusion. The requirement of fusion for infection has made Env an attractive target for HIV therapy development and led to the FDA approval of enfuvirtide, a fusion inhibitor. Continued development of entry inhibitors is warranted because enfuvirtide resistant HIV-1 strains have emerged. In this study, a novel HIV-1 fusion assay was validated using neutralizing antibodies and then used to investigate the mechanism of action of eCD4-Igmim2, an HIV-1 inhibitor proposed to cooperatively bind the CD4 binding site and the sulfotyrosine-binding pocket of gp120. Greater reduction in fusion levels was observed with eCD4-Igmim2 in the fusion assay than all of the gp120 antibodies evaluated. Lab adapted isolates, HIV-1HXB2 and HIV-1YU2, were sensitive to eCD4-Igmim2 in the fusion assay, while primary isolates, HIV-1BG505 and HIV-1ZM651 were resistant. These results correlated with greater IC50 values for primary isolates compared to the lab adapted isolates observed in a virus neutralization assay. Analysis of gp120 models identified differences in the V1 and V2 domains that are associated with eCD4-Igmim2 sensitivity. This study highlights the use of a fusion assay to identify key areas for improving the potency of eCD4-Igmim2.

The baboon as a nonhuman primate model for the study of natural Zika virus infection

Background: Zika virus (ZIKV) was first isolated from a sentinel rhesus macaque in the Zika forest of Uganda. Baboons are a nonhuman primate species widely distributed in Africa that could reasonably be a natural reservoir for ZIKV. We characterized the early phases of ZIKV infection in naïve captive baboons and tested immunity induced by primary infection against reinfection with a distant ZIKV strain. Methods & Materials: Four juvenile baboons were injected with 104 or 106 TCID50 of the Puerto Rico strain of ZIKV by the subcutaneous route. Viral loads were determined by RT-PCR in blood, urine, and mucosal swabs. Infection was followed by measuring fever and systemic cytokine changes, and by observing clinical signs. Humoral immune responses were determined by ELISA, and cellular responses by flow cytometry. Transcriptomic analysis was performed on days 0, 3 and 15. Six months after primary infection, the same animals were exposed to 104 TCID50 of the Uganda strain of ZIKV, and virological and immunological outcomes were performed as described before. Results: Viremia was present in all animals and lasted for about 5 days. Virus was transiently present in the urine of some animals. There were no clinical signs of infection, and body temperature was stable during the viremic phase. Cytokine analysis did not show evident peaks of inflammatory cytokines in circulation; however, RNAseq analysis showed a clear inflammatory antiviral response by day 3 PI that resolved by day 15 PI. All animals developed low levels of anti-ZIKV NS1 and crossreactive anti-Dengue GP antibodies, and there was also a detectable cell-mediated immune response to viral antigens. After challenge with ZIKV Uganda strain, there was no detectable viremia and this correlated with a lack of anamnestic humoral and cell-mediated immune response to the viral antigens. Conclusion: Similarl to the majority of human cases, ZIKV infection of baboons resulted in a subclinical infection. However, this infection was able to induce a protective immune response against re-exposure with a distant ZIKV. The baboon may be a useful NHP model of natural ZIKV infection in which to test antivirals and vaccines efficacy.

HIV-1 RNA testing of pooled dried blood spots is feasible to diagnose acute HIV infection in resource limited settings

Objectives:Rapid human immunodeficiency virus (HIV) antibody tests, routinely used for diagnosis in adults and older children in resource-limited settings (RLS), do not detect early HIV infections prior to seroconversion or when antibody levels are still low. Nucleic acid amplification to detect HIV-1 RNA is the most sensitive method for acute HIV infection diagnosis, but is costly. We therefore investigated HIV- 1 RNA testing of pooled dried blood spots (DBS) to diagnose acute HIV infection.Design:Laboratory-based investigation.Methods:DBS were collected from HIV-1 Voluntary Counselling and Testing (HVCT) clients who tested negative on the Advanced QualityTM HIV antibody rapid test. DBS samples from five participants were pooled and tested on the COBAS AmpliPrep/COBAS TaqMan HIV-1 (CAP/CTM) Test v2. Individual DBS were tested when pools tested positive ( 200 RNA copies/ml). Acute infection was confirmed by HIV viral load testing, two fourth-generation HIV serological assays, and Geenius™ HIV 1/2 Assay for antibody band identification.Results:Of 482 participants who were tested, one (0.2%) had acute. HIV infection: Fourth generation serology was low-level positive, the plasma HIV viral load was 15 929 HIV-1 RNA copies/ml, gp160 and gp41 antibody bands were positive and the p31 band was negative, indicating a Fiebig Stage 5 infection.Conclusions: Pooled DBS HIV-1 RNA testing is efficient compared to individual testing for acute HIV infection diagnosis. Early identification of participants with acute HIV infection facilitates immediate initiation of antiretroviral therapy to improve immune recovery and prevent transmission to others.

A novel Ebola virus antibody-dependent cell-mediated cytotoxicity (Ebola ADCC) assay

Ebolaviruses are highly virulent pathogens that cause Ebola viral disease (EVD). Data from non-human primate (NHP) models and from human survivors of EVD suggest that anti-Ebola antibodies play an integral role in protection. Antibody-dependent cell-mediated cytotoxicity (ADCC) is a potential mechanism through which anti-Ebola antibodies may mediate protection. We developed a robust Ebola-specific ADCC assay for use in ongoing trials of Ebola vaccines. Stable cell lines for inducible Zaire ebolavirus glycoprotein (EBOV GP) expression were developed to provide a uniform source of target cells in the assay, and were combined with an existing human natural killer (NK) cell line as the effector cell. When applied to commercially available anti-EBOV GP monoclonal antibodies, the assay clearly differentiated antibody with high ADCC activity from those with low or no ADCC activity. Anti-EBOV ADCC activity was also detected in plasma samples from rhesus macaques immunized with a candidate Ebola vaccine. The Ebola ADCC assay reported here will be a useful tool in studying the functionality of anti-EBOV GP antibodies elicited by Ebola vaccines in ongoing and future clinical trials.

Characterization of HIV-1 gp120 antibody specificities induced in anogenital secretions of RV144 vaccine recipients after late boost immunizations.

Sexual transmission is the principal driver of the human immunodeficiency virus (HIV) pandemic. Understanding HIV vaccine-induced immune responses at mucosal surfaces can generate hypotheses regarding mechanisms of protection, and may influence vaccine development. The RV144 (ClinicalTrials.gov NCT00223080) efficacy trial showed protection against HIV infections but mucosal samples were not collected, therefore, the contribution of mucosal antibodies to preventing HIV-1 acquisition is unknown. Here, we report the generation, magnitude and persistence of antibody responses to recombinant gp120 envelope and antigens including variable one and two loop scaffold antigens (gp70V1V2) previously shown to correlate with risk in RV144. We evaluated antibody responses to gp120 A244gD and gp70V1V2 92TH023 (both CRF01_AE) and Case A2 (subtype B) in cervico-vaginal mucus (CVM), seminal plasma (SP) and rectal secretions (RS) from HIV-uninfected RV144 vaccine recipients, who were randomized to receive two late boosts of ALVAC-HIV/AIDSVAX®B/E, AIDSVAX®B/E, or ALVAC-HIV alone at 0 and 6 months. Late vaccine boosting increased IgG geometric mean titers (GMT) to gp120 A244gD in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (28 and 17 fold, respectively), followed by SP and RS. IgG to gp70V1V2 92TH023 increased in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (11–17 fold) and SP (2 fold) two weeks post first boost. IgG to Case A2 was only detected in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM. Mucosal IgG to gp120 A244gD (CVM, SP, RS), gp70V1V2 92TH023 (CVM, SP), and Case A2 (CVM) correlated with plasma IgG levels (p<0.001). Although the magnitude of IgG responses declined after boosting, anti-gp120 A244gD IgG responses in CVM persisted for 12 months post final vaccination. Further studies in localization, persistence and magnitude of envelope specific antibodies (IgG and dimeric IgA) in anogenital secretions will help determine their role in preventing mucosal HIV acquisition.

Immunoassay Multiplexing on a Complementary Metal Oxide Semiconductor Photodiode Array.

Scalable immunoassay multiplexing offers a route to creating rapid point-of-care (POC) diagnostics. We present a method for multiplexing immunoassays on the surface of a complementary metal oxide semiconductor (CMOS) sensor array integrated circuit (IC) without the use of physical separators such as wells or channels. Major advantages of using a CMOS sensor array include low mass-manufacturing costs, the possibility to multiplex multiple assays on a single IC, and improved signal when averaging multiple sensors, along with providing a platform where wash steps can be incorporated to maximize selectivity and sensitivity compared to paper based lateral flow immunoassay. The device was able to differentiate between samples containing either, neither, or both rabbit anti-mouse (RAM) antibodies and/or anti-HIV gp120 antibodies in serum using a gold-nanoparticle promoted silver enhancement immunoassay. HIV antibody concentrations down to 100 μg/mL were readily detected, which is three times lower than those typically found in infected humans (300–500 μg/mL), and the limit of detection was 10 μg/mL.

P-C2 Protection against or delay of intrarectal SHIV acquisition by mucosal vaccines in the absence of Env-antibody responses

To identify the protective mechanisms of an HIV mucosal vaccine similar to RV144, we carried out a pilot study in which we mucosally immunized rhesus macaques with HIV/SIV peptides, SIV-expressing MVA, and full-length single chain protein of HIV-gp120 fused to CD4. In the macaques that received this combination, 3/14 were sterilely protected after high-dose SHIVSF162P4 intrarectal challenge, compared to 0/29 controls (p = 0.03). We observed mucosal antigen-specific T cell responses, but not antibody responses. We then tested efficacy of this HIV mucosal vaccine against repeated low-dose intrarectal challenge with SHIVSF162P4. With 21 vaccinees and 7 controls, we achieved 44% vaccine efficacy (p = 0.028). Consistent with the pilot study, the vaccine did not induce Env-specific antibody responses in the plasma or rectal mucosa. It induced gag- and Env-specific T cells in colorectal mucosa/MLN, but the magnitude did not correlate with delay of viral acquisition. Interestingly, the vaccine led to accumulation of myeloid-derived suppressor cells in the PBMCs and CD14+ monocytes in the colorectal intraepithelial compartment, which correlated with delay of viral acquisition. The vaccine also decreased rectal gp41 antibody, total rectal mucosal plasma cells, and gut microbiome richness. The bacterial PCA-1 correlated with number of exposures to achieve infection, suggesting gut microbiome's possibly influencing HIV susceptibility. Overall, the mucosal vaccine had different protective mechanisms from the RV144 trial. Thus, a vaccine inducing mucosal T cells without antibodies can protect against mucosal SHIV acquisition. Combination with a systemically-delivered antibody-inducing vaccine might improve protection.

Detection, characterization, and enrollment of donors of Ebola convalescent plasma in Sierra Leone.

BACKGROUNDPassive therapy with convalescent plasma provides an early opportunity to intervene in Ebola virus disease (EVD). Methods for field screening and selection of potential donors and quantifying plasma antibody are needed.STUDY DESIGN AND METHODSRecombinant Ebola virus glycoprotein (EBOV GP) was formatted into immunoglobulin G‐capture, competitive, and double‐antigen bridging enzyme immunoassays (EIAs). EVD survivors in Freetown, Sierra Leone, were recruited as potential plasma donors and assessed locally using sera alone and/or paired sera and oral fluids (ORFs). Uninfected controls comprised unexposed Gambians and communities in Western Area, Sierra Leone. Antibody neutralization in selected sera was measured retrospectively in a pseudotype virus assay.RESULTSA total of 115 potential donors were considered for enrollment: 110 plasma samples were concordantly reactive in the three EIAs; three were concordantly unreactive and two were reactive in two of three EIAs (98.2% agreement; 95% confidence interval [CI], 93.9%‐99.8%). In 88 donors with paired ORF and plasma, G‐capture EIA reactivity correlated well in the two analytes (R2 = 0.795). Plasma and ORF from 44 Gambians were unreactive. ORF samples from 338 of 339 unexposed Western Area community controls were unreactive (specificity, 99.7%; 95% CI, 98.4%‐99.7%); ORF samples from 113 of 116 Kerry Town EVD survivors were reactive (sensitivity, 97.4%; 95% CI, 92.5%‐99.5%). Strong reactivity in G‐capture and/or competitive EIAs identified donors with high plasma EBOV GP antibody levels in the double‐antigen bridging assay, correlating with high levels of neutralizing antibody.CONCLUSIONSIn‐field testing can qualify convalescent donors for providing high‐titer antibody.

Vaccine-Associated Maintenance of Epithelial Integrity Correlated With Protection Against Virus Entry.

To identify the mechanisms by which human immunodeficiency virus type 1 (HIV-1) might penetrate the epithelial barrier during sexual transmission to women and the mechanisms of vaccine-associated protection against entry, we characterized early epithelial responses to vaginal inoculation of simian immunodeficiency virus strain mac251 (SIVmac251) in naive or SIVmac239Δnef-vaccinated rhesus macaques. Vaginal inoculation induced an early stress response in the cervicovaginal epithelium, which was associated with impaired epithelial integrity, damaged barrier function, and virus and bacterial translocation. In vaccinated animals, early stress responses were suppressed, and the maintenance of epithelial barrier integrity correlated with prevention of virus entry. These vaccine-protective effects were associated with a previously described mucosal system for locally producing and concentrating trimeric gp41 antibodies at the mucosal interface and with formation of SIV-specific immune complexes that block the stress responses via binding to the epithelial receptor FCGR2B and subsequent inhibitory signaling. Thus, blocking virus entry may be one protective mechanism by which locally concentrated non-neutralizing Ab might prevent HIV sexual transmission to women.

Cross-reactivity of HIV vaccine responses and the microbiome.

A successful human immunodeficiency virus-type 1 (HIV-1) vaccine will require immunogens that induce protective immune responses. However, recent studies suggest that the response to HIV-1 and perhaps other viruses may be altered by immune system exposure to intestinal microbiota-antigens. This review will discuss select aspects of these studies. Naïve CD4 T and B cell repertoires can be imprinted by intestinal microbiota-antigens to respond to virus epitopes prior to virus infection. A multiclade envelope (Env) gp145 DNA prime, recombinant adenovirus type 5 boost vaccine tested in a HIV Vaccine Trials Network (HVTN) phase IIb human vaccine efficacy trial (HVTN 505) induced a dominant gp41-reactive antibody response that was non-neutralizing and cross-reactive with intestinal microbiota. This vaccine regimen also induced a dominant gp41-reactive, intestinal microbiota-cross-reactive gp41 antibody response in neonatal and adult Rhesus macaques. Studies of naïve CD4 T cells have demonstrated cross-reactivity to both HIV-1 and influenza peptides. HIV-1 Env vaccine-induced CD4 T and B cell responses can originate from a pool of intestinal microbiota-cross-reactive immune cells. Moreover, intestinal microbiota-cross-reactive HIV-1 Env antibodies are ineffective in protection against HIV-1 infection. Thus, intestinal microbiota-imprinting of the B cell repertoire may be one of several roadblocks to the induction of protective HIV-1 antibodies.

Further Investigations of the Effects of Anti-β2GP1 Antibodies on Collagen-Induced Platelet Aggregation.

Anti-beta-2-glycoprotein 1 (anti-β2GP1) antibodies are associated with increased thrombotic risk in patients with autoimmune disease. There is conflicting evidence on the effects of anti-β2GP1 antibodies on platelets, with both enhanced and inhibited aggregation previously reported. However, previous studies did not include isotype antibodies to ensure the observed effects were due to anti-β2GP1 antibodies. The aims of this study were to (1) investigate the effects of anti-β2GP1 antibodies on collagen-induced platelet aggregation in parallel with negative control (buffer normal saline) and isotype control antibodies and (2) determine the lupus anticoagulant (LA) activity of anti-β2GP1 antibodies used. Three animal-derived anti-human-β2GP1 antibodies (1.25, 2.5, and 5 μg/mL) incubated with healthy platelet-rich plasma were activated by collagen (2.5 μg/mL). Each anti-β2GP1 antibody demonstrated the inhibition of aggregation compared to negative control, but not to isotype control. No anti-β2GP1 antibody demonstrated LA activity, suggesting they were probably nonpathological. This study highlights both negative and isotype control markers are important to validate the effects of anti-β2GP1 antibodies. Assays to measure anti-domain I-β2GP1 antibodies are recommended to be used in conjunction with functional measures to further investigate the effects of anti-β2GP1 antibodies.

Open-label phase I clinical trial of Ad5-EBOV in Africans in China

ABSTRACTBackground: To determine the safety and immunogenicity of a novel recombinant adenovirus type 5 vector based Ebola virus disease vaccine (Ad5-EBOV) in Africans in China.Methods: A phase 1, dose-escalation, open-label trial was conducted. 61 healthy Africans were sequentially enrolled, with 31 participants receiving one shot intramuscular injection and 30 participants receiving a double-shot regimen. Primary and secondary end points related to safety and immunogenicity were assessed within 28 d after vaccination. This study was registered with ClinicalTrials.gov (NCT02401373).Results: Ad5-EBOV is well tolerated and no adverse reaction of grade 3 or above was observed. 53 (86.89%) participants reported at least one adverse reaction within 28 d of vaccination. The most common reaction was fever and the mild pain at injection site, and there were no significant difference between these 2 groups. Ebola glycoprotein-specific antibodies appeared in all 61 participants and antibodies titers peaked after 28 d of vaccination. The geometric mean titres (GMTs) were similar between these 2 groups (1919.01 vs 1684.70 P = 0.5562). The glycoprotein-specific T-cell responses rapidly peaked after 14 d of vaccination and then decreased, however, the percentage of subjects with responses were much higher in the high-dose group (60.00% vs 9.68%, P = 0.0014). Pre-existing Ad5 neutralizing antibodies could significantly dampen the specific humoral immune response and cellular response to the vaccine.Conclusion: The application of Ad5-EBOV demonstrated safe in Africans in China and a specific GP antibody and T-cell response could occur 14 d after the first immunization. This acceptable safety profile provides a reliable basis to proceed with trials in Africa.

The Final (Oral Ebola) Vaccine Trial on Captive Chimpanzees?

Could new oral vaccine technologies protect endangered wildlife against a rising tide of infectious disease? We used captive chimpanzees to test oral delivery of a rabies virus (RABV) vectored vaccine against Ebola virus (EBOV), a major threat to wild chimpanzees and gorillas. EBOV GP and RABV GP-specific antibody titers increased exponentially during the trial, with rates of increase for six orally vaccinated chimpanzees very similar to four intramuscularly vaccinated controls. Chimpanzee sera also showed robust neutralizing activity against RABV and pseudo-typed EBOV. Vaccination did not induce serious health complications. Blood chemistry, hematologic, and body mass correlates of psychological stress suggested that, although sedation induced acute stress, experimental housing conditions did not induce traumatic levels of chronic stress. Acute behavioral and physiological responses to sedation were strongly correlated with immune responses to vaccination. These results suggest that oral vaccination holds great promise as a tool for the conservation of apes and other endangered tropical wildlife. They also imply that vaccine and drug trials on other captive species need to better account for the effects of stress on immune response.

A cytometry microparticle platform approach for screening tobacco microRNA changes after agrobacterium delivery

MicroRNAs are a class of non-coding regulatory RNAs that can modulate development as well as alter innate antiviral defenses in plants. In this study we explored changes in Nicotiana benthamiana tobacco microRNA expression as it relates to expression of a recombinant anti-Ebola GP1 antibody. The antibody was delivered to tobacco leaves through a bacterial Agrobacterium tumefaciens “agroinfiltration” expression strategy. A multiplex microparticle-based cytometry assay tracked the expression changes of 53 host tobacco microRNAs. Our results revealed that the most abundant microRNAs in actively growing leaves corresponded to nanoparticle probes specific to nta-mir-6149 and nta-miR-168b. After agroinfiltration, probes specific for nta-mir-398, and nta-mir-482d were significantly altered in their respective expression levels, however changes were partially attributed to the infiltration broth medium used in the antibody delivery process. Confirmation of nta-mir-398 and nta-mir-482d expression changes was also verified through RT-qPCR. To our knowledge this study is the first to profile medium and Agrobacterium injection at the microRNA level through a multiplex microparticle approach.

Overcoming the Constraints of Anti-HIV/CD89 Bispecific Antibodies That Limit Viral Inhibition.

Innovative strategies are necessary to maximize the clinical application of HIV neutralizing antibodies. To this end, bispecific constructs of human antibody F240, reactive with well-conserved gp41 epitope and antibody 14A8, reactive with the IgA receptor (CD89) on effector cells, were constructed. A F240 × 14A8 bispecific single chain variable region (scFv) molecule was constructed by linking two scFvs using a conventional GGGGS linker. Despite immunoreactivity with HIV gp41 and neutrophils, this bispecific scFv failed to inhibit HIV infection. This is in sharp contrast to viral inhibition using a chemical conjugate of the Fab of these two antibodies. Therefore, we constructed two novel Fab-like bispecific antibody molecules centered on fusion of the IgG1 CH1 domain or CH1-hinge domain to the C-terminus of F240scFv and fusion of the kappa chain CL domain to the C-terminus of 14A8scFv. Both Bi-Fab antibodies showed significant ADCVI activity for multiple clade B and clade C isolates by arming the neutrophils to inhibit HIV infection. The approach presented in this study is unique for HIV immunotherapy in that the impetus of neutralization is to arm and mobilize PMN to destroy HIV and HIV infected cells.

Modulating the durability of anti-HIV gp120 antibody responses after vaccination: a comment on Wilson & Karp (2015).

In their opinion piece [[1][1]], Wilson and Karp discuss the poor durability of the anti-gp120 humoral response, an important feature that poses a significant difficulty for HIV vaccine development [[2][2]]. The authors make the case that short-lived anti-gp120 responses are not seen in all studies