Publications
121 results found
Kratochvil S, McKay PF, Chung AW, et al., 2018, Immunoglobulin G1 Allotype Influences Antibody Subclass Distribution in Response to HIV gp140 Vaccination (vol 8, 1883, 2017), FRONTIERS IN IMMUNOLOGY, Vol: 9, ISSN: 1664-3224
Anderson J, Olafsdottir TA, Kratochvil S, et al., 2018, Molecular signatures of a TLR4 agonist-adjuvanted HIV-1 vaccine candidate in humans, Frontiers in Immunology, Vol: 9, ISSN: 1664-3224
Systems biology approaches have recently provided new insights into the mechanisms of action of human vaccines and adjuvants. Here, we investigated early transcriptional signatures induced in whole blood of healthy subjects following vaccination with a recombinant HIV-1 envelope glycoprotein subunit CN54gp140 adjuvanted with the TLR4 agonist glucopyranosyl lipid adjuvant-aqueous formulation (GLA-AF) and correlated signatures to CN54gp140-specific serum antibody responses. Fourteen healthy volunteers aged 18-45 years were immunized intramuscularly three times at 1-month intervals and whole blood samples were collected at baseline, 6 h, and 1, 3, and 7 days post first immunization. Subtle changes in the transcriptomic profiles were observed following immunization, ranging from over 300 differentially expressed genes (DEGs) at day 1 to nearly 100 DEGs at day 7 following immunization. Functional pathway analysis revealed blood transcription modules (BTMs) related to general cell cycle activation, and innate immune cell activation at early time points, as well as BTMs related to T cells and B cell activation at the later time points post-immunization. Diverse CN54gp140-specific serum antibody responses of the subjects enabled their categorization into high or low responders, at early ( < 1 month) and late (up to 6 months) time points post vaccination. BTM analyses revealed repression of modules enriched in NK cells, and the mitochondrial electron chain, in individuals with high or sustained antigen-specific antibody responses. However, low responders showed an enhancement of BTMs associated with enrichment in myeloid cells and monocytes as well as integrin cell surface interactions. Flow cytometry analysis of peripheral blood mononuclear cells obtained from the subjects revealed an enhanced frequency of CD56 dim NK cells in the majority of vaccines 14 days after vaccination as compared with the baseline. These results emphasize the utility of a systems biology approa
Muir L, McKay PF, Petrova VN, et al., 2018, Optimisation ofex vivomemory B cell expansion/differentiation for interrogation of rare peripheral memory B cell subset responses [version 2; referees: 2 approved], Wellcome Open Research, Vol: 2, Pages: 97-97, ISSN: 2398-502X
Background: Human memory B cells play a vital role in the long-term protection of the host from pathogenic re-challenge. In recent years the importance of a number of different memory B cell subsets that can be formed in response to vaccination or infection has started to become clear. To study memory B cell responses, cells can be culturedex vivo,allowing for an increase in cell number and activation of these quiescent cells, providing sufficient quantities of each memory subset to enable full investigation of functionality. However, despite numerous papers being published demonstrating bulk memory B cell culture, we could find no literature on optimised conditions for the study of memory B cell subsets, such as IgM+memory B cells. Methods:Following a literature review, we carried out a large screen of memory B cell expansion conditions to identify the combination that induced the highest levels of memory B cell expansion. We subsequently used a novel Design of Experiments approach to finely tune the optimal memory B cell expansion and differentiation conditions for human memory B cell subsets. Finally, we characterised the resultant memory B cell subpopulations by IgH sequencing and flow cytometry. Results:The application of specific optimised conditions induce multiple rounds of memory B cell proliferation equally across Ig isotypes, differentiation of memory B cells to antibody secreting cells, and importantly do not alter the Ig genotype of the stimulated cells. Conclusions:Overall, our data identify a memory B cell culture system that offers a robust platform for investigating the functionality of rare memory B cell subsets to infection and/or vaccination.
Pankrac J, Klein K, McKay PF, et al., 2018, A heterogeneous human immunodeficiency virus-like particle (VLP) formulation produced by a novel vector system., npj Vaccines, Vol: 3, ISSN: 2059-0105
First identified as the etiological agent behind Acquired Immunodeficiency Syndrome (AIDS) in the early 1980s, HIV-1 has continued to spread into a global pandemic and major public health concern. Despite the success of antiretroviral therapy at reducing HIV-1 viremia and preventing the dramatic CD4+ T-cell collapse, infected individuals remain HIV positive for life. Unfortunately, it is increasingly clear that natural immunity is not, and may never be, protective against this pathogen. Therefore, efficacious vaccine interventions, which can either prevent infection or eradicate the latent viral reservoir and effect cure, are a major medical priority. Here we describe the development of a safe vaccine platform, currently being utilized in on-going prophylactic and therapeutic preclinical studies and consisting of highly heterogeneous virus-like particle formulations that represent the virus diversity within infected individuals. These VLPs contain no 5'LTR, no functional integrase, and have a severely mutated stem loop 1-thereby preventing any potential reverse transcription, integration, and RNA packaging. Furthermore, we demonstrate that these VLPs are morphologically identical to wild-type virus with polyvalent Env in a functional form. Finally, we show that the VLPs are antigenic and capable of generating strong immune recall responses.
Kratochvil S, McKay PF, Chung AW, et al., 2017, Immunoglobulin G1 Allotype Influences Antibody Subclass Distribution in Response to HIV gp140 Vaccination, Frontiers in Immunology, Vol: 8, ISSN: 1664-3224
Antibody subclasses exhibit extensive polymorphisms (allotypes) that could potentially impact the quality of HIV-vaccine induced B cell responses. Allotypes of immunoglobulin (Ig) G1, the most abundant serum antibody, have been shown to display altered functional properties in regard to serum half-life, Fc-receptor binding and FcRn-mediated mucosal transcytosis. To investigate the potential link between allotypic IgG1-variants and vaccine-generated humoral responses in a cohort of 14 HIV vaccine recipients, we developed a novel protocol for rapid IgG1-allotyping. We combined PCR and ELISA assays in a dual approach to determine the IgG1 allotype identity (G1m3 and/or G1m1) of trial participants, using human plasma and RNA isolated from PBMC. The IgG1-allotype distribution of our participants mirrored previously reported results for caucasoid populations. We observed elevated levels of HIV gp140-specific IgG1 and decreased IgG2 levels associated with the G1m1-allele, in contrast to G1m3 carriers. These data suggest that vaccinees homozygous for G1m1 are predisposed to develop elevated Ag-specific IgG1:IgG2 ratios compared to G1m3-carriers. This elevated IgG1:IgG2 ratio was further associated with higher FcγR-dimer engagement, a surrogate for potential antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) function. Although preliminary, these results suggest that IgG1 allotype may have a significant impact on IgG subclass distribution in response to vaccination and associated Fc-mediated effector functions. These results have important implications for ongoing HIV vaccine efficacy studies predicated on engagement of FcγR-mediated cellular functions including ADCC and ADCP, and warrant further investigation. Our novel allotyping protocol provides new tools to determine the potential impact of IgG1 allotypes on vaccine efficacy.
Pinder CL, kratochvil S, Cizmeci D, et al., 2017, Isolation and Characterization of Antigen-Specific Plasmablasts Using a Novel Flow Cytometry–Based Ig Capture Assay, Journal of Immunology, ISSN: 1550-6606
We report the development of a novel flow cytometry–based Ig capture assay (ICA) for the identification and sorting of individual Ab-secreting cells based on their Ag reactivity. The ICA represents a fast and versatile tool for single-cell sorting of peripheral plasmablasts, streamlining subsequent Ab analysis, and cloning. We demonstrate the utility of the assay by isolating Ag-reactive plasmablasts from cryopreserved PBMC obtained from volunteers vaccinated with a recombinant HIV envelope protein. To show the specificity of the ICA, we produced Ag-specific Abs from these cells and subsequently verified their Ag reactivity via ELISA. Furthermore, we used the ICA to track Ag-specific plasmablast responses in HIV-vaccine recipients over a period of 42 d and performed a head-to-head comparison with a conventional B cell ELISpot. Results were highly comparable, highlighting that this assay is a viable alternative for monitoring Ag-specific plasmablast responses at early time points after infection or vaccination. The ICA provides important added benefits in that phenotypic information can be obtained from the identified Ag-specific cells that can then be captured for downstream applications such as B cell sequencing and/or Ab cloning. We envisage the ICA as being a useful tool in Ab repertoire analysis for future clinical trials.
Muir L, McKay P, Petrova V, et al., 2017, Optimisation of ex vivo memory B cell expansion/differentiation for interrogation of rare peripheral memory B cell subset responses [version 2; peer review: 2 approved], Wellcome Open Research, Vol: 2, ISSN: 2398-502X
Background: Human memory B cells play a vital role in the long-term protection of the host from pathogenic re-challenge. In recent years the importance of a number of different memory B cell subsets that can be formed in response to vaccination or infection has started to become clear. To study memory B cell responses, cells can be cultured ex vivo, allowing for an increase in cell number and activation of these quiescent cells, providing sufficient quantities of each memory subset to enable full investigation of functionality. However, despite numerous papers being published demonstrating bulk memory B cell culture, we could find no literature on optimised conditions for the study of memory B cell subsets, such as IgM+ memory B cells.Methods: Following a literature review, we carried out a large screen of memory B cell expansion conditions to identify the combination that induced the highest levels of memory B cell expansion. We subsequently used a novel Design of Experiments approach to finely tune the optimal memory B cell expansion and differentiation conditions for human memory B cell subsets. Finally, we characterised the resultant memory B cell subpopulations by IgH sequencing and flow cytometry.Results: The application of specific optimised conditions induce multiple rounds of memory B cell proliferation equally across Ig isotypes, differentiation of memory B cells to antibody secreting cells, and importantly do not alter the Ig genotype of the stimulated cells. Conclusions: Overall, our data identify a memory B cell culture system that offers a robust platform for investigating the functionality of rare memory B cell subsets to infection and/or vaccination.
Kratochvil S, McKay PF, Kopycinski JT, et al., 2017, A phase 1 human immunodeficiency virus vaccine Trial for cross-profiling the kinetics of serum and mucosal antibody responses to CN54gp140 modulated by two homologous prime-boost vaccine regimens, Frontiers in Immunology, Vol: 8, ISSN: 1664-3224
A key aspect to finding an efficacious human immunodeficiency virus (HIV) vaccine is the optimization of vaccine schedules that can mediate the efficient maturation of protective immune responses. In the present study, we investigated the effect of alternate booster regimens on the immune responses to a candidate HIV-1 clade C CN54gp140 envelope protein, which was coadministered with the TLR4-agonist glucopyranosyl lipid A-aqueous formulation. Twelve study participants received a common three-dose intramuscular priming series followed by a final booster at either 6 or 12 months. The two homologous prime-boost regimens were well tolerated and induced CN54gp140-specific responses that were observed in both the systemic and mucosal compartments. Levels of vaccine-induced IgG-subclass antibodies correlated significantly with FcγR engagement, and both vaccine regimens were associated with strikingly similar patterns in antibody titer and FcγR-binding profiles. In both groups, identical changes in the antigen (Ag)-specific IgG-subclass fingerprint, leading to a decrease in IgG1 and an increase in IgG4 levels, were modulated by booster injections. Here, the dissection of immune profiles further supports the notion that prime-boost strategies are essential for the induction of diverse Ag-specific HIV-1 responses. The results reported here clearly demonstrate that identical responses were effectively and safely induced by both vaccine regimens, indicating that an accelerated 6-month regimen could be employed for the rapid induction of immune responses against CN54gp140 with no apparent impact on the overall quality of the induced immune response. (This study has been registered at http://ClinicalTrials.gov under registration no. NCT01966900.)
Aw, McKay, Shattock, et al., 2017, Expressing anti-HIV VRC01 antibody using the murine IgG1 secretion signal in Pichia pastoris, AMB Express, Vol: 7, ISSN: 2191-0855
The use of the recombinant expression platform Pichia pastoris to produce pharmaceutically important proteins has been investigated over the past 30 years. Compared to mammalian cultures, expression in P. pastoris is cheaper and faster, potentially leading to decreased costs and process development times. Product yields depend on a number of factors including the secretion signal chosen for expression, which can influence the host cell response to recombinant protein production. VRC01, a broadly neutralising anti-HIV antibody, was expressed in P. pastoris, using the methanol inducible AOX1 promoter for both the heavy and light chains. Titre reached up to 3.05 μg mL-1 in small scale expression. VRC01 was expressed using both the α-mating factor signal peptide from Saccharomyces cerevisiae and the murine IgG1 signal peptide. Surprisingly using the murine IgG1 signal peptide resulted in higher yield of antibody capable of binding gp140 antigen. Furthermore, we evaluated levels of secretory stress compared to the untransformed wild-type strain and show a reduced level of secretory stress in the murine IgG1 signal peptide strains versus those containing the α-MF signal peptide. As bottlenecks in the secretory pathway are often the limiting factor in protein secretion, reduced levels of secretory stress and the higher yield of functional antibody suggest the murine IgG1 signal peptide may lead to better protein folding and secretion. This work indicates the possibilities for utilising the murine IgG1 signal peptide for a range of antibodies, resulting in high yields and reduced cellular stress.
Joseph S, Quinn K, Greenwood A, et al., 2017, A comparative phase I study of combination, homologous subtype-C DNA, MVA, and Env gp140 protein/adjuvant HIV vaccines in two immunization regimes, Frontiers in Immunology, Vol: 8, ISSN: 1664-3224
There remains an urgent need for a prophylactic HIV vaccine. We compared combined MVA and adjuvanted gp140 to sequential MVA/gp140 after DNA priming. We expected Env-specific CD4+ T-cells after DNA and MVA priming, and Env-binding antibodies in 100% individuals after boosting with gp140 and that combined vaccines would not compromise safety and might augment immunogenicity. Forty volunteers were primed three times with DNA plasmids encoding (CN54) env and (ZM96) gag-pol-nef at 0, 4 and 8 weeks then boosted with MVA-C (CN54 env and gag-pol-nef) and glucopyranosyl lipid adjuvant—aqueous formulation (GLA-AF) adjuvanted CN54gp140. They were randomised to receive them in combination at the same visit at 16 and 20 weeks (accelerated) or sequentially with MVA-C at 16, 20, and GLA-AF/gp140 at 24 and 28 weeks (standard). All vaccinations were intramuscular. Primary outcomes included ≥grade 3 safety events and the titer of CN54gp140-specific binding IgG. Other outcomes included neutralization, binding antibody specificity and T-cell responses. Two participants experienced asymptomatic ≥grade 3 transaminitis leading to discontinuation of vaccinations, and three had grade 3 solicited local or systemic reactions. A total of 100% made anti-CN54gp140 IgG and combining vaccines did not significantly alter the response; geometric mean titer 6424 (accelerated) and 6578 (standard); neutralization of MW965.2 Tier 1 pseudovirus was superior in the standard group (82 versus 45% responders, p = 0.04). T-cell ELISpot responses were CD4+ and Env-dominant; 85 and 82% responding in the accelerated and standard groups, respectively. Vaccine-induced IgG responses targeted multiple regions within gp120 with the V3 region most immunodominant and no differences between groups detected. Combining MVA and gp140 vaccines did not result in increased adverse events and did not significantly impact upon the titer of Env-specific binding antibodies, which were seen in 100% individuals. The ap
McKay PF, Mann JFS, Pattani A, et al., 2017, Intravaginal immunisation using a novel antigen-releasing ring device elicits robust vaccine antigen-specific systemic and mucosal humoral immune responses, Journal of Controlled Release, Vol: 249, Pages: 74-83, ISSN: 1873-4995
The generation of effective levels of antigen-specific immunity at the mucosal sites of pathogen entry is a key goal for vaccinologists. We explored topical vaginal application as an approach to initiate local antigen-specific immunity, enhance previously existing systemic immunity or re-target responses to the mucosae. To deliver a protein vaccine formulation to the vaginal mucosal surface, we used a novel vaginal ring device comprising a silicone elastomer body into which three freeze-dried, rod-shaped, hydroxypropylmethylcellulose inserts were incorporated. Each rod contained recombinant HIV-1 CN54gp140 protein (167 μg) ± R848 (167 μg) adjuvant. The inserts were loaded into cavities within each ring such that only the ends of the inserts were initially exposed.Sheep received a prime-boost vaccination regime comprising intramuscular injection of 100 μg CN54gp140 + 200 μg R848 followed by three successive ring applications of one week duration and separated by one month intervals. Other sheep received only the ring devices without intramuscular priming. Serum and vaginal mucosal fluids were sampled every two weeks and analysed by CN54gp140 ELISA and antigen-specific B cells were measured by flow cytometry at necropsy. Vaccine antigen-specific serum antibody responses were detected in both the intramuscularly-primed and vaginal mucosally-primed groups. Those animals that received only vaginal vaccinations had identical IgG but superior IgA responses. Analysis revealed that all animals exhibited mucosal antigen-specific IgG and IgA with the IgA responses 30-fold greater than systemic levels. Importantly, very high numbers of antigen-specific B cells were detected in local genital draining lymph nodes.We have elicited local genital antigen-specific immune responses after topical application of an adjuvanted antigen formulation within a novel vaginal ring vaccine release device. This regimen and delivery method elicited high levels of antigen-specifi
Muir L, Mckay PF, Petrova VN, et al., 2016, Optimisation of ex vivo memory B cell expansion/differentiation for interrogation of rare subsets in response to effective vs ineffective vaccination, Conference on HIV Research for Prevention (HIV R4P), Publisher: Mary Ann Liebert, Pages: 336-336, ISSN: 0889-2229
Aldon Y, Kratochvil S, Shattock RJ, et al., 2016, Programming T and B cell homing to mucosal sites to induce protective and/or therapeutic vaccination using chemokine-adjuvanted DNA plasmids, Conference on HIV Research for Prevention (HIV R4P), Publisher: Mary Ann Liebert, Pages: 84-84, ISSN: 0889-2229
Mann JF, Tregoning JS, Aldon Y, et al., 2016, CD71 targeting boosts immunogenicity of sublingually delivered influenza haemagglutinin antigen and protects against viral challenge in mice., Journal of Controlled Release, Vol: 232, Pages: 75-82, ISSN: 1873-4995
The delivery of vaccines to the sublingual mucosa is an attractive prospect due to the ease and acceptability of such an approach. However, novel adjuvant and delivery approaches are required to optimally vaccinate at this site. We have previously shown that conjugation of protein antigen to the iron transport molecule, transferrin, can significantly enhance mucosal immune responses. We tested whether conjugating influenza haemagglutinin to transferrin could improve the immune response to sublingually delivered antigen. Transferrin conjugated haemagglutinin induced a significant antibody and T cell response in both naïve animals and previously immunized animals. The immune response generated was able to protect mice against influenza virus challenge. Sublingually administered antigen dispersed more widely through the gastro-intestinal tract than intranasally delivered antigen and transferrin conjugation had a more marked effect on sublingually delivered antigen than intranasal immunisation. From these studies we conclude that transferrin conjugation of antigen is effective at boosting immune responses to sublingually delivered antigen and may be an attractive approach for influenza vaccines, particularly when mass campaigns are required.
Badamchi-Zadeh A, McKay PF, Korber BT, et al., 2016, A multi-component prime-boost vaccination regimen with a consensus MOMP antigen enhances Chlamydia trachomatis clearance, Frontiers in Immunology, Vol: 7, ISSN: 1664-3224
Background: A vaccine for Chlamydia trachomatis is of urgent medical need. We explored bioinformatic approaches to generate an immunogen against C. trachomatis that would induce cross-serovar T cell responses as (i) CD4+ T cells have been shown in animal models and human studies to be important in chlamydial protection, and (ii) antibody responses may be restrictive and serovar-specific.Methods: A consensus antigen based on over 1,500 MOMP sequences provided high epitope coverage against the most prevalent C. trachomatis strains in silico. Having designed the T cell immunogen, we assessed it for immunogenicity in prime-boost regimens. This consensus MOMP transgene was delivered using plasmid DNA, Human Adenovirus-5 (HuAd5) or modified vaccinia Ankara (MVA) vectors with or without MF59® adjuvanted recombinant MOMP protein. Results: Different regimens induced distinct immune profiles. The DNA-HuAd5-MVA-Protein (DAMP) vaccine regimen induced a cellular response with a Th1 biased serum antibody response, alongside high serum and vaginal MOMP-specific antibodies. This regimen significantly enhanced clearance against intravaginal C. trachomatis serovar D infection in both BALB/c and B6C3F1 mouse strains. This enhanced clearance was shown to be CD4+ T cell dependent. Future studies will need to confirm the specificity and precise mechanisms of protection. Conclusions: A C. trachomatis vaccine needs to induce a robust cellular response with broad cross-serovar coverage and that a heterologous prime-boost regimen may be an approach to achieve this.
McKay PF, King DFL, Mann JFS, et al., 2016, TLR4 and TLR7/8 adjuvant combinations generate different vaccine antigen-specific immune outcomes in minipigs when administered via the ID or IN routes, PLOS One, Vol: 11, ISSN: 1932-6203
The induction of high levels of systemic and mucosal humoral immunity is a key goal for many prophylactic vaccines. However, adjuvant strategies developed in mice have often performed poorly in the clinic. Due to their closer similarity to humans, minipigs may provide a more accurate picture of adjuvant performance. Based on their complementary signalling pathways, we assessed humoral immune responses to model antigens after co-administration with the toll-like receptor 4 (TLR4) stimulator glucopyranosyl lipid adjuvant (GLA-AF) or the TLR7/8 agonist resiquimod (R848) (alone and in combination) via the intradermal (ID), intranasal (IN) or combined routes in the Gottingen minipig animal model. Surprisingly, we discovered that while GLA-AF additively enhanced the adjuvant effect of R848 when injected ID, it abrogated the adjuvant activity of R848 after IN inoculation. We then performed a route comparison study using a CN54 gp140 HIV Envelope model antigen adjuvanted with R848 + GLA-AF (ID) or R848 alone (IN). Animals receiving priming inoculations via one route were then boosted by the alternate route. Although differences were observed in the priming phase (IN or ID), responses converged upon boosting by the alternative route with no observable impact resultant from the order of administration (ID/IN vs IN/ID). Specific IgG responses were measured at a distal mucosal site (vaginal), although there was no evidence of mucosal linkage as these closely reflected serum antibody levels. These data indicate that the complex in vivo cross-talk between innate pathways are likely tissue specific and cannot be predicted by simple in vitro models.
King DFL, McKay PF, Mann JFS, et al., 2015, Plasmid DNA Vaccine Co-Immunisation Modulates Cellular and Humoral Immune Responses Induced by Intranasal Inoculation in Mice, PLOS One, Vol: 10, ISSN: 1932-6203
BackgroundAn effective HIV vaccine will likely require induction of both mucosal and systemic cellularand humoral immune responses. We investigated whether intramuscular (IM) delivery ofelectroporated plasmid DNA vaccine and simultaneous protein vaccinations by intranasal(IN) and IM routes could be combined to induce mucosal and systemic cellular and humoralimmune responses to a model HIV-1 CN54 gp140 antigen in mice.ResultsCo-immunisation of DNA with intranasal protein successfully elicited both serum and vaginalIgG and IgA responses, whereas DNA and IM protein co-delivery did not induce systemicor mucosal IgA responses. Cellular IFNγ responses were preserved in coimmunisationprotocols compared to protein-only vaccination groups. The addition of DNAto IN protein vaccination reduced the strong Th2 bias observed with IN protein vaccinationalone. Luminex analysis also revealed that co-immunisation with DNA and IN proteininduced expression of cytokines that promote B-cell function, generation of TFH cells andCCR5 ligands that can reduce HIV infectivity.SignificanceThese data suggest that while IN inoculation alone elicits both cellular and humoralresponses, co-administration with homologous DNA vaccination can tailor these towards amore balanced Th1/Th2 phenotype modulating the cellular cytokine profile while elicitinghigh-levels of antigen-specific antibody. This work provides insights on how to generate differentialimmune responses within the same vaccination visit, and supports co-immunisationwith DNA and protein by a mucosal route as a potential delivery strategy for HIVvaccines.
Badamchi-Zadeh A, McKay PF, Holland MJ, et al., 2015, Intramuscular Immunisation with Chlamydial Proteins Induces <i>Chlamydia trachomatis</i> Specific Ocular Antibodies, PLOS ONE, Vol: 10, ISSN: 1932-6203
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Stieh DJ, King DF, Klein K, et al., 2015, Discrete partitioning of HIV-1 Env forms revealed by viral capture, RETROVIROLOGY, Vol: 12, ISSN: 1742-4690
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McKay PF, King DFL, Mann JFS, et al., 2014, Combinations of TLR4 and TLR7/8 Adjuvants Administered via the ID or IN Routes Generate Different Vaccine Antigen-specific Immune Outcomes in Minipigs, Symposium on HIV Research for Prevention (HIV R4P), Publisher: MARY ANN LIEBERT, INC, Pages: A194-A195, ISSN: 0889-2229
King DFL, McKay PF, Mann JFS, et al., 2014, Single and Combined Vaccination Modalities Result in Distinct Immunological Profiles in HIV-1 gp140-immunised Mice, Symposium on HIV Research for Prevention (HIV R4P), Publisher: MARY ANN LIEBERT, INC, Pages: A244-A244, ISSN: 0889-2229
Mann JFS, Mckay PF, Fiserova A, et al., 2014, Enhanced immunogenicity of an HIV-1 DNA vaccine delivered with electroporation via combined intramuscular and intradermal routes, Journal of Virology, Vol: 88, Pages: 6959-6969, ISSN: 1098-5514
It is accepted that an effective prophylactic HIV-1 vaccine is likely to have the greatest impact on viral transmission rates. As previous reports have implicated DNA-priming, protein boost regimens to be efficient activators of humoral responses, we sought to optimize this regimen to further augment vaccine immunogenicity. Here we evaluated single versus concurrent intradermal (i.d.) and intramuscular (i.m.) vaccinations as a DNA-priming strategy for their abilities to elicit humoral and cellular responses against a model HIV-1 vaccine antigen, CN54-gp140. To further augment vaccine-elicited T and B cell responses, we enhanced cellular transfection with electroporation and then boosted the DNA-primed responses with homologous protein delivered subcutaneously (s.c.), intranasally (i.n.), i.m., or transcutaneously (t.c.). In mice, the concurrent priming regimen resulted in significantly elevated gamma interferon T cell responses and high-avidity antigen-specific IgG B cell responses, a hallmark of B cell maturation. Protein boosting of the concurrent DNA strategy further enhanced IgG concentrations but had little impact on T cell reactivity. Interestingly protein boosting by the subcutaneous route increased antibody avidity to a greater extent than protein boosting by either the i.m., i.n., or t.c. route, suggesting that this route may be preferential for driving B cell maturation. Using an alternative and larger animal model, the rabbit, we found the concurrent DNA-priming strategy followed by s.c. protein boosting to again be capable of eliciting high-avidity humoral responses and to also be able to neutralize HIV-1 pseudoviruses from diverse clades (clades A, B, and C). Taken together, we show that concurrent multiple-route DNA vaccinations induce strong cellular immunity, in addition to potent and high-avidity humoral immune responses.
McKay PF, Cope AV, Mann JFS, et al., 2014, Glucopyranosyl lipid A adjuvant significantly enhances HIV specific T and B cell responses elicited by a DNA-MVA-protein vaccine regimen, PLOS One, Vol: 9, ISSN: 1932-6203
Using a unique vaccine antigen matched and single HIV Clade C approach we have assessed the immunogenicity of a DNApoxvirus-proteinstrategy in mice and rabbits, administering MVA and protein immunizations either sequentially orsimultaneously and in the presence of a novel TLR4 adjuvant, GLA-AF. Mice were vaccinated with combinations of HIV env/gag-pol-nef plasmid DNA followed by MVA-C (HIV env/gag-pol-nef) with HIV CN54gp140 protein (+/2GLA-AF adjuvant) andeither co-administered in different muscles of the same animal with MVA-C or given sequentially at 3-week intervals. TheDNA prime established a population of B cells that were able to mount a statistically significant anamnestic response to theboost vaccines. The greatest antigen-specific antibody response was observed in animals that received all vaccinecomponents. Moreover, a high proportion of the total mucosal IgG (20 – 50%) present in the vaginal vault of thesevaccinated animals was vaccine antigen-specific. The potent elicitation of antigen-specific immune responses to this vaccinemodality was also confirmed in rabbits. Importantly, co-administration of MVA-C with the GLA-AF adjuvanted HIVCN54gp140 protein significantly augmented the antigen-specific T cell responses to the Gag antigen, a transgene productexpressed by the MVA-C vector in a separate quadriceps muscle. We have demonstrated that co-administration of MVA andGLA-AF adjuvanted HIV CN54gp140 protein was equally effective in the generation of humoral responses as a sequentialvaccination modality thus shortening and simplifying the immunization schedule. In addition, a significant further benefit ofthe condensed vaccination regime was that T cell responses to proteins expressed by the MVA-C were potently enhanced,an effect that was likely due to enhanced immunostimulation in the presence of systemic GLA-AF.
Mann JFS, McKay PF, Arokiasamy S, et al., 2013, Pulmonary delivery of DNA vaccine constructs using deacylated PEI elicits immune responses and protects against viral challenge infection, JOURNAL OF CONTROLLED RELEASE, Vol: 170, Pages: 452-459, ISSN: 0168-3659
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Mann JFS, Mckay PF, Arokiasamy S, et al., 2013, Mucosal Application of gp140 Encoding DNA Polyplexes to Different Tissues Results in Altered Immunological Outcomes in Mice, PLOS ONE, Vol: 8, ISSN: 1932-6203
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King DFL, Siddiqui AA, Buffa V, et al., 2013, Mucosal Tissue Tropism and Dissemination of HIV-1 Subtype B Acute Envelope-Expressing Chimeric Virus, JOURNAL OF VIROLOGY, Vol: 87, Pages: 890-899, ISSN: 0022-538X
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Pattani A, McKay PF, Garland MJ, et al., 2012, Microneedle mediated intradermal delivery of adjuvanted recombinant HIV-1 CN54gp140 effectively primes mucosal boost inoculations, JOURNAL OF CONTROLLED RELEASE, Vol: 162, Pages: 529-537, ISSN: 0168-3659
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McKay PF, Cope AV, Swales J, et al., 2012, Antigen-specific T lymphocyte responses elicited by a DNA - MVA HIV CN54gp140 immunization regime are significantly altered by the TLR4 adjuvant GLA, Publisher: BIOMED CENTRAL LTD, ISSN: 1742-4690
McKay PF, Mann JF, Pattani A, et al., 2012, Intravaginal immunization using a novel antigen delivery device elicits robust vaccine antigen-specific systemic and mucosal humoral immune responses, Publisher: BIOMED CENTRAL LTD, ISSN: 1742-4690
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Mann JF, McKay PF, Swales J, et al., 2012, Optimising CN54gp140 plasmid delivery by comparing intramuscular and intradermal vaccination combinations with and without electroporation, Publisher: BIOMED CENTRAL LTD, ISSN: 1742-4690
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