scholarly journals Analysis of the role of TpUB05 antigen from Theileria parva in immune responses to malaria in humans compared to its homologue in Plasmodium falciparum; UB05 antigen

2019 ◽  
Author(s):  
Jerome Nyhalah Dinga ◽  
Stanley Dobgima Gamua ◽  
Dieudonné Lemuh Njimoh ◽  
Francis N. G. Chuma ◽  
Apollinaire Djikeng ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Immune Responses ◽  
Protective Immunity ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Theileria Parva ◽  
Endemic Region ◽  
Experimental Conditions ◽  
Potential Marker ◽  
As Species

Abstract Despite the amount of resources deployed and technological advancements in Molecular Biology, vaccinology, immunology, genetics, and biotechnology, there is still no effective vaccines against malaria. Immunity to either malaria or East Coast fever is usually seen as species- and/or strain-specific. But there is growing body of evidence suggesting the possibility of the existence of cross strain, cross species and cross genus immune responses in apicomplexans. The principle of gene conservations indicates that homologues play similar role in closely related organisms. UB05 antigen (XP_001347656.2) from Plasmodium falciparum is part of chimeric UB05-09 antigen; a potential vaccine candidate has been demonstrated to be a marker of protective immunity in malaria. The homologue of UB05 in Theileria parva is TpUB05 (XP_763711.1) which was also tested and shown to be a potential marker of protective immunity in ECF as well. In a bid to identify potent markers of protective immunity to aid malaria vaccine development, TpUB05 was tested in malaria caused by Plasmodium falciparum . UB05 antigen was tested in malaria using ELISpot, ELISA, and Growth Inhibition assays with samples from a malaria endemic region, and published. During these same experiments, TpUB05 antigen was tested alongside UB05, in separate wells but on the same plates and exposed to the same experimental conditions and the result presented here. Here we compare the performance of TpUB05 to that of UB05 in terms of the type and magnitude of immune responses provoked in malaria. It was observed that TpUB05 provoked stronger immune responses in malaria compared to UB05 antigen ex-vivo . This suggests that TpUB05 from Theileria parva is a better marker of protective immunity in malaria compared to its homologue UB05 from Plasmodium falciparum .

scholarly journals Analysis of the role of TpUB05 antigen from Theileria parva in immune responses to malaria in humans compared to its homologue in Plasmodium falciparum; UB05 antigen

2019 ◽  
Author(s):  
Jerome Nyhalah Dinga ◽  
Stanley Dobgima Gamua ◽  
Stephanie Numenyi Perimbie ◽  
Francis N. G. Chuma ◽  
Dieudonné Lemuh Njimoh ◽  
...  
Keyword(s):  
Immune Responses ◽  
Protective Immunity ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Growth Inhibition Assay ◽  
Potential Marker ◽  
As Species ◽  
Potential Vaccine ◽  
First Time

Abstract Background: Despite the amount of resources deployed and technological advancements in Molecular Biology, vaccinology, immunology, genetics, and biotechnology, there is still no effective vaccines against malaria. Immunity to either malaria or East Coast fever is usually seen as species- and/or strain-specific. But there is growing body of evidence suggesting the possibility of the existence of cross strain, cross species and cross genus immune responses in apicomplexans. The principle of gene conservations indicates that homologues play similar role in closely related organisms. UB05 antigen (XP_001347656.2) from P. falciparum is part of chimeric UB05-09 antigen; a potential vaccine candidate has been demonstrated to be a marker of protective immunity in malaria. The homologue of UB05 in T. parva is TpUB05 (XP_763711.1) which was also tested and shown to be a potential marker of protective immunity in ECF as well. In a bid to identify potent markers of protective immunity to aid malaria vaccine development, TpUB05 was tested in malaria caused by P. falciparum . Results: It was observed that TpUB05 provoked stronger immune responses in malaria compared to UB05 antigen as tested using ELISA, ex-vivo ELISpot assay and in vitro growth inhibition assay. Conclusion: This study suggests for the first time that TpUB05 from T. parva is a better marker of protective immunity in malaria compared to its homologue UB05 from P. falciparum .

scholarly journals Analysis of the Role of TpUB05 Antigen from Theileria parva in Immune Responses to Malaria in Humans Compared to Its Homologue in Plasmodium falciparum the UB05 Antigen

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 271
Author(s):  
Jerome Nyhalah Dinga ◽  
Stephanie Numenyi Perimbie ◽  
Stanley Dobgima Gamua ◽  
Francis N. G. Chuma ◽  
Dieudonné Lemuh Njimoh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Immune Responses ◽  
Protective Immunity ◽  
Vaccine Development ◽  
Theileria Parva ◽  
Peripheral Blood Mononuclear ◽  
Significant Difference ◽  
First Time

Despite the amount of resources deployed and the technological advancements in molecular biology, vaccinology, immunology, genetics, and biotechnology, there are still no effective vaccines against malaria. Immunity to malaria is usually seen to be species- and/or strain-specific. However, there is a growing body of evidence suggesting the possibility of the existence of cross-strain, cross-species, and cross-genus immune responses in apicomplexans. The principle of gene conservation indicates that homologues play a similar role in closely related organisms. The homologue of UB05 in Theileria parva is TpUB05 (XP_763711.1), which has been tested and shown to be associated with protective immunity in East Coast fever. In a bid to identify potent markers of protective immunity to aid malaria vaccine development, TpUB05 was tested in malaria caused by Plasmodium falciparum. It was observed that TpUB05 was better at detecting antigen-specific antibodies in plasma compared to UB05 when tested by ELISA. The total IgG raised against TpUB05 was able to block parasitic growth in vitro more effectively than that raised against UB05. However, there was no significant difference between the two study antigens in recalling peripheral blood mononuclear cell (PBMC) memory through IFN-γ production. This study suggests, for the first time, that TpUB05 from T. parva cross-reacts with UB05 from P. falciparum and is a marker of protective immunity in malaria. Hence, TpUB05 should be considered for possible development as a potential subunit vaccine candidate against malaria.

scholarly journals IMRAS—Immunization with radiation-attenuated Plasmodium falciparum sporozoites by mosquito bite: Cellular immunity to sporozoites, CSP, AMA1, TRAP and CelTOS

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256396
Author(s):  
Martha Sedegah ◽  
Michael R. Hollingdale ◽  
Harini Ganeshan ◽  
Maria Belmonte ◽  
Jun Huang ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Immune Responses ◽  
Vaccine Efficacy ◽  
Malaria Infection ◽  
Protective Immunity ◽  
Ex Vivo ◽  
Vaccine Dose ◽  
Vaccine Trials ◽  
Controlled Human Malaria Infection ◽  
Ifn Γ

Background Immunization with radiation-attenuated sporozoites (RAS) by mosquito bites provides >90% sterile protection against Plasmodium falciparum malaria in humans. We conducted a clinical trial based on data from previous RAS clinical trials that suggested that 800–1200 infected bites should induce ~50% protective vaccine efficacy (VE) against controlled human malaria infection (CHMI) administered three weeks after the final immunization. Two cohorts were immunized separately. VE was 55% in Cohort 1 but 90% in Cohort 2, the cohort that received a higher first dose and a reduced (fractional) fifth dose. Immune responses were better boosted by the fractional fifth dose in Cohort 2 and suggested the importance of the fractional fifth dose for increased protection in Cohort 2 responses. Three protected subjects were later boosted and were protected suggesting that protection could be extended to at least 67 weeks. Methods The ex vivo FluoroSpot assay was used to measure peripheral IFN-γ, IL2, and IFN-γ+IL2 responses to PfNF54 sporozoites and malaria antigens CSP, AMA1, TRAP, and CelTOS using pools of synthetic overlapping 15mer peptides spanning each antigen. Results There was no correlation between IFN-γ, IL2, and IFN-γ+IL2 responses to sporozoites and protection, but fold-increases between post-4th and post-5th responses greater than 1.0 occurred mostly in protected subjects. IFN-γ and IL2 responses to TRAP, CelTOS and CSP occurred only in protected subjects. Peripheral IFN-γ, IL2, and IFN-γ+IL2 responses were short-lived and low by 27 weeks post-CHMI but were restored by boosting. Conclusions These studies highlight the importance of vaccine dose and schedule for vaccine efficacy, and suggest that CSP, TRAP, AMA1 and CelTOS may be targets of protective immunity. The correlation between fold-increases in responses and protection should be explored in other vaccine trials. Trial registration ClinicalTrials.gov NCT01994525.

scholarly journals Mucosal Vaccine Development Based on Liposome Technology

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Valentina Bernasconi ◽  
Karin Norling ◽  
Marta Bally ◽  
Fredrik Höök ◽  
Nils Y. Lycke
Keyword(s):  
Immune Responses ◽  
Protective Immunity ◽  
Recent Progress ◽  
Vaccine Development ◽  
Mucosal Vaccine ◽  
Limiting Factor ◽  
Successful Development ◽  
Mucosal Vaccines ◽  
Increasing Demand ◽  
Portal Of Entry

Immune protection against infectious diseases is most effective if located at the portal of entry of the pathogen. Hence, there is an increasing demand for vaccine formulations that can induce strong protective immunity following oral, respiratory, or genital tract administration. At present, only few mucosal vaccines are found on the market, but recent technological advancements and a better understanding of the principles that govern priming of mucosal immune responses have contributed to a more optimistic view on the future of mucosal vaccines. Compared to live attenuated vaccines, subcomponent vaccines, most often protein-based, are considered safer, more stable, and less complicated to manufacture, but they require the addition of nontoxic and clinically safe adjuvants to be effective. In addition, another limiting factor is the large antigen dose that usually is required for mucosal vaccines. Therefore, the combination of mucosal adjuvants with the recent progress in nanoparticle technology provides an attractive solution to these problems. In particular, the liposome technology is ideal for combining protein antigen and adjuvant into an effective mucosal vaccine. Here, we describe and discuss recent progress in nanoparticle formulations using various types of liposomes that convey strong promise for the successful development of the next generation of mucosal vaccines.

scholarly journals Plasmodium falciparum schizont stage transcriptome variation among clinical isolates and laboratory-adapted clones

2018 ◽  
Author(s):  
Sarah J Tarr ◽  
Ofelia Díaz-Ingelmo ◽  
Lindsay B Stewart ◽  
Suzanne E Hocking ◽  
Lee Murray ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Experimental Studies ◽  
Differentially Expressed ◽  
Clinical Isolates ◽  
Schizont Stage ◽  
Variable Expression ◽  
The Impact

AbstractMalaria parasite genes exhibit variation in both sequence and expression level. There is much information on sequence polymorphism, but less resolution on natural variation in transcriptomes of parasites at specific developmental stages. This is largely because it is challenging to obtain highly replicated sampling of transcriptomes to overcome potentially confounding technical and biological variation. We address the issue in the major human parasite Plasmodium falciparum by obtaining RNA-seq profiles of multiple independent replicate preparations of mature schizont-stage parasites from a panel of clinical isolates recently established in culture and from long-term laboratory-adapted clones. With a goal of robustly identifying variably expressed genes, we show that increasing the numbers of biological sample replicates greatly improves the discovery rate. Generally, six independent replicates of each parasite culture is recommendable as being significantly to lower numbers, although for highly expressed genes variable expression can be detected when fewer replicates are available. A broad comparison identifies genes differing in relative expression between cultured clinical isolates and laboratory-adapted clones. Genes more highly expressed in the laboratory-adapted clones include an AP2 transcription factor gene Pf3D7_0420300 and putative methyl transferase genes. The variable expression of several known merozoite invasion ligands is confirmed, and previously uncharacterised genes are shown to be differentially expressed among clinical isolates. New RT-qPCR assays validate the variation in transcript levels of these genes, and allow quantitation of expression to be extended to a wider panel of clinical isolate samples. These variably expressed genes are new candidates for investigation as potential determinants of alternative parasite developmental pathways or targets of immunity.Author summaryUnderstanding parasite diversity and adaptation may require characterisation of gene expression variation, and is vital if chemotherapeutic or vaccine development is to consider new candidate targets, but it is technically challenging to generate precise data on clinical isolates. Here, we analyse the transcriptomes of mature Plasmodium falciparum schizonts using RNA-sequencing, using large numbers of biological replicate samples to minimise the impact of inter-replicate variation on observed patterns of differential expression. This identifies genes that are differentially expressed in long term laboratory-adapted parasites and recently cultured clinical isolates, as well as among different clinical isolates. In additional samples of schizonts grown in the first cycle ex vivo prior to any erythrocyte invasion, expression levels of a selected panel of these genes vary among isolates, but mean levels are similar to those in the continuously cultured clinical isolates, indicating that the latter are useful for experimental studies requiring biological replication.

scholarly journals The Epstein-Barr Virus Lytic Protein BZLF1 As a Candidate Target Antigen for Vaccine Development

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4144-4144
Author(s):  
Alex S. Hartlage ◽  
Tom Liu ◽  
John T. Patton ◽  
Sabrina L Garman ◽  
Xiaoli Zhang ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Scid Mice ◽  
Target Antigen ◽  
Barr Virus ◽  
Candidate Target ◽  
Ifn Γ ◽  
Epstein Barr

Abstract The Epstein-Barr virus (EBV) is an oncogenic, γ-herpesvirus associated with a broad spectrum of disease. While most immune-competent individuals can effectivley develop efficient adaptive immune responses to EBV, immunocompromised individuals are at serious risk for developing lifethreatening pathology such as Hodgkin’s lymphoma and post-transplant lymphoproliferative disorder (PTLD). Given the significant morbidity associated with EBV in high-risk populations, there is a need to develop vaccine strategies that restore or enhance EBV-specific immune responses. Here, we identify the EBV immediate-early protein BZLF1, a transcription factor that initiates latency to lytic cycle transition, as a potential target antigen for vaccine development. IHC assays on primary lymphoma samples from patients with PTLD and a chimeric human-murine model of EBV-driven lymphoproliferative disorder (EBV-LPD) revealed significant expression of BZLF1 protein (>10% tumor cells). Other EBV-positive lymphomas that exhibited staining for BZLF1 included lymphomatoid granulomatosis (1/3) and diffuse large B-cell lymphoma (5/10); whereas EBV(+) Hodgkin’s and EBV(+) unclassifiable lymphomas failed to demonstrate any BZLF1 signal. To examine the immunomodulatory properties of BZLF1, PBMCs were isolated from 24 healthy, EBV-seropositive donors of various HLA types and cultured in vitro with adenovirus encoding recombinant BZLF1 (rAd5F35/BZLF1) or null control (rAd5F35/null) for 18 hrs. Quantification of the number of IFN-γ secreting cells by ELISPOT revealed increased immune activation in response to BZLF1 exposure in the majority (20/24) of donors. These results led us to hypothesize that enhanced recognition of BZLF1 by antigen-specific cellular immunity may provide a protective effect against EBV. To address this, we next investigated whether DCs loaded with recombinant BZLF1 protein could mediate the expansion of BZLF1-specific CD8(+) T-cells in vitro. DCs were generated in vitro from healthy PBMC monocytes. Coculture of rBZLF1-loaded DCs and autologous PBMCs led to increased frequencies of BZLF1-specific CD8(+) T-cells as determined by tetramer flow assays. To determine whether BZLF1 vaccination could prime BZLF1-specific T-cell immunity in vivo, SCID mice depleted of murine NK cells were engrafted with EBV-positive PBMCs (hu-PBL-SCID) and injected simultaneously with rBZLF1 (100 µg/mouse). Four weeks post-vaccination, ex vivo splenocytes were reexposed to BZLF1-presenting DCs in vitro and assayed for IFN-γ secretion by ELISPOT. In comparison to vehicle, vaccination with rBZLF1 alone significantly enhanced BZLF1-specific IFN-γ responses (p=0.0007, n=3). In order to generate broader, more sustained immune responses against BZLF1, we next explored BZLF1 virally-transduced DC vaccination as a potential approach to prevent EBV-LPD. Monocyte-derived DCs were infected with rAd5F35/BZLF1 or rAd5F35/null (MOI=10) and cocultured with autologous PBMCs for 7 days. Exposure to BZLF1-transduced DCs induced a robust expansion of BZLF1-specific CD8(+) cells that was comparatively higher than recombinant protein presentation. Finally, we examined whether vaccination of hu-PBL-SCID mice with rAd5F35/BZLF1-transduced DCs would positively enhance cellular immunity and improve survival against fatal EBV-LPD. Hu-PBL-SCID mice were injected IP with 5 x 106 BZLF1-transduced DCs (or control). Mice in the “booster group” received a second dose of either rAd5F35/BZLF1 (or control) DCs as a booster. Five weeks post-vaccination, ex-vivo splenocytes were cultured 1:1 with autologous lymphoblastoid cell lines (LCLs) and assayed for IFN-γ secretion by ELISPOT. Mice vaccinated with rAd5F35/BZLF1-transduced DCs showed significantly higher responsiveness to LCLs relative to vector control mice (p<0.0001, n=3). Furthermore, single vaccination with BZLF1-transduced DCs showed a trend toward improved survival (p=0.085, n=10); however, vaccination followed by booster delivery at 2 weeks significantly delayed the development of EBV-LPD (p=0.014, n=10, median survival: rAd5F35/BZLF1, 62 days; rAd5F35/null, 48 days). These findings identify BZLF1 as a candidate target protein in the immunosurveillance of EBV and provide rationale for considering BZLF1 in vaccine strategies to enhance primary and recall immune responses and potentially prevent EBV-associated diseases. Disclosures No relevant conflicts of interest to declare.

scholarly journals Technical Considerations in Ex Vivo Human Regulatory T Cell Migration and Suppression Assays

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 487
Author(s):  
Ahmad Adebayo Irekeola ◽  
Engku Nur Syafirah E. A. R. ◽  
Norhafiza Mat Lazim ◽  
Rohimah Mohamud ◽  
Chan Yean Yean ◽  
...  
Keyword(s):  
Reproducibility Of Results ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Clinical Samples ◽  
Experimental Conditions ◽  
Functional Studies ◽  
T Cell Migration ◽  
Self Tolerance ◽  
And Migration ◽  
Assay Conditions

Regulatory T cells (Tregs) are renowned for maintaining homeostasis and self-tolerance through their ability to suppress immune responses. For over two decades, Tregs have been the subject of intensive research. The immunosuppressive and migratory potentials of Tregs have been exploited, especially in the areas of cancer, autoimmunity and vaccine development, and many assay protocols have since been developed. However, variations in assay conditions in different studies, as well as covert experimental factors, pose a great challenge to the reproducibility of results. Here, we focus on human Tregs derived from clinical samples and highlighted caveats that should be heeded when conducting Tregs suppression and migration assays. We particularly delineated how factors such as sample processing, choice of reagents and equipment, optimization and other experimental conditions could introduce bias into the assay, and we subsequently proffer recommendations to enhance reliability and reproducibility of results. It is hoped that prioritizing these factors will reduce the tendencies of generating false and misleading results, and thus, help improve our understanding and interpretation of Tregs functional studies.

Detection and Ex Vivo Expansion of Anti-Viral T Cells Isolated From Recipients of Unrelated Umbilical Cord Blood Transplant.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2245-2245
Author(s):  
Luciana C Marti ◽  
Ann M. Leen ◽  
Sylvia Janetzki ◽  
Jennifer H Baker ◽  
Paul Szabolcs
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Protective Immunity ◽  
Ex Vivo ◽  
Specific Response ◽  
Cord Blood Transplant

Abstract Abstract 2245 Poster Board II-222 Background: Viral infection is commonly detected within the first weeks after umbilical cord blood transplant (UCBT), likely triggering T cell activation and in vivo priming of infused naïve T cells. This hypothesis is supported by the observation that despite the continuous exposure to immunosuppressive (IS) drugs, viremia may resolve even in the absence of antiviral agents. However, IS may delay or even prevent effective T cell priming and the development of protective immunity, therefore causing significant morbidity and mortality. Hypothesis and Objective: Our laboratory has a long standing interest in defining pre-requisites of protective immunity after UCBT. In this study we focused on two of the most common potentially fatal viruses, CMV and Adenovirus to assess antigen-specific immune reconstitution. We hypothesized that 1) threshold numbers of CTL precursors can be identified for each virus that will impact clinical outcome 2) there may be circulating CTL precursors even if below the level of detection in lymphopenic patients that receive IS drugs, however, ex vivo restimulation could lead to expansion and subsequent quantitation. Methods: We have established in vitro assays to test the impact of cytokines and new culture techniques to promote anti-viral precursor survival and expansion. Monocytes in bulk cultures, infected with replication incompetent adenovirus vectors encoding the pp65 CMV matrix protein (Ad5f35pp65), served as APC. Antiviral responses were quantitated by ELISPOT, utilizing computerized enumeration of interferon gamma (IFNg) producing spot forming cells (SFC) in response to overlapping peptide spanning immunodominant viral antigens. Hexon and penton for adenovirus, and pp65 and EI-1 for CMV. Results: There were 8 patients enrolled on this IRB approved study transplanted at a median age of 9.9 years (range 2-17). Blood samples was obtained at a median of 70 days (range 34-470). Only 1 of 3 patients with adenovirus infection ( stool x1, urine x1, respiratory tract x 1) had previous viremia while all five (5) patients with CMV had viremia. Only 1 of the 3 adeno patients had detectable SFC from freshly drawn peripheral blood, 11 SFC/1×10e5 cells against hexon and penton respectively. None of the 5 CMV+ patients had detectable pp65 or EI-1-specific T cell responses from freshly drawn blood. However, after 9-12 days of ex vivo culture, in the presence of IL7 (10ng/ml), we were able to enumerate significantly amplified CTL responses in 7 of the 8 patients, with one CMV viremic the exception. In the remaining patients the median adenovirus hexon-specific response was 52 SFC/1×10e5 cells (range 20-90). the median penton-specific CTLp frequency was 13 SFC/1×10e5 (range 1 - 25). The median CMV pp65-specific response was 6.7 SFC/1×10e5 (range 0-14) while no responses were recorded against EI-1 demonstrating the critical role of antigenic restimulation provided by the Ad5f35pp65 construct lacking IE. The amplified immune responses were highly restricted; in the CMV+ patients (all adeno-) we were able to detect SFC only against pp65 and to neither IE or penton/hexon, while in the adenovirus+/CMV- patients (n=-3) we were able to detect SFC solely in those wells that were stimulated by hexon and penton peptides. All patients have survived at a median of 220 days after transplant (range 81-532). Conclusion: To our knowledge these ongoing experiments are the first to demonstrate that dormant virus-specific immune responses are present already in the first 100 days in most UCBT recipients (7/8 in this dataset) if infected with either adenovirus or CMV despite failure to detect these extremely rare events by standard ELISPOT assays from freshly isolated blood. Moreover, these data suggests that anti-viral CTLp can be expanded ex vivo by antigen specific restimulation that lends support to further efforts aimed at developing adoptive anti-viral T cell therapies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Controlled analysis of nanoparticle charge on mucosal and systemic antibody responses following pulmonary immunization

2014 ◽  
Vol 112 (2) ◽  
pp. 488-493 ◽  
Author(s):  
Catherine A. Fromen ◽  
Gregory R. Robbins ◽  
Tammy W. Shen ◽  
Marc P. Kai ◽  
Jenny P. Y. Ting ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Surface Charge ◽  
Cell Expansion ◽  
Vaccine Development ◽  
Ex Vivo ◽  
Germinal Center B Cell ◽  
Antibody Titers ◽  
Print Process

Pulmonary immunization enhances local humoral and cell-mediated mucosal protection, which are critical for vaccination against lung-specific pathogens such as influenza or tuberculosis. A variety of nanoparticle (NP) formulations have been tested preclinically for pulmonary vaccine development, yet the role of NP surface charge on downstream immune responses remains poorly understood. We used the Particle Replication in Non-Wetting Templates (PRINT) process to synthesize hydrogel NPs that varied only in surface charge and otherwise maintained constant size, shape, and antigen loading. Pulmonary immunization with ovalbumin (OVA)-conjugated cationic NPs led to enhanced systemic and lung antibody titers compared with anionic NPs. Increased antibody production correlated with robust germinal center B-cell expansion and increased activated CD4+ T-cell populations in lung draining lymph nodes. Ex vivo treatment of dendritic cells (DCs) with OVA-conjugated cationic NPs induced robust antigen-specific T-cell proliferation with ∼100-fold more potency than soluble OVA alone. Enhanced T-cell expansion correlated with increased expression of surface MHCII, T-cell coactivating receptors, and key cytokines/chemokine expression by DCs treated with cationic NPs, which were not observed with anionic NPs or soluble OVA. Together, these studies highlight the importance of NP surface charge when designing pulmonary vaccines, and our findings support the notion that cationic NP platforms engender potent humoral and mucosal immune responses.

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