bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neonatal vaccination primes persistent HIV Env-specific antibodies that are augmented by a single booster immunization in late infancy
Authors: Curtis Alan Dale , Dennis Maria , Eudailey Joshua , Cronin Kenneth , Pollara Justin , Ferrari Guido , Hudgens Michael , Van Rompay Koen , Permar Sallie , De Paris Kristina 
Published: January 2023

Abstract
Breastmilk transmission of HIV remains unacceptably high. Vaccine approaches that prime robust virus-specific immune responses in infancy may prevent acquisition during the breastfeeding period. Moreover, vaccine responses that generate robust immunological memory that persists into adolescence could prevent sexual transmission later in life.
The current study investigated the immunological benefit of late boosting following vaccination in infancy. Two groups of neonatal rhesus macaques were immunized with a clade C HIV Env protein adjuvanted with 3M-052 stable emulsion (SE) vaccine (Env Only) alone or together with a modified vaccinia Ankara (MVA) vector expressing HIV Env and SIV Gag (MVA/Env) at 0, 6, and 12 weeks of age. Env-specific B cells were present in blood yet absent from lymph nodes in the Env Only group by week 14. At week 32, 18 weeks following the last immunization, we could still detect Env-specific plasma IgG responses capable of autologous and heterologous HIV Env binding, Env-specific ADCC activity and CD4 blocking in both groups. A final booster immunization at week 32 enhanced avidity and function of Env-specific plasma IgG in both groups. These data confirmed previous work by our group that demonstrated HIV Env protein adjuvanted with the TLR7/8-based 3M-052-SE primed greater immune responses than Span85-Tween 80 Squalene.
Our data from the Env Only vaccine regimen are consistent with the induction of Env-specific antibody responses in human infants. These results support the idea that early life vaccination is an effective means to induce persistent HIV Env-specific IgG responses that can be boosted in infancy and could be exploited to drive protective immunity against HIV acquisition prior to sexual debut.
Differential protection of Mayaro virus antigen-antibody binding by various inactivation approaches: Implication in vaccine development
Authors: Sharma Anuj , Sharma Shreya , Galasso Bianca , Knollmann-Ritschel Barbara 
Published: January 2023

Abstract
Mayaro virus (MAYV) is an emerging alphavirus in the family Togaviridae that causes a self-limited febrile illness accompanied by maculopapular rash and arthralgia. MAYV is reported throughout South America and the Caribbean and has potential to cause widespread outbreaks. There is no FDA-approved vaccine for MAYV. The overall objectives of this study were to inactivate MAYV utilizing various inactivation approaches, and to identify a highly safe vaccine candidate with optimum immunogenicity. MAYV was inactivated by three different mechanisms: formalin; 1, 5 iodonaphthyl azide (INA); and γ-radiation. Formalin inactivation (F-iMAYV) was performed with 0.05 or 0.1% formalin at 35°C. INA-inactivation (INA-iMAYV) was performed with 10, 50, or 100 μM INA combined with UV exposure. Lastly, MAYV was inactivated with 10, 20, or 30 kGy of γ-radiation in the presence of a protein-protecting manganese-decapeptide-phosphate complex (MDP-iMAYV). MAYV was inactivated by all the three approaches. Dose- and incubation time-dependent effects were observed with formalin inactivation. 0.1% formalin with an incubation time of 48h inactivated MAYV; however, further evaluation is ongoing. MAYV was completely inactivated with &gt;50 μM dose of INA and by all three doses of γ-radiation. Differential protection of MAYV epitopes was observed after inactivation with three agents and with different doses of the inactivating agent. The most consistent antigen (Ag)-antibody (Ab) binding was observed in INA-iMAYV, followed by MDP-iMAYV. Ag-Ab binding was almost completely lost in F-iMAYV. The data suggests that INA and MDP-inactivated MAYV can be further studied as vaccine candidates. Studies are planned to evaluate immunogenicity in-vivo.
Cervicovaginal and Alveolar Macrophage responses of Rhesus Macaques following Mucosal Adenovirus-SIV recombinant priming and systemic SIV envelope boosting
Authors: Hunegnaw Ruth , Hait Sabrina Helmold , Rahman Mohammad Arif , Enyindah-Asonye Gospel M , Hoang Tanya , Robert-Guroff Marjorie 
Published: January 2023

Abstract
Vaccine strategies targeting the earliest stages of HIV infection at the mucosal portal of entry may prevent acquisition. Thus, understanding the immune profiles of mucosal cells after immunization is important for vaccine design. We vaccinated rhesus macaques with replicating Ad5hr-SIVenv/gag/nef or empty Ad5hr vector orally/intranasally and intra-tracheally, followed by intramuscular gp120 boosts in alum or alum only. Macaques were repeatedly challenged intravaginally with low doses of SIVmac251. We evaluated cervicovaginal macrophage (CM) responses to Ad5hr 3d post-immunization, and alveolar macrophage (AM) responses in BAL, as initial immunization was to the upper respiratory tract. CM showed significantly increased expression of the chemokines CCL3 (p&lt;0.01), CCL4, CCL5 and CXCL8 (p&lt;0.0001 for all) after the first prime, which decreased post-2nd boost. CD4+ T-cell frequency in the cervical mucosa was unchanged. CD16 expression was significantly increased post 2nd Ad and positively correlated with the number of challenges needed for infection (r=0.6763; p=0.0051). Immunization also increased expression of CD16 on AMs up to the 1st boost time point. Activation of AMs was evident by increased expression of CD40 and CD80 post-2nd Ad compared to naïve macaques. APRIL expression also significantly increased post-2nd Ad compared to naive levels and correlated with B cell frequency in BAL (r=0.7329; p=0.0019) and total IgG in BAL-Fluid (r=0.525; p=0.0471). These data indicate that the vaccine regimen did not induce recruitment of susceptible cells to the vaginal mucosa but increased CM CD16 expression associated with delayed SIV acquisition, and further induced AM cytokine expression that may be associated with B cell help.
Chimeric VP1-PCV2bCap protein as antigen for construction of recombinant vaccine against porcine circovirus type 2
Authors: Vrablikova Alena , Hezova Renata , Kotoucek Jan , Kulich Pavel , Turanek-Knotigova Pavlina , Gebauer Jan , Fojtikova Martina , Psikal Ivan , Turanek Jaroslav 
Published: January 2023

Abstract
Porcine circovirus type 2 (PCV2) is the main causative agents of post-weaning multi-systemic wasting syndrome leading to significant economic losses in swine population. Although vaccination is the most effective strategy to decrease morbidity and mortality rate, the virus persist in immunized populations and causes subclinical infections with symptoms similar to porcine circovirus diseases.
To develop new effective vaccine against PCV2 infection, we prepared chimeric complex VP1-PCV2bCap containing PCV2bCap protein fused with mouse polyomavirus (MPyV). Complex was expressed in baculovirus expression system and purified by nickel agarose. From eluate containing large aggregates of purified proteins, fraction containing pantameres of VP1-PCV2bCap protein was separated by Asymmetrical flow field-flow fractionation and fractions were analyzed by electron microscopy with nano-gold labeling of PCV2Cap portion of the fused protein.
6 weeks old BALB/c mice were subcutaneously vaccinated by 50ug of purified chimeric protein alone or in combination with incomplete Freund adjuvants (50%) or Emulsigen (10%). Immunity response was monitored by indirect ELISA. After the first immunization strong immunity response that gradually increased after the second and third immunization was detected in all mice immunized by chimeric protein. The best immunity response was detected in mice immunized by vaccine with Emulsigen (10%) as adjuvant.
Purified chimeric protein VP1-PCV2bCap has a high potential as a DIVA (differentiating infected form vaccinated animals) vaccine against PCV2b infections in pigs. The biggest benefit of this type of vaccine is possibility to distinguish between naturally infected and vaccinated animals
Exploration of roles of CD4 T cell help in recruitment of rare B cells to germinal centers
Authors: Lee Jeong Hyun , Nakao Catherine , Moyer Tyson J. , Irvine Darrell J. , Schief William R. , Crotty Shane 
Published: January 2023

Abstract
The elicitation of broadly neutralizing antibody (bnAb) responses is a major goal for developing an efficacious HIV vaccine. The HIV Env trimer is a weak immunogen, but it will be a necessary component in a HIV vaccine immunization schedule to drive affinity maturation to bnAbs. There are substantial biological challenges; bnAb precursor B cells are rare in humans, and B cell responses are typically directed to non-neutralizing immunodominant Env epitopes. HIV bnAb development relies heavily on germinal centers (GC) for affinity maturation. The survival of GC B cells is dependent on help from follicular helper CD4 T cells (TFH). Here, we have studied whether the modulation of TFH cells affect B cell immunodominance and competitiveness of rare B cells. We generated Env-specific TCR transgenic mice specific for a I-Ab MHCII epitope we mapped in Env. By utilizing our previously defined VRC01gHL B cell transfer model (Abbott et al., Immunity 2018), combined with co-transfer of CD4 T cells from our new Env-specific TCR transgenic mouse, we examined the competitive fitness of VRC01gHL B cells responding to Env antigens engineered to exhibit varying affinities for VRC01gHL. Increased availability of Env-specific CD4 T cells accelerated the initial expansion of GC VRC01gHL cells in response to a high affinity immunogen. However, improvements in early GC VRC01gHL cells were not observed for low affinity Env trimer immunogens. We are actively exploring whether slow delivery immunization strategies (Cirelli et al., Cell 2019) enhance the ability of Env-specific CD4 T cells to recruit rare VRC01-class B cells to GCs in mice.
Long-term sterile immunity induced by an adjuvant-containing live-attenuated AIDS virus
Authors: Yasutomi Yasuhiro 
Published: January 2023

Abstract
Previous studies have been performed using vaccine viruses attenuated by genetic disruption of key regulatory genes. The moderately attenuated prototypic vaccine strain SIVmac239Δnef has been used in most studies; however, it does not provide sufficient effects to prevent infection. Ag85B is one of the most dominant proteins secreted from most mycobacterial species. It has been shown to induce substantial Th1 cell proliferation and vigorous Th1 cytokine production. In the present study, we genetically constructed a live nef-deleted simian human immunodeficiency virus to express the adjuvant molecule Ag85B (SHIV-Ag85B) and assessed vaccine effects in cynomolgus macaques. SHIV-Ag85B could not be detected at 4 weeks after injection in cynomolgus macaques. When these macaques in which SHIV-Ag85B had become undetectable were challenged with pathogenic SHIV89.6P at 37 weeks after SHIV-Ag85B became undetectable, SHIV89.6P could not be detected at 36 weeks after the challenge in most of the macaques. In these macaques, SHIV antigen-specific CD8+ T cell responses with polyfunctionality were rapidly induced after SHIV89.6P injection. Eradication of pathogenic SHIV89.6P was confirmed by adoptive transfer experiments and CD8+ cell depletion study. These results suggest that SHIV-Ag85B elicited viral antigen-specific CD8+ T cell responses against pathogenic SHIV and provide the possibility of eradicating a pathogenic lentivirus from the infected cells. The results of this study provide further insights into the containment of HIV infections as well as new opportunities to develop a better therapeutic vaccines and cure.
Therapeutic vaccination with Ad48/MVA and TLR7 stimulation in SIV-infected, ART-treated infant rhesus macaques
Authors: Bricker Katherine M , Obregon-Perko Veroncia , Uddin Ferzan , Williams Brianna , Hesselgesser Joseph , Robb Merlin , Michael Nelson , Barouch Dan H , Chahroudi Ann 
Published: January 2023

Abstract
Antiretroviral therapy (ART) improves outcomes for the 2.1 million children living with HIV globally but is not a cure. Therefore strategies to reduce, eliminate, or control the persistent HIV reservoir would be highly beneficial. In this study, we sought to evaluate the impact of a therapeutic vaccine and TLR7 agonist in SIV-infected, ART-treated infant rhesus macaques (RMs). Four-week-old RMs (n=16) were infected orally with SIVmac251 then after an additional 4 weeks placed on a daily ART regimen. After 22 weeks post-infection (wpi) 8 RMs received 2 doses of Ad48 vectors expressing SIVgag-pol-env 8 weeks apart and 2 doses of MVA vectors expressing SIVgag-pol-env at 38 and 50 wpi; 10 oral doses of the TLR7 agonist (GS-986) were administered every other week beginning at 40 wpi. The remaining 8 RMs served as experimental controls. The magnitude of SIV-specific cellular immune responses, measured by IFN-γ ELISPOT and multiparametric intracellular cytokine staining, was increased in vaccinated RMs following Ad48-prime and was boosted by MVA. GS-986 induced an elevation of CD14+CD169+ monocytes 24 h after doses 1, 5, and 10. Four weeks after the last GS-986 dose daily ART was stopped to assess efficacy and animals were evaluated for 8 weeks. A similar time to rebound was observed in treated and control RMs. Despite the fact that SIV-infected ART-treated infant RMs are capable of mounting a robust vaccine response and immune activation by the TLR7 agonist this regimen was not sufficient to impact viral rebound. These results are distinct from previous studies performed in acutely infected adult RMs and highlight the importance of a pediatric model to evaluate HIV cure interventions during the unique period of immune development.
Isotype-specific outcomes in Fc gamma receptor targeting of PspA using fusion proteins as a vaccination strategy against Streptococcus pneumoniae infection
Authors: Bitsaktsis Constantine , Wiedinger Kari 
Published: January 2023

Abstract
Streptococcus pneumoniae (Spn) remains a considerable threat to public health despite the availability of antibiotics and polysaccharide conjugate vaccines. The lack of mucosal immunity in addition to capsular polysaccharide diversity, has proved to be problematic in developing a universal vaccine against Spn. Targeting antigen to Fc receptors is an attractive way to augment both innate and adaptive immunity against mucosal pathogens. The effect of targeting Fcγ receptors (FcγR) is highly influenced by the IgG subclass, which bares differential affinities for activating and inhibitory FcγR. In the current study we demonstrate targeting activating FcγR with fusion proteins consisting of PspA and IgG2a Fc enhance PspA-specific immune responses, and effectively protect against mucosal Spn challenge. Specifically, targeting PspA to FcyR polarized alveolar macrophage to the AM1 phenotype and increased conventional dendritic cell subsets in the lung in addition to augmenting Th1 cytokines and PspA-specific IgG and IgA. In contrast, fusion proteins consisting of PspA fused to the IgG1 Fc provided minimal benefit as a result of interaction with the inhibitory FcγRIIB. Protective efficacy of the IgG1 fusion protein was significantly enhanced in animals deficient for FcγRIIB accompanied by increased B cell maturation and proliferation levels in these animals. These studies demonstrate FcγR targeting is an effective strategy for inducing potent cellular and humoral responses via mucosal immunization with Fc fusion proteins, however, careful consideration of the Fc region utilized, is required. Fc-engineering with specific attention to FcγRIIB engagement presents a valuable vaccine strategy for protecting against Spn infection.
Human B cell responses to a live attenuated cholera vaccine
Authors: Adekunle Oluwaseyi , Kauffman Robert , Cho Alice , Nyhoff Lindsay , Rouphael Nadine , Wrammert Jens 
Published: January 2023

Abstract
Vibrio cholerae is a bacterial pathogen which causes cholera, a severe acute diarrheal disease. A symptomatic incident of cholera can lead to long term protection against subsequent exposure; however, the generation of immunity and mechanisms of protection are undetermined. A thorough understanding of the immune response to V. cholerae is needed to identify parameters which are key for the generation and maintenance of immunity. To approach this, we utilized a live attenuated cholera vaccine to model the response to V. cholerae exposure.
In this study, we found that vaccination induced plasmablasts which were specific for the two immunodominant antigens of cholera, lipopolysaccharide (LPS) and cholera toxin (CT). These antigens induced a preferential isotype response with LPS driving IgM and IgA plasmablasts while CT drives an IgG and IgA plasmablast. Serum responses had corresponding increases in both antigen binding and functional titers that remained detectable one-year post vaccination. Additionally, LPS specific IgA memory B cells were detectable at 90 days post vaccination. These cells, along with mucosal plasma cells likely play a role in long term cholera immunity. Collectively, these findings demonstrate the use of the live attenuated cholera vaccine as an effective tool to examine the primary and long term immune response to V. cholerae exposure. Additionally, it provides insight into the phenotype and specificity of the cells which likely return to and mediate immunity at the mucosa as determined by our analysis of gut-homing receptor (CCR9) expression levels on antigen specific cells. A thorough understanding of these properties will likely inform future vaccine development to both cholera and other mucosal pathogens.
Harnessing the immunogenicity of peptide-based glycoconjugate vaccines
Authors: Stefanetti Giuseppe , Okan Nihal , Kasper Dennis L 
Published: January 2023

Abstract
Glycoconjugate vaccines provide enormous health benefits globally, although they have been less successful in some populations at high risk for developing disease. In most cases, conjugation of the sugar antigen to the carrier protein has been done empirically with little attention on variables critical for the immune response. Recent findings offer new insights on their mechanism of actionsuggesting that carbohydrate presentation to T cells by antigen-presenting cells may enhance the efficacy of antibody responses and suggesting the use of a peptide instead a whole protein as carrier.
Herein, we have developed a platform to optimize glycopeptide vaccine design by determining optimal polysaccharide chain length, peptide composition and conjugation site. We first determined that the use of a full-length polysaccharide induce optimal immunogenicity. We have further demonstrated the role of the peptide linker and the conjugation site in enhancing both the conjugation efficiency and the immune response to vaccines. When immunizing mice, we found—using GBSIII CPS as a model—that these glycoconjugates induced full protection in the challenge model. We extended the platform to develop a prototype vaccine for Francisella tularensis, coupling the O polysaccharide to an optimized peptide and observing significant protection. Remarkably, protection with a glycoconjugate vaccine against F. tularensis has been only recently obtained by using a genetically enlarged polysaccharide.
The results show that peptide glycoconjugate vaccines provide a strong protection against bacterial challenges. We are currently applying the acquired knowledge to create more efficacious and longer lasting immunity to glycoconjugate vaccines.
Vaccination with a Live Attenuated Brucella abortus Mutant Stimulates Cytotoxic CD8+ T Cell Responses
Authors: Hoffman Carol , Goodwin Zakia I , Yang Xinghong , Pascual David W 
Published: January 2023

Abstract
To effect protection against mucosal and systemic tissue colonization, the B. abortus mutant strain expressing lacZ (znBAZ) was administered mucosally into BALB/c mice, and conferred nearly complete protection against pulmonary challenge with wild-type (wt) BA 2308. In fact, it was more effective than the conventional BA RB51 or S19 vaccines. Past studies with conventional brucellosis vaccines have shown the importance of stimulating CD4+ T cells for protection; however, znBAZ-vaccinated mice produced elevated levels of effector and resident memory CD8+ T cells in the lungs. In pursuit to identify cellular mechanisms of protection, we hypothesize cytolytic activity contributes to this protection. Mucosally or intravenously vaccinated mice with znBAZ induced IFN-γ-producing CD8+ T cells, both after in vitro culture or ex vivo by intracellular staining. Granzyme B+ CD8+ T cells were also induced. To assess its function, fluorescently stained RAW264.7 macrophages were infected with znBAZ at varying ratios for 2hrs, and following antibiotic treatment, were used as targets when mixed with lymph node and splenic lymphocytes for a short exposure. Cytotoxic T cell (CTL) activity was detected subsequent to granzyme B injection into znBAZ-infected macrophages, and measured by cleavage of fluorescent substrate for granzyme B. Increased CTL activity was detected with lymphocytes from vaccinated mice compared to naïve lymphocytes. Purified CD8+ T cell fractions contained this activity. Hence, these studies demonstrate that cytolytic activity is a potential effector mechanism to rid Brucella-infected cells. Work is supported by NIH AI123244 & AI125516.
Combination immunotherapy of αPD-1 and extended half-life IL-2 clears established GL261 gliomas in an MHC class I independent fashion
Authors: Tritz Zachariah Peter , Ayasoufi Kathy , Malo Courtney , Himes Benjamin , Khadka Roman , Yokanovich Lila , Goddery Emma , Fain Cori , Hansen Michael , Jin Fang , Wang Chensu , Irvine Darrell J , Wittrup K. Dane , Parney Ian F , Johnson Aaron J 
Published: January 2023

Abstract
Glioblastoma multiforme (GBM) is a deadly CNS malignancy with an average survival of ~12 months post diagnosis despite aggressive treatment. Immunotherapy approaches to treat GBM are being developed, but the unique immune environment of the brain and the immunosuppressive features of GBM have complicated early efforts. Even αPD-1 checkpoint blockade, highly useful in the context of melanoma, has proved ineffective in the treatment of GBM. In order to promote the efficacy of αPD-1 against the GL261 murine model of GBM, we supplemented this therapy with an engineered IL-2 cytokine. IL-2 therapy has been used clinically for metastatic melanoma and renal cancer, but its short half-life in circulation necessitated dangerously high doses to keep the drug concentration sufficiently high. Fusing IL-2 to the mouse serum albumin molecule (MSA-IL-2), extends the cytokine’s half-life. While neither αPD-1 nor MSA-IL-2 are effective monotherapies against the GL261 model tumor, we have found this combination immunotherapy to provide durable tumor clearance and to create immunologic memory capable of resisting GL261 rechallenge. Most strikingly, this combination therapy is independent of the CD8 T cell function, clearing established GL261 tumors in mice incapable of MHC class I restricted antigen presentation. Independence of MHC class I restricted antigen presentation makes this combination immunotherapy using αPD-1 checkpoint blockade both highly novel and translatable to clinical use.