bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of anti-OX40 to PD-1 and CTLA-4 blockade in T cell immunization/priming models (TUM3P.1047)
Authors: Vercellini Jonna , Tucker Christopher , Moran Amy , Polesso Fanny , Weinberg Andrew 
Published: January 2023

Abstract
OX40 agonists have shown to enhance anti-tumor immunity in several mouse tumor models with similar efficacy to PD-1 and CTLA-4 blockade. We wanted to compare these T cell immune enhancing strategies in subcutaneous vaccine models to understand the role that each of these Abs might have in immune priming. We used both the OVA-specific CD4 and CD8 TCR transgenic adoptive transfer models, D011.10 and OT1, to determine the effect these antibodies have upon vaccination with ovalbumin (OVA). Mice were immunized with whole OVA protein in the absence of adjuvant (soluble OVA). The Abs were delivered on the day of immunization and one day later. Peripheral blood and spleens were analyzed at several time points after immunization. We found that the OX40 agonist in both T cell models enhanced the % and numbers of Ag-specific T cells to a greater extent then either CTLA-4 or PD-1 blockade. This was true both early after activation (4 days) as well as survival of T cells 28 days following immunization in both models. Based on this evidence we hypothesize that OX40 agonists may be more important for immune cell priming to tumor Ags and that PD-1 and CTLA-4 blockade may play a role in decreasing T cell tolerance within the tumor microenvironment. Hence these immune activating pathways most likely have non-overlapping pathways to activate T cells and we now have compelling in vivo evidence that combining OX40 agonists with checkpoint inhibitors have synergistic effects in mouse tumor models.
PD-1 mediates paralysis of ovarian cancer-infiltrating dendritic cells through SHP-2 dependent and independent NFkB inactivation (TUM3P.1048)
Authors: Karyampudi Lavakumar , Lamichhane Purushottam , krempski James , Kalli Kimberly , Behrens Marshall , Vargas Doris , Hartmann Lynn , Janco Jo Marie , Hedin Karen , Dietz Allan , Goode Ellen , Knutson Keith 
Published: January 2023

Abstract
The PD-1:PD-L1 axis is a major immune regulatory pathway that blunts T cell activation in the tumor microenvironment. We recently identified that PD-1 is also upregulated on ovarian mouse tumor-infiltrating myeloid dendritic cells (TIDCs) that exhibit an immune suppressive phenotype. Extending those observations in this study, we now report that PD-1 is also expressed on human myeloid TIDCs of ovarian cancer patients, on which it suppresses the expression of co-stimulatory molecules (CD40 and CD80) as well as production of inflammatory cytokines. Mechanistic studies revealed that PD-1 on TIDCs is associated with Src homology domain-containing phosphatase-2 (SHP-2) and that PD-1-mediated blockade of NFkB-dependent cytokine release is SHP-2 dependent. PD-1 also inhibits NFkB-mediated antigen presentation which appears, however, to be independent of SHP-2. Thus, suppression of NFkB is critical in mediating PD-1-induced paralysis of ovarian tumor-associated immune TIDCs and is mediated through multiple signaling circuits that are both SHP-2 dependent and independent.
Follicular CD8+ T cells: a novel subset in immune protection and antibody responses. (VAC3P.1062)
Authors: Cross Eric , Edwards Lindsay , Kedl Ross 
Published: January 2023

Abstract
Endogenous antigen-specific CD8 T cells have been detected within B cell zones of the splenic white pulp during the primary response to multiple infections. The physiologic implications of CD8 T cell recruitment to B cell zones are unknown. However, such CD8 T cell localization may be beneficial for immunity in multiple ways, including, but not limited to: 1) direct CD8 T cell-mediated costimulation of B cells, 2) CD8 T cell-derived signals lowering the threshold of help required from CD4 follicular helper T cells (Tfh) for B cell maturation, and/or 3) direct CD8 T cell-mediated support of Tfh cells. We show here that after a combined TLR agonist and anti-CD40 antibody immunization (TLR/CD40) the follicular-homing CD8 T cell population is increased compared to infection, particularly at 2-3 days post-immunization. Concurrently, CD8 T cells upregulate Tfh cell-associated markers including CXCR5, PD-1, and ICOS. IL-21 is secreted robustly by CD8 T cells at this time point, which could help support B cell germinal center maintenance, class-switching, and Tfh cell differentiation. Indeed, in the context of TLR/CD40 immunization, the absence of CD8 T cells does not affect the IgM response, but reduces an isotype thought to be directed by IL-21, IgG2c, to levels seen in CD4 T cell-depleted animals. Our data indicates that CD8 T cells can assume a Tfh-like phenotype, we call follicular cytotoxic T cells (Tfc), early after challenge and direct antibody responses.
Toll-like receptor ligands differentially activate human innate immune system and distinctively enhance antigen-specific T cell response to vaccination in humanized mice (VAC4P.1105)
Authors: Cheng Liang , Zhang Zheng , Zurawski Sandra , Zurawski Gerard , Levy Yves , Su Lishan 
Published: January 2023

Abstract
TLR-Ls represent a new class of novel vaccine adjuvant. However, their immunologic effects in humans remain poorly defined in vivo. Here we investigated how TLR-Ls stimulated human immune system in vivo and their application as immune adjuvant using the humanized mouse model. To our surprise, we found that various TLR-Ls (CpG-A/CpG-B/CpG-C, R848, R837, MPLA and Poly I:C) stimulated human cytokines very differently in humanized mice in vivo compared to that in human PBMCs in vitro. The different in vivo response to TLR-Ls was not due to the improper development of human immune cells in vivo because splenocytes from humanized mice showed identical responses as human PBMC in vitro to various TLR-Ls. Importantly, the human innate immune response to specific TLR-Ls in humanized mice in vivo was different from that reported in C57/BL6 mice, but similar to that reported in nonhuman primates. Furthermore, we showed that distinct TLR-Ls differentially activated and mobilized human pDCs, mDCs and monocytes in different organs in vivo. Finally, we showed that Poly I:C and R848 were superior to CpG-B, for enhancing antigen specific CD4+ and CD8+ T cell responses to a CD40-targeting HIV candidate vaccine in humanized mice, which correlated with their ability to activate human CD141+ mDCs and IL-12 induction. Thus, we conclude that humanized mice serve as a highly relevant model to evaluate and rank the human immunologic effects of novel adjuvants in vivo prior to testing in humans.
A novel DNA vaccine against Mycobacterium tuberculosis infection (VAC4P.1109)
Authors: Tang Jiansong , Liang Jianguo , Cai Yi , zhou jingying , TAN ZHIWU , Tang Xian , Zhang Chi , Cheng Lin , Liu Wan , Yam Wing , Chen Xinchun , Chen Zhiwei 
Published: January 2023

Abstract
Background: Mycobacterium tuberculosis (M.tb.) pandemic continues to grow together with serious issues of increasing drug resistance, HIV co-infection and mortality. Since the existing BCG vaccine does not provide significant protection in adults, novel protective strategies should be explored with urgency. Methods: DNA vaccines that express TB antigens Ag85B, ESAT-6, Rv2660c and fusion BER, were investigated in BALB/c mice intramuscularly with electroporation (EP). Immunogenicity and efficacy assessments of these DNA vaccines were then determined before or after aerosol challenge of 100CFU M.tb H37Rv strain. Results: Compared with BCG and other DNA/EP vaccines, pBER/EP induced high frequency of Ag85B-specific CD8+ T cells (up to 41%) in tetramer assay. Moreover, pBER/EP also elicited significantly higher frequencies of antigen-specific CD4+ T cells by ELIspot and ICS assays. Surprisingly, these T cell responses were also significantly higher than those induced by a heterologous DNA/EP prime and vaccinia-85B boost regimen. Critically, pBER/EP conferred significantly better protection against M.tb H37Rv challenge when compared to other DNA/EP vaccines, with lower CFU count in the lungs (p&lt;0.01) and the absence of lung pathology. Conclusions: pBER/EP is a promising DNA vaccine candidate that does not have major issues of safety and pre-existing anti-vector immunity (e.g. vaccinia vector). Our findings warrant further investigation of pBER/EP for TB prevention and immunotherapy.
Temporal regulation of adenovirus vector-elicited antibody responses by CD4 T cells (VAC4P.1111)
Authors: Provine Nicholas , Badamchi-Zadeh Alexander , Bricault Christine , Penaloza-MacMaster Pablo , Larocca Rafael , Parenteau Lily , Blackmore Stephen , Borducchi Erica , Barouch Dan 
Published: January 2023

Abstract
BACKGROUND: Recombinant adenovirus (Ad) vectors have recently garnered interest as vaccine platforms to elicit robust antibody (Ab) responses. In this study we seek to determine the timing of CD4 T cell help for the induction of these Ab responses. METHODS: B6 mice were immunized intramuscularly with 1010 vp of Ad serotype 26 expressing SIVmac239 Env. Anti-CD4 Ab (GK1.5) was used to deplete CD4 T cells. Serum Env-specific IgG was quantified by ELISA. Statistical analysis was performed by Mann-Whitney U test. RESULTS: Depletion of CD4 T cells at immunization completely abolished SIV Env-specific Ab responses at day 30 post-immunization. Surprisingly, by day 60 post-immunization Env-specific IgG responses spontaneously developed in these mice, and by day 90 these responses were of equal titer to those in control mice (Endpoint titer of 18225 for untreated vs. 12150 for anti-CD4 treated mice; P=0.9). Delayed Ab responses coincided temporally with the recovery of CD4 T cells following anti-CD4 Ab treatment. Recovery of CD4 T cells was necessary for this phenomenon, as repeated administration of anti-CD4 Ab blocked the development of Env-specific Ab responses long term. CONCLUSION: These data demonstrate that CD4 T cells actively promote the development of Ad vector-elicited Ab responses even when CD4 T cells are absent at the time of immunization. These data have potential implications for the utility of Ad vectors in immunocompromised individuals, such as AIDS patients.
Immunogenicity of TB vaccine H56 in non-human primates (VAC4P.1113)
Authors: Wong Eileen , Agger Else , Andersen Peter , Flynn JoAnne 
Published: January 2023

Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a major global health problem. Several TB vaccine candidates are currently in various stages of development and clinical testing, including the protein subunit vaccine H56, from Statens Serum Institute (Copenhagen, Denmark). The cationic liposome adjuvant CAF09 was recently developed to enhance the CD4 and CD8 T cell response when administered with H56 vaccine. We vaccinated non-human primates (NHP) with H56 vaccine and CAF09 adjuvant by intranasal and subcutaneous routes and compared differences in immunogenicity. We measured the immune response to the vaccine in blood samples at multiple time points by IFN-γ ELISPOT and intracellular cytokine staining (IFN-γ, IL-2, TNF, IL-17, IL-6, IL-10) and in bronchoalveolar lavage fluid (BAL) by intracellular cytokine staining. NHPs were challenged with Mtb, and recall responses assessed. Frequencies of activated T cells producing cytokines transiently increased following vaccinations, but were generally low. CD4 responses were highest to the Ag85B vaccine component, while CD8 responses were highest to the Rv2660c vaccine component. There were no significant differences in cytokine production between the two vaccination routes in blood or BAL. This may lead to further H56/CAF09 vaccine trials in NHPs with Mtb challenge and future clinical trials, while strengthening understanding of the immune response necessary for protection from TB.
Direct involvement of neutrophils and Th17 cells in the protective immune response to tuberculosis after vaccination (VAC4P.1067)
Authors: Trentini Monalisa , de Oliveira Fábio , Kipnis André , Junqueira-Kipnis Ana Paula 
Published: January 2023

Abstract
Introduction: In 2013, 1.5 million died from TB, the BCG vaccine is the only TB vaccine currently available, but does not protect adults. The mc2CMX vaccine developed by our group was able to generate similar protection in mice, but induced higher levels of Th17 cells when compared with BCG. Objective: To study the role of Th17 cells in the protection induced by mc2CMX vaccine. Methodology: WT, IL22KO, and IL17KO mice were immunized twice with mc2CMX. Mice were challenged with Mycobacterium tuberculosis. Fifteen days after the last immunization, the lesions were collected and stained with HE, and the spleen cells were analyzed by flow cytometry before and after Mtb challenge. Results: Although WT mice induced vaccine lesions showing peripheral neutrophilia, central necrosis and few macrophages, both KO mice strains showed reduced injuries with lower neutrophils migration. Only IL-22KO and WT vaccinated mice presented vaccine specific Th1 and Th17 responses and reduced the lung and spleen bacterial load 30 days after challenging with Mtb. Adoptive transfer of splenocytes from vaccinated WT mice to naïve IL17KO and WT animals restored partially the protection. WT mice neutrophils depletion provoked reduction in lung specific Th1 and Th17 responses after mc2CMX vaccination. Conclusion: The results show for the first time, the protective role of vaccine induced Th17 specific cells, and also the assistance of neutrophils in the generation of such protection against TB.
Abrogation of CD59 function restores activities of neutralizing and non-neutralizing antibodies in triggering antibody-dependent complement-mediated lysis of HIV-1 virions and provirus-activated latently infected cells (VIR1P.1125)
Authors: Yang Kai , Lan Jie , Shepherd Nicole , Hu Ningjie , Byrd Daniel , Amet Tohti , Jewell Corlin , Gupta Samir , Yu Qigui 
Published: January 2023

Abstract
Abrogation of the biological function of RCA members, particularly CD59 (a key RCA member that controls formation of the membrane attack complex at the terminal stage of the complement activation cascades via all three activation pathways), has rendered both HIV-1 virions and infected cells sensitive to ADCML mediated by anti-Env Abs or sera/plasma from patients at different stages of viral infection. In the current study, we used the well-characterized anti-HIV-1 neutralizing Abs (nAbs) including 2G12, 2F5, and 4E10 and non-nAbs including 2.2C, A32, N5-i5, and N12-i15 to investigate whether the ADCML enhancement by blockage of CD59 function is mediated by nAbs, non-nAbs, or both. We found that all nAbs and two non-nAbs (N5-i5 and A32) strongly reacted to both laboratory-adapted R5, X4, and R5/X4 strains of HIV-1 and 6 primary isolates examined, as well as provirus-activated ACH-2 cells. In contrast, non-nAbs 2.2C and N12-i15 reacted weakly and did not react to these targets, respectively. After blockage of CD59 function, the reactive Abs, regardless their neutralizing activities, significantly enhanced specific ADCML of HIV-1 virions of both laboratory strains and primary isolates and provirus-activated latently infected cells. Thus, abrogation of RCA function represents a novel approach to restore activities of both nAbs and non-nAbs in triggering ADCML of HIV-1 virions and provirus-activated latently infected cells
The establishment of immune protection against a CNS viral challenge (VIR1P.1157)
Authors: Garcia Samantha , Hooper Douglas 
Published: January 2023

Abstract
The neuroinvasive rabies virus (RABV) requires CD4 T and B cell infiltration into CNS tissue and local production of virus neutralizing antibody (VNA) in order to be successfully cleared. This occurs during attenuated but not in wild-type dog RABV infection. Effective protection against a CNS challenge with dog RABV is only established by a vaccination regimen that delivers RABV-specific immune effectors to the CNS. Mice that recover from an attenuated RABV of the CNS are protected long term against subsequent CNS challenge by pathogenic dog RABV, whereas long term protection is not seen in mice that received attenuated RABV in the gastrocnemius. This difference is likely to be due to the increased formation of memory like cells which remain in the brain following a direct CNS vaccination, resulting in a more robust and effective response during CNS challenge. Since the blood-brain barrier (BBB) evidently remains intact during dog RABV infection, it is likely that immune memory cells capable of reactivating to produce VNA upon challenge must be resident in the CNS rather than enter from the periphery. In support of this concept, adoptive transfer of RABV immune cells fails to protect against a dog RABV infection of the CNS. A robust CNS immune response during initial vaccination appears to be the only effective way to establish long term protection against a pathogenic RABV infection that reaches the CNS.
Glycosylphosphatidylinositol deficiency attenuates the production of infectious HIV-1 and renders the virions sensitive to complement attack (VIR1P.1128)
Authors: Amet Tohti , Byrd Daniel , Lan Jie , Shepherd Nicole , Yang Kai 
Published: January 2023

Abstract
Human immunodeficiency virus type 1 (HIV-1) escapes complement-mediated destruction by incorporating regulators of complement activation (RCA) from the host cells. Abrogation of RCA function leads to complement-mediated virolysis. However, little is known about the mechanism by which HIV-1 incorporates RCA from the host cell. Here we used glycosylphosphatidylinositol (GPI)-deficient Jurkat (Jurkat-7) cells that only express intracellular CD59 (a key member of RCA), but not on the surface, to study how HIV-1 incorporates CD59 from an infected cell. Compared to wild type Jurkat cells, Jurkat-7 cells are less susceptible to HIV-1 infection, and produces lower amount of virions due to the impaired GPI biosynthesis. Interestingly, virions produced from Jurkat-7 cells did not contain CD59, while virions from wild-type Jurkat cells did contain CD59 with a certain amount of viral protein expression. This indicates that HIV-1 incorporates CD59 from the surface of host cell rather than from the intracellular compartments. Virions produced from Jurkat-7 cells are less infectious, but more susceptible to complement-mediated virolysis due to the failed CD59 incorporation into the virus surface. Furthermore, transient restoration of GPI anchor in Jurkat-7 cells resulted in recovered surface expression of CD59. These results reveal a critical role of GPI anchor and GPI-anchored proteins in HIV-1 life cycle and incorporation of CD59, probably other host cell proteins into the HIV-1 virions.
Triggering of organ-specific autoimmunity through synergy of defects in key tolerance checkpoints
Authors: Proekt Irina , Miller Corey , Jeanne Marion , Fasano Kayla , Lowell Clifford A , Gould Douglas , Anderson Mark S , DeFranco Anthony L 
Published: January 2023

Abstract
Studies of genetic factors associated with human autoimmunity suggest a multigenic origin of autoimmune susceptibility. To address how defects in different immune tolerance pathways cooperate to result in disease, we investigated whether genetic alterations in two such pathways might synergize to produce autoimmunity in mice. The intracellular protein tyrosine kinase Lyn is critical for inhibitory receptor function in innate immune cells and B cells. Lyn-deficient mice develop systemic but not organ-specific autoimmunity. In contrast, Autoimmune Regulator (Aire) promotes expression of tissue-specific antigens by thymic epithelial cells and T-cell negative selection. Aire-deficient mice develop multiorgan autoimmunity, including autoimmune uveitis, due to lack of thymic expression of the retina-specific interphotoreceptor retinoid binding protein (IRBP). AireGW/+ knockin mice express a dominant negative allele of Aire, have low but detectable thymic expression of IRBP and do not develop uveitis. To determine whether lack of Lyn inhibitory pathways could cooperate with a partial defect in T cell central tolerance, we generated AireGW/+ Lyn−/− double mutants. Remarkably, over 50% of these mice developed severe uveitis that was accompanied by a rise in anti-IRBP antibodies and an expansion of IRBP-specific CD4 T cells. To determine the contribution of different Lyn-expressing cell subsets to uveitis, we crossed AireGW/+ mice to a panel of Cre lines with an inducible Lyn knockout allele. Deletion of Lyn selectively in dendritic cells (DCs) was sufficient to drive disease, suggesting that Lyn-deficient DCs may have increased ability to prime IRBP-specific T cells that have escaped negative selection in the AireGW/+ thymus.
The effect of dietary phytoestrogen content on the development of systemic lupus erythematosus in the MRL/lpr mouse.
Authors: Edwards Michael Richard , Dai Rujuan , Heid Bettina , Cowan Catharine R , Ahmed S Ansar 
Published: January 2023

Abstract
Systemic lupus erythematosus is a prototypical autoimmune disease, characterized by the loss of immune cell tolerance to self-antigens, and the subsequent production of autoantibodies leading to multi-organ damage. SLE is an incurable, highly variable autoimmune disease that most often affects women of child-bearing age. We investigated the effects of three standard commercial diets with varying phytoestrogen content on the development of lupus in female MRL/lpr mice. The diets include Harlan 2018 which contains soybean meal, Teklad 7013 which contains both soy and alfalfa, and Research Diets Inc. D11112226 (RD) purified ingredients diet, containing no measurable phytoestrogens. Mice fed the 2018 diet developed severe glomerulonephritis with high levels of complement C3 protein deposition and moderate IgG immune-complex deposition, while mice fed the RD diet developed minimal evidence of renal damage and protein deposition. The mice fed the RD diet, however, had increased levels of multiple pro-inflammatory cytokines, while immune cell populations remained unchanged. Immunofluorescence revealed distinct infiltrating cellular phenotypes in the kidney, dependent on dietary source. Splenocyte miRNA-148a was markedly elevated in mice fed the 2018 and 7013 diets, while circulating miRNA values were not statistically different. Our results suggest that dietary isoflavones can worsen the development of glomerulonephritis due to enhanced immune complex protein deposition and altered cellular infiltration phenotypes. Our results also support that each organ system must be evaluated independently, and that what is measured in circulation does not necessarily reflect what is occurring in disease target organs.