bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and characterization of human MDSC from peripheral blood of patients with various malignancies (TUM6P.971)
Authors: Wyczechowska Dorota , Hernandez Claudia , Zheng Liqin , Rodriguez Paulo , Ochoa Augusto 
Published: January 2023

Abstract
Myeloid-derived suppressor cells are a heterogeneous population of early myeloid progenitors that possess a strong immunosuppressive capacity and accumulate in multiple diseases characterized by chronic inflammation. In tumors, MDSC play a major role in the down-modulation of anti-tumor immune responses mediated by T cells and natural killer cells. Murine MDSC are defined as CD11b+/GR1+ and specific phenotypic markers have been identified for the distinction of monocytic MDSC and granulocytic MDSC. However, there is no consensus on how human subsets of MDSC should be phenotypically defined. Using peripheral blood mononuclear cells from patients with various malignancies, we determined by flow cytometry specific panels for the distinction of M-MDSC and G-MDSC. M-MDSC’s were identified as CD11b+ CD14+ CD33+high HLA-DRneg/low and CD66bneg, while G-MDSC’s are identified as CD11b+ CD14neg CD33+low HLA-DRneg CD66b+. Additional experiments established the expression of specific markers associated with energy metabolism in MDSC subsets. Therefore, our results characterize a panel for the distinction of MDSC subsets in patients with cancer and suggest potential metabolic differences between MDSC subpopulations in humans.
Mycobacterium bovis Bacillus Calmette-Guérin (BCG) reprograms M2 macrophages to promote antitumor T cell responses (TUM6P.1007)
Authors: Lardone Ricardo , Ramos Romela , Navarrete Marian , Torisu-Itakura Hitoe , Faries Mark , Sieling Peter , Lee Delphine 
Published: January 2023

Abstract
M2 Macrophages (MΦs), also known as tumor-associated MΦs, infiltrate solid tumors and impair antitumor immunity. M. bovis Bacille Calmette-Guérin (BCG) is an intralesional (IL) therapy for cutaneous metastatic melanoma (NCCN Guidelines), and induces regression of injected, but also non-injected lesions. Since MΦs play a pivotal role in tumors and mycobacterial infections, we hypothesized that IL-BCG affects tumor regression by altering M2 MΦs. Thus, we investigated the effects of BCG on in vitro polarized M2 MΦs. BCG induced dramatic transcriptional changes in M2 MΦs on genes involving inflammation, immune cell recruitment, cross-talk and activation. To determine whether BCG could alter the classical M2 phenotype, we compared BCG vs mock-treated M2-MΦ cell surface phenotype and response to LPS. BCG-treated M2-MΦ expressed lower CD163 (p&lt;0.01) and secreted less IL-10 (p&lt;0.05), with no effect on IL-12p40, vs mock-treated M2-MΦ. We also investigated the ability of BCG-treated M2-MΦ to activate T cells, and found an increased frequency of IFN-γ producing CD4+ T cells responding to BCG vs mock-treated M2-MΦ (p&lt;0.05), suggesting an adjuvant effect of BCG. Moreover, supernatant from BCG-treated M2-MΦ increased the frequency of granzyme B-producing CD8+ T cells responding to autologous melanoma cell lines (p&lt;0.01). Together, our data indicates IL-BCG therapy could contribute to a tumor-rejecting environment by inducing a reprogramming of M2 MΦs towards a proinflammatory phenotype.
PD-1 blockade reverts motility arrest of transferred tumor-infiltrating CD8+ T cells in adoptive cell transfer immunotherapy (TUM7P.1014)
Authors: Mehta Gautam , Sukumar Madhuhasan , McGavern Dorian , Restifo Nicholas 
Published: January 2023

Abstract
Adoptive cell transfer (ACT) immunotherapy can result in complete responses in the treatment of metastatic solid cancers, however the majority of patients eventually progress. Although many immune regulatory programs are context-dependent, the in vivo behavior of adoptively-transferred CD8+ T cells over time remains unknown. Using the Pmel-1 model, we performed intravital microscopy of subcutaneous tumors in mice to visualize the in vivo motility of transferred tumor-specific CD8+ T cells. This revealed that CD8+ T cell motility arrest increased over time after adoptive transfer. By ex vivo analyses, behavioral change coincided with a reduction in IFN-γ production and glucose uptake. As the transferred cells strongly expressed PD-1, we treated mice with both ACT and anti-PD-1 blocking antibody to determine the effect of immune checkpoint blockade on cellular motility. In mice treated with anti-PD-1 blocking antibody, transferred intratumoral CD8+ T cell motility arrest diminished, as compared with controls. This corresponded with an increase in CD8+ T cell glucose uptake. These data demonstrate that intratumoral CD8+ T cell behavior in ACT is dynamic and that greater motility is associated with increased functionality and bioenergetic demand. Furthermore, concurrent PD-1 blockade exerts a cell-intrinsic effect on transferred CD8+ T cells suggesting synergy between ACT and anti-PD-1 immunotherapy and the potential for their combinatorial use in the treatment of cancer
Melanoma induces, and adenosine suppresses, CXCR3-cognate chemokine production and T cell infiltration of lungs bearing metastatic-like disease (TUM7P.1017)
Authors: Mullins David , Perekslis Thomas , Croteau Walburga , Turk Mary Jo , Huang Yina , Clancy-Thompson Eleanor 
Published: January 2023

Abstract
Melanoma-specific vaccines have minimal efficacy in patients with established disease but enhance survival when administered in the adjuvant setting. Therefore, we hypothesized that organs bearing metastatic-like melanoma may differentially produce T cell chemotactic proteins over the course of tumor development. Using an established model of metastatic-like melanoma in lungs, we assessed the production of specific cytokines and chemokines over a time-course of tumor growth, and we correlated chemokine production with chemokine receptor-specific T cell infiltration. CXCR3-cognate chemokines (CXCL9 and CXCL10) were significantly increased in lungs bearing minimal metastatic lesions, but chemokine was at or below basal levels in lungs with substantial disease. Chemokine production correlated with infiltration of the organ compartment by transferred CD8+ tumor antigen-specific T cells in a CXCR3- and host IFN-γ-dependent manner. Adenosine signaling suppressed chemokine production and T cell infiltration in the advanced metastatic lesions, and suppression could be partially reversed by the adenosine receptor antagonist aminophylline. Our data demonstrate that CXCR3-cognate ligand expression is required for efficient T cell access of tumor-infiltrated lungs, and ligands are expressed in a temporally-restricted pattern that is governed, in part, by adenosine. Modulation of adenosine activity may impart therapeutic efficacy to immunogenic but clinically ineffective vaccines.
ImmTACs: bi-specific TCR-based reagents for targeted cancer immunotherapy (VAC7P.1037)
Authors: Jakobsen Bent 
Published: January 2023

Abstract
ImmTACs (immune mobilizing monoclonal T cell receptors against cancer) are a new class of soluble bi-specific reagent that exploit the natural antigen recognition pathway mediated by the T cell receptor (TCR). As TCRs recognise HLA-presented peptides, ImmTACs can access the larger pool of intracellular tumor antigens unavailable to antibody based therapies. ImmTACs target tumors via a soluble monocloncal TCR, engineered to recognise a given tumor associated peptide-HLA complex with exceptionally high sensitivity and specificity. Once bound to their target, ImmTACs redirect host polyclonal T cells via an anti-CD3 antibody fragment. In this way ImmTACs facilitate targeted T cell recognition of tumors leading to potent T cell activation and tumor cell killing, with the potential to break T cell tolerance. ImmTACs are specific for humans, thus efficacy, specificity and off target effects cannot be assessed in animal models. Using antigen positive tumor cells and HLA appropriate primary human cell lines representing a range of tissues, the in vitro pre-clinical package can be predictive of in vivo clinical observations. A first ImmTAC, IMCgp100, has entered phase I/IIa clinical trials for patients with advanced melanoma. The drug is well tolerated and many patients show tumor shrinkage after the first dose of ImmTAC with tumor shrinkage improving with each dose. Emerging data demonstrate durable partial responses in three patients and a complete response in a fourth patient.
Adoptive cellular therapy containing T cells and CD25+ NKT cells modulates myeloid cells and stimulates endogenous anti-tumor immune function (VAC7P.1038)
Authors: Payne Kyle , Graham Laura , Bear Harry , Manjili Masoud 
Published: January 2023

Abstract
Myeloid-derived suppressor cells (MDSCs) are a type of myeloid regulatory cell (Mreg) that suppresses the anti-tumor activity of immune effector cells. We have previously demonstrated that CD25+ NKT cells function as cellular adjuvants for converting MDSC into immune stimulatory myeloid cells, thereby rescuing anti-tumor T cell function from MDSCs in vitro. Here, we sought to characterize the in vivo efficacy of adoptive cellular therapy (ACT) utilizing reprogrammed T cells and CD25+ NKT cells in modulating MDSCs in FVBN202 mice. We demonstrate a significant 2-fold decrease in the frequency and absolute number of splenic MDSCs in recipients of ACT compared with control mice bearing comparable lung metastases. We also observed a significant 2-fold increase in the frequency and absolute number of mature myeloid cells (CD11b-MHC-II+CD40+CD86+). Functional analysis was performed in which CD11b- myeloid cells from ACT-recipient animals bearing lung metastases were cultured with autologous splenocytes. CD11b- MHC II+ cells induced a significant release of splenocyte-derived IFN-γ; this response was enhanced greater than 20-fold upon the addition of tumor cells. Importantly, ACT recipients of mice bearing Ki-67hi circulating tumor cells experienced extended time to progression compared to control animals. These data suggest CD25+ NKT cells may act to promote ‘vaccination in situ’ of endogenous T cells, in addition to boosting anti-tumor efficacy of ACT.
Nasal immunization with M cell-targeting ligand-conjugated ApxIIA toxin fragment induces protective immunity against Actinobacillus pleuropneumoniae infection in a murine model (VAC8P.1056)
Authors: Jang Yong-Suk , Park Jisang , Kim Sae-Hae 
Published: January 2023

Abstract
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia and severe economic loss in the swine industry has been caused by the infection. Therefore, the development of an effective vaccine against the bacteria is necessary. ApxII toxin, among virulence factors expressed by the bacteria, is considered to be a promising vaccine candidate because ApxII toxin not only accompanies cytotoxic and hemolytic activities, but is also expressed in all 15 serotypes of bacteria except serotypes 10 and 14. In this study, we identified the peptide ligand capable of targeting the ligand-conjugated ApxIIA#5 fragment antigen to nasopharynx-associated lymphoid tissue. It was found that nasal immunization with ligand-conjugated ApxIIA#5 induced efficient mucosal and systemic immune responses measured at the levels of antigen-specific antibodies, cytokine-secreting cells after antigen exposure, and antigen-specific lymphocyte proliferation. More importantly, the nasal immunization induced protective immunity against nasal challenge infection of the bacteria, which was confirmed by histopathological studies and bacterial clearance after challenge infection. Collectively, we confirmed that the ligand capable of targeting the ligand-conjugated antigen to nasopharynx-associated lymphoid tissue can be used as an effective nasal vaccine adjuvant to induce protective immunity against A. pleuropneumoniae infection.
Enhancing immunogenicity of recombinant protein vaccines in mice with vaccine self-assembling immune matrix, a non-viral delivery platform (VAC8P.1059)
Authors: Shollenberger Lisa , Grenfell Rafaella , Samli E. , Harn Donald 
Published: January 2023

Abstract
Vaccination remains the most effective public health tool to prevent infectious disease. Many vaccines are marginally effective in general, or are less efficacious when used in immune-compromised populations. To enhance vaccine immunogenicity, we exploited the biphasic property of the (RADA)4 synthetic oligopeptide to create a new vaccine delivery method, VacSIM (vaccine self-assembling immune matrix). Vaccine components are mixed with the VacSIM solution for injection, after which the (RADA)4 peptides self-assemble into hydrated nanofiber gel-matrices, forming a vaccine depot with the vaccine antigens in the aqueous phase, allowing for slow-release of vaccine components over time. Thus, we have a non-viral, inert, biodegradable delivery system, not requiring formulation that can deliver a multitude of vaccines. We hypothesize that slow-release of vaccine components provides antigen persistence, driving enhanced vaccine-specific responses that are improved in both quantity and quality of the response. We have tested VacSIM with live bacterial vectors, inactivated virus and multiple recombinant protein vaccines. Shown here, VacSIM improves vaccine responses to protein immunogens in 2 strains of mice and remains stable after long-term storage. In addition, VacSIM by itself does not activate antigen presenting cells. Enhancement of vaccine responses by VacSIM administration could represent a fundamental paradigm shift in how vaccines are delivered.
Therapeutic role of interleukin 22 in abdominal bacterial infection in mice (VAC8P.1049)
Authors: Zheng Mingquan , Kumar Pawan , Stefanovski Matthew , Pociask Derek , Good Misty 
Published: January 2023

Abstract
IL-22 is an IL-10-related cytokine and produced by Th17 and other immune cells that signals via IL-22Ra1 and IL-10R2. IL-22RA is widely expressed on non-immune tissues. IL-22 binding to IL-22 receptor complex leads to STAT3 activation. IL-22 has shown to have hepatoprotective effects through STAT3 in liver injury model. However it is unclear if IL-22 can directly regulate antimicrobial programs in the liver. Using intra-abdominal infection with Klebsiella pneumoniae (KP) where recombinant IL-22 (rIL-22) was administered 2 hours after infection, we found that rIL-22 reduced bacterial burdens in liver. This was associated with reduced liver necrosis and reduced serum ALT levels. rIL-22 required hepatic IL-22Ra1 as rIL-22 therapy was ineffective in liver specific IL-22Ra1 KO mice in terms of controlling bacterial burden or liver injury. rIL-22 also required hepatic STAT3 as rIL-22 therapy was also ineffective in liver specific STAT3 KO mice. Administration of anti-gp-130 conferred a mark increase in KP growth in the liver but this could be rescued by rIL-22, demonstrating that the effect of rIL-22 is independent of gp130. Serum from rIL-22 treated mice showed potent bacteriostatic activity against KP and this activity was dependent on lipocalin-2 (Lcn2). However, in vivo, the antimicrobial activity was independent of Lcn2 as rIL-22 was still therapeutic in Lcn2-/- mice. We are currently investigating the mechanisms underlying the lcn-2 independent activity of rIL-22.
Induction of anti-microbial immune responses in severely immunodeficient hosts by IFNγ-expressing Salmonella enterica serovar Typhimurium correlates with efficient activation of macrophage effectors (VAC8P.1050)
Authors: Al-Ramadi Basel , Al-Sbiei Ashraf , Mohamed Yassir , Bashir Ghada , Al-Ojali Samia , Fernandez-Cabezudo Maria 
Published: January 2023

Abstract
Susceptibility to infection by the intracellular bacterial pathogen, Salmonella enterica serovar Typhimurium (S. typhimurium), is controlled by many genes of innate and adaptive immunity. One of the most critical genes is IFN-γ and mice deficient in IFN-γ synthesis are highly susceptible to Salmonella. Previously, we also demonstrated that mice deficient in MyD88, an adaptor that regulates TLR signaling, are susceptible to Salmonella infection. In the current study, we compared immune responses in mice deficient in IFN-γ or MyD88 with wild-type controls following infection with an attenuated strain of S. typhimurium (designated BRD509) or a recombinant derivative engineered to express murine IFN-γ (GIDIFN). Infection studies with BRD509 or GIDIFN revealed that the latter strain was significantly less virulent in immunodeficient mice than BRD509 and correlated with decreased bacterial loads in systemic organs. Enhanced responsiveness was due to GIDIFN strain’s ability to activate effector macrophages, as shown by increased synthesis of inflammatory cytokines and anti-microbial effector molecules, including NO. Gene expression profiling by qPCR demonstrated stronger induction of key inflammatory modulators by GIDIFN in macrophages of immunodeficient animals. These findings suggest that immunotherapeutic approaches using attenuated bacterial strains expressing immunomodulatory genes is more efficacious and offers a superior safety profile even in severely immunodeficient hosts.
A novel recombinant adjuvant replacing the CD4+ T helper cell functions in inducing IgG isotype antibodies and protection by T cell dependent influenza split vaccines (VAC8P.1052)
Authors: Ko Eun-Ju , Lee Young-tae , Jung Yu-Jin , Lee Youri , Kim Min-Chul , Kang Sang 
Published: January 2023

Abstract
The action mechanisms of adjuvants have not been well understood yet. We hypothesized that an effective adjuvant would overcome a defect in CD4+ T cell help for the induction of immune responses and protection by T cell dependent vaccines. We found that current influenza split vaccine was not able to induce antibodies and protection in a CD4+ T cell deficient condition. In an attempt to develop an effective adjuvant, we developed a recombinant virus-like particle expressing flagellin (FliC-VLP) and investigated its adjuvant effects and mechanisms by comparing alum adjuvant. CD4 knockout (CD4KO) mice that were immunized with influenza split vaccine plus FliC-VLP (or MF59, AS04 human adjuvant) induced IgG isotype-switched antibodies, germinal center formation, and virus-specific memory cells, all of which were not induced in CD4KO mice with split vaccine alone. Levels of antibodies and protective efficacy in CD4KO mice with split vaccine plus FliC-VLP were significantly higher than those in C57BL/6 wild type mice without adjuvant and CD4KO mice adjuvanted by alum. The adjuvanticity of FliC-VLP was partially dependent on TLR5 when tested in TLR5KO mice. Taken together, the results provide evidence that FliC-VLP adjuvant can stimulate the induction of antigen-specific immune responses and improve protection against lethal infection in CD4KO mice immunized with T cell dependent split vaccines, indicating CD4+ T cell independent action mechanisms of adjuvant.
Effects of Ag/adjuvant ratio on the systemic and mucosal antibody responses of BALB/c mice immunized intradermally with CfaEB, a minor-major subunit fusion of the enterotoxigenic E. coli CFA/I fimbriae, and LT(R192G/L211A) (VAC9P.1104)
Authors: Maciel Milton , Vaidyanathan Deepika , Hulsey William , Savarino Stephen 
Published: January 2023

Abstract
The ratio of Ag/adjuvant in a vaccine can modulate the immune response as well as side effects. We studied the effects of different doses of CfaEB, a minor-major subunit fusion of the enterotoxigenic E. coli (ETEC) CFA/I fimbriae, given ID with the adjuvant LT(R192G/L211A), or dmLT, an attenuated form of the ETEC heat-labile enterotoxin. BALB/c mice were immunized with 0.1, 1, 10 or 100 mg of CfaEB alone or with 10 or 100 ng of dmLT on days 0 and 21. Sera from days 21 and 28 were tested by ELISA and hemagglutination inhibition assay. Mucosal responses were assessed in day 28 fecal pellets. Serum anti-CfaE IgG Ab titers directly correlated with the dose in groups receiving no adjuvant but the highest titers were seen in the two groups receiving 10 mg of CfaEB plus 10 or 100 ng dmLT. A similar pattern was observed with serum anti-CfaE IgA responses, although 100 mg of CfaEB plus 10 or 100 ng of adjuvant elicited the highest levels. Groups receiving 10 or 100 mg of CfaEB plus 100 ng dmLT manifested the highest functional Ab titers. The adjuvant at either dose was required to elicit a strong fecal anti-CfaE IgA response, and it directly correlated with CfaEB dose in the adjuvanted groups. Our results demonstrate the importance of dmLT in promoting mucosal Ab responses to our vaccine when given by the ID route. Since optimal mucosal vs. systemic functional Ab responses are elicited by different Ag/adjuvant ratios, the ratio should be selected to elicit the desired immune response.
Humoral and cellular immune responses to Mycobacterium tuberculosis antigens delivered through recombinant DNA plasmids and live mycobacteria (VAC9P.1105)
Authors: Mustafa Abu 
Published: January 2023

Abstract
The failures to provide consistent protection by the currently available vaccine against tuberculosis, i.e. Mycobacterium bovis BCG, have led to efforts to develop alternative vaccines. The three low molecular weight major antigenic proteins, i.e. PE35, CFP10 and ESAT6, encoded by Mycobacterium tuberculosis-specific region are among the candidates to develop new vaccines. In this study, two DNA vaccine vectors and three live mycobacterial vectors were evaluated for delivery of these antigens. DNA corresponding to the genes of above proteins were amplified from the genomic DNA of M. tuberculosis and cloned into two DNA vaccine vectors and a shuttle plasmid capable of transforming mycobacteria. The recombinant shuttle plasmids were electroporated into M. bovis BCG, M. vaccae and M. smegmatis. The recombinant DNA any mycobacterial constructs were tested for protein expression in vitro and for the induction of antigen-specific antibody and cellular immune responses in mice, guinea-pigs or rabbits. The results showed that the in vitro expression of PE35 and CFP10 was observed by one or more recombinant constructs. Furthermore, the induction of both humoral (antibody) and cellular immune responses (cell proliferation, protective cytokine secretion and induction of delayed-type hypersensitivity responses) were consistently observed only with the vaccine constructs expressing PE35. These results suggest the superiority of PE35 antigen as a new vaccine candidate against tuberculosis.
Vaccination does not protect aged mice from influenza-induced lung inflammation (VAC9P.1062)
Authors: Lorenzo Erica , Hopkins Jacob , Lefebvre Julie , Haynes Laura 
Published: January 2023

Abstract
Aging predisposes individuals to increased susceptibility to influenza infection and delays in viral clearance. Importantly, we show that age-related delays in viral clearance are correlated with lingering inflammation in the lungs of aged mice. This is critical since inflammation in the lungs is associated with an enhanced susceptibility to secondary bacterial infection, which is a significant sequela to flu infection and often causes death. Inflammation in young lungs following flu infection can be significantly reduced by prior flu immunity, such as that generated following vaccination with recombinant influenza nucleoprotein (rNP). This protection is characterized by reduced lung inflammation, reduced lung damage, reduced susceptibility to flu challenge and also correlates with increased levels of IL-10 and anti-NP antibodies. In contrast, vaccination of aged mice with rNP does not reduce lung inflammation and shows no protection from weight loss and no reduction in viral titers in the lungs following subsequent flu infection. Additionally, aged mice generate lower levels of NP-specific antibodies, which are absolutely critical for reducing lung inflammation. Consequently, unlike young mice, these NP vaccinated aged mice are not protected from death due to secondary bacterial infection. Thus, when considering a universal flu vaccine such as rNP, it is important to understand how efficacious it can be in highly susceptible populations such as the elderly.