bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of novel ligands that alter the function of type II NKT cells
Authors: Nishio Kumiko , Camara Kaddy , Pasquet Lise , Bloom Anja C , Richardson Stewart K , Cardell Susanna L , Howell Amy R , Terabe Masaki , Olkhanud Purevdorj , Berzofsky Jay A 
Published: January 2023

Abstract
Natural killer T (NKT) cells are distinct innate lymphocytes which recognize lipid antigens in the context of the major histocompatibility complex-like molecule CD1d. When activated, these cells can rapidly produce a variety of cytokines and modulate innate and adaptive immune responses. There are two main subsets of NKT cells, termed type I and type II NKT cells. Type I NKT cells are characterized primarily on the basis of their invariant TCRα expression and reactivity to the glycolipid α-galactosyl ceramide (αGalCer), whereas type II NKT cells express a different and more diverse TCR repertoire than type I NKT cells. Currently, the most widely studied antigen for type II NKT cells is sulfatide. Sulfatide-reactive type II NKT cells are reported to have the immunosuppressive function in autoimmune diseases and cancer. We previously showed a role for sulfatide-reactive type II NKT cells in suppressing tumor immunosurveillance in a murine model of lung metastasis. The activation of type II NKT cells in this model by the injection of sulfatide increased the development of lung metastasis. We synthesized diverse sulfatide-analogues varying in the number of double bonds and hydroxyl groups in the ceramide. In vitro, analogues having a phytosphingosine sphingoid base activated both type II and type I NKT cell hybridomas. On the other hand, the analogue C24:2 with a sphingosine base activated only the type II NKT cell hybridoma. In vivo, the C24:2 analogue significantly reduced the development of lung metastasis, showing distinct and opposite effects from sulfatide. The identification of new ligands inducing altered functional activity of type II NKT cells could be of great interest for developing new anti-tumor immunotherapies.
Antigen-presenting cells lead to severe T cell exhaustion in glioblastoma
Authors: Polania Jessica Waibl , Woroniecka Karolina , Sanchez-Perez Luis , Fecci Peter 
Published: January 2023

Abstract
Glioblastoma (GBM) is the most common primary brain cancer in adults and remains universally lethal. Median survival remains a bleak 15–17 months from time of diagnosis, calling for new therapeutic strategies. Current immunotherapeutic efficacy continues to be hindered by the robust immunosuppression of the GBM tumor microenvironment (TME). T cells, critical for tumor clearance, are particularly affected and many take on an exhausted phenotype within the tumor. We have previously observed significantly worse exhaustion in models of glioma relative to other solid tumor models, suggesting a TME-specific phenomenon. In an orthotopic murine model of GBM, T cell exhaustion was identified using surface expression of inhibitory ligands, PD1, TIM3, and LAG3. Functional status was examined using intracellular flow cytometry for IFNy, TNFa, and IL-2. We consistently observed T cell exhaustion among antigen-experienced tumor-specific CD8+ T cells, suggesting that tumor-imposed exhaustion is dependent upon T cells encountering their antigen. It remains undetermined, however, which cell within the GBM microenvironment provokes a uniquely severe T cell exhaustion phenotype. Using CRISPR-Cas9 gene editing, we modified tumor cells to lack antigen-presentation capacities and revealed persistence of T cell exhaustion. In contrast, when the same capacity was removed from infiltrating, hematopoietic cells, T cells in the GBM microenvironment were less exhausted and retained their function. This suggests antigen-presenting cells (APC) are critical for T cell exhaustion within GBM. Our findings uncover an important role for APCs in eliciting T cell exhaustion, which will provide novel interactions for targeted immunotherapies.
Antigen-cross presentation promotes development of terminally differentiated CD8 T cells in young individuals
Authors: Moustaki Ardiana , Crawford Jeremy Chase , Alli Shanta , Zamora Anthony E , Fan Yiping , Boi Shannon , McDonald Natalie MN , Thomas Paul Glyndwr , Pappo Alberto , Dyer Michael , Stewart Elizabeth , Federico Sara , Youngblood Benjamin A 
Published: January 2023

Abstract
Cancer immunotherapeutic approaches that rely on endogenous T cell responses have shown limited success in children, a pattern attributed to the low mutational burden of pediatric tumors. Here, we report that CD8 T cells isolated from a diverse set of pediatric solid tumors are enriched for an antigen-experienced phenotype. The limited ability of immune checkpoint blockade therapy (ICBT) to trigger anti-tumor responses in children, despite the presence of activated CD8 T cells, prompted us to explore alternative underlying mechanisms restricting anti-tumor responses. Using a novel mouse tumor model that expresses a well-characterized epitope coupled to an mCherry marker, we identified antigen cross-presentation by tumor infiltrating myeloid cells as a key regulator of CD8 T cell effector function in tumors. Strikingly, age-related changes in the TME resulted in a skewing of the CD8 T cell effector fate toward a terminally differentiated state in young tumor-bearing mice. Profiling of tumor infiltrating antigen presenting cells by scRNAseq revealed a proinflammatory M1 macrophage polarization in young tumors but a predominant M2 “wound healing” response in adult tumors. Consistent with our mouse findings, analysis of immune infiltrates from human pediatric solid tumors revealed a strong correlation between the expression of PDL1 on myeloid cells and enrichment of tumor-associated CD8 T cells with an exhaustion phenotype. Collectively, these data indicate that the “young” microenvironment of an actively developing tissue/individual contributes to the generation of an immune response skewed towards a terminally differentiated state with limited plasticity, thus narrowing the window for immunotherapeutic interventions.
Elucidating the Role of HDACs in T Cell Biology and Comparing Distinct HDAC Inhibitors in Augmenting Responses to Cancer Immunotherapy
Authors: Triplett Todd A , Holay Nisha , Kottapalli Srividya , VanDenBerg Carla , Capasso Anna 
Published: January 2023

Abstract
Histone deacetylases have canonically been known to suppress gene expression via epigenetic mechanism involving modulating histone acetylation status. While HDAC inhibitors are currently used in the clinic to treat cancer, their mechanism of action is not clear as acetylation is now known to control myriad cellular processes, such as protein stability of signaling. Importantly, it is now recognized that tumor regression during HDACi monotherapy relies on CD8+ T cells and is synergistic with immunotherapy (IMT). However, most previous studies have found HDACi to be detrimental to T cells. Thus, it is still unknown if the increase in anti-tumor immune responses is mediated through directly affecting tumor immunogenicity, T cell effector function, or both. Given the role of epigenetics in T cell differentiation, we first determined their effect on distinct populations. Rather than an expected global increase, all cytokines evaluated (IL-2, IFNy, IL-5, IL-17A) were downregulated during HDACi treatment except for TNFa, which drastically increased. Examination of the distinct subsets revealed that this effect was mostly confined to naïve T cells compared to memory. This suggests acetylation differentially affects cytokine production by distinct T cell subsets. As multiple inhibitors with varying specificities are used in the clinic, understanding their impact on T cell function could identify rational combinations. In support of this, our results demonstrate drastic differences between inhibitors on their effects on T cell cytokine production and survival. Future studies will determine the role of specific HDACs in these functions and compare inhibitors on immune infiltrates in the tumor and ability to augment immunotherapies.
CD28 and glycogen synthase kinase-3 (GSK-3) inhibitor combination therapy generates tumor infiltrating T-cells (TILs) with a reversal of markers for T-cell exhaustion
Authors: Kazanova Alexandra , Krueger Janna , Rudd Christopher E. 
Published: January 2023

Abstract
Immune checkpoint blockade (ICB) of inhibitory receptors such as PD-1 has revolutionized the treatment of cancer. ICB is dependent on CD28 co-receptor expression introducing the question of whether the positive co-receptor could be targeted for the reversal of T-cell exhaustion in immunotherapy. We previously showed that the serine/threonine kinase glycogen synthase kinase-3 (GSK-3) is a central regulator of programmed cell death-1 (PD-1) transcription (Taylor et al., 2016, Immunity) and that small molecule inhibitors of GSK-3 (GSK-3 SMI) are as effective as anti-PD-1 blocking antibody in the control of tumor growth (Taylor et al., 2018, Cancer Research). In this study, we now show that anti-CD28 can synergise with GSK-3α/β inhibitors to regress tumors that are resistant to anti-PD-1 immunotherapy. Combination therapy showed responses in &gt;55% mice with an overall reduction in tumor volume of 70% in responders compared to control mice (182 mm3 vs. 611 mm3). Flow cytometry analysis of tumor infiltrating lymphocytes (TILs) shows that, while non-treated mice were enriched with TOX+TIM3+PD1+CD8+, combination therapy increased tumor infiltration of TOX-negative CD8 T cells with TIM3-PD1int CD8 phenotype. Remarkably, this reversal involved only a single injection of anti-CD28 (PV-1) and GSK-3 SMI (SB415286). These results showed that CD28/GSK-3 combination therapy greatly reduced TOX, TIM-3 and PD1markers indicative of exhaustion. Our findings offer a small molecule approach for synergy with anti-CD28 that leads to an increase tumor infiltration with TOX-negative CD8 T cells that have decrease expression of inhibitory receptors.
Effects of aging on immunosenescence and checkpoint inhibitor efficacy in a C57BL/6J syngeneic model
Authors: Yang Jiwon , Schile Andrew , Cheng Mingshan , Keck James G 
Published: January 2023

Abstract
Aging is a complex dynamic process that leads to increased susceptibility to various diseases including cancer. Immunosenescence is a state of aging-related gradual deterioration of the immune system in the elderly. T cells are a major part of an adaptive immune system and orchestrate the cellular immune response. However, only limited studies were conducted on how aging, immunosenescence, and cancer therapy affect each other. Our goals in this study were to establish a mouse model that shows immunosenescence and to study how the immunosenescence affects checkpoint inhibitor efficacy in a C57BL/6J syngeneic model. Young (7 weeks of age), mid-aged (54 weeks) and aged (76–78 weeks) female mice were used. The spleen and blood were collected from the naïve mice and analyzed using a flow cytometer. In both samples, we found a decrease in naïve CD4+ and CD8+ T cells in mid-aged and aged mice compared to the young counterparts, which is a sign of immunosenescence. Compared to young mice naïve aged mice showed increased regulatory T cells (Tregs) in the spleen without a significant difference in the blood. When the mice were inoculated with MC38 tumors and treated with isotype control or anti-PD1 antibody for 3 weeks, anti-PD1 treatment was found to significantly slow down tumor growth in all age groups but was the most efficacious in aged mice. Anti-PD1 treatment increased T cell infiltration into the tumor with the greatest effect observed in the mid-aged group. In conclusion, we have established a preclinical mouse model that shows immunosenescence, and immunosenescence is a possible cause of the difference in response to the checkpoint inhibitor in the elderly.
ANT2 (SLC25A5) balances the pro-apoptotic vs. effector signals of Bim in CD8 T cells
Authors: Gicobi Joanina K , Yu Xiatong , Dronca Roxana S. , Liu Xin , Barham Whitney , Wen Ti , Zhang Henan , Zhu Mojun , Harrington Susan M. , Vianzon Vianca , Hirdler Jacob , Dong Haidong 
Published: January 2023

Abstract
The immune response to anti-PD-1 therapy in cancer patients is not completely defined due to lack of reliable biomarkers that can determine T cell function. Bim, a member of the Bcl-2 family, was recently identified as a downstream signaling molecule in the PD-1 pathway. Within CD8 T cells, Bim appears to have a dual function, and can be pro-apoptotic or promote effector activity. Our clinical data has shown that high levels of Bim in CD8 T cells are predictive of response to anti-PD-1 therapy in metastatic melanoma whereas in colorectal cancer, a low level of Bim is associated with treatment response. Thus, we sought to determine what molecular partners might influence the role of Bim. Using co-immunoprecipitation, high resolution microscopy and FRET we identified ANT2 (Adenine Nucleotide Translocase 2), an inner membrane protein of mitochondria, as a protein that interacts with Bim. Accordingly, we found CD8 T cells with low and high mitochondrial potential demonstrated different ANT2/Bim ratios, and a low ANT2/Bim ratio was present in effector T cells with low mitochondrial potential but high cytotoxic activity. Given the pro-survival function of ANT2, our results indicate that ANT2 may balance the pro-apoptotic and effector roles of Bim in mitochondria in order to preserve effector T cells before contraction. Understanding the molecular mechanism of Bim and ANT2 interactions in CD8 T cells may provide a novel marker to predict clinical response to anti-PD-1 therapy.
Oral administration of a self-assembling nanofiber-based vaccine generates neutralizing antibodies against HIV and expands CD8+ memory T cell populations
Authors: Files Megan A , Rudra Jai S , Endsley Mark 
Published: January 2023

Abstract
Human immunodeficiency virus (HIV) is the world’s sixth leading cause of death. Antiretroviral therapy (ART) is the current standard of treatment, but issues of accessibility and compliance pose additional hurdles. In 2018, there were 37.9 million people living with HIV, but only 62% were on ART. The development of a successful vaccine is imperative to combat the transmission of HIV, of which one of the major goals is to generate broadly neutralizing antibodies (bnAb). The membrane-proximal external region (MPER) of gp41 in the envelope glycoprotein (Env) is a largely conserved motif, a key player in fusion, and the target of bnAb in a subset of patients with long-term HIV infections. We previously demonstrated the efficacy of a nanofiber vaccine platform as evidenced by the generation of both strong humoral and cell-mediated responses against viral targets, and enhanced protection against infection. In recent studies, we observed that serial oral dosing of nanofibers (NF) bearing the MPER epitope (NF-MPER) in mice correlated with a significant increase in serum and mucosal neutralizing antibodies against HIV. The NF-MPER vaccine also augmented CD8+ memory T cell populations in the colon, which were further characterized as effector memory T cells (TEM), using surface marker phenotypes (CD69+/− CD103+ CD44+ CD62Llo). Additionally, we observed significant expansion of CD8+ TEM pools in the spleen, a reservoir for HIV, a subset of which were similar to tissue resident memory T cells (TRM) seen in human elite controllers. These results suggest that oral immunization with a NF-based vaccine elicits the production of bnAb and enhanced CD8+ TEM populations, in non-lymphoid and lymphoid tissues, that are necessary for a successful HIV vaccine.
Bacteria-like particle bead complexes as an immunostimulatory platform for high-throughput vaccine antigen capture and delivery
Authors: Jan Sharon , Felgner Jiin , Assis Rafael , Davies Jenny , Albin Tyler , Nakajima Rie , Jasinskas Algis , Davies David Huw , Felgner Philip 
Published: January 2023

Abstract
Vaccines are cited as the most cost-effective public health measure in controlling infectious diseases. Scalable and high-throughput platforms can accelerate vaccine discovery, which reduces the burden on human life, morbidity and health system resources. To expedite the antigen identification and production process during the first steps of vaccine development, we have developed a highly efficient bead capture system that allows for rapid antigen capture and delivery. This technology can be used in conjunction with protein microarrays to swiftly screen and identify antigens as potential vaccine candidates.
Model antigens from Coxiella burnetii, a known biothreat and the etiological agent of Q fever, were chosen based on previous protein microarray data and expressed from plasmids containing a His-tag in a cell-free expression system. To demonstrate proof-of-concept, we used polystyrene beads with tris-NTA linkers to capture antigens from the mixture. The resulting antigen-conjugated beads were administered directly to C57BL/6 mice individually, multiplexed, and/or with an adjuvant cocktail of MPLA/CpG/squalene-in-water emulsion. Sera collected at regular intervals were screened against protein microarrays to monitor the dynamics and isotypes of the antibody response. Cytokine levels were assessed in antigen recall assays on splenocyte cell cultures through ELISPOT or by bead-based cytometric assay. Here we observed robust, durable and antigen-specific T cell and antibody responses. IgG isotypes and cytokine levels revealed that including adjuvants tuned the Th1/Th2 responses to a balanced profile. In vitro studies are currently underway to determine antibody functionality and neutralization potential.
Endogenous dendritic cell subset cDC1 mediates DC vaccine immunity against gamma herpesvirus in syngeneic BMT recipients
Authors: Zhou Xiaofeng , Chadwick Matthew M. , Chan Paul R. , Buonavolonta James J. , Wilke Carol A. , Moore Bethany B. 
Published: January 2023

Abstract
Dendritic cell (DC) vaccines are a promising immunotherapy for viral infections and cancers, however the mechanisms underlying their action are still not clear. The objective of this study is to understand how DC vaccines stimulate the expansion of cytotoxic T lymphocytes (CTLs) against gamma herpesvirus in bone marrow transplant (BMT) recipients. Herpesviruses commonly reactivate after transplantation of hematopoietic cells in patients and cause high mortality and morbidity. Similarly, infections with murine gamma herpesvirus 68 (MHV-68), a mouse homolog of Epstein-Barr virus, after syngeneic BMT in mice cause severe pulmonary fibrosis and pneumonitis.
We prepared DC vaccines by sorting CD11c+ cells from the lungs at 3 days post infection (dpi) with MHV-68. We administered DC vaccines i.v. to BMT mice one day before infection with MHV-68. CTLs of the lung, spleen and mediastinal draining lymph nodes were analyzed by flow cytometry at 7 dpi. Lung sections were prepared at 21 dpi for histology analysis.
Adoptive transfer of the DC vaccine stimulates the expansion of viral specific CD8 T cells in MHV-68 infected syn-BMT mice at 7 dpi, and protects them from pneumonitis and fibrosis at 21 dpi. Surprisingly, none of the transferred conventional DC (cDC) subsets, nor migration into draining lymph nodes, nor MHC class I or class II molecule expression are essential for the DC vaccine to activate CD8 T cells in BMT mice. Instead, DC vaccination of BMT mice lacking endogenous cDC1s resulted in reduced CD8 T cells and failed to suppress lytic viral infection.
Our results suggest that endogenous cDC1s in BMT mice mediate DC vaccine immunity against gamma herpesvirus. We have thus revealed a previously unknown pathway of DC vaccination.
Polyanhydride-based RSV prefusion F nanoparticle vaccine establishes lasting protection mediated by humoral and cellular immune responses
Authors: Stephens Laura , Ross Kathleen A. , Hartwig Stacey M. , McLellan Jason S. , Narasimhan Balaji , Legge Kevin L. , Varga Steven M. 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children, accounting for nearly 7% of deaths in those less than one year of age. Despite the morbidity, mortality, and high economic burden caused by RSV worldwide, no licensed vaccine is available. Thus, there is a critical need for a safe, and highly efficacious vaccine to prevent RSV-induced disease. We have developed a novel vaccine utilizing a prefusion-stabilized variant of the RSV fusion (F) protein (DS-Cav1) encapsulated within polymer nanoparticles with a CpG1668 oligodeoxynucleotide adjuvant. The prefusion conformation of RSV F allows for better exposure of the major antigenic site, termed site Ø, a primary target of neutralizing antibody responses in human serum. To evaluate this vaccine candidate, BALB/c mice were vaccinated intranasally and then boosted 4 weeks later. Vaccination with the RSV nanovaccine significantly ameliorated weight loss and pulmonary dysfunction compared to unvaccinated mice in response to an RSV challenge. Additionally, vaccinated mice significantly reduced virus titers in the lungs as early as day 2 post-infection. Protection from disease and enhanced viral clearance remained until 100 days post prime vaccination. Vaccination also established an elevated number of tissue-resident memory CD4 and CD8 T cells in the lungs. The vaccine-induced protection was mediated by both humoral and cellular immune responses, as serum transfers from vaccinated mice provided only partial protection from weight loss and pulmonary dysfunction. Based on the robust immune response elicited and the high level of protection observed, our prefusion RSV F nanoparticle formulation may be a promising RSV vaccine candidate.
Vaccine-induced protection against intrarectal AIDS virus transmission in the absence of anti-Env antibodies mediated by trained innate immunity
Authors: Berzofsky Jay A , Keele Brandon F , Miller Christopher J , Sui Yongjun 
Published: January 2023

Abstract
Although anti-Envelope antibodies have been viewed as the primary means of protection against SIV or SHIV acquisition, we have found in two distinct vaccine studies that protection against intrarectal SHIV or SIV acquisition in repeated low-dose challenge can be achieved in the absence of anti-Env antibodies (Vaccine efficacy = 44% in one study and 81% in the other). Specific CD8+ T cells were induced but did not correlate with protection, and in one of the studies, CD8+ depletion experiments excluded any CD8-dependence of the protection. Rather, protection correlated with protective myeloid cells and inversely with suppressive myeloid-derived suppressor cells. Trained innate immunity of monocytes lasting at least 7 weeks after vaccination was confirmed by demonstrating the ability of monocytes from vaccinated animals to produce more IL-6, TNFa and/or Mip1a when re-exposed to virus than those from control animals. This trained innate response correlated with the number of exposures required to achieve infection. Trained innate immunity has been shown to be mediated by epigenetic changes in monocytes, and indeed, we have been able to detect such epigenetic changes. Thus, vaccine protection against rectal acquisition of SHIV or SIV can be achieved in the absence of anti-Env antibodies and even of CD8+ T cells, and can be mediated by trained innate monocyte immunity. These findings suggest a new mode of vaccine protection that needs to be investigated in future AIDS vaccine clinical trials.