bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Vaccine-Specific T Cell Frequency After Peptide-Based Vaccination Correlates with Increased Susceptibility to In Vitro Stimulation But Does Not Lead to Tumor Regression
Authors: Lee Kang-Hun , Wang Ena , Nielsen Mai-Britt , Wunderlich John , Migueles Steven , Connors Mark , Steinberg Seth M. , Rosenberg Steven A. , Marincola Francesco M. 
Published: January 2023

AbstractAlthough in vitro sensitization assays have shown increased melanoma Ag (MA)-specific CTL reactivity after vaccination with MA peptides, clinical responses have been uncommon. This paradox questions whether data obtained from the in vitro stimulation and expansion of T cells lead to an overestimation of the immune response to vaccines. Using HLA/peptide tetramer (tHLA), we enumerated MA-specific T cell precursor frequency (TCPF) directly in PBMC from 23 melanoma patients vaccinated with gp100:209–217(210M) (g209–2M) peptide. Vaccine-specific TCPF was higher in postvaccination PBMC from seven of seven patients treated with peptide alone and four of five patients treated with peptide plus IL-12 (range of postvaccination TCPF, 0.2–2.4% and 0.2–2.5%, respectively). The increased TCPF correlated with enhanced susceptibility to in vitro stimulation with the relevant epitope. Paradoxically, no increase in postvaccination TCPF was observed in most patients who had been concomitantly treated with IL-2 (1 of 11 patients; range of postvaccination TCPF, 0.02–1.0%), a combination associated with enhanced rates of tumor regression. The lack of increase in TCPF seen in these patients corresponded to inability to elicit expansion of vaccine-specific T cells in culture. This study shows that a peptide-based vaccine can effectively generate a quantifiable T cell-specific immune response in the PBMC of cancer patients, though such a response does not associate with a clinically evident regression of metastatic melanoma.
HLA-E and HLA-G Expression on Porcine Endothelial Cells Inhibit Xenoreactive Human NK Cells Through CD94/NKG2-Dependent and -Independent Pathways
Authors: Sasaki Hitomi , Xu Xiao-Chun , Mohanakumar T. 
Published: January 2023

Abstract
Human NK cells contribute a significant role to host defense as well as xenogeneic cytotoxicity. Previous studies using human 721.221 cell line have shown that peptides derived from the leader sequence of the HLA-G binds and up-regulates the surface expression of HLA-E molecules, which was considered to consequently provide negative signals to human NK cells. However, the direct role of HLA-G in inhibiting human NK cells remains controversial. In this study, we showed that the expression of HLA-G or HLA-E in porcine endothelial cells directly protected sensitive porcine cells from human NK cell-mediated xenogeneic cytotoxicity. Ab blocking assays using F(ab′)2 of the HLA class I-specific mAb PA2.6 indicated that the protection was directly mediated by the expression of HLA-G and HLA-E on the porcine cells. The HLA-E-mediated protection was blocked by anti-human CD94 Ab. In addition, the engagement of HLA-E lead to the phosphorylation of the CD94/NKG2 complex and the recruitment of SH2 domain-containing protein phosphatase 1 (SHP-1) to the complex. Therefore, HLA-E protected porcine cells from xenoreactive human NK cells through a CD94/NKG2-dependent pathway. In contrast, HLA-G inhibited human NK cells in the absence of CD94/NKG2 phosphorylation or SHP-1 recruitment, and the inhibition was not blocked by anti-CD94 Ab. Therefore, HLA-G protected porcine cells from human NK cells through a CD94/NKG2-independent pathway. These results demonstrated that both HLA-E and HLA-G could directly inhibit human NK cells in the absence of other endogenous HLA class I molecules. These results also have practical implications in preventing xenograft rejection mediated by human NK cells.
Anti-Double-Stranded DNA Antibodies and Immunostimulatory Plasmid DNA in Combination Mimic the Endogenous IFN-α Inducer in Systemic Lupus Erythematosus
Authors: Vallin Helena , Perers Anders , Alm Gunnar V. , Rönnblom Lars 
Published: January 2023

AbstractPatients with systemic lupus erythematosus (SLE) have increased blood levels of IFN-α, which correlate to disease activity. We previously identified an IFN-α-inducing factor (IIF) in the blood of SLE patients that activated the natural IFN-α-producing cells in cultures of normal PBMC. The SLE-IIF contained DNA and IgG, possibly as small immune complexes. In our study, we demonstrated that SLE-IIF correlated to the presence of anti-dsDNA Abs in patients and contained anti-dsDNA Abs as an essential component. Purified anti-DNA Abs or SLE-IgG caused only a weak IFN-α production in cultures of normal PBMC in the presence of costimulatory IFN-α2b. However, they converted the plasmid pcDNA3, which itself induced no IFN-α production in PBMC, into an efficient IFN-α inducer. A human monoclonal anti-ss/dsDNA Ab had the same effect. This IFN-α-inducing activity of the plasmid was abolished by methylation, suggesting that unmethylated CpG DNA motifs were important. Like IIF in SLE serum, the combination of SLE-IgG and pcDNA3 appeared to stimulate IFN-α production in natural IFN-α-producing cells, a unique cell population resembling immature dendritic cells. The IFN-α production was greatly enhanced by IFN-α2b and IFN-β, and for SLE-IIF it was also enhanced by GM-CSF but inhibited by IL-10. We have therefore identified a new function of DNA-anti-DNA Ab complexes, IFN-α induction, that might be important in the pathogenesis of SLE.
Virus-specific production of IFN-gamma and IL-17 by CD4+ T cells from patients infected with West Nile virus (128.18)
Authors: Latham Lesley  P , Bramson Jonathan 
Published: January 2023

Abstract
The mechanisms that underlie the pathology of neuroinvasive West Nile virus (WNV) remain unknown. The goal of this study was to characterize the CD4+ T cell response to WNV in individuals with neuroinvasive and non-neuroinvasive symptoms. WNV-infected subjects were screened for CD4+ T cell reactivity with peptide pools derived from a library spanning the WNV polyprotein. Virus-specific CD4+ T cells were directed primarily against E, NS1, and NS3. Most WNV-specific CD4+ T cells produced IFN-γ. Surprisingly, IL-17 production was primarily associated with NS3-reactive cells. Single cell analysis revealed three distinct populations: IFN-γ+/IL-17-, IFN-γ+/IL-17+, IFN-γ-/IL-17+. Preliminary analysis suggests that elevated frequencies of virus-specific CD4+ T cells producing both IFN-γ and IL-17 are associated with protection against WNV neuroinvasive disease. This work was funded by a contract from NIAID (N01-AI-40066).
Role of lipid structure in the humoral immune response in mice to covalent lipid-peptides derived from the membrane proximal region of HIV-1 gp41 (128.2)
Authors: Watson Douglas , Szoka Francis 
Published: January 2023

Abstract
The membrane proximal region (MPR) of HIV-1 gp41 is a desirable target for development of a vaccine that elicits neutralizing antibodies since the patient-derived monoclonal antibodies, 2F5 and 4E10, bind to MPR and neutralize primary isolates. The 2F5 and 4E10 antibodies cross-react with lipids and structural studies suggest that MPR immunogens may be presented in a membrane environment. We hypothesized that covalent attachment of lipid anchors would enhance the immunogenicity of MPR-derived peptides presented in liposomal bilayers. In a comparison of eight different lipids conjugated to an extended 2F5 epitope peptide, a sterol, cholesterol hemisuccinate (CHEMS), was found to promote the strongest anti-peptide immune response in BALB/C mice. Differences in immunogenicity amongst the conjugates could not be explained solely by any one factor, such as: the presence of a phosphate in the lipid, membrane partitioning of the lipid anchor or peptide secondary structure. Conjugation to CHEMS also rendered a 4E10 epitope peptide immunogenic. Finally, conjugation of CHEMS to a helically constrained immunogen spanning both epitopes elicited antibodies that bound to each of the individual 4E10 and 2F5 epitopes as well as to an oligomeric recombinant envelope protein. Further research into the mechanism of how structure influences the immune response to the MPR may lead to immunogens that could be useful in prime-boost regimens for focusing the immune response in an HIV vaccine.
Quantitative bioimaging of the WR and IHDJ vaccinia virus dissemination and the effects of prophylactic immunoglobulin treatments (128.23)
Authors: Zaitseva Marina , Meseda Clement , Kapnick Senta , Manischewitz Jody , Nelson Henriette , Merchlinsky Michael , Weir Jerry , Golding Hana 
Published: January 2023

Abstract
Protection from lethal challenge with recombinant WR-Luciferase (TK+) and IHDJ-Luciferase (TK+) vaccinia viruses (VV) was studied by detecting firefly luciferase activity in live Balb/c mice using IVIS technology. High correlation (R2=0.8-0.9) was observed between viral loads in the organs measured by plaque assay and bioluminescence. WR- and IHDJ VV that generate predominantly IMV and EEV forms, respectively, induced lethality within 8-10 days after intranasal challenge with 10^5 pfu yet their dissemination and susceptibility to therapies differed. WR persisted at significantly higher levels than IHDJ at the site of challenge, while IHDJ replicated better in the liver in agreement with the roles of EEV and IMV in host dissemination and inter host transmission. Vaccinia immunoglobulin (VIGIV) at Day -2 completely protected from the WR but not from IHDJ challenge. Sym002, a mixture of 26 human anti-vaccinia mAbs (Symphogen, Denmark), completely protected from WR challenge at 1000 lower dose than VIGIV, but only partially protected from IHDJ. Protection by Sym002 correlated with a significantly reduced flux at the nasopharyngeal area and in the liver. Importantly, our study detected significantly higher bioluminescence at the nasopharyngeal area and in the lungs in non-survivors than in survivors suggesting that bioimaging can substitute for lethality endpoint for evaluation of anti-smallpox treatments.
CD8+ T cell inflation and differentiation during persistent CMV infection is independent of viral replication (128.29)
Authors: Snyder Christopher M , Cho Kathy S. , Bonnett Elizabeth L , Hill Ann B. 
Published: January 2023

Abstract
Murine cytomegalovirus establishes systemic, chronic infection in mice and drives the dramatic accumulation of virus-specific CD8+ T cells over time. Though the virus is thought to achieve true latency, a small amount of persistent viral replication may occur as well. We have been investigating the development and maintenance of the inflationary CD8+ T cells that result from chronic infection. These cells remain functional, but appear to be differentiated into effector cells by repeated antigen stimulation. We have recently shown that most of these T cells do not divide during chronic infection and have a short life span in circulation. Dying cells can be replaced by newly primed T cells. However, further evidence suggests that the majority of the short-lived T cells in circulation are replaced by the progeny of clones primed early infection. Thus our data suggest that the inflationary T cells are maintained by continuous production of short-lived, effector T cells from a memory population. We had assumed that this equilibrium would be dependent on persistent viral replication to drive the differentiation of new T cells. However, blocking viral replication with anti-viral drugs or infecting with a replication deficient virus still resulted in CD8+ T cell inflation and differentiation. These data suggest that viral persistence and CD8+ T cell accumulation does not require viral replication.
Specificity-dependent cross reactive capacity of HIV-specific CTLs (128.9)
Authors: Motozono Chihiro , Takiguchi Masafumi , Ueno Takamasa 
Published: January 2023

Abstract
Although CTLs having a potent cross reactive capacity toward HIV variants is important for control of viral replication, what inherent characteristics of antigenic peptides influence it remains elusive. We addressed this issue based on immunodominant HLA-B35-restricted CTLs specific for 2 overlapping Nef epitopes, VY8 (VPLRPMTY) and RY11 (RPQVPLRPMTY). The TCR analysis of CD8 T cells from 6 HLA-B35+ HIV-infected subjects showed that the majority of VY8-specific cells had a same TCR-α variable segment whereas RY11-specific cells had diverse TCR clonotypes. We then transduced 6 representative pairs of TCR-αβ chains specific for VY8 and RY11 into TCR-deficient T cells and analyzed their individual fine specificity toward an array of variant peptides. Each RY11-specific TCR retained its reactivity toward lager numbers of variant peptides than any VY8-specific TCRs, indicating the highly cross-reactive nature of individual RY11-specific TCR clonotypes. Moreover, unlike VY8-specific TCRs, each individual RY11-specific TCR had the ability to recognize different peptide variants. Taken together, the overall cross reactive capacity of the oligoclonal CTL populations specific for RY11 is more potent than those specific for VY8, highlighting the specificity-dependent cross reactive capacity of antiviral CTL responses.
Select human anthrax protective antigen (PA) epitope-specific antibodies provide protection from lethal toxin challenge in vitro and in vivo (129.16)
Authors: Crowe Sherry R , Ash Linda L , Engler Renata J M , Ballard Jimmy D , Harley John B , Farris A Darise , James Judith A 
Published: January 2023

Abstract
The release of Bacillus anthracis spores can cause significant morbidity and mortality and an effective vaccine as well as directed immunotherapeutics are needed. The currently licensed vaccine requires six primary vaccinations, annual boosters, and has been associated with serious adverse events. Thus there is increasing interest in developing an improved vaccination strategy which can generate lasting protective immunity with reduced vaccinations. This study seeks to identify the major humoral targets of B. anthracis that provide protection. To this end, plasma was obtained from two hundred vaccinated individuals and thirty unvaccinated controls. Ninety-five percent of all vaccinated individuals had anti-protective antigen antibodies and these antibodies correlated with in vitro protection against lethal toxin. Utilizing overlapping decapeptides, we identified common antigenic regions within those individuals with high toxin neutralizing activity. Epitope-specific antibodies directed against three of these regions were isolated and were able to mediate protection in vitro and in a mouse model of in vivo lethal toxin challenge. Identification of common, protective, peptide-specific humoral immune responses provide key information for further immunotherapeutic and vaccine development. NIAID: 5U19AI062629
Human CD1-restricted T cells from leprosy lesions display distinct and complementary functions in comparison to MHC-restricted T cells (129.28)
Authors: Sieling Peter A , Hunger Robert , Modlin Robert L 
Published: January 2023

Abstract
CD1 proteins are a family of MHC-like polypeptides that present lipids rather than peptides to T cells. We have examined the role of CD1-restricted T cells in the context of mycobacterial infection since T cells mediate host defense against mycobacterial infection and the mycobacterial envelope contains a high concentration of lipids. To determine whether CD1 and MHC-restricted T cells represent distinct or complementary functional populations, T cells derived from lesions of leprosy patients were activated through their CD3 receptor, gene expression patterns were evaluated, and protein expression measured using ELISA. CD1- and MHC-restricted T cells exhibited a similar profile of cytokine production, particularly Th1 and Th2 cytokines. In contrast, the two populations of T cells were more distinct in their chemokine expression. CD1-restricted T cells produced CCL20, which shares a receptor with antimicrobial β-defensins; in contrast, MHC-restricted T cells produced CXCL10, a chemokine whose receptor is expressed on activated Th1 T cells. Our data reveal both complementary and distinct functions of CD1- and MHC-restricted T cells and suggest that CD1-restricted T cells function in the rapid response to microbial infection in contrast to MHC-restricted T cells, which regulate adaptive immunity.
Generation of non-specific and specific B cell responses to the Trypanosoma cruzi B cell Mitogen TcPRAC (129.4)
Authors: Bryan Marianne A , Norris Karen A 
Published: January 2023

Abstract
Acute Trypanosoma cruzi infection results in polyclonal B cell activation and a delay of specific humoral immunity. TcPRAC, a T. cruzi B cell mitogen may contribute to this dysfunction. Stimulation of splenocytes with TcPRAC induced B cell proliferation, secretion of IgM and IL-10, and up-regulation of CD69 and CD86. During experimental infection, TcPRAC specific IgG was undetectable when responses to other T. cruzi antigens developed. Genetic immunization generated TcPRAC specific IgG without apparent B cell dysfunction. TcPRAC immune sera inhibited TcPRAC-induced B cell proliferation in vitro. These results suggest that TcPRAC may contribute to delayed specific antibody development during experimental infection by non-specifically activating B cells and inducing IL-10 and non-specific IgM secretion. In addition, we demonstrated that while TcPRAC was not antigenic during experimental infection, delivery of TcPRAC via genetic immunization elicited specific antibodies. Further experiments will analyze the effect of TcPRAC immunization and neutralization on the generation of T. cruzi specific humoral immunity during early acute phase infection.
Distinct bacterial genes influence on Th1 and Th2 responses during Listeria monocytogenes infection (129.6)
Authors: Kanoh Makoto , Shen Hau , Maruyama Saho , Matsumoto Akira , Shinomiya Hiroto , Cossart Pascale , Goebel Werner , Asano Yoshihiro 
Published: January 2023

Abstract
CD4+T cells are divided into four types according to the set of lymphokines they produce, i.e., Th1 cells, Th2 cells, Th17 cells and Treg cells. The differentiation process of T cells into each subset is controlled by cytokines produced during the innate immune response in its early phase. We showed a two-step induction mechanism for differentiation of T cell subsets during pathogenic infection. The first step is induced by the basal function of dendritic cells and is antigen-independent and antigen-nonspecific. This step affects the precursor frequency of Th1 and Th2 T cell subsets. In the present study, we investigated bacterial genes, which involved in the host-pathogen interaction and is required for the initiation of T cell subset differentiation in the early phase of pathogenic infection. We demonstrate that TLR2 and MyD88 molecules are not essentially required for the induction of Th1 cell differentiation during Listeria infection, although those molecules are required for early inflammatory gene induction. It is also demonstrated that genes involved in the expression of the pathogenisity of Listeria are not required for the induction of Th1 cell subset. Finally, it is demonstrated that the induction of Th1 cell subset and the inhibition of Th2 cell subset induction are separate phenomenon and are mediated by distinct genes carried by Listeria genome.
Role of IL-17 receptor alpha (IL-17Rα) signaling in Helicobacter pylori-host interactions (129.7)
Authors: Algood Holly M Scott , Allen Shannon Sedberry , Washington Kay , Peek Richard , Cover Timothy L 
Published: January 2023

Abstract
H. pylori persistently colonizes the human stomach and induces a gastric mucosal inflammatory response. To investigate a potential role of Th17 responses in modulating H. pylori-host interactions, wild-type C57Bl/6 (WT) mice and IL-17Rα-/- mice were orogastrically infected with H. pylori. By 3 months post-infection, H. pylori colonization density was significantly higher in IL-17Rα-/- mice than in WT mice. Gastric inflammation, assessed by histologic staining, was significantly more severe in H. pylori-infected IL-17Rα-/- mice than in infected WT mice. FACS analysis indicated that infected IL-17Rα-/- mice had significantly higher numbers of gastric CD4+ cells and B cells and significantly lower numbers of gastric neutrophils, compared to infected WT mice. IFNγ, IL-4, and multiple chemokines (KC, LIX, MIP2) were expressed at significantly higher levels in stomachs of infected WT mice than in infected IL-17Rα-/- mice. In contrast, gastric IL-17 transcript levels were 9-fold higher in infected IL-17Rα-/- mice than in infected WT mice. Primary gastric epithelial cells (PGEC) harvested from WT mice expressed KC and GM-CSF in response to recombinant IL-17, whereas cells from IL-17Rα-/- mice did not. PGECs from both WT and IL-17Rα-/- mice expressed IL-6, IL-1β, and MIP2 in response to IL-17. These data indicate that IL-17Rα signaling has an important role in modulating the gastric mucosal response to H. pylori.
CD8+ T cells clear human intestinal Cryptosporidium infection through cytotoxic granule release (129.8)
Authors: Pantenburg Birte , Castellanos-Gonzalez Alejandro , Dann Sara M. , Connelly Rhykka L. , Lewis Dorothy E. , Ward Honorine D. , White, Jr Arthur Clinton 
Published: January 2023

Abstract
INTRODUCTION: A key factor in the human adaptive immune response towards Cryptosporidium, associated with resistance to infection, is IFNg. Its function and the cells involved in clearing the parasite from the human intestinal epithelium are unknown. As CD4+ and CD8+ cells produce IFNg after re-stimulation with parasite antigens in vitro we hypothesized that CD8+ cells contribute to control of the infection. METHODS: We studied CD8+ cell cytotoxicity by 51Chromium (51Cr) release assay and fluorescent microscopy. Targets were 51Cr labeled CaCo2 cells. Effectors were CD8+ cells isolated from peripheral blood mononuclear cells of sensitized or naïve volunteers after 6 day culture with IL-2 + IL-15 +/- C. hominis glycoprotein 15 (gp15). RESULTS: Gp15 stimulated CD8+ cells from a sensitized donor matched at HLA-A and HLA-B killed infected cells, with killing increasing with effector numbers, in contrast to CD8+ cells from a naïve donor. In microscopy experiments the same primed CD8+ cells released cytolytic granules into infected cells. CD8+ cells from sensitized donors matched at HLA-A, but not at HLA-B did not kill infected targets as efficiently. HLA-A and HLA-B antibodies inhibited cytotoxicity. CONCLUSION: The data suggest that re-stimulated CD8+ cells from sensitized individuals kill infected cells through release of cytotoxic granules. HLA-B seems to be at least partially required for peptide recognition.
Aging increases susceptibility to systemic infection with L. monocytogenes (129.9)
Authors: Smithey Megan J , Foster Sarah , Rudd Brain , Nikolich-Zugich Janko 
Published: January 2023

Abstract
Aging is accompanied by changes that affect components of both the innate and adaptive immune system, often resulting in a variable state of poorly-understood immunodeficiency. Using the murine model of systemic infection with the intracellular bacterium L. monocytogenes, we have investigated several parameters of the primary and secondary CD8 T-cell response to determine the impact of age on this arm of adaptive immunity. Comparison of these responses in young adult (8 week) and old (18 month) C57BL/6 mice revealed a dose-dependent decrease in survival, as well as a delayed ability to clear the bacterium in old animals. Kinetic analysis of the antigen-specific CD8 T-cell response revealed a markedly reduced magnitude of expansion in the primary effector T-cell population in old mice; however, antigen-specific CD8 T cells differentiating in old animals exhibited production of IFNγ and TNFα equivalent to those in adult counterparts. These results suggest that the quality of the CD8 T-cell response in old animals may be maintained with age. However, reduced primary expansion of Ag-specific CD8 T-cells and/or reduced precursor frequency of these cells may result in an effector CD8 T-cell population that is insufficient in size to protect against high-dose exposure to a new pathogen. Further experiments are in progress to test this hypothesis.