bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innate immune cells are the major determinants of host-related susceptibility differences to experimental spotted fever rickettsiosis (42.24)
Authors: Fang Rong , Ismail Nahed , Shelite Thomas , Walker David 
Published: January 2023

Abstract
Infection of C3H/HeN (C3H) mice with 3 × 105 PFU of R. conorii resulted in 100% mortality, while all C57BL/6 (B6) mice survived the same inoculum. To unravel the strategy by which R. conorii establishes acute fatal disease, we explored its early interaction with the different immune systems in these two mouse strains. Compared to sublethal infection in C3H mice, rickettsiae induced a greater cytotoxic T cell response in infected B6 mice. Lethal infection suppressed antigen-specific proliferation of CD4+ and CD8+ T cells on day 5 post infection, which correlated with upregulated expression levels of PD-1/PD-L1 on T cells and dendritic cells (DCs), respectively. Resistant mice completely cleared the bacteria in four days with greatly expanded cytotoxic NK cells, IFN-γ(+) CD8+ T cells, DCs, but not neutrophils, and enhanced production of MCP-1, MCP-5, RANTES, and IL-12p70. The high resistance of RAG -/- mice on a B6 background to rickettsial infection suggested that the host resistance was determined at the innate immune cell level. Finally, R. conorii induced altered expression of TLR2 and TLR9 in bone marrow derived DCs from C3H and B6 mice, respectively, suggesting that differential TLR signaling pathway was involved in the innate immune responses to rickettsial infection in these two mouse strains. These data suggest that NK cell activation by DCs and their migration to infected sites may play a critical role in innate resistance against Rickettsia.
Alternate delivery systems to improve vaccine performance against foot-and-mouth disease virus (43.15)
Authors: Pandya Mital , Bishop Elizabeth , Pacheco Juan , Scherer Charles , Milward Francis , Doel Timothy , Golde William 
Published: January 2023

Abstract
Foot-and-mouth disease virus (FMDV) is a highly infectious disease of cloven-hoofed animals, with severe agricultural and economic implications. The standard needle inoculation method is not the most efficient system of swiftly vaccinating large numbers of animals at once, as in outbreak situations. Therefore, we conducted studies using a needle free system for vaccination with the killed virus vaccine as a rapid consistent delivery platform. Cattle were vaccinated using a commercially available vaccine formulation at 1x, 1/4x and 1/16x dose using the needle free system and then challenged intradermalingually with FMDV, strain O1 Manisa at 7, 21, or 31 days post vaccination (DPV). All non-vaccinated control cattle exhibited clinical disease, including fever, viremia and vesicle formation. However, cattle vaccinated with the 1/16x and 1/4x doses using the needle free device were partially protected at 7 DPV and fully protected at 21 or 31 DPV. These data suggest that protective vaccination can be achieved with 1/16x vaccine dose when delivered using the needle free intradermal delivery system. This is an indication that the current vaccine stockpile can be extended by many fold using this system.
Determining peptide binding motifs for the SLA-2*0401 Class I MHC and identification of epitopes from foot-and-mouth disease virus (FMDV) P1 protein. (43.16)
Authors: Pedersen Lasse , Patch Jared , Jungersen Gregers , Nielsen Morten , Buus Soren , Golde William 
Published: January 2023

Abstract
To date, little is known about the binding specificities for Swine Leukocyte Antigens (SLA) compared to the enormous amount of data available for the Human Leukocyte Antigens (HLA). The increase in immunology and infectious disease research using pigs as an experimental model would benefit from an increased understanding of SLA class I peptide presentation. In this work, we have determined the binding motifs for the SLA-2*0401 molecule, a commonly expressed allele in swine and the PK13 and PK15 cell lines. These peptide motifs were identified using a prediction model developed for the Class I MHC of human and applied to SLA-2*0401. With this, we derived 10 candidate T cell epitopes from the P1 region of the FMDV strain A24 and two more from Ebola virus and V. cholera for comparison. These candidate peptides were tested for binding SLA-2*0401 using an ELISA based protein association assay developed previously for HLA-I molecules. Five of the ten predicted FMDV peptides bound SLA-2*0401 in vitro. These data are now being applied to the analysis of porcine T cell responses to FMDV infection and vaccination.
Comparative analysis of Xenopus immune-related genes (43.22)
Authors: Ota Yuko , Flajnik Martin 
Published: January 2023

Abstract
Evolutionarily, Xenopus species shared a common ancestor with humans ~350 million years ago, and it is one of the high connectivity animals linking mammals to lower vertebrate taxa. Through an in silico approach, we have uncovered many new genes that have important roles in the Xenopus immune system and have analyzed their syntenic relationships relative to other vertebrates. We found that, in contrast to teleost fish, the genomic synteny is remarkably similar between the human and Xenopus, yet in some cases apparent ancestral syntenies can be still found only in the Xenopus genome. We predict that the evolutionarily conserved genes might have vital roles in fundamental immune function, whereas novel genes found only in particular species, especially those within ancient linkage groups, could impart new insights into the immune system. We are specifically interested in the genes that belong to the variable (V) and the constant (C1)-type of the immunoglobulin superfamily (IgSF), including immunoglobulin, T cell receptor, MHC, and B7. In order to understand the phylogenetic relationship and the evolutionary history of these gene families, we used comparative approach; database searches and comparative genomics among different vertebrate classes. Our analysis revealed insights into the architecture of the primordial immune complex that might have played important roles during evolution.
Fishing for CD4 positive cells in the zebrafish. (43.28)
Authors: Mitra Suman , van der Sar Astrid , Alnabulsi Ayham , Secombes Chris , Bird Steve 
Published: January 2023

Abstract
Differentiation of naïve CD4+ T-cells into functionally distinct subsets is essential for an effective immune response against different types of pathogens. The recent discovery of CD4 like molecules in teleost fish and many of the genes important in adaptive immunity, now gives us the opportunity to study the role of T-cells in lower vertebrate immune responses. Despite these discoveries the lack of molecular tools, such as antibodies, in organisms other than mammals has made this difficult to do. Due to this we have begun to develop a number of polyclonal and monoclonal antibodies to immune genes in zebrafish. Zebrafish has become a popular model to study immunity and is being used by several laboratories worldwide to study disease. Using the zebrafish genome we have discovered a locus that contains four CD4 like genes, which is different to the two discovered in other teleost genomes to date. Although related to other vertebrate CD4 molecules, these genes exhibit low identity to each other. Homology modelling of these genes identifies only one of these to be similar to mammalian CD4, as it is the only one predicted to contain 4 immunoglobulin domains. Using a peptide approach we have developed a polyclonal antibody towards this CD4 molecule and have begun using it to study CD4+ cells in the zebrafish using FACS and immunofluorescence analysis. In addition, we have looked by realtime PCR at the expression of all 4 genes in embryos and healthy or infected adult zebrafish.
Chicken IgM interacts with IgY-sensitized cells (43.31)
Authors: Koppenheffer Thomas , Malpede Brian 
Published: January 2023

Abstract
Normal chicken serum agglutinates both homologous RBC and sheep RBC sensitized with specific IgY, but does not agglutinate sheep RBC sensitized with rabbit IgG. This hemagglutination-enhancing (HE) activity indicates recognition of IgY by a component of chicken serum. The HE activity is greatly enhanced in serum that was previously frozen as compared to fresh serum, and when the former is used as a source for isolating macroglobulins with HE activity, gel filtration chromatography (Sephacryl S-300 HR) reveals tow distinct peaks of activity. The first fraction elutes with the column void volume and consists entirely of IgM, as determined by SDS-polyacrylamide gel electrophoresis under non-reducing conditions and Western blotting, while a lower mol. wt. fraction contains both IgM and a smaller macromolecule. It appears, therefore, that chicken IgM has the capacity to bind antigen-bound IgY, and that this activity is enhanced by the tendency of IgM to aggregate during experimental manipulation. While there is as yet no known functional role for this phenomenon, a number of reports have noted that target RBC undergo pronounced agglutination during the course of hemolytic complement tests in which avian serum is used as complement source. This raises the possibility that chicken IgM might modulate effector functions of IgY.
An FcμR expressed by channel catfish, Ictalurus punctatus, clonal CTL mediates inhibitory effector functions and recruits SHIP (43.7)
Authors: Nayak Deepak , Wilson Melanie , Bengtén Eva 
Published: January 2023

Abstract
Flow cytometric analyses of catfish clonal alloantigen dependent cytotoxic T lymphocyte (CTL) line, TS32.15, grown in the presence of 3% catfish serum revealed that all cells stain positive for IgM and both IgL F and IgL G isotypes, which suggests passive uptake of serum IgM via a putative FcμR. This IgM expression was sensitive to protease treatment, while phosphatidylinositol specific phospholipase C had no effect. Three FcμR or FcμR associated proteins of sizes 52, 40, and 38 kDa were co-immunoprecipitated from biotinylated TS32.15 CTL using anti-catfish IgM. Importantly, FcμR cross-linking led to tyrosine phosphorylation of the 52 kDa protein. Also, Western blot of immunoselect material demonstrated that Src homology 2 domain-containing inositol phosphatase (SHIP) was co-selected with the putative FcμR. However no increase in intracellular calcium was observed. Unlike the previously described catfish IgM bound by catfish NK cells, TS32.15 bound IgM did not mediate antibody dependent cell mediated cytotoxicity. In contrast, IgM cross-linking of TS32.15 cells resulted in reduced cell division and marked decrease in cytotoxicity against allogeneic targets. Cell cycle analyses revealed that cross-linked cells were predominately arrested in the G0/G1 phase and this blockage could be completely reversed by allogeneic stimulation. Together these data indicate this putative FcμR likely functions as an inhibitory Fc-receptor.
Impaired T cell homing and transendothelial migration in CIP4 null mice caused by defective integrin-mediated adhesion (44.1)
Authors: Koduru Suresh , Kumar Lalit , Ozcan Esra , Oyoshi Michiko , Massaad Michel , Le Bras Severine , Ramesh Narayanaswamy , Kaku Mayumi , Fujiwara Yuko , Kremer Lenor , King Sandra , Fuhlbrigge Robert , Sage Peter , Carman Chris , Alcaide Pilar , Luscinskas Francis , Geha Raif 
Published: January 2023

Abstract
The F-BAR domain-containing protein CIP4 interacts with Cdc42 and WASP/N-WASP and is thought to participate in the assembly of filamentous actin. CIP4-/- mice had normal T and B lymphocyte development but impaired T cell-dependent antibody production, IgG antibody affinity maturation, and germinal center formation, despite intact CD40L-CD40 axis. CIP4-/- T cells, but not B cells, homed poorly to lymphoid organs. CIP4-/- mice had impaired contact hypersensitivity (CHS) and their T cells failed to adoptively transfer CHS. CD4+ effector T cells from CIP4-/-/OT-II mice migrated poorly to antigen challenged skin. CIP4-/- T cells exhibited normal rolling on endothelial selectins and chemotaxis to SDF-1α, but impaired adhesion and polarization on immobilized VCAM-1 and ICAM-1, and defective arrest and transmigration across murine endothelial cells under shear flow conditions. These results demonstrate an important role for CIP4 in integrin-mediated T cell adhesive events that are essential for normal recruitment to lymphoid organs and sites of antigen driven immune reactions.
Flotillins and ERM proteins function to promote uropod formation in T cells (44.10)
Authors: Chen Emily , Shaffer Meredith , Niggli Verena , Burkhardt Janis 
Published: January 2023

Abstract
Migrating and adherent T cells form a protruding leading edge and a constricted tail-like structure termed the uropod. The formation of these two structures involves the segregation of specific cytoskeletal elements and cell surface molecules, including proteins that organize cell polarity in other systems. Among the proteins that are segregated to the uropod are ezrin and moesin, ERM family proteins that organize cell membrane domains by linking cytoplasmic and cytosolic proteins to the actin cytoskeleton. Using conditional ezrin-deficient mice in conjunction with siRNA for moesin, we show that ezrin and moesin are required for uropod formation. In addition to ERM proteins, we find that the lipid-raft associated actin-binding proteins flotillins/reggies are also associated with the T cell uropod. Flotillins form a polarized cap even under conditions where a constricted uropod has not formed. Suppression of flotillin expression inhibits uropod formation and the polarization of ERM proteins and their binding partners. These data support a model in which flotillins mark a cell surface domain to which ERM proteins are recruited, and ERM proteins then promote formation of a constricted uropod structure. Since flotillins are not known to interact directly with ERM proteins, intermediary molecules, such as their common binding partner, PSGL-1, may be involved.
Extracellular adenosine triggers lymphocyte entry into the central nervous system during experimental autoimmune encephalomyelitis by regulating chemokine and adhesion molecule expression in the brain (44.12)
Authors: Mills Jeffrey , Alabanza Leah , Mueller Cynthia , Bynoe Margaret 
Published: January 2023

Abstract
Lymphocyte entry into the central nervous system (CNS) is a highly regulated process which serves to promote tissue repair while protecting against potentially fatal inflammation. As the formation of extracellular adenosine (catalyzed from ATP by CD39 and CD73) during inflammation serves as a negative-feedback signal to prevent excessive cell damage, our results suggest that adenosine receptor (AR) signaling also regulates CNS lymphocyte infiltration. We have shown that extracellular adenosine is required for the progression experimental autoimmune encephalomyelitis (EAE), the animal model of autoimmune inflammatory disease Multiple Sclerosis. We now show that AR signaling induces the CNS expression of the chemokine CX3CL1 (fractalkine), which acts as a chemoattractant for monocytes, lymphocytes, and NK cells. In addition, CX3CL1 expression is up-regulated in the CNS immediately prior to EAE onset only in wild type, but not CD73-/- mice, which cannot produce extracellular adenosine, are protected from EAE, and have minimal CNS lymphocyte infiltration following EAE induction. Moreover, CD39, CD73, and ARs are found clustered in the brain only at the choroid plexus, a structure which is known to regulate lymphocyte migration into the CNS. As AR signaling can induce CX3CL1 and ICAM-1 expression and lymphocyte transmigration across an in vitro choroid plexus transwell barrier, we conclude that AR signaling regulates lymphocyte entry into the CNS.
Memory T cells are selectively enriched in lymph nodes of selectin ligand deficient mice (44.14)
Authors: Harp John , Gilchrist Michael , Onami Thandi 
Published: January 2023

Abstract
Selectin mediated tethering is one of the earliest steps in T cell entry to lymph nodes (LNs). Selectin binding is dependent on the synthesis of the sialyl Lewis X (sLex) structure, which requires the activity of several glycosyltransferases, including fucosyltransferases -IV and -VII. Mice deficient in expression of both enzymes (FtDKO) reveal profound impairment in T cell trafficking to LNs. We show that T cells isolated from FtDKO LNs were predominantly “memory/effector” (CD44Hi) cells. We analyzed the generation of effector and memory CD8 T cells in FtDKO mice following infection with LCMV. At day 8, the proportion of Ag-specific cells was similar in LNs of FtDKO mice compared to WT. In contrast, at day 60 p.i., we observed ~5-fold increase in the proportion of Ag-specific memory CD8 T cells in LNs of FtDKO. We then examined whether Ag-specific memory CD8 T cells were able to selectively enter LNs of FtDKO recipient mice. Memory CD8 T cells were profoundly impaired in entry to the LNs of FtDKO mice. Additionally, while we measured no differences in exit rate of naïve and memory CD8 T cells out of the LNs, we found more naïve T cells entered the LNs from the blood compared to memory. We hypothesize that an unknown mechanism leads to the selective retention of memory T cells in FtDKO LNs.
Behavior and function of CD11c+ cells within the brain during chronic Toxoplasmosis (44.8)
Authors: John Beena , Harris Tajie , Ricart Brendon , Tait Elia , Hammer Daniel , Weninger Wolfgang , Hunter Christopher 
Published: January 2023

Abstract
Under normal conditions the brain is an immune-privileged site, however during toxoplasmic encephalitis (TE), there is significant increase in the proportion of T cells and antigen presenting cells (APCs) within the brain. Using a combination of real time imaging techniques, transgenic reporter mice, and recombinant parasites, the current studies have characterized the in vivo phenotype and function of CD11c+ cells present within the brain during this infection. These approaches have revealed the presence of an extensive network consisting of microglia and dendritic cells (including myeloid, lymphoid and plasmacytoid subsets) during TE. The CNS resident CD11c+ cells are functional APCs, as revealed by their ability to stimulate naïve antigen specific T cells in vitro. Further, real time imaging studies showed that these cells interacted with antigen specific T cells (for short durations) suggesting in vivo antigen presentation capabilities. The present studies have also identified a distinct chemokine receptor expression pattern on CD11c+ cells isolated from the brain, suggesting the importance of these receptors in trafficking of these cells into the inflamed brain. Using an adoptive transfer system, we show that the migration of DCs into the brain is Pertussis toxin sensitive. This latter model provides an opportunity to define the chemokine receptors responsible for the recruitment and retention of DCs in the brain.
Exhausted CD8 T cells become unresponsive to activation by innate cytokines and bystander bacterial infections (45.12)
Authors: Ingram Jennifer , Zajac Allan 
Published: January 2023

Abstract
During many chronic infections T cell responses initially develop, but succumb to exhaustion, as they lose their ability to produce interferon-γ (IFNγ) in response to antigen. Combinations of interleukins (IL)- 12, 18, and 21 have been shown to induce the antigen-independent production of IFNγ by prototypic memory CD8 T cells; therefore, we evaluated the sensitivity of exhausted lymphocytic choriomeningitis virus (LCMV)-specific CD8 T cells to activation with these cytokines. Our findings show that following acute infection, effector CD8 T cells respond synergistically to stimulation by these cytokines, but this responsiveness is abolished in exhausted T cells. To evaluate mechanisms responsible for this loss of responsiveness, we examined the expression of the cognate cytokine receptors. Whereas effector and memory T cells express the IL-18R, exhausted T cells downregulated the IL-18R but expressed higher levels of the IL-21R. To evaluate the biological consequences of this decreased sensitivity, we challenged cohorts of LCMV infected mice with the intracellular bacterial pathogen Listeria. Although LCMV-specific memory CD8 T cells vigorously respond to the bacterial infection, this responsiveness is severely compromised during protracted or chronic LCMV infections. Collectively, our findings show that exhausted cells downregulate IL-18R and become desensitized to activation by innate cytokines, rendering them unresponsive to secondary bacterial infections.
Rheumatoid Arthritis latent tuberculosis infection identification based on the cellular and humoral specific response to rHSP-x, Mycobacterium tuberculosis antigen (45.13)
Authors: Guerreiro Reis Michelle , Tanus Silva Daniela , Silva Bruna , Fouad Rabahi Marcelo , Junqueira-Kipnis Ana Paula 
Published: January 2023

Abstract
We previously showed that recent latently tuberculosis infected individuals could be identified by their antibody response against rHspx, an antigen related to latent/early tuberculosis. Here, using different tests we tried to identify latency among individuals with Rheumatoid Arthritis (RA). Twenty-two RA patients were classified by tuberculin skin test (TST) and tested using IgM ELISA to rHspx, specific rHspx TCD4+IFNγ+ quantified by flow cytometry(FC) and Elispot TB (TSPOT.TB). A cut off was established for each test and those who had a positive response were considered possible latently infected individuals. Sixteen healthy controls (HC) were also classified and tested. TST, here considered as a golden standard test for latency, identified 18% of the RA individuals latently infected, while specific TCD4+IFNγ+ recognized 72,7%, ELISA 63,6% and Elispot 27,2%. These results show incongruent identification of TB latency by several tests among RA patients. When combining two tests, the identification of latent tuberculosis among RA individuals changed: FC/ELISA identified 50%, FC/Elispot 18%, ELISA/Elispot 13,6%. The last two associations work the same way as TST. However, FC and ELISA were better than TST in identifying latently infected among RA patients. These results suggest that it may be useful an association of tests (FC and ELISA) to discriminate latently infected individuals among RA patients from an endemic area.
Seoul virus alters proinflammatory and antiviral responses of macrophages from Norway rats (45.14)
Authors: Li Wei , Au Rebecca , Klein Sabra 
Published: January 2023

Abstract
Hantaviruses cause persistent infection, upregulation of regulatory responses, and downregulation of proinflammatory responses in reservoir hosts. To determine whether hantaviruses suppress the inflammatory activity of antigen presenting cells, we infected bone marrow-derived macrophages (BMDMs) from Norway rats with Seoul virus (SEOV). The expression of MHCII and CD80, production of IL-6, IL-10, and TNF-α, and expression of Ifnβ were attenuated after infection. Stimulation of BMDMs with poly I:C prior to SEOV infection increased the expression of activation markers and production of inflammatory cytokines and suppressed SEOV replication. Infection with SEOV also suppressed LPS-induced activation of BMDMs, including NF-κB signaling and production of proinflammatory cytokines. Because inhalation is a major route of hantavirus transmission between rodents, with alveolar macrophages providing the first line of defense against inhaled pathogens and playing a pivotal role in the initiation of infection-induced inflammatory response, we are currently investigating whether rat alveolar macrophages response to SEOV infection in a similar manner as BMDMs and whether SEOV infection of alveolar macrophages enhances regulatory responses, including TGF-β production. Hantavirus-induced inhibition of inflammatory responses of macrophages may be one mechanism contributing to the persistence of virus in reservoir hosts.