bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non-infected, but not infected dendritic cells undergo maturation in vivo following vaccinia virus infection (43.42)
Authors: Yammani Rama D. , Alexander-Miller Martha A. 
Published: January 2023

Abstract
Recently there has been renewed interest in poxvirus pathogenesis. Vaccinia virus (VACV) serves as a useful model for the study of poxvirus infection in vivo. Understanding how vaccinia virus generates immunity necessitates an appreciation for how this virus interacts with dendritic cells (DC), which are the most potent activators of naïve T cells. A number of in vitro studies have shown that DC infected with VACV fail to undergo maturation. However, the effect of VACV infection on DC in vivo remains less defined. We have found that following intravenous administration of vaccinia virus, both CD8+ and CD8− dendritic cells are infected. The number of infected DC peaks at 6 hours and is highly decreased by 24h postinfection. Dendritic cells infected with vaccinia virus have an immature phenotype. However, non-infected dendritic cells, both CD8+ and CD8− subsets, show increased expression of CD80, CD86, and CD40, suggesting that there is a generalized maturation of non-infected DC. In contrast to the generalized upregulation of costimulatory molecules, cytokine analysis suggests that only a subset of these mature DC may be relevant for activation of T cells, as IL-12 production is restricted to a small percentage of cells. These findings provide new insights into the control of DC maturation in vivo following vaccinia virus infection.
This work was supported by NIH grant P01 AI60642.
PD-1 expression on memory CD8 and CD4 T-cell subsets in healthy humans (43.43)
Authors: Duraiswamy Jaikumar , Miller Joseph D , Masopust David , Ibegbu Chris C , Wu Hong , Freeman Gordon J , Ahmed Rafi 
Published: January 2023

Abstract
It has been shown that the PD-1 (programmed death-1) inhibitory pathway is an important regulator of virus-specific CD8 T cell immune responses during a chronic viral infection in mice. Recent reports in HIV-infected people have shown that PD-1 is significantly upregulated on HIV-specific CD8 T cells and these exhausted cells can be reinvigorated by PD-1 blockade. We have tested the profile of PD-1 expression on chronic virus-specific CD8 T cells in normal healthy virus carriers. Analyses of CD8 T-cell subsets revealed that PD-1 was preferentially expressed by effector memory T cells rather than naive or central memory T cells. PD-1 was expressed by most CD8 T cells specific for human chronic infections, such as Epstein-Barr virus and cytomegalovirus, and at a lower level among CD8 T cells specific for infections that are cleared, such as influenza and vaccinia viruses. Blockade of PD-1 signaling using anti-PD-L1 antibody enhanced the ability of virus specific PD-1+ CD8 T cells to proliferate in response to antigen. These data support a role for PD-1 in suppressing CD8 T cells during chronic viral infections in humans.
The first two authors contributed equally to this work.
Interaction of Respiratory Dendritic cells with Influenza Virus Infection in vitro (43.44)
Authors: Hao Xueli , Braciale Thomas 
Published: January 2023

Abstract
Influenza A virus is a major cause of infection of the respiratory tract worldwide. Approximately 10–20% of U.S. population is estimated to be infected by this virus each year. Respiratory tract dendritic cells (RDC) are believed to play a major role as antigen presenting cells in initiating adaptive immune response to influenza virus infection. We have examined the effect of influenza virus infection of purified RDC in vitro at different MOI (Multiplicity of Infection) on virus protein expression, co-stimulatory molecules expression, and cytokines production. We found that there is not only an MOI dependent increase in the percentage of infected RDC, but also the infection of RDC at high MOI results in higher level and accelerated viral protein synthesis at early time post infection. Production of tested cytokines and chemokines by RDC increases with increasing of MOI except for IL-12 p40. Furthermore, we found that at high MOI total RDCs can be divided to several populations based on CD40 and influenza nucleoprotein (NP) expression: CD40high NPlow, CD40low NPhigh, and CD40negNPnegDCs. In conclusion, our results suggest that there is a diverse response of RDC to influenza virus at different MOI as reflected by their susceptibility to infection and cytokine production. These results may provide insight into how RDC modulate host response in the lung to influenza virus infection.
(Support: USPHS grant, NIH AI-15608, HL-33391,HL-71875)
The Characterization of Dendritic Cells in the MAIDS Model (43.46)
Authors: Giles Josephine Ruth , Nardiello Tricia Lynn , Stranford Sharon 
Published: January 2023

Abstract
Murine acquired immunodeficiency syndrome (MAIDS) is an animal model used to study human AIDS and is induced by murine leukemia virus. There are two different strains of mice used in this model system; BALB/c animals are naturally resistant and C57BL/6 are susceptible to MAIDS. Our laboratory’s previous studies examined differential immune responses during the first week of infection by comparing lymphoid organ gene expression patterns in BALB/c and C57BL/6 mice using DNA microarrays. Based on these data, it appears that the inability of C57/BL6 mice to develop an effective immune response may be due, in part, to changes in dendritic cell function or homing to lymph nodes. Based on microarray results, we hypothesize that this is due to lymphatic vessel remodeling differences. In the first part of this study, strain-specific differences in the mRNA expression patterns of specific DC function related genes identified by DNA microarray (e.g., CD83, DC-SIGN, and DCAR) were quantified using real-time RT-PCR.
In the second part of this study, immunofluorescent staining was used to visualize and quantify differences in the lymphatic vessel networks in the lymph nodes of disease resistant versus susceptible mice after MuLV infection. Our data suggest that by 3 days post infection, lymphatic vessel branching is more extensive in BALB/c mice (MAIDS resistant) than C57BL/6 animals (MAIDS susceptible). Further studies are underway to support and further quantify these preliminary results.
Early Events in the T cell Response to Respiratory Virus Infection - ‘Conveyor belt’ like sequential activation of CD8+ T cells in the lymph nodes. (43.48)
Authors: Yoon Heesik , Legge Kevin L , Sung Sun-Sang J , Braciale Thomas J 
Published: January 2023

Abstract
We have examined the tempo of T cell activation and proliferation in the draining lymph nodes in response to type A influenza virus infections with TCR transgenic CD8+ T cells. The CD8+ T cell activation/proliferation revealed by CFSE intensity correlated with the tempo of accelerated respiratory dendritic cells (RDC) migration from the infected lungs to the draining lymph nodes in response to influenza virus infection. In vivo administration of blocking anti-CD62L antibody at various time points before and after infection revealed that the virus specific CD8+ T cells entered the lymph nodes and activated in a sequential ‘conveyor belt’ like fashion. In conclusion, the onset of CD8+ T cell activation/proliferation after viral infection is controlled by the availability of DC harboring influenza antigens and the migration of these DC from the lungs to the draining lymph nodes.
This work is supported by USPHS grants AIO15608, HL03391, and HL071875.
Unique features of Vγ2Vδ2 T cell memory provides for bridge immunity to infections (44.16)
Authors: Morita Craig T. , Puan Kia-Joo , Lee Hoi K. , Wang Hong , Raker Amy M. , Moser Bernhard , Kuzuyama Tomohisa , Jin Chenggang 
Published: January 2023

Abstract
Human Vγ2Vδ2 T cells play important roles in mediating immunity against microbial pathogens and have potent anti-tumor activity. They recognize prenyl pyrophosphates such as isopentenyl pyrophosphate (IPP). We and others find that hydroxymethyl-butenyl pyrophosphate (HMBPP) is the major Vγ2Vδ2 antigen for many eubacteria. HMBPP is an intermediate in the MEP pathway for isoprenoid biosynthesis used by bacteria and protozoans. HMBPP was a 30,000-fold more potent antigen than IPP. The ubiquitous presence of prenyl pyrophosphates results in unique features of Vγ2Vδ2 T cell memory. Although exhibiting similar kinetics of expansion as CD8 αβ T cells after infections, almost all adult γδ T cells are memory cells that can be distinguished by expression of CD28, CD27 and CD45RA. High proportions of intermediate/late effector memory cells can be found in some donors even in early adulthood. Each memory subset displays distinct functional properties and chemokine receptors. Intermediate/late memory cells express CXCR1, CXCR2 and CX3CR1, whereas early central memory cells express CXCR6, CCR1 and CCR2. Late effector cells proliferate poorly compared with early and intermediate cells. Thus, different inflammatory chemokines attract distinct Vγ2Vδ2 memory subsets with different functional capabilities. The rapid conversion from naïve to memory T cells due to the recognition of a widespread microbial metabolite allows Vγ2Vδ2 T cells to mount memory responses to primary infections by bacteria and parasites using the MEP pathway.
Protective role of CCL6 during severe sepsis through interferon-γ generation and interferon-producing killer dendritic cells recruitment (44.18)
Authors: Coelho Ana Lucia , Schaller Matthew , Hogaboam Cory , Kunkel Steven 
Published: January 2023

Abstract
Our group has previously demonstrated that CCL6 enhanced antimicrobial immunity during sepsis through an unknown mechanism. The goal of this study was to investigate the mechanism involved in the protective role of CCL6 during the severe sepsis. C57BL/6 transgenically overexpressing CCL6 (Tg) in the lung and wild type (WT) mice were submitted to cecal ligation and puncture (CLP) and sham operation, and survival was evaluated for up to 7 days post-CLP. Cells from peritoneal cavity (PC) were obtained 3 days after surgery. The CCL6 Tg group exhibited greater levels of CCL6 in the lung and PC when compared to WT group after sham and CLP surgery. While CCL6 Tg mice presented 90% of survival at day 7 only 20% of WT mice survived. High levels of interferon-γ (IFN-γ) were detected in the PC of CCL6 Tg mice at 3 days post-CLP. Also, cells obtained from PC of these mice produced significantly levels of IFN-γ. When CCL6 Tg mice received anti-IFN-γ prior CLP, only 20% were alive. At 3 days after sham and CLP operation, the number of natural killer (NK) cells and interferon-producing killer dendritic cells (IKDCs) was increased in the peritoneal cavity of CCL6 Tg mice when compared to WT mice. These data suggest that the protective role of CCL6 may be due to its ability to contain the consequences of an inappropriate type 2-cytokine response during anti-pathogen responses. CCL6 may achieve this through promotion of IFN-γ and NK cells and IKDCs recruitment.
ATP-binding to the CATERPILLER protein Monarch-1, is required for its inhibitory function (44.19)
Authors: Ye Zhengmao , Lich John D , Moore Christopher , Williams Kristi L , Duncan Joseph A , Ting Jenny P._Y 
Published: January 2023

Abstract
The newly discovered CATERPILLER (NOD, NLR) family is defined by a nucleotide-binding domain (NBD) that consists of the Walker A and B motifs and ten additional motifs. It is conserved from plants to humans, and is important in immune regulation and several genetic disorders. Although the NBD is a defining feature of this family, there is a paucity of data to indicate that these proteins bind nucleotides, or the binding of nucleotides modulate their functions. Monarch-1/Pypaf7 is a negative regulator of IRAK-1 and NIK. In this report, we successfully purified recombinant Monarch-1 proteins to homogeneity. Purified Monarch-1 binds ATP but not CTP, GTP and UTP and exhibits ATP hydrolysis activity. Intact Walker A/B sequences are required for nucleotide binding. Overexpression of Monarch-1 nucleotide-binding defective mutant in THP-1 cells resulted in a dramatic increase of IL-6, chemokine CCL1, CXCL6 and CXCL13 to the extent that is comparable to the THP-1 Monarch-1 shRNA knock down cells in response to TLR2 agonist. This indicates that ATP binding is required for the inhibitory function of Monarch-1 and the nucleotide binding-defective mutant displays a dominant negative effect. Intact nucleotide-binding domain is also required for IRAK-1 dephosphorylation and p100 processing suggesting a nucleotide binding-dependent mechanism of Monarch-1 function in both canonical and non-canonical NF-κB pathway.
Antisense gene therapy in thermally injured mice orally infected with Enterococcus faecalis (44.27)
Authors: Shigematsu Kenji , Yoshida Tsuyoshi , Tsuda Yasuhiro , Kobayashi Makiko , Herndon David N , Suzuki Fujio 
Published: January 2023

Abstract
Infectious complications stemming from E. faecalis translocation in burn mice are influenced by a special subset of neutrophils (immunosuppressive PMN, PMN-II). CCL2 released from PMN-II has been characterized as an effector molecule when translocated bacteria spread systemically in these mice. In the present study, we tried to protect burn mice orally infected with E. faecalis using antisense gene therapy. c-fos antisense ODN was utilized in this gene therapy, because c-fos was described as a promoter of CCL2 gene expression. One day after burn injury (3rd degree, 25% TBSA burn), decontaminated BALB/c mice were infected orally with a lethal dose of E. faecalis (107 CFU/mouse), and treated s.c. with c-fos antisense ODN 6 hrs before, and 2 and 4 days after infection. These mice were observed once daily for a week, to determine their survival rates. In some experiments, sera obtained from burn mice, that were treated with or without c-fos antisense ODN, were assayed for CCL2 using ELISA. In the results, after E. faecalis oral infection, 90% of burn mice subjected to antisense therapy survived, while an 80% mortality rate was shown in the same mice treated with c-fos sense ODN. CCL2 was not detected in sera of burn mice treated with c-fos antisense ODN. These results indicate that infectious complications caused by E. faecalis translocation are controllable in thermally injured mice by antisense gene therapy using c-fos antisense ODN.
This study was supported by SHC NA #8840.
Regulation of neutrophil-mediated host defense to pneumococcal infection by NKT and gamma-delta T cells (44.34)
Authors: Hatta Masumitsu , Nakamatsu Masashi , Nakasone Chikara , Fujita Jiro , Kaku Mitsuo , Kawakami Kazuyoshi 
Published: January 2023

Abstract
Recently, NKT and gamma-delta T cells have garnered attention in the host defense to various infectious pathogens. In the current study, we examined the role of these lymphocytes in neutrophil-mediated host defense to pulmonary infection with Streptococcus pneumoniae, a leading causative bacterium in community-acquired pneumonia. Both J alpha 18 KO and V gamma 4 KO mice, lacking iNKT cells and TCR-V gamma 4+ T cells respectively, were more susceptible to this infection than wild-type (WT) mice, which was associated with attenuated synthesis of TNF-alpha and MIP-2 and reduced accumulation of neutrophils in lung. The attenuated responses and host defense in J alpha 18 KO mice were completely recovered by administration of either rIFN-gamma or liver mononuclear cells (LMNC) obtained from WT mice, which effect was abrogated when LMNC were prepared from IFN-gamma KO mice. By contrast, such recovery effect by rIFN-gamma administration was not or marginally observed in V gamma 4 KO mice. Taken together, these results demonstrate that both iNKT cells and gamma-delta T cells play an important role in neutrophil-mediated host defense to pneumococcal infection and suggest that these lymphocytes may work in a different mechanism.
IFN-λ contributes to dendritic cell-mediated expansion of regulatory T cells during HCV infection. (44.38)
Authors: Dolganiuc Angela , Paek Edward , Fair Joshlean , Szabo Gyongyi 
Published: January 2023

Abstract
IFN-λ inhibits HCV replication and triggers IFN-dependent genes. We hypothesized that IFN-λ is immunomodulatory and evaluated its effects on myeloid dendritic cells (DC). DCs generated with IFN-λ (IFN-λ-DC) expressed normal levels of DC markers, but showed reduced allostimulatory capacity in mixed lymphocyte reaction (MLR), similar to DCs of patients with chronic HCV infection (HCV-DC). No additive effects of IFN-λ subtypes were observed. The inhibition of MLR was due to preferential expansion of CD4+CD25+ T cells in the presence of HCV-DCs or IFN-λ-DC, but not normal DCs. Purified CD4+CD25+ T cells from MLR were Foxp3+, CD45RA+, produced IL-10 and TGFb, and inhibited CD4+CD25− T cell proliferation. HCV-DCs produced increased levels of IFN-λ compared to controls. In vitro generation of DCs in the presence of LPS increased expression of IFN-λ. Interestingly, we found increased plasma levels of LPS in HCV patients compared to controls suggesting a possible in vivo mechanism for IFN-λ induction. Further, in vitro DCs generation with LPS resulted in expansion of Tregs and inhibition of MLR, thus mimicking the effects of HCV-DCs and IFN-λ-DCs. We also identified an increased frequency of Tregs in peripheral blood of HCV patients (12±2%) compared to controls (5±1%) (p&lt;0.05). In conclusion, increased frequency of Tregs in HCV infection is associated with increased IFN-λ production by DCs that promote Treg generation.
MyD88-mediated signals induce in vivo production of the bactericidal lectin RegIIIγ and protect against intestinal Listeria monocytogenes infection (44.4)
Authors: Brandl Katharina , Plitas George , DeMatteo Ronald P. , Hooper Laura V. , Pamer Eric G. 
Published: January 2023

Abstract
Listeria monocytogenes (L. monocytogenes) is an intracellular bacterium that causes systemic infections after traversing the intestinal mucosa. To test the hypothesis that the Toll-like receptor pathway is involved in defense against intestinal L. monocytogenes infection, we analyzed the role of the common intracellular adaptor molecule myeloid differentiation primary-response protein 88 (MyD88) following oral infection with L. monocytogenes. We found that MyD88 deficient mice have increased susceptibility to intestinal L. monocytogenes infection with higher bacterial burden in spleen, liver, mesenteric lymph nodes, intestinal lumen, and small intestine (lamina propria and intestinal epithelium). Further in vitro and in vivo studies showed that MyD88 mediated protection primarily occurs in the distal small intestine. Recently, it was shown that the intestinal bactericidal lectin RegIIIγ has antibacterial activity against L. monocytogenes. RT-PCR and Western Blot analysis of distal small intestines showed that RegIIIγ is significantly diminished in MyD88 deficient mice. Since optimal expression of RegIIIγ requires MyD88-mediated signals, our findings suggest that increased susceptibility to intestinal L. monocytogenes infection in MyD88-deficient mice results from diminished levels of this bactericidal lectin in the distal small bowel.
Characterization of constitutive antimicrobial activity associated with leukocyte lysates from the nurse shark, Ginglymostoma cirratum (44.42)
Authors: Hinds Nichole A , Smith Sylvia L 
Published: January 2023

Abstract
Antimicrobial peptides are mediators of innate immunity. Studies have shown that peptide fragments of histones, proteins primarily involved with DNA packaging, display antimicrobial activity. This project examines the antibacterial activity associated with shark leukocyte lysates and the potential role of histone fragments in constitutive innate immunity. Preliminary studies have demonstrated antimicrobial activity, distinct from that of lysozyme, in crude cell lysates prepared from unstimulated shark blood leukocytes. The antimicrobial activity has been partially purified using a combination of ion exchange, size exclusion and affinity chromatography. SDS PAGE analysis of fractions showed the presence of several low molecular weight (&lt;15 kDa) protein bands. N-terminal amino acid sequence analysis of four peptides identified them as histone fragments with sequence similarity to mammalian histones H2A, H2B and H4. The peptide sequences are also similar to histone fragments described for the catfish and the Asian toad, which exhibit antibacterial activity. The spectrum of antibacterial activity, biochemical characterization and mode of action of shark histone fragments is under investigation. Such information will determine their potential use against clinically significant organisms.
The research was supported in part by FIU’s Comparative Immunology Initiative (NIH R25GM061347).
HIV-1 induces targeted down-regulation of the Ig gene-diversifying enzyme AID in the germinal center of infected lymphoid follicles (45.1)
Authors: Santini Paul A , He Bing , Chiu April , Ball Susan C , Chen Kang , Kingsley Lawrence A , Rinaldo Charles R , Knowles Daniel M , Chadburn Amy , Xu Weifeng , Cerutti Andrea 
Published: January 2023

Abstract
Class switching from IgM to IgG and IgA is essential for antiviral immunity and requires activation-induced cytidine deaminase (AID), an APOBEC family member with DNA-editing activity. Germinal center (GC) B cells express AID upon activation by CD4+ T cells through CD40 ligand (CD40L) and IL-4. HIV-1 is thought to impair IgG and IgA responses to viral antigens, opportunistic pathogens and vaccines by causing progressive loss of CD4+ T cells and by rendering B cells poorly responsive to CD4+ T cell help. It remains unknown whether HIV-1 targets AID to hamper protective IgG and IgA responses. We found that infected GCs contained less AID, but normal APOBEC3G, an AID-related RNA-editing protein. AID down-regulation was not associated with local loss of CD4+ T cells and CD40L, but rather correlated with decreased activation of AID-inducing transcription factors, such as NF-κB and STAT6, and with increased expression of feedback inhibitors of NF-κB and STAT6, including IκBα, SOCS1 and SOCS3. AID down-regulation also correlated with accumulation of the viral protein Nef in the GC and with trafficking of Nef within membrane channels connecting infected myeloid cells to B cells. Together with our recent in vitro studies showing that Nef penetrates B cells and inhibits class, the present in vivo data suggest that HIV-1 evades protective IgG and IgA responses by targeting the class switch recombinase machinery.
Differential Protease Activity in the Secondary Lymphoid Tissues of Disease Resistant and Susceptible Mouse Strains in the MAIDS Model (45.12)
Authors: Nardiello Tricia Lynn , Giles Josephine Ruth , Stranford Sharon A. 
Published: January 2023

Abstract
Murine leukemia virus (MuLV) is used as a mouse model system to study human AIDS. There are two strains of mice used in this model, BALB/c and C57 BL/6. Although both strains of mice will become infected, BALB/c strain recover while the BL/6 strain becomes immunocompromised (MAIDS). Previous DNA microarray work comparing the two strains has shown that certain proteases are up regulated in the BALB/c lymph nodes and spleen shortly after infection. Lymphatic remolding and cell activation are possible consequences of protease activity, and therefore the up regulation of these proteases in the BALB/c strain may be important for recovery.
Using immunofluoresent microscopy and in situ zymography, quantification of protease activity in the lymph nodes of each strain was studied in the first days after MuLV infection. Serial sections were stained for lymphatic (LYVE-1) and vascular (CD31) endothelial structures using primary and fluorescently-conjugated secondary antibodies. This was combined with protease-mediated activation of quenched substrate fluorphores (in situ zymography) allowing co-localization of protease activity and lymphatic morphology.
Preliminary in situ zymography results show that there is an increase in protease activity in BALB/c mice when compared to BL/6 in the lymph nodes. Furthermore, preliminary immunofluorescent results show an increase in the vascular and lymphatic branching within the BALB/c lymph nodes following MuLV infection.