bluuebunny/crossref_metadata_2025_split huggingface dataset:
Borrelia burgdorferi elicits dysregulated IL-10 production by macrophages via a TLR2-dependent, yet distinct, signaling pathway than those involved in pro-inflammatory responses (37.40)
Authors: Chung Yutein , Wells Daniel , Waldman Joshua , Arden Jessica , Wooten R. Mark 
Published: January 2023

Abstract
Borrelia burgdorferi (Bb) is a tick-borne spirochete that causes Lyme disease. Bb efficiently evade host defenses and persist in host tissue despite eliciting strong immune responses that involve Toll-like receptor 2 (TLR2)-mediated events. Virulent Bb are known to rapidly elicit substantial IL-10 production by skin-resident antigen presenting cells (APCs) such as macrophages (MΦs), and blocking IL-10 significantly enhances Bb clearance and APC immune functions. We hypothesize that the mechanisms involved in the dysregulated IL-10 response are initiated rapidly and distinct from those involved in proinflammatory responses. To address this, APCs were pretreated with cytochalasin D (block Bb phagocytosis) and/or antibodies that specifically neutralize TLR2 function, thus allowing delineation of early responses to Bb. MΦs produced significant IL-10 levels in response to Bb independent of phagocytosis events, whereas most proinflammatory mediators required phagocytosis. IL-10 produced in response to intact Bb was only partially reduced after TLR2-blockage, while IL-10 elicited by the Bb lipoprotein OspA was completely abrogated by TLR2-blockage. Studies using chemical inhibitors indicated that IL-10 production was dependent on both PI3 kinase and MAPK p38 activity, while most Bb-elicited proinflammatory mediators were not. These studies suggest that dysregulated IL-10 responses to Bb involve a TLR2-associated, but distinct pathway from those utilized in proinflammatory responses.
NK cells are required for defense against pulmonary K. pneumoniae infection in mice and mediate optimal production of protective cytokines, including IL-22. (37.41)
Authors: Xu Xin , Weiss Ido , Wilson Mark , Farber Joshua 
Published: January 2023

Abstract
Among the products of Th17 cells are IL-17A and IL-22, which are required for protection against extracellular pathogens, such as K. pneumoniae. Although published data suggest that T cells are the source of these cytokines during pulmonary infection with K. pneumoniae, we found that Rag2-/- mice did not differ from wild-type mice in survival, bacterial counts or levels of IL-22 in the lungs after intratracheal infection with K. pneumoniae. By contrast, K. pneumoniae-infected Rag2-/-γc-/- mice failed to produce IL-22 and had higher bacterial counts as compared with wild-type controls. Together, these data suggested a possible role for NK cells in host defense, and in the production of IL-22, during K. pneumoniae infection. Lung NK cells showed a conventional surface phenotype and lacked NKp46 and CCR6, markers for IL-22-producing (“NK22”) NK cells. Moreover, we found no increase in lung NK cells during infection. However, as compared with control mice, mice depleted of NK-cells using anti-Asialo GM1 showed decreased survival and higher bacterial counts, as well as increased dissemination of K. pneumoniae to blood and liver. In addition, NK cell depletion led to decreased production of IL-22 and other cytokines important for protection, including IL-12, TNF-α, and IL-6. Together, our data show that NK cells are required for defense against pulmonary K. pneumoniae infection and optimal production of protective cytokines, including IL-22. Supported by the IRP, NIH, NIAID.
Alternatively activated macrophages kill the parasitic nematode Strongyloides stercoralis in conjunction with neutrophils through two unique mechanisms. (37.44)
Authors: Bonne-Annee Sandra , O’Connell Amy , Hess Jessica , Abraham David 
Published: January 2023

Abstract
Previous studies have demonstrated that protective adaptive immunity in mice against the parasitic nematode Strongyloides stercoralis requires Th2 cytokines, antibody and complement activation. In addition, neutrophils function in both the innate and adaptive immune responses. The goal of this study was to determine the role of macrophages (MΦ) in the protective immune response against S. stercoralis. Bone marrow-derived MΦ were either 1) cocultured with neutrophils and larvae in Transwell plates or 2) placed in diffusion chambers with larvae and implanted subcutaneously into naïve or immunized mice. Larval killing did not occur when either MΦ or neutrophils were cultured independently with larvae in vitro. Larval killing did occur when both cell types were in contact with the worms. In addition, MΦ with soluble help from neutrophils or neutrophils with soluble help from MΦ could also kill the worms. MΦ killed larvae in both naïve and immunized mice when implanted with diffusion chambers. MΦ were stimulated ex-vivo with IL-4 to induce alternatively activated macrophages (AAMΦ) or IFN-γ/LPS to induce classically activated macrophages CAMΦ). AAMΦ and not CAMΦ 1) killed larvae in vitro and 2) provided soluble help to neutrophils to kill the larvae. AAMΦ and not CAMΦ killed larvae in vivo during the innate and adaptive immune responses. We conclude from these studies that AAMΦ can directly and indirectly, in conjunction with neutrophils, kill the nematode S. stercoralis.
Differential expression and regulation of inflammatory mediators in macrophages from Lyme disease-resistant C57BL/6J and disease-susceptible C3H/HeN mice (37.6)
Authors: Gautam Aarti , Embers Monica , Dixit Saurabh , Singh Shree , Morici Lisa , Gautam Rajeev , Dennis Vida 
Published: January 2023

Abstract
C3H/HeN (C3H) mice develop severe arthritis whereas; C57BL/6J (C57) mice develop mild arthritis after experimental infection with the Lyme disease spirochete Borrelia burgdorferi. We hypothesize that these host responses may depend on differences in the expression and regulation of inflammatory mediators induced by spirochetes during the early stage of Lyme disease. In the present study, bone marrow-derived macrophages from C3H and C57 mice were stimulated with live B. burgdorferi or with its lipoprotein outer surface protein A; supernatants were collected and subjected to proteome analysis using multiplex ELISA. Both stimulants induced significantly higher levels of IL-6, TNF-α, IFN-γ, KC, IL-9, MCP1/CCL2, IL-5, GM-CSF, and IL-12p70 in cells of C3H than in those of C57 mice. In contrast, MIP1α/CCL3, MIP1β/CCL4, RANTES/CCL5, IP-10/CXCL10, MIP2/CXCL2, IL-17, IL-1α, IL-1β, LIX/CXCL5, G-CSF, CXCL9/MIG and IL-10 levels were significantly greater in C57 than in C3H mice. Exogenous IL-10 abrogated the expression levels of inflammatory mediators. Neutralization of endogenous IL-10 resulted in enhanced production of mediators; the effect was more evident in C57 mice. Our data show differential expression and regulation of inflammatory mediators in B. burgdorferi-stimulated macrophages of C57 and C3H mice. The potent action of endogenous IL-10, especially in C57, suggests a key role played by IL-10 to abrogate inflammation during the early stage of Lyme disease in this mouse strain.
Evaluation of West Nile virus IgY polyclonal antibodies (38.10)
Authors: Hunter SheRae , Konschak Sarah , Adkins Steven , Schiltz James , Petell James , Bradley David 
Published: January 2023

Abstract
Previously, we have demonstrated that goose-derived anti-West Nile Virus (WNV) antibodies are both protective against WNV infection in avian and mammalian subjects, and specific for a broad spectrum of WNV proteins. West Nile Virus (WNV), a single stranded positive sense RNA virus from the family Flaviviridae, is capable of causing severe disease in humans including meningitis, encephalitis, and/or poliomyelitis and may ultimately lead to permanent paralysis or death. The natural reservoir for WNV is wild birds, but the virus can be spread through a mosquito vector to mammals. The epidemiology of WNV infections indicates that a population-wide vaccine is neither necessary nor cost-effective. However, an effective passive therapeutic antibody treatment would provide an excellent alternative for individuals with WNV infection involving the CNS. Characterization of the protective WNV-specific goose antibodies indicates a polyclonal response predominately of the IgY isotype with diverse specificities, including WNV proteins E, pre-M and NS3. Further evaluation indicates that multiple epitopes are recognized on the E, M, NS1, and NS3 proteins. This diverse reactivity suggests enhanced recognition of and protection against various replicative and envelope components within the virus, across WNV strains, and potentially for other flaviviruses.
The Y-chromosome translocation, Yaa, decreases murine susceptibility to herpes simplex encephalitis (38.16)
Authors: Richardson Angela , Kreutzberger Christine , Jennings Stephen , Blankenhorn Elizabeth 
Published: January 2023

Abstract
The C57BL/6J.YSB consomic males bear a Y chr with a translocation (Yaa) from X bearing TLR7. The translocation reduces susceptibility to EAE, a mouse model of multiple sclerosis. We hypothesized that B6.Yaa mice would also show decreased susceptibility to herpes simplex encephalitis (HSE), another neuroinflammatory condition, compared to the consomic partner, C57BL/6J (B6). Four week-old B6 and B6.Yaa male mice were inoculated with neurovirulent HSV-1. B6.Yaa mice had significantly increased survival (MST = 8 days; 40% survival) compared to B6 (MST = 6 days; 0% survival) by log-rank test. Surprisingly, the brains of the less susceptible B6.Yaa mice had a significantly greater number of viral genome copies than B6 mice (p = 7 x 10-9), as measured by quantitative real-time PCR. We analyzed expression levels of known markers of susceptibility to HSE in the two strains (including cell surface markers, cytokines, and cell-signaling molecules) by real-time PCR assays of RNA from draining lymph nodes and infected tissues. Brains of infected B6.Yaa mice demonstrated significantly increased expression of CD4, IL-1α, IL-1β, IL-6, and TNFα compared to B6 mice on dpi 5. Cluster analysis of expression levels from the 26 transcripts studied (including 21 host transcripts and 5 viral transcripts) in the brains of B6 and B6.Yaa mice demonstrated distinct patterns of gene expression. Thus the Yaa translocation alters the adaptive immune response to HSV-1 and increases survival in these mice.
Immune evasion protein mK3 defines the physiological importance of non-lysine ubiquitination of MHCI substrates (38.8)
Authors: Wang Xiaoli , Herr Roger , Rabelink Martijn , Hoeben Rob , Wiertz Emmanuel , Hansen Ted 
Published: January 2023

Abstract
Ubiquitin modification of proteins plays a prominent role in regulation of multiple cell processes including ER-associated degradation. Until recently ubiquitination of substrates was thought to occur only via isopeptide bonds, typically to lysine residues or less frequently to the N-terminus of a substrate. We and others recently found that certain viral MARCH E3 ligases can promote ubiquitin conjugation to non-lysine residues via ester or thiolester bonds. The molecular basis for these novel modifications, however, remained undetermined. To probe the mechanism and importance of non-lysine ubiquitination, we have studied the viral immune evasion protein mK3, a RING-CH type E3 ligase encoded by γHV68. We recently identified Ube2j2 as the primary cellular E2 required for mK3-induced MHCI heavy chain ubiquitination and degradation in the proteasome. Surprisingly, Ube2j2-mK3 preferentially ubiquitinates serine residues via ester bonds even when lysine residues are present on wildtype substrates. Furthermore, Ube2j2-mK3 not only adds the initial ubiquitin on the substrates but also promotes assembly of a lysine 48-linked polyubiquitin chain. These findings demonstrate for the first time the physiological important of this novel ubiquitination mechanism and that the same E2-E3 complex can catalyze the coupling of ubiquitin to substrates via an ester bond and assemble a specific polyubiquitin chain via isopeptide bonds.
Aberrant activation of STAT3 in primary human endothelial cells by the latent KSHV protein kaposin B (39.18)
Authors: King Christine , Gillis Laura , McCormick Craig 
Published: January 2023

Abstract
The proto-oncogene STAT3 is a latent transcription factor that upon activation drives the expression of a number of genes involved in cell proliferation, survival, and immune responses. Canonical STAT3 activation occurs via phosphorylation of Y705, dimerization, and nuclear translocation, followed by phosphorylation of S727 for maximal transcriptional activity. Kaposi’s sarcoma associated herpesvirus (KSHV) is the infectious cause of several AIDS-related cancers including Kaposi’s sarcoma (KS). Here we show that latent KSHV infection of primary human endothelial cells (ECs) activates STAT3, and identify a key latency protein, kaposin B, that contributes to this activation. Kaposin B expression in ECs causes STAT3 phosphorylation at S727, relocalization to punctate structures within the nucleus known as ‘STAT3 bodies’, and enhanced expression of STAT3 target genes. Recent work shows that the tripartite motif-containing protein 28 (TRIM28, a.k.a. TIF-1β, KAP-1) negatively regulates STAT3 by recruiting transcriptional silencing complexes. Here, we demonstrate for the first time that TRIM28 is a bona fide target of the host cell kinase MK2 and show that KSHV infection and kaposin B expression results in MK2 activation and concomitant phosphorylation and inactivation of TRIM28. Taken together, our studies reveal an important new regulatory mechanism governing STAT3 activation in endothelial cells and suggest novel protein targets for the treatment of KS.
Continual cell cycle progression during migration permits rapid CTL division at sites of viral infection (39.24)
Authors: McGavern Dorian , Kang Silvia , Herz Jasmin , Kim Jiyun , Dustin Michael 
Published: January 2023

Abstract
Following virus infection, cytotoxic T lymphocytes (CTL) divide rapidly to eradicate the pathogen and prevent the establishment of persistence. The magnitude of an anti-viral CTL response is thought to be controlled by the initiation of a cell cycle program within lymphoid tissues. However, it is presently not known whether this division program proceeds during migration or is influenced locally at sites of viral infection. Here we demonstrate that anti-viral CTL remain in cell cycle while transiting to infected tissues. One third of virus-specific CTL within blood were found to be in various stages of cell cycle following infection with lymphocytic choriomeningitis virus (LCMV). Using two-photon microscopy, we revealed that effector CTL divided within the virus-infected central nervous system (CNS) as well as meningeal blood vessels. Within the CNS, MHC I-dependent interactions with antigen presenting cells influenced the division program by pushing effector CTL into cell cycle. These results demonstrate that CTL are poised to divide in transit and that their numbers can be influenced at the site of infection through interactions with local APCs.
RSV Strain 2-20 Induces More Severe Disease in BALB/c Mice than RSV Strain 3-12 (39.25)
Authors: Stokes Kate , Lee Sujin , Chi Michael , Sturkie Carla , Peebles R. , Moore Martin 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) is the chief cause of bronchiolitis and viral pneumonia in infants. Mucus production contributes to morbidity and mortality in RSV disease. The TH2 cytokine IL-13 is a mediator of mucus production. RSV strain differences can play a role in differential immunologic phenotypes. The pathogenesis of RSV clinical isolate strains was examined in BALB/c mice. RSV strain 2-20 induced significant weight loss, lung IL-13 levels, and bronchiolitis in BALB/c mice. In contrast, RSV 3-12 exhibited a less severe phenotype similar to the RSV A2 laboratory strain. Mucin expressing cells in the lungs of BALB/c mice infected with RSV A2, 2-20, or 3-12 were quantified with a digital scanning microscope. RSV 2-20 induced greater mucin expression than RSV 3-12 and RSV A2. T cell and IFN-γ-expressing T cells were enumerated by flow cytometry. RSV 2-20 infection resulted in fewer IFN-γ-expressing T cells and lower overall T cell numbers in the lungs of BALB/c mice compared to RSV 3-12 and RSV A2 infection. These data correlate the heighted virulence and mucogenicity of RSV 2-20 with a diminished T cell response. RSV strain differences have an impact on RSV immunopathogenesis.
A model of natural oral Salmonella infection without the need for force-feeding (40.19)
Authors: McCarra Joshua , O'Donnell Hope , McSorley Stephen 
Published: January 2023

Abstract
The current murine model for Salmonella infection uses oral gavage, a methodology that forces large quantities of Salmonella into the stomach after pre-treatment with sodium bicarbonate. This methodology differs substantially from natural oral infections where small quantities of bacteria are delivered in contaminated food or water. In this study, we examined whether simply adding Salmonella to the drinking water of C57BL/6 mice could result in productive infection. Mice administered water bottles containing 1x10(9) cfu/ml of salmonella became sick and eventually succumbed to infection. While sodium bicarbonate treatment increased bacterial loads it was not required for successful infection. Mice could be productively infected with Salmonella using doses as low as 8x10(6) cfu/ml. We are currently examining the kinetics of bacterial infection and mucosal T cell activation using this new model of oral infection.
The compositional organization of Mycobacterium tuberculosis granulomas is analogous to ectopic lymphoid organs (40.2)
Authors: Slight Samantha , Rangel-Moreno Javier , Lin Yinyao , Selman Moises , Randall Troy , Khader Shabaana 
Published: January 2023

Abstract
Secondary lymphoid organs (SLOs) are integral in generating an effective adaptive immune response. Homing of cells to SLOs is a result of homeostatic chemokines, such as CXCL13. CXCL13, the ligand for CXCR5, is responsible for the recruitment of germinal center cells including B cells, T follicular helper (Tfh) cells and follicular dendritic cells (FDCs). Recently, CXCL13 has been reported in the lungs of mice following infection with Mycobacterium tuberculosis (Mtb). We found CXCL13 to be localized within the granuloma in both mice and human lungs as early as day 22 post infection in mice. In addition, we found Tfh cells, B cells, and FDCs localized within the granuloma of mice and humans. Recruitment of Tfh cells was seen in the draining lymph nodes by day 15 with accumulation in the lung by day 21 in Mtb infected mice. Infiltration of Tfh cells in the lung coincided with an increase in mRNA for known Tfh factors such as ICOS, BCL-6, IL-6 and IL-21, which followed upregulation of CXCL13 at day 18. Interestingly, another CXCR5+ population infiltrated the lung prior to accumulation of Tfh cells. These cells accumulate at day 12 and express surface markers suggestive of a monocyte lineage. Further, CXCR5-/- mice are more susceptible to Mtb infection by day 21. Our data suggest that the Mtb granuloma may function as an ectopic lymphoid organ, which may require involvement of CXCR5+ cells to elicit protective immunity.
Role of host lymphopenia in the immune reconstitution disease triggered by CD4 T cell transfer into mycobacterial infected T cell deficient mice (40.20)
Authors: Barber Daniel , Mayer-Barber Katrin , Antonelli Lis , Sher Alan 
Published: January 2023

Abstract
Approximately 10-30% of HIV patients develop a paradoxical inflammatory disease shortly after beginning anti-retroviral therapy (ART), termed Immune Reconstitution Inflammatory Syndrome (IRIS), that is emerging as a major problem in the clinical management of the HIV pandemic. Patients with the lowest CD4 counts, the most rapid drop in viral loads after ART and an AIDS defining illness, such as mycobacterial infection, are at highest risk. This indicates that T cell reconstitution itself may be pathogenic rather than beneficial when CD4 T cells suddenly repopulate a lymphopenic host harboring an opportunistic infection. Here we demonstrate that a rapidly fatal wasting occurs in mice when CD4 T cells are transferred into Mycobacterium avium infected TCRαKO animals. This reconstitution disease was dependent on IFNγ and TNFα but not IL-4 or IL-17A. Non-specific T cells induced no disease, but transfer of T cells specific for bacterial or endogenous antigens was rapidly lethal. Importantly, M. avium infected TCRαKO and ovalbumin-specific TCR Tg mice were susceptible hosts, whereas M. avium-specific TCR Tg mice were resistant to reconstitution disease. These data demonstrate that during M. avium infection of lymphopenic hosts the lack of bacteria-specific T cells, rather than the lymphopenic environment per se, predisposes the host to develop reconstitution disease when repopulating CD4 T cells encounter Ag. This work was supported by the NIAID intramural research program.
Predominant IFN-γ-mediated expression of CXCL9, CXCL10, and CCL5 proteins in the brain during chronic infection with Toxoplasma gondii in BALB/c mice resistant to development of toxoplasmic encephalitis (40.21)
Authors: Suzuki Yasuhiro , Kudo Tomoya , Wen Xiangshu , Payne Laura , Wang Xisheng , Rodgers Laurel 
Published: January 2023

Abstract
We examined the role of IFN-γ in expression of chemokine mRNA and proteins in the brain during chronic infection with Toxoplasma gondii using BALB/c and BALB/c-background IFN-γ knockout (IFN-γ-/-) mice. BALB/c mice are genetically resistant to development of toxoplasmic encephalitis and establish a latent, chronic infection in the brain through IFN-γ-mediated immune responses. Amounts of mRNA for CXCL9, CXCL10, CXCL11, CCL2, CCL3, and CCL5 significantly increased in the brains of wild-type mice after infection. CXCL9, CXCL10, and CCL5 mRNA were most abundant among these chemokines. An increase in amounts of mRNA for CXCL10, CCL2, CCL3, and CCL5 was also observed in the brains of IFN-γ-/- mice after infection, although CXCL10 and CCL5 mRNA levels in infected IFN-γ-/- mice were significantly lower than those of infected wild-type animals. Amounts of mRNA for CXCL9 and CXCL11 remained at the basal levels in infected IFN-γ-/- mice. When amounts of the chemokine proteins were examined in the brain homogenates of uninfected and infected mice of both strains, large amounts of CXCL9, CXCL10, and CCL5 were detected only in infected wild-type animals. These results indicate that CXCL9, CXCL10, and CCL5 are the chemokines predominantly induced in the brains of genetically resistant BALB/c mice during chronic infection with T. gondii, and their expression is dependent on IFN-γ.