Immunology of Infectious Disease Commons^™

Iiv-6 Inhibits Nf-Kappab Responses In Drosophila, Cara C. West, Florentina Rus, Ying Chen, Anni Kleino, Monique Gangloff, Don B. Gammon, Neal S. Silverman

Neal Silverman

The host immune response and virus-encoded immune evasion proteins pose constant, mutual selective pressure on each other. Virally encoded immune evasion proteins also indicate which host pathways must be inhibited to allow for viral replication. Here, we show that IIV-6 is capable of inhibiting the two Drosophila NF-kappaB signaling pathways, Imd and Toll. Antimicrobial peptide (AMP) gene induction downstream of either pathway is suppressed when cells infected with IIV-6 are also stimulated with Toll or Imd ligands. We find that cleavage of both Imd and Relish, as well as Relish nuclear translocation, three key points in Imd signal transduction, occur …

Control Of Antiviral Innate Immune Response By Protein Geranylgeranylation, Shigao Yang, Zhaozhao Jiang, Katherine A. Fitzgerald, Donghai Wang

Katherine A. Fitzgerald

The mitochondrial antiviral signaling protein (MAVS) orchestrates host antiviral innate immune response to RNA virus infection. However, how MAVS signaling is controlled to eradicate virus while preventing self-destructive inflammation remains obscure. Here, we show that protein geranylgeranylation, a posttranslational lipid modification of proteins, limits MAVS-mediated immune signaling by targeting Rho family small guanosine triphosphatase Rac1 into the mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) at the mitochondria-ER junction. Protein geranylgeranylation and subsequent palmitoylation promote Rac1 translocation into MAMs upon viral infection. MAM-localized Rac1 limits MAVS' interaction with E3 ligase Trim31 and hence inhibits MAVS ubiquitination, aggregation, and activation. Rac1 also facilitates …

Central Role Of Il-23 And Il-17 Producing Eosinophils As Immunomodulatory Effector Cells In Acute Pulmonary Aspergillosis And Allergic Asthma, Evelyn V. Santos Guerra, Chrono K. Lee, Charles A. Specht, Bhawna Yadav, Haibin Huang, Ali Akalin, Jun R. Huh, Christian Mueller, Stuart M. Levitz

Christian Mueller

Aspergillus fumigatus causes invasive pulmonary disease in immunocompromised hosts and allergic asthma in atopic individuals. We studied the contribution of lung eosinophils to these fungal diseases. By in vivo intracellular cytokine staining and confocal microscopy, we observed that eosinophils act as local sources of IL-23 and IL-17. Remarkably, mice lacking eosinophils had a >95% reduction in the percentage of lung IL-23p19+ cells as well as markedly reduced IL-23 heterodimer in lung lavage fluid. Eosinophils killed A. fumigatus conidia in vivo. Eosinopenic mice had higher mortality rates, decreased recruitment of inflammatory monocytes, and decreased expansion of lung macrophages after challenge with …

A Fluorescent Reporter Mouse For Inflammasome Assembly Demonstrates An Important Role For Cell-Bound And Free Asc Specks During In Vivo Infection, Te-Chen Tzeng, Stefan A. Schattgen, Brian G. Monks, Donghai Wang, Anna M. Cerny, Eicke Latz, Katherine A. Fitzgerald, Douglas T. Golenbock

Katherine A. Fitzgerald

Inflammasome activation is associated with numerous diseases. However, in vivo detection of the activated inflammasome complex has been limited by a dearth of tools. We have developed transgenic mice that ectopically express the fluorescent adaptor protein, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and characterized the formation of assembled inflammasome complexes ("specks") in primary cells and tissues. In addition to hematopoietic cells, we have found that a stromal population in the lung tissues formed specks during the early phase of influenza infection, whereas myeloid cells showed speck formation after 2 days. In a peritonitis and group B streptococcus …

Genomic Insights Into The Ixodes Scapularis Tick Vector Of Lyme Disease, Monika Gulia-Nuss,, Daniel R. Caffrey, Neal S. Silverman, Adam R. Wespiser, Catherine A. Hill

Neal Silverman

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing approximately 57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, …

Hla Class I Supertype Associations With Clinical Outcome Of Secondary Dengue Virus Infections In Ethnic Thais, Sasijit Vejbaesya, Rungrot Thongpradit, Siripen Kalayanarooj, Komon Luangtrakool, Panpimon Luangtrakool, Robert V. Gibbons, Duangporn Srinak, Somporn Ngammthaworn, Kusuma Apisawes, In-Kyu Yoon, Stephen J. Thomas, Richard G. Jarman, Anon Srikiatkhachorn, Sharone Green, Dasnayanee Chandanayingyong, Sangshin Park, Jennifer Friedman, Alan L. Rothman, Henry A.F. Stephens

Sharone Green

BACKGROUND: Human leukocyte antigen (HLA) supertypes are groups of functionally related alleles that present structurally similar antigens to the immune system.

OBJECTIVES: To analyze HLA class I supertype associations with clinical outcome in hospitalized Thai children with acute dengue illness.

METHODS: Seven hundred sixty-two patients and population-matched controls recruited predominantly in Bangkok were HLA-A and -B typed. HLA supertype frequencies were compared and tested for significant dengue disease associations using logistic regression analyses. Multivariable models were built by conducting forward stepwise selection procedures.

RESULTS: In the final logistic regression model, the HLA-B44 supertype was protective against dengue hemorrhagic fever (DHF) …

Human Type 2 Myeloid Dendritic Cells Produce Interferon-Lambda And Amplify Interferon-Alpha In Response To Hepatitis C Virus Infection, Shuye Zhang, Karen Kodys, Kui Li, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND and AIMS: The type III interferons (IFN-lambdas: interleukin [IL]-28a, IL-28b, and IL-29) have important roles in hepatitis C virus (HCV) infection, but little is understood about what cells produce these cytokines or how production is activated. We investigated whether human immune cells recognize HCV-infected cells and respond by producing IFN-lambda. METHODS: We cultured healthy human peripheral blood mononuclear cells (PBMCs) with different populations of immune cells and Japanese fulminant hepatitis-1 (JFH-1) HCV-infected Huh7.5 (cell culture-derived HCV particles [HCVcc]/Huh7.5) cells. RESULTS: Human PBMCs recognized HCVcc/Huh7.5 cells and responded by producing IFN-alpha, IFN-gamma, and IFN-lambda. A rare subset of myeloid dendritic …

Innate Immune Cell Networking In Hepatitis C Virus Infection, Banishree Saha, Gyongyi Szabo

Gyongyi Szabo

Persistent viral infection, such as HCV infection, is the result of the inability of the host immune system to mount a successful antiviral response, as well as the escape strategies devised by the virus. Although each individual component of the host immune system plays important roles in antiviral immunity, the interactive network of immune cells as a whole acts against the virus. The innate immune system forms the first line of host defense against viral infection, and thus, virus elimination or chronic HCV infection is linked to the direct outcome of the interactions between the various innate immune cells and …

Caspase-8 And Rip Kinases Regulate Bacteria-Induced Innate Immune Responses And Cell Death, Dan Weng, Robyn Lynn Marty-Roix, Sandhya Ganesan, Megan K. Proulx, Gregory I. Vladimer, William J. Kaiser, Edward S. Mocarski, Kimberly Lea Pouliot, Francis Ka-Ming Chan, Michelle A. Kelliher, Phillip A. Harris, John Bertin, Peter J. Gough, Dmitry M. Shayakhmetov, Jon D. Goguen, Katherine A. Fitzgerald, Neal S. Silverman, Egil Lien

Katherine A. Fitzgerald

A number of pathogens cause host cell death upon infection, and Yersinia pestis, infamous for its role in large pandemics such as the "Black Death" in medieval Europe, induces considerable cytotoxicity. The rapid killing of macrophages induced by Y. pestis, dependent upon type III secretion system effector Yersinia outer protein J (YopJ), is minimally affected by the absence of caspase-1, caspase-11, Fas ligand, and TNF. Caspase-8 is known to mediate apoptotic death in response to infection with several viruses and to regulate programmed necrosis (necroptosis), but its role in bacterially induced cell death is poorly understood. Here we provide genetic …

Caspase-8 And Rip Kinases Regulate Bacteria-Induced Innate Immune Responses And Cell Death, Dan Weng, Robyn Lynn Marty-Roix, Sandhya Ganesan, Megan K. Proulx, Gregory I. Vladimer, William J. Kaiser, Edward S. Mocarski, Kimberly Lea Pouliot, Francis Ka-Ming Chan, Michelle A. Kelliher, Phillip A. Harris, John Bertin, Peter J. Gough, Dmitry M. Shayakhmetov, Jon D. Goguen, Katherine A. Fitzgerald, Neal S. Silverman, Egil Lien

Neal Silverman

A number of pathogens cause host cell death upon infection, and Yersinia pestis, infamous for its role in large pandemics such as the "Black Death" in medieval Europe, induces considerable cytotoxicity. The rapid killing of macrophages induced by Y. pestis, dependent upon type III secretion system effector Yersinia outer protein J (YopJ), is minimally affected by the absence of caspase-1, caspase-11, Fas ligand, and TNF. Caspase-8 is known to mediate apoptotic death in response to infection with several viruses and to regulate programmed necrosis (necroptosis), but its role in bacterially induced cell death is poorly understood. Here we provide genetic …

Caspase-8 And Rip Kinases Regulate Bacteria-Induced Innate Immune Responses And Cell Death, Dan Weng, Robyn Lynn Marty-Roix, Sandhya Ganesan, Megan K. Proulx, Gregory I. Vladimer, William J. Kaiser, Edward S. Mocarski, Kimberly Lea Pouliot, Francis Ka-Ming Chan, Michelle A. Kelliher, Phillip A. Harris, John Bertin, Peter J. Gough, Dmitry M. Shayakhmetov, Jon D. Goguen, Katherine A. Fitzgerald, Neal S. Silverman, Egil Lien

Robyn Marty-Roix

A number of pathogens cause host cell death upon infection, and Yersinia pestis, infamous for its role in large pandemics such as the "Black Death" in medieval Europe, induces considerable cytotoxicity. The rapid killing of macrophages induced by Y. pestis, dependent upon type III secretion system effector Yersinia outer protein J (YopJ), is minimally affected by the absence of caspase-1, caspase-11, Fas ligand, and TNF. Caspase-8 is known to mediate apoptotic death in response to infection with several viruses and to regulate programmed necrosis (necroptosis), but its role in bacterially induced cell death is poorly understood. Here we provide genetic …

Naı¨Ve T Cells Re-Distribute To The Lungs Of Selectin Ligand Deficient Mice, Thandi M. Onami, John R. Harp

Thandi M. Onami

BACKGROUND: Selectin mediated tethering represents one of the earliest steps in T cell extravasation into lymph nodes via high endothelial venules and is dependent on the biosynthesis of sialyl Lewis X (sLe(x)) ligands by several glycosyltransferases, including two fucosyltransferases, fucosyltransferase-IV and -VII. Selectin mediated binding also plays a key role in T cell entry to inflamed organs. METHODOLOGY/PRINCIPAL FINDINGS: To understand how loss of selectin ligands (sLe(x)) influences T cell migration to the lung, we examined fucosyltransferase-IV and -VII double knockout (FtDKO) mice. We discovered that FtDKO mice showed significant increases (approximately 5-fold) in numbers of naïve T cells in …

The Generation Of Influenza-Specific Humoral Responses Is Impaired In St6gal I-Deficient Mice., Thandi M. Onami, J Zeng, H. M. Joo, B. Rajini, J. P. Wrammert, M. Y. Sangster

Thandi M. Onami

Posttranslational modification of proteins, such as glycosylation, can impact cell signaling and function. ST6Gal I, a glycosyltransferase expressed by B cells, catalyzes the addition of alpha-2,6 sialic acid to galactose, a modification found on N-linked glycoproteins such as CD22, a negative regulator of B cell activation. We show that SNA lectin, which binds alpha-2,6 sialic acid linked to galactose, shows high binding on plasma blasts and germinal center B cells following viral infection, suggesting ST6Gal I expression remains high on activated B cells in vivo. To understand the relevance of this modification on the antiviral B cell immune response, we …

Role Of Chromodomain Helicase Dna-Binding Protein 2 In Dna Damage Response Signaling And Tumorigenesis., Thandi M. Onami, P. Nagarajan, S. Rajagopalan, S. Kania, R. Donnell, S. Venkatachalam

Thandi M. Onami

The chromodomain helicase DNA-binding proteins (CHDs) are known to affect transcription through their ability to remodel chromatin and modulate histone deacetylation. In an effort to understand the functional role of the CHD2 in mammals, we have generated a Chd2 mutant mouse model. Remarkably, the Chd2 protein appears to play a critical role in the development, hematopoiesis and tumor suppression. The Chd2 heterozygous mutant mice exhibit increased extramedullary hematopoiesis and susceptibility to lymphomas. At the cellular level, Chd2 mutants are defective in hematopoietic stem cell differentiation, accumulate higher levels of the chromatin-associated DNA damage response mediator, cH2AX, and exhibit an aberrant …

Systemic And Mucosal Infection Program Protective Memory Cd8 T Cells In The Vaginal Mucosa., Thandi M. Onami, P. K. Suvas, H. M. Dech, J. Zeng

Thandi M. Onami

Whether mucosal immunization is required for optimal protective CD8 T cell memory at mucosal surfaces is controversial. In this study, using an adoptive transfer system, we compare the efficacy of two routes of acute lymphocytic choriomeningitis viral infection on the generation, maintenance, and localization of Ag-specific CD8 T cells in tissues, including the vaginal mucosa. Surprisingly, at day 8, i.p. infection results in higher numbers of Ag-specific CD8 T cells in the vaginal mucosa and iliac lymph node, as well as 2-3x more Ag-specific CD8 T cells that coexpress both IFN-gamma and TNF-alpha in comparison to the intranasal route of …

Lack Of Antigen-Specific Tissue Remodeling In Mice Deficient In The Macrophage Galactose-Type Calcium-Type Lectin 1/Cd301a., Thandi M. Onami, K. Sato, Y. Imai, N. Higashi, Y. Kumamoto, S. M. Hedrick, T. Irimura

Thandi M. Onami

Macrophage galactose-type C-type lectins (MGLs), which were recently named CD301, have 2 homologues in mice: MGL1 and MGL2. MGLs are expressed on macrophages and immature dendritic cells. The persistent presence of granulation tissue induced by a protein antigen was observed in wild-type mice but not in mice lacking an endogenous, macrophage-specific, galactose-type calcium-type lectin 1 (MGL1) in an air pouch model. The anti-MGL1 antibody suppressed the granulation tissue formation in wild-type mice. A large number of cells, present only in the pouch of MGL1-deficient mice, were not myeloid or lymphoid lineage cells and the number significantly declined after administration of …

Cd43 Modulates Severity And Onset Of Experimental Autoimmune Encephalomyelitis., Thandi M. Onami, M. L. Ford, A. Sperling, R. Ahmed, B. D. Evavold

Thandi M. Onami

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis characterized by infiltration of activated CD4(+) T lymphocytes into tissues of the CNS. This study investigated the role of CD43 in the induction and progression of EAE. Results demonstrate that CD43-deficient mice have reduced and delayed clinical and histological disease severity relative to CD43(+/+) mice. This reduction was characterized by decreased CD4(+) T cell infiltration of the CNS of CD43(-/-) mice but similar numbers of Ag-specific T cells in the periphery, suggesting a defect in T cell trafficking to the CNS. The absence of CD43 also affected cytokine production, …

Primary And Secondary Immunocompetence In Mixed Allogeneic Chimeras, Thandi M. Onami, M. A. Williams, A. B. Adams, M. B. Walsh, N. Shirasugi, T. C. Pearson, R. Ahmed, C. P. Larsen

Thandi M. Onami

Targeted disruption of T cell costimulatory pathways, particularly CD28 and CD40, has allowed for the development of minimally myeloablative strategies for the induction of mixed allogeneic chimerism and donor-specific tolerance across full MHC barriers. In this study we analyze in depth the ability of mixed allogeneic chimeras in two strain combinations to mount effective host-restricted and donor-restricted antiviral CD4 and CD8 responses, as well as the impact of development of mixed chimerism on the maintenance of pre-existing memory populations. While antiviral CD8 responses in mixed chimeras following acute viral infection with lymphocytic choriomeningitis virus Armstrong or vaccinia virus are largely …

Tcr Signal Transduction In Antigen-Specific Memory Cd8 T Cells, Thandi M. Onami, Ellen N. Kersh, Susan M. Kaech, Miriana Moran, E. John Wherry, M. Carrie Miceli, Rafi Ahmed

Thandi M. Onami

Memory T cells are more responsive to Ag than naive cells. To determine whether memory T cells also have more efficient TCR signaling, we compared naive, effector, and memory CD8 T cells of the same antigenic specificity. Surprisingly, initial CD3 signaling events are indistinguishable. However, memory T cells have more extensive lipid rafts with higher phosphoprotein content before TCR engagement. Upon activation in vivo, they more efficiently induce phosphorylation of-LAT (linker for activation of T cells), ERK (extracellular signal-regulated kinase), JNK (c-Jun N-terminal kinase), and p38. Thus, memory CD8 T cells do not increase their TCR sensitivity, but are better …

Cutting Edge: Persistent Viral Infection Prevents Tolerance Induction And Escapes Immune Control Following Cd28/Cd40 Blockade-Based Regimen, Thandi M. Onami, M. A. Williams, A. B. Adams, M. M. Durham, T. C. Pearson, R. Ahmed, C. P. Larsen

Thandi M. Onami

A continuing concern with CD28 and/or CD40 blockade-based strategies to induce tolerance and mixed chimerism is their potential to disrupt protective immunity to preexisting infections. In this report, we find that preexisting persistent infection with lymphocytic choriomeningitis virus (LCMV) clone 13 prevents the induction of tolerance, mixed chimerism, and donor-reactive T cell deletion. Mice continue to be refractory to tolerance induction even after viremia has been resolved and virus is present only at very low levels in peripheral tissues. Conversely, we find that the full tolerance regimen, or costimulation blockade alone, specifically inhibits already ongoing antiviral immune responses, leading to …

Molecular Cloning And Characterization Of A Novel Mouse Macrophage C-Type Lectin, Mmgl2, Which Has A Distinct Carbohydrate Specificity From Mmgl1, Thandi M. Onami, M. Tsuiji, M. Fujimori, Y. Ohashi, N. Higashi, S. M. Hendrick, T. Irimura

Thandi M. Onami

A novel mouse macrophage galactose-type C-type lectin 2 (mMGL2) was identified by BLAST analysis of expressed sequence tags. The sequence of mMGL2 is highly homologous to the mMGL, which should now be called mMGL1. The open reading frame of mMGL2 contains a sequence corresponding to a type II transmembrane protein with 332 amino acids having a single extracellular C-type lectin domain. The 3'-untranslated region included long terminal repeats of mouse early transposon. The Mgl2 gene was cloned from a 129/SvJ mouse genomic library and sequenced. The gene spans 7,136 base pairs and consists of 10 exons, which is similar to …

Generation Of Mice Deficient For Macrophage Galactose- And N-Acetylgalactosamine-Specific Lectin: Limited Role In Lymphoid And Erythroid Homeostasis And Evidence For Multiple Lectins, Thandi M. Onami, M. Y. Lin, D. M. Page, S. A. Reynolds, C. D. Katayama, J. D. Marth, T. Irimura, A. Varki, N. Varki, S. M. Hedrick

Thandi M. Onami

Macrophage receptors function in pattern recognition for the induction of innate immunity, in cellular communication to mediate the regulation of adaptive immune responses, and in the clearance of some glycosylated cells or glycoproteins from the circulation. They also function in homeostasis by initiating the engulfment of apoptotic cells. Evidence has suggested that macrophage receptors function to recognize cells that are destined for programmed cell death but not yet overtly apoptotic. We have examined the function of a macrophage receptor specific for unsialylated glycoproteins, known as the mouse macrophage galactose- and N-acetylgalactosamine-specific lectin (mMGL) (Ii et al., J. Biol. Chem. 265:11295-11298, …

Dynamic Regulation Of T Cell Immunity By Cd43, Thandi M. Onami, L. E. Harrington, M. A. Williams, M. Galvan, C. P. Larsen, T. C. Pearson, N. Manjunath, L. G. Baum, B. D. Pearce, R. Ahmed

Thandi M. Onami

During a viral response, Ag-specific effector T cells show dramatically increased binding by the mAb 1B11 and the lectin peanut agglutinin (PNA). We investigated the contribution of CD43 expression to 1B11 and PNA binding as well as its role in generation and maintenance of a CD8 T cell response. Analysis of CD43(-/-) mice revealed no increased 1B11 binding and reduced PNA binding on virus-specific CD8 T cells from -/- mice compared with +/+ mice. Furthermore, we examined the role of CD43 in the kinetics of an immune response. We show that CD43 expression modestly effects generation of a primary virus-specific …