scholarly journals Preferential Activation of Toll-Like Receptor Nine by CD46-Utilizing Adenoviruses

2006 ◽  
Vol 81 (3) ◽  
pp. 1305-1312 ◽  
Author(s):  
Milena Iacobelli-Martinez ◽  
Glen R. Nemerow
Keyword(s):  
Mononuclear Cells ◽  
Vaccine Development ◽  
Type I ◽  
Immune Recognition ◽  
Toll Like Receptor ◽  
Peripheral Blood Mononuclear ◽  
Host Immune Responses ◽  
Entry Pathway ◽  
Endosomal Acidification ◽  
Adenovirus Receptor

ABSTRACT Adenoviruses (Ads) are responsible for respiratory, ocular, and gastrointestinal illnesses in humans. While the majority of serotypes utilize coxsackievirus-adenovirus receptor (CAR) as their primary attachment receptor, subgroup B and subgroup D Ad37 serotypes use CD46. Given the propensity of Ad vectors to activate host immune responses, we sought to investigate their potential for type I interferon induction. We found that CD46 Ads were capable of alpha interferon (IFN-α) induction by peripheral blood mononuclear cells and that plasmacytoid dendritic cells (pDCs) were the principal producers of this cytokine. IFN-α induction correlated with the permissivity of pDCs to CD46- but not CAR-utilizing Ad serotypes. A role for Toll-like receptor 9 (TLR9) recognition of Ad was supported by the requirement for viral DNA and efficient endosomal acidification and by the ability of a TLR9-inhibitory oligonucleotide to attenuate IFN-α induction. Cell lines expressing TLR9 that are permissive to infection by both CAR- and CD46-utilizing serotypes showed a preferential induction of TLR9-mediated events by CD46-utilizing Ads. Specifically, the latter virus types induced higher levels of cytokine expression and NF-κB activation in HeLa cells than CAR-dependent Ad types, despite equivalent infection rates. Therefore, infectivity alone is not sufficient for TLR9 activation, but this activation instead is regulated by a specific receptor entry pathway. These data reveal a novel mode of host immune recognition of Ad with implications for Ad pathogenesis and for the use of unconventional Ad vectors for gene delivery and vaccine development.

scholarly journals Toll-Like Receptor 7 Agonist GS-9620 Induces HIV Expression and HIV-Specific Immunity in Cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Angela Tsai ◽  
Alivelu Irrinki ◽  
Jasmine Kaur ◽  
Tomas Cihlar ◽  
George Kukolj ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Mononuclear Cells ◽  
Antiviral Immunity ◽  
Type I ◽  
Toll Like Receptor ◽  
Peripheral Blood Mononuclear ◽  
Effector Functions ◽  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv

ABSTRACT Antiretroviral therapy can suppress HIV replication to undetectable levels but does not eliminate latent HIV, thus necessitating lifelong therapy. Recent efforts to target this persistent reservoir have focused on inducing the expression of latent HIV so that infected cells may be recognized and eliminated by the immune system. Toll-like receptor (TLR) activation stimulates antiviral immunity and has been shown to induce HIV from latently infected cells. Activation of TLR7 leads to the production of several stimulatory cytokines, including type I interferons (IFNs). In this study, we show that the selective TLR7 agonist GS-9620 induced HIV in peripheral blood mononuclear cells (PBMCs) from HIV-infected individuals on suppressive antiretroviral therapy. GS-9620 increased extracellular HIV RNA 1.5- to 2-fold through a mechanism that required type I IFN signaling. GS-9620 also activated HIV-specific T cells and enhanced antibody-mediated clearance of HIV-infected cells. Activation by GS-9620 in combination with HIV peptide stimulation increased CD8 T cell degranulation, production of intracellular cytokines, and cytolytic activity. T cell activation was again dependent on type I IFNs produced by plasmacytoid dendritic cells. GS-9620 induced phagocytic cell maturation and improved effector-mediated killing of HIV-infected CD4 T cells by the HIV envelope-specific broadly neutralizing antibody PGT121. Collectively, these data show that GS-9620 can activate HIV production and improve the effector functions that target latently infected cells. GS-9620 may effectively complement orthogonal therapies designed to stimulate antiviral immunity, such as therapeutic vaccines or broadly neutralizing antibodies. Clinical studies are under way to determine if GS-9620 can target HIV reservoirs. IMPORTANCE Though antiretroviral therapies effectively suppress viral replication, they do not eliminate integrated proviral DNA. This stable intermediate of viral infection is persistently maintained in reservoirs of latently infected cells. Consequently, lifelong therapy is required to maintain viral suppression. Ultimately, new therapies that specifically target and eliminate the latent HIV reservoir are needed. Toll-like receptor agonists are potent enhancers of innate antiviral immunity that can also improve the adaptive immune response. Here, we show that a highly selective TLR7 agonist, GS-9620, activated HIV from peripheral blood mononuclear cells isolated from HIV-infected individuals with suppressed infection. GS-9620 also improved immune effector functions that specifically targeted HIV-infected cells. Previously published studies on the compound in other chronic viral infections show that it can effectively induce immune activation at safe and tolerable clinical doses. Together, the results of these studies suggest that GS-9620 may be useful for treating HIV-infected individuals on suppressive antiretroviral therapy.

Class I–unrestricted noncytotoxic anti–HTLV-I activity of CD8+ T cells

Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1994-1995 ◽  
Author(s):  
Masako Moriuchi ◽  
Hiroyuki Moriuchi
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Mononuclear Cells ◽  
Membrane Filter ◽  
Cd8 T Cell ◽  
Class I ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Permeable Membrane

Abstract Although it is widely believed that viral clearance is mediated principally by the destruction of infected cells by cytotoxic T cells, noncytolytic antiviral activity of CD8+ T cells may play a role in preventing the progression to disease in infections with immunodeficiency viruses and hepatitis B virus. We demonstrate here that (1) replication of human T-lymphotropic virus type I (HTLV-I) is more readily detected from CD8+ T-cell–depleted (CD8−) peripheral blood mononuclear cells (PBMCs) of healthy HTLV-I carriers than from unfractionated PBMCs, (2) cocultures of CD8− PBMCs with autologous or allogeneic CD8+ T cells suppressed HTLV-I replication, and (3) CD8+ T-cell anti-HTLV-I activity is not abrogated intrans-well cultures in which CD8+ cells are separated from CD8− PBMCs by a permeable membrane filter. These results suggest that class I-unrestricted noncytolytic anti–HTLV-I activity is mediated, at least in part by a soluble factor(s), and may play a role in the pathogenesis of HTLV-I infection.

scholarly journals The 2′-O-methylation status of a single guanosine controls transfer RNA–mediated Toll-like receptor 7 activation or inhibition

2012 ◽  
Vol 209 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Stefanie Jöckel ◽  
Gernot Nees ◽  
Romy Sommer ◽  
Yang Zhao ◽  
Dmitry Cherkasov ◽  
...  
Keyword(s):  
Influenza A ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Thermus Thermophilus ◽  
Methylation Status ◽  
Transfer Rna ◽  
Type I ◽  
Peripheral Blood Mononuclear ◽  
Molecular Pattern

Foreign RNA serves as pathogen-associated molecular pattern (PAMP) and is a potent immune stimulator for innate immune receptors. However, the role of single bacterial RNA species in immune activation has not been characterized in detail. We analyzed the immunostimulatory potential of transfer RNA (tRNA) from different bacteria. Interestingly, bacterial tRNA induced type I interferon (IFN) and inflammatory cytokines in mouse dendritic cells (DCs) and human peripheral blood mononuclear cells (PBMCs). Cytokine production was TLR7 dependent because TLR7-deficient mouse DCs did not respond and TLR7 inhibitory oligonucleotides inhibited tRNA-mediated activation. However, not all bacterial tRNA induced IFN-α because tRNA from Escherichia coli Nissle 1917 and Thermus thermophilus were non-immunostimulatory. Of note, tRNA from an E. coli knockout strain for tRNA (Gm18)-2′-O-methyltransferase (trmH) regained immunostimulatory potential. Additionally, in vitro methylation of this immunostimulatory Gm18-negative tRNA with recombinant trmH from T. thermophilus abolished its IFN-α inducing potential. More importantly, Gm18-modified tRNA acted as TLR7 antagonist and blocked IFN-α induction of influenza A virus–infected PBMCs.

Toll like receptor 9 (TLR 9) expression in peripheral blood mononuclear cell (PBMCs) from treated and untreated Grave’s disease patients

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ashraf M Okba ◽  
Rasha Y Shaheen ◽  
Gehan M. H Mostafa ◽  
Hanan M Ali ◽  
Sylvia W Abo El Fadle ◽  
...  
Keyword(s):  
Peripheral Blood Mononuclear Cell ◽  
Mononuclear Cell ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Peripheral Blood Lymphocytes ◽  
Graves Disease ◽  
Toll Like Receptor ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Abstract Background It is well known that Autoimmune thyroid disease is multifactorial with multiple genetic and environmental factors, immune malfunction also incriminated in the development of this disease, The exact pathogenesis of this disease remains unclear despite the fact that the production of autoantibodies destroys self-tolerance and agitate the adaptive immune system. Our study will answer the question is there a difference in Toll like receptor 9 (TLR 9) expression in peripheral blood mononuclear cell (PBMCs) from Grave’s disease patients. Objective to measure TLR9 percentage expression on peripheral blood mononuclear cells in patients with Graves’ disease. Methods 60 subjects were included in this study; 30 with Graves’ disease and 30 healthy individuals as control group. All the patients were subjected to the following: Full history, clinical examination, thyroid functions, Thyroid ultrasound, Radioisotope thyroid scan: to assess uptake of thyroid gland and Toll like receptor 9 (TLR 9) percentage expression on peripheral blood mononuclear cells will be analyzed using flow cytometry technique. Results The present study proved that patients with Graves’ disease had higher levels of percentage expression of TLR 9 on peripheral blood lymphocytes. Conclusion percentage expression of TLR9 on peripheral blood lymphocytes is higher in Graves’ patients.

scholarly journals Cloning, Expression, and Immunological Evaluation of Two Putative Secreted Serine Protease Antigens ofMycobacterium tuberculosis

1999 ◽  
Vol 67 (8) ◽  
pp. 3998-4007 ◽  
Author(s):  
Yasir A. W. Skeiky ◽  
Michael J. Lodes ◽  
Jeffrey A. Guderian ◽  
Raodoh Mohamath ◽  
Teresa Bement ◽  
...  
Keyword(s):  
Serine Protease ◽  
Recombinant Proteins ◽  
Mononuclear Cells ◽  
Vaccine Development ◽  
High Titer ◽  
In Vitro Assays ◽  
Protease Gene ◽  
Expression Library ◽  
Peripheral Blood Mononuclear ◽  
Polyclonal Rabbit

ABSTRACT Culture filtrate proteins (CFP) of Mycobacterium tuberculosis have been shown to contain immunogenic components that elicit at least partial protective immunity againstMycobacterium infection. To clone genes encoding some of the immunogenic proteins, we made a high-titer rabbit anti-CFP serum and used it to screen an M. tuberculosis genomic expression library in Escherichia coli. In this paper, we describe the molecular cloning of two new protein components of CFP and identified them as members of the serine protease gene family. Their open reading frames contain N-terminal hydrophobic secretory signals consistent with their detection in CFP. The predicted molecular masses of the mature, fully processed forms of both antigens are ∼32 kDa, in agreement with their observed sizes on immunoblots of CFP probed with polyclonal rabbit antisera made to the recombinant proteins. Thus, these proteins have been designated MTB32A and MTB32B. Interestingly, and despite 66% amino acid sequence homology between the two proteins, polyclonal rabbit antisera made to each of the recombinant proteins were found to be specific for the respective immunizing antigens. The recombinant proteins were also evaluated in in vitro assays with donor peripheral blood mononuclear cells (PBMC) from healthy purified protein derivative (PPD)-positive individuals of diverse ethnic backgrounds. MTB32A but not MTB32B stimulated PBMC from healthy PPD-positive donors but not from PPD-negative donors to proliferate and secrete gamma interferon. MTB32A is encoded by a single-copy gene which is present in both virulent and avirulent strains of the M. tuberculosiscomplex and the BCG strain of Mycobacterium bovis but absent in the environmental mycobacterial species tested. In addition, nucleotide sequence comparison of mtb32a of the avirulent H37Ra strain and the virulent Erdman strain, as well as with the corresponding sequences (identified in the databases) of strain H37Rv and the clinical isolate CSU93, revealed 100% identity. MTB32A, therefore, represents a candidate for inclusion in subunit vaccine development. Finally, the possible role of MTB32 serine proteases as a virulence factor(s) during Mycobacterium spp. infection is discussed.

scholarly journals Integrated single-cell analysis unveils diverging immune features of COVID-19, influenza, and other community-acquired pneumonia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alex R Schuurman ◽  
Tom DY Reijnders ◽  
Anno Saris ◽  
Ivan Ramirez Moral ◽  
Michiel Schinkel ◽  
...  
Keyword(s):  
Single Cell ◽  
Influenza A ◽  
Mononuclear Cells ◽  
Single Cell Analysis ◽  
Community Acquired Pneumonia ◽  
Type I ◽  
Cell Analysis ◽  
Peripheral Blood Mononuclear ◽  
The Common ◽  
Peripheral Immune Response

The exact immunopathophysiology of community-acquired pneumonia (CAP) caused by SARS-CoV-2 (COVID-19) remains clouded by a general lack of relevant disease controls. The scarcity of single-cell investigations in the broader population of patients with CAP renders it difficult to distinguish immune features unique to COVID-19 from the common characteristics of a dysregulated host response to pneumonia. We performed integrated single-cell transcriptomic and proteomic analyses in peripheral blood mononuclear cells from a matched cohort of eight patients with COVID-19, eight patients with CAP caused by Influenza A or other pathogens, and four non-infectious control subjects. Using this balanced, multi-omics approach, we describe shared and diverging transcriptional and phenotypic patterns—including increased levels of type I interferon-stimulated natural killer cells in COVID-19, cytotoxic CD8 T EMRA cells in both COVID-19 and influenza, and distinctive monocyte compositions between all groups—and thereby expand our understanding of the peripheral immune response in different etiologies of pneumonia.

scholarly journals Elevated STAT1 expression but not phosphorylation in lupus B cells correlates with disease activity and increased plasmablast susceptibility

Rheumatology ◽  
2020 ◽  
Vol 59 (11) ◽  
pp. 3435-3442 ◽  
Author(s):  
Arman Aue ◽  
Franziska Szelinski ◽  
Sarah Y Weißenberg ◽  
Annika Wiedemann ◽  
Thomas Rose ◽  
...  
Keyword(s):  
B Cells ◽  
Disease Activity ◽  
B Cell ◽  
Mononuclear Cells ◽  
Janus Kinase ◽  
T Cell Subsets ◽  
Type I ◽  
Type I Ifn ◽  
Peripheral Blood Mononuclear ◽  
B Cell Subsets

Abstract Objectives SLE is characterized by two pathogenic key signatures, type I IFN and B-cell abnormalities. How these signatures are interrelated is not known. Type I-II IFN trigger activation of Janus kinase (JAK) – signal transducer and activator of transcription (STAT). JAK-STAT inhibition is an attractive therapeutic possibility for SLE. We assess STAT1 and STAT3 expression and phosphorylation at baseline and after IFN type I and II stimulation in B-cell subpopulations of SLE patients compared with other autoimmune diseases and healthy controls (HD) and related it to disease activity. Methods Expression of STAT1, pSTAT1, STAT3 and pSTAT3 in B and T cells of 21 HD, 10 rheumatoid arthritis (RA), seven primary Sjögren’s (pSS) and 22 SLE patients was analysed by flow cytometry. STAT1 and STAT3 expression and phosphorylation in PBMCs (peripheral blood mononuclear cells) of SLE patients and HD after IFNα and IFNγ incubation were further investigated. Results SLE patients showed substantially higher STAT1 but not pSTAT1 in B- and T-cell subsets. Increased STAT1 expression in B-cell subsets correlated significantly with SLEDAI and Siglec-1 on monocytes, a type I IFN marker. STAT1 activation in plasmablasts was IFNα dependent while monocytes exhibited dependence on IFNγ. Conclusion Enhanced expression of STAT1 by B-cell candidates as a key node of two immunopathogenic signatures (type I IFN and B-cells) related to important immunopathogenic pathways and lupus activity. We show that STAT1 is activated upon IFNα exposure in SLE plasmablasts. Thus, Jak inhibitors, targeting JAK-STAT pathways, hold a promise to block STAT1 expression and control plasmablast induction in SLE.

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