scholarly journals Inhibition of CD1 Antigen Presentation by Human Cytomegalovirus

2008 ◽  
Vol 82 (9) ◽  
pp. 4308-4319 ◽  
Author(s):  
Martin J. Raftery ◽  
Manuel Hitzler ◽  
Florian Winau ◽  
Thomas Giese ◽  
Bodo Plachter ◽  
...  
Keyword(s):  
Immune Response ◽  
Antigen Presentation ◽  
Human Cytomegalovirus ◽  
Antigen Presenting Cells ◽  
Interleukin 10 ◽  
Antiviral Immune Response ◽  
Simplex Virus ◽  
Antigen Presenting ◽  
Group 1

ABSTRACT The betaherpesvirus human cytomegalovirus (HCMV) encodes several molecules that block antigen presentation by the major histocompatibility complex (MHC) proteins. Humans also possess one other family of antigen-presenting molecules, the CD1 family; however, the effect of HCMV on CD1 expression is unknown. The majority of CD1 molecules are classified on the basis of homology as group 1 CD1 and are present almost exclusively on professional antigen-presenting cells such as dendritic cells, which are a major target for HCMV infection and latency. We have determined that HCMV encodes multiple blocking strategies targeting group 1 CD1 molecules. CD1 transcription is strongly inhibited by the HCMV interleukin-10 homologue cmvIL-10. HCMV also blocks CD1 antigen presentation posttranscriptionally by the inhibition of CD1 localization to the cell surface. This function is not performed by a known HCMV MHC class I-blocking molecule and is substantially stronger than the blockage induced by herpes simplex virus type 1. Antigen presentation by CD1 is important for the development of the antiviral immune response and the generation of mature antigen-presenting cells. HCMV present in antigen-presenting cells thus blunts the immune response by the blockage of CD1 molecules.

scholarly journals Susceptibility to Polyomavirus-Induced Tumors in Inbred Mice: Role of Innate Immune Responses

2002 ◽  
Vol 76 (19) ◽  
pp. 9657-9663 ◽  
Author(s):  
Palanivel Velupillai ◽  
John P. Carroll ◽  
Thomas L. Benjamin
Keyword(s):  
Antigen Presenting Cells ◽  
Interleukin 10 ◽  
Cytokine Response ◽  
Innate Immune ◽  
Interleukin 12 ◽  
Cytokine Responses ◽  
Induced Tumors ◽  
Antigen Presenting ◽  
Type 1 Cytokine

ABSTRACT Mice of the PERA/Ei strain (PE mice) are highly susceptible to tumor induction by polyomavirus and transmit their susceptibility in a dominant manner in crosses with resistant C57BR/cdJ mice (BR mice). BR mice respond to polyomavirus infection with a type 1 cytokine response and develop effective cell-mediated immunity to the virus-induced tumors. By enumerating virus-specific CD8+ T cells and measuring cytokine responses, we show that the susceptibility of PE mice is due to the absence of a type 1 cytokine response and a concomitant failure to sustain virus-specific cytotoxic T lymphocytes. (PE × BR)F1 mice showed an initial type 1 response that became skewed toward type 2. Culture supernatants of splenocytes from infected PE mice stimulated in vitro contained high levels of interleukin-10 and no detectable gamma interferon, while those from BR mice showed the opposite pattern. Differences in the innate immune response to polyomavirus by antigen-presenting cells in PE mice and BR mice led to polarization of T-cell cytokine responses. Adherent cells from spleens of infected BR mice produced high levels of interleukin-12, while those from infected PE and F1 mice produced predominantly interleukin-10. PE and F1 mice infected by polyomavirus responded with increases in antigen-presenting cells expressing B7.2 costimulatory molecules, whereas BR mice responded with increased expression of B7.1. Administration of recombinant interleukin-12 along with virus resulted in partial protection of PE mice and provided complete protection against tumor development in F1 animals.

scholarly journals Induction of antigen-specific regulatory T lymphocytes by human dendritic cells expressing the glucocorticoid-induced leucine zipper

Blood ◽  
2007 ◽  
Vol 110 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Haifa Hamdi ◽  
Véronique Godot ◽  
Marie-Christine Maillot ◽  
Maria Victoria Prejean ◽  
Nicolas Cohen ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Lymphocytes ◽  
Antigen Presentation ◽  
Leucine Zipper ◽  
Ex Vivo ◽  
Antigen Presenting Cells ◽  
Interleukin 10 ◽  
Therapeutic Effects ◽  
Regulatory T Lymphocytes ◽  
Antigen Presenting

Dendritic cells (DCs) determine whether antigen presentation leads to immune activation or to tolerance. Tolerance-inducing DCs (also called regulatory DCs) act partly by generating regulatory T lymphocytes (Tregs). The mechanism used by DCs to switch toward regulatory DCs during their differentiation is unclear. We show here that human DCs treated in vitro with glucocorticoids produce the glucocorticoid-induced leucine zipper (GILZ). Antigen presentation by GILZ-expressing DCs generates CD25highFOXP3+CTLA-4/CD152+ and interleukin-10–producing Tregs inhibiting the response of CD4+ and CD8+ T lymphocytes. This inhibition is specific to the antigen presented, and only proliferating CD4+ T lymphocytes express the Treg markers. Interleukin-10 is required for Treg induction by GILZ-expressing DCs. It is also needed for the suppressive function of Tregs. Antigen-presenting cells from patients treated with glucocorticoids generate interleukin-10–secreting Tregs ex vivo. These antigen-presenting cells produce GILZ, which is needed for Treg induction. Therefore, GILZ is critical for commitment of DCs to differentiate into regulatory DCs and to the generation of antigen-specific Tregs. This mechanism may contribute to the therapeutic effects of glucocorticoids.

CD11c+ dendritic cells and plasmacytoid DCs are activated by human cytomegalovirus and retain efficient T cell-stimulatory capability upon infection

Blood ◽  
2006 ◽  
Vol 107 (5) ◽  
pp. 2022-2029 ◽  
Author(s):  
Espen Ø. Kvale ◽  
Jakob Dalgaard ◽  
Fridtjof Lund-Johansen ◽  
Halvor Rollag ◽  
Lorant Farkas ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Immune System ◽  
Human Cytomegalovirus ◽  
Immunosuppressive Treatment ◽  
Antigen Presenting Cells ◽  
Renal Transplant Recipients ◽  
Low Frequencies ◽  
Plasmacytoid Dcs ◽  
Antigen Presenting

It has been suggested that human cytomegalovirus (HCMV) evades the immune system by infecting and paralyzing antigen-presenting cells. This view is based mainly on studies of dendritic cells (DCs) obtained after culture of monocytes (moDCs). It is contradicted by the asymptomatic course of HCMV infection in healthy persons, indicating that other key antigen-presenting cells induce an efficient immune response. Here we show that HCMV activates CD11c+ DCs and plasmacytoid DCs (PDCs). In contrast to moDCs, CD11c+ DCs and PDCs produced interferon (IFN) type 1 when exposed to HCMV. Autocrine IFN type 1 partially protected CD11c+ DCs against infection, whereas PDCs were resistant to HCMV even when IFN type 1 activity was inhibited. HCMV exposure induced the maturation of CD11c+ DCs by IFN type 1-dependent and -independent mechanisms. Importantly, CD11c+ DCs infected by inhibiting IFN type 1 activity retained full capacity to stimulate T cells. Renal transplant recipients receiving immunosuppressive treatment had lower frequencies of CD11c+ DCs and PDCs in blood than did healthy controls. The results show that HCMV activates the immune system by interacting with CD11c+ DCs and PDCs and that recipients of renal transplants have low frequencies of these cell types in blood.

scholarly journals Selenoproteins Regulate Antigen Processing and Presentation in Antigen Presenting Cells (P24-024-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Sarah Sumner ◽  
Bhuvana Katkere ◽  
Mckayla Nicol ◽  
Rachel Markley ◽  
Ashley Shay ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cells ◽  
Antigen Presentation ◽  
Antigen Processing ◽  
Antigen Presenting Cells ◽  
Underlying Mechanism ◽  
Cell Receptor ◽  
Calcium Flux ◽  
Funding Sources ◽  
Antigen Presenting

Abstract Objectives Selenium (Se), which exerts its effects via selenoproteins, is an essential micronutrient that has been shown to be required for optimal functioning of the immune system. Although numerous studies have examined the effects of selenoproteins on various aspects of the immune response, few studies have investigated the effects of Se on antigen presentation. Moreover, these studies have provided conflicting results indicating the need for further research regarding the effect of Se on Antigen Presenting Cells (APCs). Our goal is to identify the role of selenoproteins in antigen presentation in professional APCs. Methods Mice deficient in selenoproteins in a cell specific manner were generated by knocking out the trspgene, which encodes for an essential tRNA for selenocysteine synthesis, utilizing the cre/lox system. The resulting mice are referred to asTrspDCand TrspBrepresenting selenoprotein deficiency specifically in dendritic cells (DCs) and B cells, respectively. Additional studies were done utilizing a diet model of Se deficiency to isolate Se-deficient DCs and B cells. Rate of endocytosis by specific receptors and expression of various surface molecule characteristics of APCs were determined by flow cytometry. Degradation of antigens by APCs in the presence or absence of selenoproteins was measured by western blot. Results In B cells, selenoprotein deficiency results in a decrease in the number of B220 + Splenocytes, B Cell Receptor (BCR) endocytosis, calcium flux following antigen stimulation, and BCR degradation following internalization. Similarly, selenoprotein deficiency in DCs results in decreased DEC-205 (a collectin-like receptor for multiple antigens) endocytosis; and a reduction in the expression of MHCII, CD80, and CD86. These results suggest a role for selenoproteins during the processing and presentation of peptides to T cells. Conclusions Loss of selenoproteins results in the decreased functionality of both B cells and DCs, which suggests that Se and selenoproteins may be involved in the regulation of antigen presentation. Further studies are needed to elucidate the underlying mechanism by which selenoproteins regulate antigen presentation. Such studies are likely to reveal novel targets for enhancing the immune response to vaccines and other specific antigens. Funding Sources NIH/NIAID to GK; NIH/GM to SS; NIH/NIDDK to KSP.

scholarly journals Herpes Simplex Virus Type 1–Encoded miR-H2-3p Manipulates Cytosolic DNA–Stimulated Antiviral Innate Immune Response by Targeting DDX41

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 756 ◽  
Author(s):  
Yongzhong Duan ◽  
Jieyuan Zeng ◽  
Shengtao Fan ◽  
Yun Liao ◽  
Min Feng ◽  
...  
Keyword(s):  
Immune Response ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Dna Sensor ◽  
Antiviral Immune Response ◽  
Simplex Virus ◽  
Hsv 1

Herpes simplex virus type 1 (HSV-1), one of the human pathogens widely epidemic and transmitted among various groups of people in the world, often causes symptoms known as oral herpes or lifelong asymptomatic infection. HSV-1 employs many sophisticated strategies to escape host antiviral immune response based on its multiple coding proteins. However, the functions involved in the immune evasion of miRNAs encoded by HSV-1 during lytic (productive) infection remain poorly studied. Dual-luciferase reporter gene assay and bioinformatics revealed that Asp-Glu-Ala-Asp (DEAD)-box helicase 41 (DDX41), a cytosolic DNA sensor of the DNA-sensing pathway, was a putative direct target gene of HSV-1-encoded miR-H2-3p. The transfection of miR-H2-3p mimics inhibited the expression of DDX41 at the level of mRNA and protein, as well as the expression of interferon beta (IFN-β) and myxoma resistance protein I (MxI) induced by HSV-1 infection in THP-1 cells, and promoted the viral replication and its gene transcription. However, the transfection of miR-H2-3p inhibitor showed opposite effects. This finding indicated that HSV-1-encoded miR-H2-3p attenuated cytosolic DNA–stimulated antiviral immune response by manipulating host DNA sensor molecular DDX41 to enhance virus replication in cultured cells.

scholarly journals Recruitment of Antigen-Presenting Cells to the Site of Inoculation and Augmentation of Human Immunodeficiency Virus Type 1 DNA Vaccine Immunogenicity by In Vivo Electroporation

2008 ◽  
Vol 82 (11) ◽  
pp. 5643-5649 ◽  
Author(s):  
Jinyan Liu ◽  
Rune Kjeken ◽  
Iacob Mathiesen ◽  
Dan H. Barouch
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dna Vaccine ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Antigen Presenting Cells ◽  
In Vivo Electroporation ◽  
Immunodeficiency Virus ◽  
Antigen Presenting

ABSTRACT In vivo electroporation (EP) has been shown to augment the immunogenicity of plasmid DNA vaccines, but its mechanism of action has not been fully characterized. In this study, we show that in vivo EP augmented cellular and humoral immune responses to a human immunodeficiency virus type 1 Env DNA vaccine in mice and allowed a 10-fold reduction in vaccine dose. This enhancement was durable for over 6 months, and re-exposure to antigen resulted in anamnestic effector and central memory CD8+ T-lymphocyte responses. Interestingly, in vivo EP also recruited large mixed cellular inflammatory infiltrates to the site of inoculation. These infiltrates contained 45-fold-increased numbers of macrophages and 77-fold-increased numbers of dendritic cells as well as 2- to 6-fold-increased numbers of B and T lymphocytes compared to infiltrates following DNA vaccination alone. These data suggest that recruiting inflammatory cells, including antigen-presenting cells (APCs), to the site of antigen production substantially improves the immunogenicity of DNA vaccines. Combining in vivo EP with plasmid chemokine adjuvants that similarly recruited APCs to the injection site, however, did not result in synergy.

The use of antiviral drug based on technologically processed antibodies to interferon-γ, CD4 receptor and histamine in the treatment of influenza in adults: results of a multicenter open-label randomized comparative trial with oseltamivir

2021 ◽  
Vol 19 (1) ◽  
pp. 39-57
Author(s):  
K.V. Zhdanov ◽  
◽  
R.F. Khamitov ◽  
V.V. Rafalsky ◽  
M.P. Mikhaylusova ◽  
...  
Keyword(s):  
Immune Response ◽  
B Cell ◽  
Open Label ◽  
Virus Elimination ◽  
Antiviral Immune Response ◽  
Cd4 Receptor ◽  
Antiviral Efficacy ◽  
Ifn Γ ◽  
Group 2 ◽  
Group 1

Objective. A multicenter open-label randomized controlled clinical trial was aimed to compare the efficacy of the study drug (SD) containing technologically processed affinity purified antibodies (high dilutions) to IFN-γ, CD4 receptor and histamine (Ergoferon) with oseltamivir, and evaluate the influence of SD on the antiviral immune response in adults with seasonal influenza. Patients and methods. 184 outpatients aged 18–70 with confirmed influenza of mild/moderate severity were included and randomized into 2 groups (in a 1:1 ratio). Patients received SD (Group 1, n = 92) or oseltamivir (Group 2, n = 92), according to the instructions for medical use for 5 days. As the primary endpoint, the percentage of patients with recovery/improvement was assessed (according to the data of the patient's diary on days 2–7 and according to the clinical examination on days 3 and 7). Additionally, the duration and severity of influenza symptoms, the percentage of patients with virus elimination (according to RT-PCR of nasopharyngeal samples), the percentage of patients with complications, the percentage of patients prescribed antipyretic drugs, the change in concentration of T cell (IL-2, IL-18, IFN-γ) and B cell antigen-specific (IL-4, IL-16) immune response regulators in serum, the leukocyte phenotypes on days 1, 3 and 7 were evaluated. Statistical analysis was performed using a “Non-Inferiority” design (or no less efficiency/safety). Intention-to-Treat (ITT) analysis data are presented. Results. According to patients’ self-assessment, 53.3% of patients in Group 1 recovered/improved on the 6th day in the morning and 65.2% – in the evening (vs. 53.3% and 57.6% in Group 2, respectively). There were 73.9% recovered/ improved patients on the 7th day in the morning (vs. 67.4% in Group 2). A generalized analysis showed that the treatment results in both groups were comparable (p < 0.0001). According to objective medical examination, 79.3% of patients in the SD group and 74.0% of patients in the Оseltamivir group recovered/improved on the 7th day (p < 0.0001). The antiviral efficacy of SD was not inferior to oseltamivir, which was confirmed by comparable periods of virus elimination, duration and severity of fever and other influenza symptoms. A moderate activating effect of SD on the immune system was evaluated. A significant, compared to oseltamivir, increase in the concentration of IL-2 and IL-4 on the 3rd day of treatment (p = 0.03 and p = 0.04 vs. the oseltamivir group), and IFN-γ on the 3rd and the 7th days (p = 0.012 and p < 0.0001, respectively, vs. the oseltamivir group). No stimulating effect of SD on the growth and differentiation of immune cells was found. Conclusion. SD is effective and safe in the treatment of patients with influenza. The therapeutic and antiviral efficacy of SD is comparable to that of oseltamivir. The antiviral activity of SD affects the interferon system and the concentration of the cytokines IL-2 and IL-4, regulators of the T and B cell immune response. At the same time, there is no significant stimulation of interferon production with further development of hyporeactivity. Key words: influenza, oseltamivir, therapy, cytokines, Еrgoferon

scholarly journals Analysis of intracellular and intraviral localization of the human cytomegalovirus UL53 protein

2002 ◽  
Vol 83 (5) ◽  
pp. 1005-1012 ◽  
Author(s):  
P. Dal Monte ◽  
S. Pignatelli ◽  
N. Zini ◽  
N. M. Maraldi ◽  
E. Perret ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Nuclear Membrane ◽  
Human Fibroblasts ◽  
Nuclear Periphery ◽  
Structural Protein ◽  
Lamin B ◽  
Mature Virus Particle ◽  
Ul53 Gene ◽  
Simplex Virus

Human cytomegalovirus (HCMV) UL53 belongs to a family of conserved herpesvirus genes. In this work, the expression and localization of the UL53 gene product was analysed. Results obtained showed that pUL53 is a new structural protein. In infected human fibroblasts, pUL53 localizes in cytoplasmic perinuclear granular formations together with other structural viral proteins. In the nucleus, pUL53 forms patches at the nuclear periphery and co-localizes with lamin B at the internal nuclear membrane level. Immunoelectron microscopy studies have disclosed that nuclear pseudo-inclusions are labelled, whereas nucleocapsid formations within the intranuclear skein are negative. Furthermore, the mature virus particle maintains pUL53 at its tegumental level. These data suggest that pUL53 could be involved either in nucleocapsid maturation or in the egress of nucleocapsids from the nucleus to the cytoplasm through the nuclear membrane, a role compatible with the function hypothesized for UL31, its positional homologue in herpes simplex virus type 1.

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