scholarly journals Viral Protein VP4 Is a Target of Human Antibodies Enhancing Coxsackievirus B4- and B3-Induced Synthesis of Alpha Interferon

2005 ◽  
Vol 79 (22) ◽  
pp. 13882-13891 ◽  
Author(s):  
Wassim Chehadeh ◽  
Pierre-Emmanuel Lobert ◽  
Pierre Sauter ◽  
Anne Goffard ◽  
Bernadette Lucas ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Insulin Dependent Diabetes Mellitus ◽  
Alpha Interferon ◽  
Dependent Diabetes Mellitus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peripheral Blood Mononuclear ◽  
Coxsackievirus B4

ABSTRACT Coxsackievirus B4 (CVB4)-induced production of alpha interferon (IFN-α) by peripheral blood mononuclear cells (PBMC) is enhanced in vitro by nonneutralizing anti-CVB4 antibodies from healthy subjects and, to a higher extent, from patients with insulin-dependent diabetes mellitus. In this study, we focused on identification of the viral target of these antibodies in CVB systems. High levels of IFN-α were obtained in supernatants of PBMC incubated with CVB4E2 or CVB3 and plasma from healthy subjects and, to a higher extent, from patients. The VP4 capsid proteins dissociated by heating at 56°C from CVB4E2 (VP4CVB4) and CVB3 (VP4CVB3) but not H antigen preincubated with plasma from healthy subjects or patients inhibited the plasma-dependent enhancement of CVB4E2- and CVB3-induced IFN-α synthesis. There was no cross-reaction between VP4CVB4 and VP4CVB3 in the inhibiting effect. IFN-α levels in culture supernatants showed dose-dependent correlation with anti-VP4 antibodies eluted from plasma specimens using VP4-coated plates. There were higher index values for anti-VP4 antibodies detected by enzyme-linked immunosorbent assay (ELISA) and higher proportions of positive detection in 40 patients than in 40 healthy subjects (80% versus 15% for anti-VP4CVB4). There was no relationship between the levels of anti-CVB neutralizing antibodies and the detection of anti-VP4 antibodies by ELISA. The CVB plasma-induced IFN-α levels obtained in PBMC cultures in the anti-VP4 antibody-positive groups were significantly higher than those obtained in the anti-VP4 antibody-negative groups regardless of the titers of anti-CVB neutralizing antibodies. These results show that VP4 is the target of antibodies involved in the plasma-dependent enhancement of CVB4E2- and CVB3-induced IFN-α synthesis by PBMC.

scholarly journals Circulating and cell-bound antibodies increase coxsackievirus B4-induced production of IFN-α by peripheral blood mononuclear cells from patients with type 1 diabetes

2002 ◽  
Vol 83 (9) ◽  
pp. 2169-2176 ◽  
Author(s):  
Didier Hober ◽  
Wassim Chehadeh ◽  
Jacques Weill ◽  
Christine Hober ◽  
Marie-Christine Vantyghem ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Healthy Subjects ◽  
Mononuclear Cells ◽  
Peripheral Blood Mononuclear ◽  
Coxsackievirus B4 ◽  
Blood Mononuclear Cells

Increased levels of IFN-α have been found in patients with type 1 diabetes who have detectable levels of coxsackievirus B4 (CVB4) RNA in their blood. The IFN-α-inducing activity of CVB4 in vitro is weak but can be enhanced by human IgGs. Therefore, it was investigated in vitro whether a preferential IFN-α response of peripheral blood mononuclear cells (PBMCs) to CVB4 exists in patients with type 1 diabetes (n=56) compared with healthy subjects (n=20) and whether antibodies play a role. In patients, the levels of IFN-α obtained after stimulation by PBMCs with CVB4 were higher (P=0·008), an individual IFN-α response by PBMCs to CVB4 was more frequent (P=0·0004) and increased levels of IFN-α were observed in CVB4-infected whole blood cultures. The IFN-α-inducing activity of patients plasma and IgGs mixed with CVB4 and then added to PBMCs was high in comparison with healthy subjects (P<0·001) and was inhibited by preincubating the cells with anti-FcγRII, anti-FcγRIII and anti-CAR (coxsackievirus and adenovirus receptor) antibodies. The strong IFN-α responsiveness of PBMCs to CVB4 suggested that IgGs bound to the cell surface might play a role. A short 56 °C incubation of PBMCs from patients responsive to CVB4 generated supernatants, which, when added to cells, exhibited IFN-α-enhancing activity in combination with CVB4, whereas those of controls did not. Specific antibodies for FcγRI, FcγRII and CAR inhibited this activity. These studies demonstrate that CVB4, through interactions with circulating and/or cell-bound IgGs, can strongly induce the production of IFN-α by PBMCs from patients with type 1 diabetes.

scholarly journals Structure-Dependent Modulation of Alpha Interferon Production by Porcine Circovirus 2 Oligodeoxyribonucleotide and CpG DNAs in Porcine Peripheral Blood Mononuclear Cells

2007 ◽  
Vol 81 (10) ◽  
pp. 4919-4927 ◽  
Author(s):  
Frida Hasslung Wikström ◽  
Brian M. Meehan ◽  
Mikael Berg ◽  
Sirje Timmusk ◽  
Josefine Elving ◽  
...  
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Dna Sequences ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Alpha Interferon ◽  
Porcine Circovirus ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Cpg Dinucleotide

ABSTRACT DNA sequences containing CpG motifs are recognized as immunomodulators in several species. Phosphodiester oligodeoxyribonucleotides (ODNs) representing sequences from the genome of porcine circovirus type 2 (PCV2) have been identified as potent inducers (ODN PCV2/5) or inhibitors (ODN PCV2/1) of alpha interferon (IFN-α) production by porcine peripheral blood mononuclear cells (poPBMCs) in vitro. In this study, the IFN-α-inducing or -inhibitory activities of specific phosphodiester ODNs were demonstrated to be dependent on their ability to form secondary structures. When a poly(G) sequence was added to a stimulatory self-complementary ODN, high levels of IFN-α were elicited, and the induction was not dependent on pretreatment with the transfecting agent Lipofectin. In addition, the IFN-α-inducing ODN required the presence of an intact CpG dinucleotide, whereas the inhibitory activity of ODN PCV2/1 was not affected by methylation or removal of the central CpG dinucleotide. Of particular significance, the IFN-α inhibition elicited by ODN PCV2/1 was only effective against induction stimulated by DNA control inducers and not RNA control inducers, indicating activity directed to TLR9 signaling. The PCV2 genome as a whole was demonstrated to induce IFN-α in cultures of poPBMCs, and the presence of immune modulatory sequences within the genome of PCV2 may, therefore, have implications with regard to the immune evasion mechanisms utilized by PCV2.

High-through identification of T cell-specific phage-exposed mimotopes using PBMCs from tegumentary leishmaniasis patients and their use as vaccine candidates against Leishmania amazonensis infection

Parasitology ◽  
2018 ◽  
Vol 146 (3) ◽  
pp. 322-332 ◽  
Author(s):  
Gerusa B. Carvalho ◽  
Lourena E. Costa ◽  
Daniela P. Lage ◽  
Fernanda F. Ramos ◽  
Thaís T. O. Santos ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Mononuclear Cells ◽  
Parasite Load ◽  
Leishmania Amazonensis ◽  
Interleukin 4 ◽  
Peripheral Blood Mononuclear ◽  
Th1 Response ◽  
Tegumentary Leishmaniasis

AbstractIn the current study, phage-exposed mimotopes as targets against tegumentary leishmaniasis (TL) were selected by means of bio-panning cycles employing sera of TL patients and healthy subjects, besides the immune stimulation of peripheral blood mononuclear cells (PBMCs) collected from untreated and treated TL patients and healthy subjects. The clones were evaluated regarding their specific interferon-γ (IFN-γ) and interleukin-4 (IL-4) production in the in vitro cultures, and selectivity and specificity values were calculated, and those presenting the best results were selected for the in vivo experiments. Two clones, namely A4 and A8, were identified and used in immunization protocols from BALB/c mice to protect against Leishmania amazonensis infection. Results showed a polarized Th1 response generated after vaccination, being based on significantly higher levels of IFN-γ, IL-2, IL-12, tumour necrosis factor-α (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF); which were associated with lower production of specific IL-4, IL-10 and immunoglobulin G1 (IgG1) antibodies. Vaccinated mice presented significant reductions in the parasite load in the infected tissue and distinct organs, when compared with controls. In conclusion, we presented a strategy to identify new mimotopes able to induce Th1 response in PBMCs from TL patients and healthy subjects, and that were successfully used to protect against L. amazonensis infection.

scholarly journals Acquisition of Hemozoin by Monocytes Down-Regulates Interleukin-12 p40 (IL-12p40) Transcripts and Circulating IL-12p70 through an IL-10-Dependent Mechanism: In Vivo and In Vitro Findings in Severe Malarial Anemia

2006 ◽  
Vol 74 (9) ◽  
pp. 5249-5260 ◽  
Author(s):  
Christopher C. Keller ◽  
Ouma Yamo ◽  
Collins Ouma ◽  
John Michael Ong'echa ◽  
David Ounah ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Interleukin 12 ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Severe Malarial Anemia ◽  
Tnf Α ◽  
Malarial Anemia

ABSTRACT Severe malarial anemia (SMA) is a primary cause of morbidity and mortality in immune-naïve infants and young children residing in areas of holoendemic Plasmodium falciparum transmission. Although the immunopathogenesis of SMA is largely undefined, we have previously shown that systemic interleukin-12 (IL-12) production is suppressed during childhood blood-stage malaria. Since IL-10 and tumor necrosis factor alpha (TNF-α) are known to decrease IL-12 synthesis in a number of infectious diseases, altered transcriptional regulation of these inflammatory mediators was investigated as a potential mechanism for IL-12 down-regulation. Ingestion of naturally acquired malarial pigment (hemozoin [PfHz]) by monocytes promoted the overproduction of IL-10 and TNF-α relative to the production of IL-12, which correlated with an enhanced severity of malarial anemia. Experiments with cultured peripheral blood mononuclear cells (PBMC) and CD14+ cells from malaria-naïve donors revealed that physiological concentrations of PfHz suppressed IL-12 and augmented IL-10 and TNF-α by altering the transcriptional kinetics of IL-12p40, IL-10, and TNF-α, respectively. IL-10 neutralizing antibodies, but not TNF-α antibodies, restored PfHz-induced suppression of IL-12. Blockade of IL-10 and the addition of recombinant IL-10 to cultured PBMC from children with SMA confirmed that IL-10 was responsible for malaria-induced suppression of IL-12. Taken together, these results demonstrate that PfHz-induced up-regulation of IL-10 is responsible for the suppression of IL-12 during malaria.

scholarly journals Human antibodies isolated from plasma by affinity chromatography increase the coxsackievirus B4-induced synthesis of interferon-α by human peripheral blood mononuclear cells in vitro

2001 ◽  
Vol 82 (8) ◽  
pp. 1899-1907 ◽  
Author(s):  
Wassim Chehadeh ◽  
Ahmed Bouzidi ◽  
Gunar Alm ◽  
Pierre Wattré ◽  
Didier Hober
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Interferon Α ◽  
Peripheral Blood Mononuclear ◽  
Coxsackievirus B4 ◽  
Healthy Donors ◽  
Blood Mononuclear Cells

Coxsackievirus B4 (CVB4) can be found in circulating blood of patients; however, the interaction of CVB4 with peripheral blood mononuclear cells (PBMCs) is poorly understood. CVB4 induced low levels of IFN-α synthesis in PBMCs from healthy donors. In contrast, preincubation of infectious CVB4 with plasma from these donors containing anti-CVB4 antibodies strongly enhanced the synthesis of IFN-α. IgG obtained from plasma by chromatography formed immune complexes with CVB4 and increased significantly the CVB4-induced production of IFN-α by PBMCs. These antibodies did not have a neutralizing effect on CVB4 infection of Hep-2 cells. The role of CVB and adenovirus receptor (CAR), FcγRII and FcγRIII in the increased synthesis of IFN-α induced by CVB4 preincubated with IgG was shown by inhibition with specific antibodies. The major interferon-α-producing cells in response to CVB4–IgG complexes were CD14+ cells and monocyte-enriched PBMCs. With the latter, detection of IFN-α by immunostaining was positive whereas in monocyte-depleted PBMCs it was not. This study shows that CVB4-induced synthesis of IFN-α by PBMCs can be enhanced by an antibody-dependent mechanism through interactions between the virus, non-neutralizing antivirus antibodies, FcγRII and III and CAR.

scholarly journals Determination of a Statistically Valid Neutralization Titer in Plasma That Confers Protection against Simian-Human Immunodeficiency Virus Challenge following Passive Transfer of High-Titered Neutralizing Antibodies

2002 ◽  
Vol 76 (5) ◽  
pp. 2123-2130 ◽  
Author(s):  
Yoshiaki Nishimura ◽  
Tatsuhiko Igarashi ◽  
Nancy Haigwood ◽  
Reza Sadjadpour ◽  
Ron J. Plishka ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Lymph Node ◽  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Passive Transfer ◽  
Neutralization Titer ◽  
Peripheral Blood Mononuclear ◽  
Vitro Assay ◽  
Immunodeficiency Virus

ABSTRACT We previously reported that high-titered neutralizing antibodies directed against the human immunodeficiency virus type 1 (HIV-1) envelope can block the establishment of a simian immunodeficiency virus (SIV)/HIV chimeric virus (SHIV) infection in two monkeys following passive transfer (R. Shibata et al., Nat. Med. 5:204-210, 1999). In the present study, increasing amounts of neutralizing immunoglobulin G (IgG) were administered to 15 pig-tailed macaques in order to obtain a statistically valid protective neutralization endpoint titer in plasma. Using an in vitro assay which measures complete neutralization of the challenge SHIV, we correlated the titers of neutralizing antibodies in plasma at the time of virus inoculation (which ranged from 1:3 to 1:123) with the establishment of infection in virus-challenged animals. Ten of 15 monkeys in the present experiment were virus free as a result of neutralizing IgG administration as monitored by DNA PCR (peripheral blood mononuclear cells and lymph node cells), RNA PCR (plasma), virus isolation, and the transfer of lymph node cell suspensions (108 cells) plus 8 ml of whole blood from protected animals to naïve macaques. The titer of neutralizing antibodies in the plasma calculated to protect 99% of virus-challenged monkeys was 1:38.

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