scholarly journals Chlamydial abortion of ewes and goats. I. Current aspects on etiology, pathogenesis, immune mechanisms and epizootiology of disease

2018 ◽  
Vol 53 (1) ◽  
pp. 9
Author(s):  
V. SIARKOU (Β. ΣΙΑΡΚΟΥ)
Keyword(s):  
Experimental Data ◽  
Immune Response ◽  
New Species ◽  
Immune Responses ◽  
Disease Transmission ◽  
Latent Infection ◽  
Recent Experimental Data ◽  
New Genera ◽  
Ifn Γ

Chlamydial abortion constitutes one of the major causes of infectious abortion in sheep and goats. The disease leads to considerable losses in most sheep and goat-rearing countries, as well as, in Greece. In this paper, a review of the causative agent, pathogenesis, host immune response and epizootiology is presented. After recent changes, that have occured in the taxonomy of chlamydiae, it is necessary to refer to new families, new genera and new species within the order Chlamydiales, with emphasis on new species of Chlamydophila abortus, the causal agent of chlamydial abortion. This study reviews the recent experimental data which indicate the sites of entry of the organism, the way of its dissemination and establishment to the placenta. It also reviews current research on the humoral and cell-mediated immune responses, the role of the IFN-γ in latent infection and this of Tcells in the protective immune response. Finally, particular reference is given on the role of the male in the disease transmission and the role of inter-species contamination in chlamydial abortion.

scholarly journals Innate Immune Responses of Bat and Human Cells to Filoviruses: Commonalities and Distinctions

2017 ◽  
Vol 91 (8) ◽  
Author(s):  
Ivan V. Kuzmin ◽  
Toni M. Schwarz ◽  
Philipp A. Ilinykh ◽  
Ingo Jordan ◽  
Thomas G. Ksiazek ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Antiviral Effect ◽  
Human Cells ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Symptomatic Disease ◽  
Ifn Γ

ABSTRACT Marburg (MARV) and Ebola (EBOV) viruses are zoonotic pathogens that cause severe hemorrhagic fever in humans. The natural reservoir of MARV is the Egyptian rousette bat (Rousettus aegyptiacus); that of EBOV is unknown but believed to be another bat species. The Egyptian rousette develops subclinical productive infection with MARV but is refractory to EBOV. Interaction of filoviruses with hosts is greatly affected by the viral interferon (IFN)-inhibiting domains (IID). Our study was aimed at characterization of innate immune responses to filoviruses and the role of filovirus IID in bat and human cells. The study demonstrated that EBOV and MARV replicate to similar levels in all tested cell lines, indicating that permissiveness for EBOV at cell and organism levels do not necessarily correlate. Filoviruses, particularly MARV, induced a potent innate immune response in rousette cells, which was generally stronger than that in human cells. Both EBOV VP35 and VP24 IID were found to suppress the innate immune response in rousette cells, but only VP35 IID appeared to promote virus replication. Along with IFN-α and IFN-β, IFN-γ was demonstrated to control filovirus infection in bat cells but not in human cells, suggesting host species specificity of the antiviral effect. The antiviral effects of bat IFNs appeared not to correlate with induction of IFN-stimulated genes 54 and 56, which were detected in human cells ectopically expressing bat IFN-α and IFN-β. As bat IFN-γ induced the type I IFN pathway, its antiviral effect is likely to be partially induced via cross talk. IMPORTANCE Bats serve as reservoirs for multiple emerging viruses, including filoviruses, henipaviruses, lyssaviruses, and zoonotic coronaviruses. Although there is no evidence for symptomatic disease caused by either Marburg or Ebola viruses in bats, spillover of these viruses into human populations causes deadly outbreaks. The reason for the lack of symptomatic disease in bats infected with filoviruses remains unknown. The outcome of a virus-host interaction depends on the ability of the host immune system to suppress viral replication and the ability of a virus to counteract the host defenses. Our study is a comparative analysis of the host innate immune response to either MARV or EBOV infection in bat and human cells and the role of viral interferon-inhibiting domains in the host innate immune responses. The data are useful for understanding the interactions of filoviruses with natural and accidental hosts and for identification of factors that influence filovirus evolution.

Abstract 116: Detrimental Role of Toll-Like Receptor 4 in Cardiovirus-Induced Myocarditis

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Fumitaka Sato ◽  
Seiichi Omura ◽  
Nicholas E Martinez ◽  
Eiichiro Kawai ◽  
Ganta V Chaitanya ◽  
...  
Keyword(s):  
Immune Responses ◽  
Acute Phase ◽  
Viral Entry ◽  
Viral Myocarditis ◽  
Chronic Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tlr4 Ligand ◽  
Ifn Γ ◽  
Deficient Mice

Picornavirus infections have been known as a leading cause of viral myocarditis in humans. Theiler’s murine encephalomyelitis virus (TMEV) belongs to the genus Cardiovirus, the family Picornaviridae and was reported to cause inflammation in the heart in one manuscript, while its pathomechanism is unclear. In viral myocarditis, viral replication in the heart and/or immune responses against virus as well as heart-antigen (autoimmunity) can contribute to the pathogenesis. Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that are important for recognizing pathogens as well as triggering innate immunity. Among TLRs, TLR4 has been demonstrated to play important roles in virus-mediated pathology: 1) TLR4 can contribute to viral entry in some viruses, 2) TLR4 may mediate tissue damage by anti-virus immune responses (immunopathology), 3) high levels of TLR4 expression were observed in the heart of patients with dilated cardiomyopathy following acute viral myocarditis, and 4) some viruses can bind to lipopolysaccharide (LPS), which is a TLR4 ligand. To determine the role of TLR4 in TMEV-induced myocarditis, we infected male C3H/HeJ (TLR4-deficient) and C3H/HeNtac (control TLR4+) mice with the DA strain of TMEV. We harvested the hearts and spleens on days 6 and 7 (acute phase) or days 63 and 64 (chronic phase) post-infection. Cardiac pathology was evaluated by hematoxylin and eosin staining and production of pro-inflammatory cytokines, interleukin (IL)-17A and interferon (IFN)-γ, from spleen cells was measured by an enzyme-linked immunosorbent assay (ELISA). In both mice, mild myocarditis was observed during the acute phase of TMEV infection. During the chronic phase, both mice developed severe pathology in the heart, including basophilic degeneration and calcification. However, the incidence of myocarditis was higher in control mice than TLR4-deficient mice. IL-17A and IFN-γ production was higher in control mice than in TLR4-deficient mice (control vs. TLR4-deficient mice, acute phase: IL-17A, 196 vs. 146 pg/ml; IFN-γ, 72 vs. 39 ng/ml; chronic phase: IL-17A, 290 vs. 229 pg/ml; IFN- γ, 142 vs. 88 ng/ml). These results suggest that TLR4 may be detrimental in TMEV-induced myocarditis by increasing pro-inflammatory cytokine production.

scholarly journals The effect of Kefir on The Immune Response of Healthy Volunteers In Vitro

2017 ◽  
Vol 3 (2) ◽  
pp. 28
Author(s):  
Desie Dwi Wisudanti
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune Responses ◽  
Healthy Volunteers ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Fermented Milk ◽  
Bioactive Components ◽  
Ifn Γ

Kefir is a functional foodstuff of probiotics, made from fermented milk with kefir grains containing various types of beneficial bacteria and yeast. There have been many studies on the effects of oral kefir on the immune system, but few studies have shown the effect of bioactive components from kefir (peptides and exopolysaccharides/ kefiran), on immune responses. The purpose of this study was to prove the effect of kefir supernatant from milk goat on healthy immune volunteer response in vitro. The study was conducted on 15 healthy volunteers, then isolated PBMC from whole blood, then divided into 5 groups (K-, P1, P2, P3 and P4) before culture was done for 4 days. The harvested cells from culture were examined for the percentage of CD4+ T cells, CD8+ T cells, IFN-γ, IL-4 using flowsitometry and IL-2 levels, IL-10 using the ELISA method. The results obtained that kefir do not affect the percentage of CD4+ T cells and CD8+ T cells. The higher the concentration of kefir given, the higher levels of secreted IFN- γ and IL-4, but a decrease in IL-2 levels. Significant enhancement occurred at levels of IL-10 culture PBMC given kefir with various concentrations (p <0.01), especially at concentrations of 1%. These results also show the important effects of kefir bioactive components on immune responses. The conclusion of this study is that kefir can improve the immune response, through stimulation of IL-10 secretion in vitro.

scholarly journals Innate, adaptive, and cell-autonomous immunity against Toxoplasma gondii infection

2019 ◽  
Vol 51 (12) ◽  
pp. 1-10 ◽  
Author(s):  
Miwa Sasai ◽  
Masahiro Yamamoto
Keyword(s):  
Immune Response ◽  
Toxoplasma Gondii ◽  
Immune Responses ◽  
Parasitophorous Vacuole ◽  
Interferon Γ ◽  
Protective Role ◽  
Ifn Γ ◽  
Acquired Immune Responses ◽  
Toxoplasma Gondii Infection ◽  
Antimicrobial Immunity

AbstractHosts have been fighting pathogens throughout the evolution of all infectious diseases. Toxoplasma gondii is one of the most common infectious agents in humans but causes only opportunistic infection in healthy individuals. Similar to antimicrobial immunity against other organisms, the immune response against T. gondii activates innate immunity and in turn induces acquired immune responses. After activation of acquired immunity, host immune cells robustly produce the proinflammatory cytokine interferon-γ (IFN-γ), which activates a set of IFN-γ-inducible proteins, including GTPases. IFN-inducible GTPases are essential for cell-autonomous immunity and are specialized for effective clearance and growth inhibition of T. gondii by accumulating in parasitophorous vacuole membranes. Recent studies suggest that the cell-autonomous immune response plays a protective role in host defense against not only T. gondii but also various intracellular bacteria. Moreover, the negative regulatory mechanisms of such strong immune responses are also important for host survival after infection. In this review, we will discuss in detail recent advances in the understanding of host defenses against T. gondii and the roles played by cell-autonomous immune responses.

scholarly journals Correlation of Cellular Immune Responses with Protection against Culture-Confirmed Influenza Virus in Young Children

2008 ◽  
Vol 15 (7) ◽  
pp. 1042-1053 ◽  
Author(s):  
Bruce D. Forrest ◽  
Michael W. Pride ◽  
Andrew J. Dunning ◽  
Maria Rosario Z. Capeding ◽  
Tawee Chotpitayasunondh ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Young Children ◽  
Immune Responses ◽  
Virus Vaccine ◽  
Elispot Assay ◽  
Influenza Virus Vaccine ◽  
The Philippines ◽  
Influenza Viruses ◽  
Ifn Γ

ABSTRACT The highly sensitive gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISPOT) assay permits the investigation of the role of cell-mediated immunity (CMI) in the protection of young children against influenza. Preliminary studies of young children confirmed that the IFN-γ ELISPOT assay was a more sensitive measure of influenza memory immune responses than serum antibody and that among seronegative children aged 6 to <36 months, an intranasal dose of 107 fluorescent focus units (FFU) of a live attenuated influenza virus vaccine (CAIV-T) elicited substantial CMI responses. A commercial inactivated influenza virus vaccine elicited CMI responses only in children with some previous exposure to related influenza viruses as determined by detectable antibody levels prevaccination. The role of CMI in actual protection against community-acquired, culture-confirmed clinical influenza by CAIV-T was investigated in a large randomized, double-blind, placebo-controlled dose-ranging efficacy trial with 2,172 children aged 6 to <36 months in the Philippines and Thailand. The estimated protection curve indicated that the majority of infants and young children with ≥100 spot-forming cells/106 peripheral blood mononuclear cells were protected against clinical influenza, establishing a possible target level of CMI for future influenza vaccine development. The ELISPOT assay for IFN-γ is a sensitive and reproducible measure of CMI and memory immune responses and contributes to establishing requirements for the future development of vaccines against influenza, especially those used for children.

scholarly journals CpG Oligodeoxynucleotides Act as Adjuvants that Switch on T Helper 1 (Th1) Immunity

1997 ◽  
Vol 186 (10) ◽  
pp. 1623-1631 ◽  
Author(s):  
Rose S. Chu ◽  
Oleg S. Targoni ◽  
Arthur M. Krieg ◽  
Paul V. Lehmann ◽  
Clifford V. Harding
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Cpg Odn ◽  
T Helper ◽  
T Helper 1 ◽  
Cpg Oligodeoxynucleotides ◽  
Cytokine Pattern ◽  
Incomplete Freund’S Adjuvant ◽  
Ifn Γ ◽  
Hen Egg

Synthetic oligodeoxynucleotides (ODN) that contain unmethylated CpG motifs (CpG ODN) induce macrophages to secrete IL-12, which induces interferon (IFN)-γ secretion by natural killer (NK) cells. Since these cytokines can induce T helper 1 (Th1) differentiation, we examined the effects of coadministered CpG ODN on the differentiation of Th responses to hen egg lysozyme (HEL). In both BALB/c (Th2-biased) and B10.D2 (Th1-biased) mice, immunization with HEL in incomplete Freund's adjuvant (IFA) resulted in Th2-dominated immune responses characterized by HEL-specific secretion of IL-5 but not IFN-γ. In contrast, immunization with IFA-HEL plus CpG ODN switched the immune response to a Th1-dominated cytokine pattern, with high levels of HEL-specific IFN-γ secretion and decreased HEL-specific IL-5 production. IFA-HEL plus CpG ODN also induced anti-HEL IgG2a (a Th1-associated isotype), which was not induced by IFA-HEL alone. Control non–CpG ODN did not induce IFN-γ or IgG2a, excepting lesser increases in B10.D2 (Th1-biased) mice. Thus, CpG ODN provide a signal to switch on Th1-dominated responses to coadministered antigen and are potential adjuvants for human vaccines to elicit protective Th1 immunity.

scholarly journals Haematophagous arthropod saliva and host defense system: a tale of tear and blood

2005 ◽  
Vol 77 (4) ◽  
pp. 665-693 ◽  
Author(s):  
Bruno B. Andrade ◽  
Clarissa R. Teixeira ◽  
Aldina Barral ◽  
Manoel Barral-Netto
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Host Defense ◽  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Defense System ◽  
Current Information ◽  
System A ◽  
Host Defense System

The saliva from blood-feeding arthropod vectors is enriched with molecules that display diverse functions that mediate a successful blood meal. They function not only as weapons against host's haemostatic, inflammatory and immune responses but also as important tools to pathogen establishment. Parasites, virus and bacteria taking advantage of vectors' armament have adapted to facilitate their entry in the host. Today, many salivary molecules have been identified and characterized as new targets to the development of future vaccines. Here we focus on current information on vector's saliva and the molecules responsible to modify host's hemostasis and immune response, also regarding their role in disease transmission.

scholarly journals Dual Role of Toll-Like Receptor 7 in the Pathogenesis of Rabies Virus in a Mouse Model

2020 ◽  
Vol 94 (9) ◽  
Author(s):  
Zhaochen Luo ◽  
Lei Lv ◽  
Yingying Li ◽  
Baokun Sui ◽  
Qiong Wu ◽  
...  
Keyword(s):  
Immune Response ◽  
Mouse Model ◽  
Immune Responses ◽  
Rabies Virus ◽  
Mouse Brain ◽  
Early Stage ◽  
Toll Like Receptor ◽  
Innate Recognition ◽  
Recognition Receptor

ABSTRACT Rabies, caused by rabies virus (RABV), is a fatal encephalitis in humans and other mammals, which continues to present a public health threat in most parts of the world. Our previous study demonstrated that Toll-like receptor 7 (TLR7) is essential in the induction of anti-RABV antibodies via the facilitation of germinal center formation. In the present study, we investigated the role of TLR7 in the pathogenicity of RABV in a mouse model. Using isolated plasmacytoid dendritic cells (pDCs), we demonstrated that TLR7 is an innate recognition receptor for RABV. When RABV invaded from the periphery, TLR7 detected viral single-stranded RNA and triggered immune responses that limited the virus’s entry into the central nervous system (CNS). When RABV had invaded the CNS, its detection by TLR7 led to the production of cytokines and chemokines and an increase the permeability of the blood-brain barrier. Consequently, peripheral immune cells, including pDCs, macrophages, neutrophils, and B cells infiltrated the CNS. While this immune response, triggered by TLR7, helped to clear viruses, it also increased neuroinflammation and caused immunopathology in the mouse brain. Our results demonstrate that TLR7 is an innate recognition receptor for RABV, which restricts RABV invasion into the CNS in the early stage of viral infection but also contributes to immunopathology by inducing neuroinflammation. IMPORTANCE Developing targeted treatment for RABV requires understanding the innate immune response to the virus because early virus clearance is essential for preventing the fatality when the infection has progressed to the CNS. Previous studies have revealed that TLR7 is involved in the immune response to RABV. Here, we establish that TLR7 recognizes RABV and facilitates the production of some interferon-stimulated genes. We also demonstrated that when RABV invades into the CNS, TLR7 enhances the production of inflammatory cytokines which contribute to immunopathology in the mouse brain. Taken together, our findings suggest that treatments for RABV must consider the balance between the beneficial and harmful effects of TLR7-triggered immune responses.

scholarly journals Crosstalk between Dendritic Cells and Immune Modulatory Agents against Sepsis

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 323 ◽  
Author(s):  
Guoying Wang ◽  
Xianghui Li ◽  
Lei Zhang ◽  
Abualgasim Elgaili Abdalla ◽  
Tieshan Teng ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Critical Role ◽  
Innate Immune ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Th2 Responses ◽  
Novel Strategy

Dendritic cells (DCs) play a critical role in the immune system which sense pathogens and present their antigens to prime the adaptive immune responses. As the progression of sepsis occurs, DCs are capable of orchestrating the aberrant innate immune response by sustaining the Th1/Th2 responses that are essential for host survival. Hence, an in-depth understanding of the characteristics of DCs would have a beneficial effect in overcoming the obstacle occurring in sepsis. This paper focuses on the role of DCs in the progression of sepsis and we also discuss the reverse sepsis-induced immunosuppression through manipulating the DC function. In addition, we highlight some potent immunotherapies that could be used as a novel strategy in the early treatment of sepsis.

The rôle of cortisol and β-endorphin in the response of the immune system to weaning in lambs

1998 ◽  
Vol 66 (2) ◽  
pp. 397-402 ◽  
Author(s):  
S. M. Rhind ◽  
H. W. Reid ◽  
S. R. McMillen ◽  
G. Palmarini
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Stress Hormone ◽  
Keyhole Limpet Haemocyanin ◽  
Weaning Stress ◽  
Cell Mediated Immune Response ◽  
Acth Treatment ◽  
Induced Changes ◽  
The Relationship

AbstractThe relationship between weaning stress-induced changes in stress hormone profiles and immune function was investigated in groups of 10 lambs immunized against adrenocorticotrophic hormone (ACTH; treatment A) or fi-endorphin (treatment B) to reduce the circulating concentrations of cortisol and fi-endorphin respectively. Control animals (treatment C) were immunized against a porcine thyroglobulin carrier protein. Application of weaning stress was associated with significantly elevated plasma cortisol concentrations but no significant increase in fi-endorphin concentrations in C lambs. Immunization against ACTH suppressed the post-weaning increase in cortisol concentration. This was associated with a transient reduction in the lymphocyte stimulation response to keyhole limpet haemocyanin (KLH) antigen in the A animals but there was no effect on the antibody response or interferon-y production by antigen stimulated lymphocytes. There were no significant effects of immunization against fi-endorphin on the capacity to mount antibody or cell-mediated immune responses. It is concluded that weaning stress-induced increases in cortisol did not inhibit the immune response. Since cortisol concentrations and the cell mediated immune response at 8 days after immunization were positively associated it is concluded that these indices are not independent measures of stress.

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