scholarly journals Sliding set-points of immune responses for therapy of autoimmunity

2010 ◽  
Vol 207 (9) ◽  
pp. 1819-1823 ◽  
Author(s):  
Chyi-Song Hsieh ◽  
Jhoanne Lynne Bautista
Keyword(s):  
T Cells ◽  
Autoimmune Disease ◽  
Animal Models ◽  
Immune Responses ◽  
Patient Outcomes ◽  
Tissue Damage ◽  
The Body ◽  
Short Term ◽  
Self Tolerance ◽  
Recent Developments

Although recent developments in the treatment of autoimmune disease have dramatically improved patient outcomes, these medications are not curative. Two studies in this issue demonstrate the feasibility of curing spontaneous autoimmunity in animal models via short-term enhancement of naturally arising regulatory T (T reg) cells, a subset of CD4+ T cells needed for maintaining self-tolerance. Importantly, these therapies seemed to generate a new equilibrium, or “set-point,” at which self-tissue damage no longer occurred long after the drug was eliminated from the body.

scholarly journals Predicting the risk of re-infection from SARS-CoV-2 using the known pattern of adaptive immune response to previous human coronavirus outbreaks

2020 ◽  
Author(s):  
Ademola Samuel Ojo ◽  
Paul Toluwatope Okediji ◽  
Ayotemide P. Akin-Onitolo ◽  
Olusegun S. Ojo ◽  
Oluyinka Oladele Opaleye
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Adaptive Immune Response ◽  
The Body ◽  
Short Term ◽  
Adaptive Immune ◽  
Short And Long Term

This paper attempts to answer the question: are recovered COVID-19 patients protected from re-infection? This review draws evidence from comparisons between immune responses to Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) and Middle East Respiratory Syndrome coronavirus (MERS-CoV), which are phylogenetically closely related to Severe Acute Respiratory Syndrome coronavirus type 2 (SARS-CoV-2). Relevant studies were identified and reviewed based on searches conducted using PubMed. Full-text original studies on short- and long-term immune responses to human coronaviruses were included. The immune dysfunction and clinical manifestations in SARS-CoV-2, SARS-CoV, and MERS-CoV were found to be similar. Infections with SARS-CoV and MERS-CoV trigger the production of antibodies and memory B- and T-cells. Serum IgM is detectable within 7 days, peak at 21-30 days and become undetectable by 180 days. IgG is detectable at 7 days, peak at 90 days, and decline to undetected levels by 2 years post-infection. Memory B- and T-cells persist in the body for up to 2 and 6 years respectively after initial infection. The short-term risk of SARS-CoV-2 re-infection is predictably low based on similarities in the short term adaptive immune response to kindred coronaviruses. However, more research will be required to determine the long-term adaptive immunity to SARS-CoV-2 and factors that may influence the existence of short- and long-term immunity against the virus.

scholarly journals A Canine-Directed Chimeric Multi-Epitope Vaccine Induced Protective Immune Responses in BALB/c Mice Infected with Leishmania infantum

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 350 ◽  
Author(s):  
Maria Agallou ◽  
Maritsa Margaroni ◽  
Stathis D. Kotsakis ◽  
Evdokia Karagouni
Keyword(s):  
T Cells ◽  
T Cell ◽  
Visceral Leishmaniasis ◽  
Immune Responses ◽  
Leishmania Infantum ◽  
Parasite Burden ◽  
Significant Loss ◽  
T Cell Epitopes ◽  
Heparin Binding ◽  
Short Term

Leishmaniases are complex vector-borne diseases caused by intracellular parasites of the genus Leishmania. The visceral form of the disease affects both humans and canids in tropical, subtropical, and Mediterranean regions. One health approach has suggested that controlling zoonotic visceral leishmaniasis (ZVL) could have an impact on the reduction of the human incidence of visceral leishmaniasis (VL). Despite the fact that a preventive vaccination could help with leishmaniasis elimination, effective vaccines that are able to elicit protective immune responses are currently lacking. In the present study, we designed a chimeric multi-epitope protein composed of multiple CD8+ and CD4+ T cell epitopes which were obtained from six highly immunogenic proteins previously identified by an immunoproteomics approach, and the N-termini of the heparin-binding hemagglutinin (HBHA) of Mycobacterium tuberculosis served as an adjuvant. A preclinical evaluation of the candidate vaccine in BALB/c mice showed that when it was given along with the adjuvant Addavax it was able to induce strong immune responses. Cellular responses were dominated by the presence of central and effector multifunctional CD4+ and CD8+ T memory cells. Importantly, the vaccination reduced the parasite burden in both short-term and long-term vaccinated mice challenged with Leishmania infantum. Protection was characterized by the continuing presence of IFN-γ+TNFα+-producing CD8+ and CD4+ T cells and increased NO levels. The depletion of CD8+ T cells in short-term vaccinated mice conferred a significant loss of protection in both target organs of the parasite, indicating a significant involvement of this population in the protection against L. infantum challenge. Thus, the overall data could be considered to be a proof-of-concept that the design of efficacious T cell vaccines with the help of reverse vaccinology approaches is possible.

scholarly journals IL-12 unmasks latent autoimmune disease in resistant mice.

1996 ◽  
Vol 184 (2) ◽  
pp. 771-775 ◽  
Author(s):  
B M Segal ◽  
E M Shevach
Keyword(s):  
T Cells ◽  
Autoimmune Disease ◽  
Immune Responses ◽  
Experimental Allergic Encephalomyelitis ◽  
Basic Protein ◽  
Inbred Mice ◽  
Allergic Encephalomyelitis ◽  
Ifn Gamma ◽  
Th 1 ◽  
Experimental Allergic

Inbred mice exhibit a spectrum of susceptibility to induction of experimental allergic encephalomyelitis (EAE). We have compared the immune responses of the susceptible SJL (H-2s) and resistant B10.S (H-2s) strains to determine factors other than the MHC background which control resistance/susceptibility to EAE. The resistance of the B10.S strain was found to be secondary to an antigen-specific defect in the generation of Th 1 cells that produce IFN gamma. This defect in IFN gamma production could be restored by exposure of the myelin basic protein (MBP)-reactive T cells to IL-12 with the subsequent induction of the ability to transfer EAE to naive recipients. These findings have important implications for the therapeutic use of IL-12 and IL-12 antagonists and may explain the association between relapses/exacerbation of autoimmune disease and infectious diseases.

Porous Materials for Immune Modulation

2018 ◽  
Vol 4 (1) ◽  
pp. 1-14
Author(s):  
Moonkyoung Jeong ◽  
Hansol Kim ◽  
Ji-Ho Park
Keyword(s):  
Immune Responses ◽  
Porous Materials ◽  
Immune Modulation ◽  
Pore Space ◽  
The Body ◽  
Immunomodulatory Agents ◽  
Recent Developments ◽  
Future Direction ◽  
Antigen Presenting ◽  
Immunomodulatory Potential

Abstract Biocompatible materials have a great potential to engineer immunology towards therapeutic applications. Among them, porous materials have attracted much attention for immune modulation due to their unique porous structure. The large surface area and pore space offer high loading capacity for various payloads including peptides, proteins and even cells. We first introduce recent developments in the porous particles that can deliver immunomodulatory agents to antigen presenting cells for immunomodulation. Then, we review recent developments in the porous implants that can act as a cellattracting/ delivering platform to generate artificial immunomodulatory environments in the body. Lastly, we summarize recent findings of immunogenic porous materials that can induce strong immune responses without additional adjuvants. We also discuss future direction of porous materials to enhance their immunomodulatory potential for immunotherapeutic applications.

scholarly journals Role of Exosomes in the Regulation of T-cell Mediated Immune Responses and in Autoimmune Disease

Cells ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 154 ◽  
Author(s):  
Alberto Anel ◽  
Ana Gallego-Lleyda ◽  
Diego de Miguel ◽  
Javier Naval ◽  
Luis Martínez-Lostao
Keyword(s):  
T Cells ◽  
T Cell ◽  
Autoimmune Disease ◽  
Immune Responses ◽  
T Regulatory Cells ◽  
Inflammatory Diseases ◽  
Activated T Cells ◽  
Regulatory Processes ◽  
Activation Induced Cell Death

: T-cell mediated immune responses should be regulated to avoid the development of autoimmune or chronic inflammatory diseases. Several mechanisms have been described to regulate this process, namely death of overactivated T cells by cytokine deprivation, suppression by T regulatory cells (Treg), induction of expression of immune checkpoint molecules such as CTLA-4 and PD-1, or activation-induced cell death (AICD). In addition, activated T cells release membrane microvesicles called exosomes during these regulatory processes. In this review, we revise the role of exosome secretion in the different pathways of immune regulation described to date and its importance in the prevention or development of autoimmune disease. The expression of membrane-bound death ligands on the surface of exosomes during AICD or the more recently described transfer of miRNA or even DNA inside T-cell exosomes is a molecular mechanism that will be analyzed.

scholarly journals Sustained suppression by Foxp3+ regulatory T cells is vital for infectious transplantation tolerance

2011 ◽  
Vol 208 (10) ◽  
pp. 2043-2053 ◽  
Author(s):  
Adrian R. Kendal ◽  
Ye Chen ◽  
Frederico S. Regateiro ◽  
Jianbo Ma ◽  
Elizabeth Adams ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Tissue Damage ◽  
Paradigm Shift ◽  
Effector T Cells ◽  
Transplantation Tolerance ◽  
Self Tolerance ◽  
Infectious Tolerance ◽  
First Time

A paradigm shift in immunology has been the recent discovery of regulatory T cells (T reg cells), of which CD4+Foxp3+ cells are proven as essential to self-tolerance. Using transgenic B6.Foxp3hCD2 mice to isolate and ablate Foxp3+ T reg cells with an anti-hCD2 antibody, we show for the first time that CD4+Foxp3+ cells are crucial for infectious tolerance induced by nonablative anti–T cell antibodies. In tolerant animals, Foxp3+ T reg cells are constantly required to suppress effector T cells still capable of causing tissue damage. Tolerated tissue contains T cells that are capable of rejecting it, but are prevented from doing so by therapeutically induced Foxp3+ T reg cells. Finally, Foxp3+ cells have been confirmed as the critical missing link through which infectious tolerance operates in vivo. Peripherally induced Foxp3+ cells sustain tolerance by converting naive T cells into the next generation of Foxp3+ cells. Empowering Foxp3+ regulatory T cells in vivo offers a tractable route to avoid and correct tissue immunopathology.

The role of cytokines in immunological tolerance: potential for therapy

2000 ◽  
Vol 2 (9) ◽  
pp. 1-20 ◽  
Author(s):  
Mark Harber ◽  
Anette Sundstedt ◽  
David Wraith
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Immune System ◽  
Animal Models ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Immunological Tolerance ◽  
Immunomodulatory Effects ◽  
Clinical Potential

Current immunosuppression protocols, although often effective, are nonspecific and therefore hazardous. Consequently, immunological tolerance that is antigen specific and does not globally depress the patient's immune system has become one of the Holy Grails of immunology. Since the discovery that cytokines have immunomodulatory effects, extensive research has investigated the potential of these molecules to induce and maintain specific immunological tolerance in the context of transplantation, allergy and autoimmunity. In this article, we review the possible mechanisms by which cytokines can modulate the immune response and the animal models that frequently confound the theory that a single cytokine, or group of cytokines, can induce tolerance in a predictable manner. Finally, we discuss the role of cytokines at a paracrine level, particularly in the context of inducing and maintaining antigen-specific, regulatory T cells with the clinical potential to suppress specific immune responses.

scholarly journals Regulatory T-cell: Regulator of Host Defense in Infection

2017 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Mousa Mohammadnia-Afrouzi ◽  
Mehdi Shahbazi ◽  
Sedigheh Baleghi Damavandi ◽  
Ghasem Faghanzadeh Ganji ◽  
Soheil Ebrahimpour
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Regulatory T Cell ◽  
Critical Role ◽  
The Body ◽  
Cell Contact ◽  
Infectious Agents ◽  
Activated T Cells

Based on diverse activities and production of several cytokines, T lymphocytes and T helper cells are divided into Th1, Th2, Th17 and regulatory T-cell (T regs) subsets based on diverse activities and production of several cytokines. Infectious agents can escape from host by modulation of immune responses as effector T-cells and Tregs. Thus, regulatory T-cells play a critical role in suppression of immune responses to infectious agents such as viruses, bacteria, parasites and fungi and as well as preserving immune homeostasis. However, regulatory T-cell responses can advantageous for the body by minimizing the tissue-damaging effects. The following subsets of regulatory T-cells have been recognized: natural regulatory Tcells, Th3, Tr1, CD8+ Treg, natural killer like Treg (NKTreg) cells. Among various markers of Treg cells, Forkhead family transcription factor (FOXP3) as an intracellular protein is used for discrimination between activated T reg cells and activated T-cells. FOXP3 has a central role in production, thymocyte differentiation and function of regulatory Tcells. Several mechanisms have been indicated in regulation of T reg cells. As, the suppression of T-cells via regulatory T-cells is either mediated by Cell-cell contact and Immunosuppressive cytokines (TGF-Beta, IL-10) mediated.

scholarly journals Multifunctional T Cell Response to DosR and Rpf Antigens Is Associated with Protection in Long-Term Mycobacterium tuberculosis-Infected Individuals in Colombia

2016 ◽  
Vol 23 (10) ◽  
pp. 813-824 ◽  
Author(s):  
Leonar Arroyo ◽  
Mauricio Rojas ◽  
Kees L. M. C. Franken ◽  
Tom H. M. Ottenhoff ◽  
Luis F. Barrera
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Immune Responses ◽  
Mononuclear Cells ◽  
T Cell Response ◽  
Short Term ◽  
Content Type ◽  
Long Term Culture

ABSTRACTMultifunctional T cells have been shown to be protective in chronic viral infections. In mycobacterial infections, however, evidence for a protective role of multifunctional T cells remains inconclusive. Short-term cultures of peripheral blood mononuclear cells stimulated with theMycobacterium tuberculosisRD1 antigens 6-kDa early secretory antigenic target (ESAT6) and 10-kDa culture filtrate antigen (CFP10), which are induced in the early infection phase, have been mainly used to assess T cell multifunctionality, although long-term culture assays have been proposed to be more sensitive than short-term assays for assessment of memory T cells, which are essential for long-term immunity. Here we used a long-term culture assay system to study the T cell immune responses to theM. tuberculosislatency-associated DosR antigens and reactivation-associated Rpf antigens, compared to ESAT6 and CFP10, in patients with pulmonary tuberculosis (PTB) and household contacts of PTB patients with long-term latent tuberculosis infection (ltLTBI), in a community in whichM. tuberculosisis endemic. Our results showed that the DosR antigens Rv1737c (narK2) and Rv2029c (pfkB) and the Rv2389c (rpfD) antigen ofM. tuberculosisinduced higher frequencies of CD4+or CD8+mono- or bifunctional (but not multifunctional) T cells producing interferon gamma (IFN-γ) and/or tumor necrosis alpha (TNF-α) in ltLTBI, compared to PTB. Moreover, the frequencies of CD4+and/or CD8+T cells with a CD45RO+CD27+phenotype were higher in ltLTBI than in PTB. Thus, the immune responses to selected DosR and Rpf antigens may be associated with long-term latency, correlating with protection fromM. tuberculosisreactivation in ltLTBI. Further study of the functional and memory phenotypes may contribute to further discrimination between the different states ofM. tuberculosisinfections.

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