Mycobacterium paratuberculosisand the bovine immune system

2001 ◽  
Vol 2 (2) ◽  
pp. 141-162 ◽  
Author(s):  
Paul M. Coussens
Keyword(s):  
T Cells ◽  
Immune System ◽  
Safety Concern ◽  
Γδ T Cells ◽  
Cell Types ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Host Immune System ◽  
Intestinal Epithelial ◽  
Rapid Deployment

AbstractMycobacterium aviumsubspeciesparatuberculosis(M. paratuberculosis) is the causative agent of Johne’s disease, a deadly intestinal ailment of ruminants. Johne’s disease is of tremendous economic importance to the worldwide dairy industry, causing major losses due to reduced production and early culling of animals. A highly controversial but developing link between exposure toM. paratuberculosisand human Crohn’s disease in some individuals has led to the suggestion thatM. paratuberculosisis also a potential food safety concern. As with many other mycobacteria,M. paratuberculosisis exquisitely adapted to survival in the host, despite aggressive immune reactions to these organisms. One hallmark of mycobacteria, includingM. paratuberculosis, is their propensity to infect macrophages. Inside the macrophage,M. paratuberculosisinterferes with the maturation of the phagosome by an unknown mechanism, thereby evading the host’s normal first line of defense against bacterial pathogens. The host immune system begins a series of attacks againstM. paratuberculosis-infected macrophages, including the rapid deployment of activated γδ T cells, CD4+T cells and cytolytic CD8+T cells. These cells interact with the persistently infected macrophage and with each other through a complex network of cytokines and receptors. Despite these aggressive efforts to clear the infection,M. paratuberculosispersists and the constant struggle of the immune system leads to pronounced damage to the intestinal epithelial cells. Enhancing our ability to control this important and tenacious pathogen will require a deeper understanding of howM. paratuberculosisinterferes with macrophage action, the cell types involved in the immune response, the cytokines these cells use to communicate, and the host genetic factors that control the response to infection.

scholarly journals The Aging of γδ T Cells

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1181 ◽  
Author(s):  
Weili Xu ◽  
Zandrea Wan Xuan Lau ◽  
Tamas Fulop ◽  
Anis Larbi
Keyword(s):  
T Cells ◽  
Immune System ◽  
Immune Cell ◽  
Γδ T Cells ◽  
Cell Types ◽  
Developed Countries ◽  
Common Denominator ◽  
Age Related ◽  
The Relationship ◽  
Diverse Interactions

In the coming decades, many developed countries in the world are expecting the “greying” of their populations. This phenomenon poses unprecedented challenges to healthcare systems. Aging is one of the most important risk factors for infections and a myriad of diseases such as cancer, cardiovascular and neurodegenerative diseases. A common denominator that is implicated in these diseases is the immune system. The immune system consists of the innate and adaptive arms that complement each other to provide the host with a holistic defense system. While the diverse interactions between multiple arms of the immune system are necessary for its function, this complexity is amplified in the aging immune system as each immune cell type is affected differently—resulting in a conundrum that is especially difficult to target. Furthermore, certain cell types, such as γδ T cells, do not fit categorically into the arms of innate or adaptive immunity. In this review, we will first introduce the human γδ T cell family and its ligands before discussing parallels in mice. By covering the ontogeny and homeostasis of γδ T cells during their lifespan, we will better capture their evolution and responses to age-related stressors. Finally, we will identify knowledge gaps within these topics that can advance our understanding of the relationship between γδ T cells and aging, as well as age-related diseases such as cancer.

scholarly journals High-dimensional immune-profiling in cancer: implications for immunotherapy

2020 ◽  
Vol 8 (1) ◽  
pp. e000363 ◽  
Author(s):  
Samuel Chuah ◽  
Valerie Chew
Keyword(s):  
Immune System ◽  
Immune Cell ◽  
Positive Impact ◽  
Cell Types ◽  
High Dimensional ◽  
Host Immune System ◽  
Cancer Therapies ◽  
Quality Of Data ◽  
New Information ◽  
Immune Profiling

Immunotherapy is a rapidly growing field for cancer treatment. In contrast to conventional cancer therapies, immunotherapeutic strategies focus on reactivating the immune system to mount an antitumor response. Despite the encouraging outcome in clinical trials, a large proportion of patients still do not respond to treatment and many experience different degrees of immune-related adverse events. Furthermore, it is now increasingly appreciated that even many conventional cancer therapies such as radiotherapy could have a positive impact on the host immune system for better clinical response. Hence, there is a need to better understand tumor immunity in order to design immunotherapeutic strategies, especially evidence-based combination therapies, for improved clinical outcomes. With this aim, cancer research turned its attention to profiling the immune contexture of either the tumor microenvironment (TME) or peripheral blood to uncover mechanisms and biomarkers which might aid in precision immunotherapeutics. Conventional technologies used for this purpose were limited by the depth and dimensionality of the data. Advances in newer techniques have, however, greatly improved the breadth and depth, as well as the quantity and quality of data that can be obtained. The result of these advances is a wealth of new information and insights on how the TME could be affected by various immune cell-types, and how this might in turn impact the clinical outcome of cancer patients . We highlight herein some of the high-dimensional technologies currently employed in immune profiling in cancer and summarize the insights and potential benefits they could bring in designing better cancer immunotherapies.

scholarly journals Potential Roles of Fungal Extracellular Vesicles during Infection

mSphere ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
Luna S. Joffe ◽  
Leonardo Nimrichter ◽  
Marcio L. Rodrigues ◽  
Maurizio Del Poeta
Keyword(s):  
Immune System ◽  
Extracellular Vesicles ◽  
Virulence Factors ◽  
Cell Types ◽  
Fungal Diseases ◽  
Host Immune System ◽  
The Past ◽  
Invasive Fungal Diseases

ABSTRACT Extracellular vesicles (EVs) are produced by virtually all cell types. Within the past few years, work in this field has revealed more information about fungal EVs. Fungal EVs have been shown to carry proteins, lipids, pigments, polysaccharides, and RNA; these components are known virulence factors, a fact which supports the hypothesis that fungal EVs concentrate pathogenic determinants. Extracellular vesicles (EVs) are produced by virtually all cell types. Within the past few years, work in this field has revealed more information about fungal EVs. Fungal EVs have been shown to carry proteins, lipids, pigments, polysaccharides, and RNA; these components are known virulence factors, a fact which supports the hypothesis that fungal EVs concentrate pathogenic determinants. Additionally, recent studies have demonstrated that fungal EVs stimulate the host immune system. In this review, putative roles of fungal EVs are discussed, including their potential as vaccination tools and their possible contribution to pathogenesis in invasive fungal diseases.

Therapeutic Anti-Tumor Immunity Mediated by Transiently Engrafting Allogeneic Lymphocytes: The “Allogeneic Effect” Revisited.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5255-5255
Author(s):  
Heather J. Symons ◽  
M. Yair Levy ◽  
Jie Wang ◽  
Xiaotao Zhou ◽  
Ephraim J. Fuchs
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Host Immune System ◽  
Tumoricidal Activity ◽  
Tumor Bearing ◽  
Anti Tumor Activity ◽  
Allogeneic Lymphocytes

Abstract The “allogeneic effect” refers to the induction of host B cell antibody synthesis or host T cell cytotoxicity, including tumoricidal activity, by an infusion of allogeneic lymphocytes. We have previously shown that treatment of mice with cyclophosphamide (Cy) followed by infusion of CD8+ T cell-depleted allogeneic spleen cells (Cy + CD8− DLI) induces anti-tumor activity in a model of minimal residual leukemia, even though the donor cells are eventually rejected by the host immune system. The purpose of the current investigation was to test the activity of Cy + CD8− DLI in the treatment of well-established cancer, and to characterize the mechanisms of the anti-tumor effect. BALB/c mice were inoculated intravenously (IV) with the syngeneic A20 lymphoma/leukemia or the RENCA renal cell carcinoma on day 0 and were then treated with nothing, Cy alone on day 14, or Cy + CD8− DLI from MHC-mismatched C57BL/6 donors on day 15. In both tumor models, the combination of Cy + CD8− DLI significantly prolonged survival compared to mice treated with nothing or with Cy alone. While depletion of CD4+ T cells from the DLI significantly diminished the beneficial effect of CD8− DLI, purified CD4+ T cells alone were inactive, demonstrating that donor CD4+ T cells and another population of cells were required for optimal anti-tumor activity. Several observations pointed to an active role for the host immune system in the anti-tumor activity of Cy + CD8− DLI. First, host T cells participated in the anti-tumor effect of treatment with Cy alone, since the drug’s activity was diminished in tumor-bearing scid mice or in normal BALB/c mice depleted of T cells. Second, while Cy + CD8− DLI caused no GVHD in tumor-bearing but immunocompetent BALB/c recipients, it caused fatal acute GVHD in either tumor-bearing scid or T-cell depleted BALB/c mice. Finally, the anti-tumor effect of Cy + CD8- DLI was also significantly inhibited in BALB/c mice that were depleted of CD8+ T cells. These results demonstrate that transiently engrafting T cells administered after Cy can induce significant anti-tumor effects against both solid and liquid tumors. We propose that upon recognition of alloantigen on host antigen-presenting cells (APCs), allogeneic donor CD4+ T cells deliver activating ligands to the APCs, thereby generating effective “help” to break tolerance in tumor-specific host CD8+ T cells. This mechanism may correspond to the “allogeneic effect” in the anti-tumor response described over three decades ago.

scholarly journals The cellular immune system in myelomagenesis: NK cells and T cells in the development of MM and their uses in immunotherapies

2015 ◽  
Vol 5 (4) ◽  
pp. e306-e306 ◽  
Author(s):  
T Dosani ◽  
M Carlsten ◽  
I Maric ◽  
O Landgren
Keyword(s):  
T Cells ◽  
Immune System ◽  
Natural Killer ◽  
Γδ T Cells ◽  
Tumor Evolution ◽  
The Status ◽  
And Function ◽  
Cellular Immune ◽  
Functional Profiles ◽  
Killer T Cells

Abstract As vast strides are being made in the management and treatment of multiple myeloma (MM), recent interests are increasingly focusing on understanding the development of the disease. The knowledge that MM develops exclusively from a protracted phase of monoclonal gammopathy of undetermined significance provides an opportunity to study tumor evolution in this process. Although the immune system has been implicated in the development of MM, the scientific literature on the role and status of various immune components in this process is broad and sometimes contradictory. Accordingly, we present a review of cellular immune subsets in myelomagenesis. We summarize the current literature on the quantitative and functional profiles of natural killer cells and T-cells, including conventional T-cells, natural killer T-cells, γδ T-cells and regulatory T-cells, in myelomagenesis. Our goal is to provide an overview of the status and function of these immune cells in both the peripheral blood and the bone marrow during myelomagenesis. This provides a better understanding of the nature of the immune system in tumor evolution, the knowledge of which is especially significant considering that immunotherapies are increasingly being explored in the treatment of both MM and its precursor conditions.

scholarly journals Immunomodulation by Gut Microbiota: Role of Toll-Like Receptor Expressed by T Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mariagrazia Valentini ◽  
Alessia Piermattei ◽  
Gabriele Di Sante ◽  
Giuseppe Migliara ◽  
Giovanni Delogu ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Gut Microbiota ◽  
Cell Types ◽  
Mutual Regulation ◽  
Close Relationship ◽  
Numerous Cell ◽  
Specific Receptors ◽  
And Function

A close relationship exists between gut microbiota and immune responses. An imbalance of this relationship can determine local and systemic immune diseases. In fact the immune system plays an essential role in maintaining the homeostasis with the microbiota that normally resides in the gut, while, at the same time, the gut microbiota influences the immune system, modulating number and function of effector and regulatory T cells. To achieve this aim, mutual regulation between immune system and microbiota is achieved through several mechanisms, including the engagement of toll-like receptors (TLRs), pathogen-specific receptors expressed on numerous cell types. TLRs are able to recognize ligands from commensal or pathogen microbiota to maintain the tolerance or trigger the immune response. In this review, we summarize the latest evidences about the role of TLRs expressed in adaptive T cells, to understand how the immune system promotes intestinal homeostasis, fights invasion by pathogens, and is modulated by the intestinal microbiota.

scholarly journals Regulatory T cells and immune profiling in johne’s disease lesions

2016 ◽  
Vol 181 ◽  
pp. 39-50 ◽  
Author(s):  
Jonathan A. Roussey ◽  
Lilian J. Oliveira ◽  
Ingeborg M. Langohr ◽  
Dodd G. Sledge ◽  
Paul M. Coussens
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Immune Profiling

Cell-Mediated Immune System Regulation in Periodontal Diseases

1997 ◽  
Vol 8 (1) ◽  
pp. 76-89 ◽  
Author(s):  
A. Mathur ◽  
B.S. Michalowicz
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Lymphocytes ◽  
Periodontal Disease ◽  
Peripheral Blood ◽  
Periodontal Diseases ◽  
Γδ T Cells ◽  
Peripheral Blood Lymphocytes ◽  
T Cell Subsets ◽  
Cell Mediated Immunity

The adaptive immune system consists of humoral and cell-mediated immunity. T-lymphocytes are the key components of cell-mediated immunity. CD4+ helper T-lymphocytes facilitate B-cells to differentiate and produce specific antibodies, whereas CD8+ cytotoxic T-lymphocytes kill virally infected cells. Periodontal diseases have been associated with a variety of imbalances in the regulation of immune responses. Changes in the ratios of peripheral blood CD4+ and CD8+ T-lymphocytes, depressed proliferative responses of peripheral blood lymphocytes, and increased frequency of CD45RO+ memory T-lymphocytes in diseased tissues have been reported in individuals with various forms of periodontal disease. While some studies have shown an increased frequency of γδ+ T-cells in periodontal lesions, the role of γδ+ T-cells in periodontal disease remains controversial. The ability of putative periodontopathic bacteria selectively to stimulate certain V(3-expressing T-cells is intriguing and could determine whether a CD4+ Th I or a CD4+ Th2 cell response is elicited. The prominence of a particular subset of helper T-cells within the periodontal lesion could be a reflection of the stage and activity of the disease, or the types of bacteria present. Regardless, longitudinal studies of the involvement of T-cell subsets and cytokines in periodontal disease are clearly needed.

scholarly journals A fetal wave of human type 3 effector γδ cells with restricted TCR diversity persists into adulthood

2021 ◽  
Vol 6 (58) ◽  
pp. eabf0125
Author(s):  
Likai Tan ◽  
Alina Suzann Fichtner ◽  
Elena Bruni ◽  
Ivan Odak ◽  
Inga Sandrock ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Throughput Sequencing ◽  
Γδ T Cells ◽  
Cell Types ◽  
Multiparameter Flow Cytometry ◽  
Expression Of Genes ◽  
Innate Effector ◽  
Type 3

Accumulating evidence suggests that the mouse embryonic thymus produces distinct waves of innate effector γδ T cells. However, it is unclear whether this process occurs similarly in humans and whether it comprises a dedicated subset of innate-like type 3 effector γδ T cells. Here, we present a protocol for high-throughput sequencing of TRG and TRD pairs that comprise the clonal γδTCR. In combination with single-cell RNA sequencing, multiparameter flow cytometry, and TCR sequencing, we reveal a high heterogeneity of γδ T cells sorted from neonatal and adult blood that correlated with TCR usage. Immature γδ T cell clusters displayed mixed and diverse TCRs, but effector cell types segregated according to the expression of either highly expanded individual Vδ1+ TCRs or moderately expanded semi-invariant Vγ9Vδ2+ TCRs. The Vγ9Vδ2+ T cells shared expression of genes that mark innate-like T cells, including ZBTB16 (encoding PLZF), KLRB1, and KLRC1, but consisted of distinct clusters with unrelated Vγ9Vδ2+ TCR clones characterized either by TBX21, FCGR3A, and cytotoxicity-associated gene expression (type 1) or by CCR6, RORC, IL23R, and DPP4 expression (type 3). Effector γδ T cells with type 1 and type 3 innate T cell signatures were detected in a public dataset of early embryonic thymus organogenesis. Together, this study suggests that functionally distinct waves of human innate-like effector γδ T cells with semi-invariant Vγ9Vδ2+ TCR develop in the early fetal thymus and persist into adulthood.

scholarly journals AIDS and COVID-19 are two diseases separated by a common lymphocytopenia

2020 ◽  
Author(s):  
Salvatore Sciacchitano ◽  
Simonetta Giovagnoli ◽  
Rachele Amodeo ◽  
Iolanda Santino ◽  
Maurizio Simmaco ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Immunological Response ◽  
Serum Levels ◽  
University Hospital ◽  
Host Immune System ◽  
Aids Patients ◽  
Cd8 Cells ◽  
Severe Reduction ◽  
The Difference

Abstract HIV and SARS-CoV-2 are responsible for two of the most dangerous and life-threatening infectious diseases of our times. To better analyze the difference in the immunological response elicited by the two infections, we compare the alterations in the lymphocyte subpopulations, measured by flow cytometry analysis (FCA) in both AIDS and COVID-19 patients, referred to our University Hospital. A total of 184 HIV infected patients were retrospectively examined and the results of FCA collected and compared to those obtained in 110 SARS-CoV-2 infected patients, examined during the actual outbreak. We observe a comparable reduction in B cells in both diseases and a more severe reduction in the total amount of T cells in COVID-19 as compared to AIDS patients. The analysis of the T cells subpopulations indicates that there is a comparable reduction in the CD4+ cells count. Conversely, a remarkable difference between them is observed in the CD8+ counts. In AIDS patients the CD8+ cells are slightly higher than normal, while in COVID-19 patients the CD8+ cell count is markedly reduced. As a result, the CD4+/CD8+ ratios, is very low in AIDS and higher than normal in COVID-19 patients. The NK cells are reduced in both diseases, but SARS-CoV-2 infection causes a more severe reduction compared to HIV infection. In conclusion, both HIV and SARS-CoV-2 viruses induce major changes in the lymphocytes count, with remarkable similarities and differences between them. The total absolute numbers of T cells and, in particular of the CD8+ subpopulation, are lower in COVID-19 patients compared to AIDS ones, while the CD4+ are reduced in both at similar levels. These results indicate that the host immune system reacts differently to the two infection, but they are responsible of a comparable dropping effect on the serum levels of CD4+ T cell population. The meaning of the similarities and of the differences in terms of T cells activation and serum depletion are discussed. The knowledge on how the immune system reacts to these two infections will be useful to better define their mechanism of action and to design specific preventive and therapeutic approaches.

Sign in / Sign up

Export Citation Format

Share Document