scholarly journals Helicobacter pyloriand T Helper Cells: Mechanisms of Immune Escape and Tolerance

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tiziana Larussa ◽  
Isabella Leone ◽  
Evelina Suraci ◽  
Maria Imeneo ◽  
Francesco Luzza
Keyword(s):  
Immune Escape ◽  
Host Susceptibility ◽  
T Cell Subsets ◽  
Host Immune System ◽  
T Helper ◽  
Chronic Infections ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
T Helper Lymphocyte ◽  
H Pylori

Helicobacter pyloricolonizes the gastric mucosa of at least half of the human population, causing a worldwide infection that appears in early childhood and if not treated, it can persist for life. The presence of symptoms and their severity depend on bacterial components, host susceptibility, and environmental factors, which allowH. pylorito switch between commensalism and pathogenicity.H. pylori-driven interactions with the host immune system underlie the persistence of the infection in humans, since the bacterium is able to interfere with the activity of innate and adaptive immune cells, reducing the inflammatory response in its favour. Gastritis due toH. pyloriresults from a complex interaction between several T cell subsets. In particular,H. pyloriis known to induce a T helper (Th)1/Th17 cell response-driven gastritis, whose impaired modulation caused by the bacterium is thought to sustain the ongoing inflammatory condition and the unsuccessful clearing of the infection. In this review we discuss the current findings underlying the mechanisms implemented byH. pylorito alter the T helper lymphocyte proliferation, thus facilitating the development of chronic infections and allowing the survival of the bacterium in the human host.

scholarly journals The impact of body mass index on adaptive immune cells in the human bone marrow

2020 ◽  
Author(s):  
Luca Pangrazzi ◽  
Erin Naismith ◽  
Carina Miggitsch ◽  
Jose’ Antonio Carmona Arana ◽  
Michael Keller ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Bone Marrow ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Immune Cells ◽  
Memory T Cells ◽  
T Cell Subsets ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Abstract Background. Obesity has been associated with chronic inflammation and oxidative stress. Both conditions play a determinant role in the pathogenesis of age-related diseases, such as immunosenescence. Adipose tissue can modulate the function of the immune system with the secretion of molecules influencing the phenotype of immune cells. The importance of the bone marrow (BM) in the maintenance of antigen-experienced adaptive immune cells has been documented in mice. Recently, some groups have investigated the survival of effector/memory T cells in the human BM. Despite this, whether high body mass index (BMI) may affect immune cells in the BM and the production of molecules supporting the maintenance of these cells it is unknown.Methods. Using flow cytometry, the frequency and the phenotype of immune cell populations were measured in paired BM and PB samples obtained from persons with different BMI. Furthermore, the expression of BM cytokines was assessed. The influence of cytomegalovirus (CMV) on T cell subsets was additionally considered, dividing the donors into the CMV- and CMV+ groups.Results. Our study suggests that increased BMI may affect both the maintenance and the phenotype of adaptive immune cells in the BM. While the BM levels of IL-15 and IL-6, supporting the survival of highly differentiated T cells, and oxygen radicals increased in overweight persons, the production of IFNγ and TNF by CD8+ T cells was reduced. In addition, the frequency of B cells and CD4+ T cells positively correlated with BMI in the BM of CMV- persons. Finally, the frequency of several T cell subsets, and the expression of senescence/exhaustion markers within these subpopulations, were affected by BMI. In particular, the levels of bona fide memory T cells may be reduced in overweight persons.Conclusion. Our work suggests that, in addition to aging and CMV, obesity may represent an additional risk factor for immunosenescence in adaptive immune cells. Metabolic interventions may help in improving the fitness of the immune system in the elderly.

Body mass index affects adaptive immune cells in the human bone marrow

2020 ◽  
Author(s):  
Luca Pangrazzi ◽  
Erin Naismith ◽  
Carina Miggitsch ◽  
Jose’ Antonio Carmona Arana ◽  
Michael Keller ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Bone Marrow ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Body Mass ◽  
Immune Cells ◽  
T Cell Subsets ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Abstract Background. Obesity has been associated with chronic inflammation and oxidative stress. Both conditions play a determinant role in the pathogenesis of age-related diseases, such as immunosenescence. Adipose tissue can modulate the function of the immune system with the secretion of molecules influencing the phenotype of immune cells. Recently, the importance of the bone marrow (BM) in the maintenance of antigen-experienced adaptive immune cells has been documented. Despite this, whether high body mass index (BMI) may affect immune cells in the BM and the production of molecules supporting the maintenance of these cells it is unknown. Methods. Using flow cytometry, the frequency and the phenotype of immune cell populations were measured in paired BM and PB samples obtained from persons with different BMI. Furthermore, the expression of BM cytokines was assessed. The influence of cytomegalovirus (CMV) on T cell subsets was additionally considered, dividing the donors into the CMV - and CMV + groups. Results. Our study suggests that increased BMI may affect both the maintenance and the phenotype of adaptive immune cells in the BM. While the BM levels of IL-15 and IL-6, supporting the survival of highly differentiated T cells, and oxygen radicals increased in overweight persons, the production of IFNγ and TNF by CD8 + T cells was reduced. In addition, the frequency of B cells and CD4 + T cells positively correlated with BMI in the BM of CMV - persons. Finally, the frequency of several T cell subsets, and the expression of senescence/exhaustion markers within these subpopulations, were affected by BMI. In particular, the levels of bona fide memory T cells may be reduced in overweight persons. Conclusion. Our work suggests that obesity may represent an independent risk factor supporting immunosenescence, in addition to aging and CMV. Metabolic interventions may help in improving the fitness of the immune system in the elderly.

scholarly journals Glances in Immunology of HIV and HCV Infection

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Maria Giovanna Quaranta ◽  
Benedetta Mattioli ◽  
Stefano Vella
Keyword(s):  
Immune System ◽  
Immune Escape ◽  
Current Knowledge ◽  
Research Field ◽  
New Drugs ◽  
Host Immune System ◽  
Immune Recognition ◽  
Genetic Associations ◽  
Efficient Treatment ◽  
Adaptive Immune

Since the identification of HIV and HCV much progress has been made in the understanding of their life cycle and interaction with the host immune system. Despite these viruses markedly differ in their virological properties and in their pathogenesis, they share many common features in their immune escape and survival strategy. Both viruses have developed sophisticated ways to subvert and antagonize host innate and adaptive immune responses. In the last years, much effort has been done in the study of the AIDS pathogenesis and in the development of efficient treatment strategies, and a fatal infection has been transformed in a potentially chronic pathology. Much of this knowledge is now being transferred in the HCV research field, especially in the development of new drugs, although a big difference still remains between the outcome of the two infections, being HCV eradicable after treatment, whereas HIV eradication remains at present unachievable due to the establishment of reservoirs. In this review, we present current knowledge on innate and adaptive immune recognition and activation during HIV and HCV mono-infections and evasion strategies. We also discuss the genetic associations between components of the immune system, the course of infection, and the outcome of the therapies.

scholarly journals B and T Cell Immunity in Tissues and Across the Ages

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 24
Author(s):  
Jayaum S. Booth ◽  
Franklin R. Toapanta
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Peripheral Blood ◽  
T Cell Immunity ◽  
T Cell Subsets ◽  
Adaptive Immune ◽  
Adaptive Immune Cells ◽  
Cell Immunity ◽  
Blood Specimens

B and T cells are key components of the adaptive immune system and coordinate multiple facets of immunity including responses to infection, vaccines, allergens, and the environment. In humans, B- and T-cell immunity has been determined using primarily peripheral blood specimens. Conversely, human tissues have scarcely been studied but they host multiple adaptive immune cells capable of mounting immune responses to pathogens and participate in tissue homeostasis. Mucosal tissues, such as the intestines and respiratory track, are constantly bombarded by foreign antigens and contain tissue-resident memory T (TRM) cells that exhibit superior protective capacity to pathogens. Also, tissue-resident memory B (BRM) cells have been identified in mice but whether humans have a similar population remains to be confirmed. Moreover, the immune system evolves throughout the lifespan of humans and undergoes multiple changes in its immunobiology. Recent studies have shown that age-related changes in tissues are not necessarily reflected in peripheral blood specimens, highlighting the importance of tissue localization and subset delineation as essential determinants of functional B and T cells at different life stages. This review describes our current knowledge of the main B- and T-cell subsets in peripheral blood and tissues across age groups.

scholarly journals The impact of body mass index on adaptive immune cells in the human bone marrow

2020 ◽  
Author(s):  
Luca Pangrazzi ◽  
Erin Naismith ◽  
Carina Miggitsch ◽  
Jose’ Antonio Carmona Arana ◽  
Michael Keller ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Bone Marrow ◽  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Immune Cells ◽  
Memory T Cells ◽  
T Cell Subsets ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Abstract Background. Obesity has been associated with chronic inflammation and oxidative stress. Both conditions play a determinant role in the pathogenesis of age-related diseases, such as immunosenescence. Adipose tissue can modulate the function of the immune system with the secretion of molecules influencing the phenotype of immune cells. The importance of the bone marrow (BM) in the maintenance of antigen-experienced adaptive immune cells has been documented in mice. Recently, some groups have investigated the survival of effector/memory T cells in the human BM. Despite this, whether high body mass index (BMI) may affect immune cells in the BM and the production of molecules supporting the maintenance of these cells it is unknown.Methods. Using flow cytometry, the frequency and the phenotype of immune cell populations were measured in paired BM and PB samples obtained from persons with different BMI. Furthermore, the expression of BM cytokines was assessed. The influence of cytomegalovirus (CMV) on T cell subsets was additionally considered, dividing the donors into the CMV- and CMV+ groups.Results. Our study suggests that increased BMI may affect both the maintenance and the phenotype of adaptive immune cells in the BM. While the BM levels of IL-15 and IL-6, supporting the survival of highly differentiated T cells, and oxygen radicals increased in overweight persons, the production of IFNγ and TNF by CD8+ T cells was reduced. In addition, the frequency of B cells and CD4+ T cells positively correlated with BMI in the BM of CMV- persons. Finally, the frequency of several T cell subsets, and the expression of senescence/exhaustion markers within these subpopulations, were affected by BMI. In particular, the levels of bona fide memory T cells may be reduced in overweight persons.Conclusion. Our work suggests that, in addition to aging and CMV, obesity may represent an additional risk factor for immunosenescence in adaptive immune cells. Metabolic interventions may help in improving the fitness of the immune system in the elderly.

scholarly journals Role of the intestinal microbiome and microbial-derived metabolites in immune checkpoint blockade immunotherapy of cancer

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Eiko Hayase ◽  
Robert R. Jenq
Keyword(s):  
Immune Responses ◽  
Immune Cells ◽  
Immune Checkpoint ◽  
Fecal Microbiota Transplantation ◽  
Checkpoint Inhibitors ◽  
Response Rates ◽  
Intestinal Microbiome ◽  
Host Immune System ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

AbstractImmune checkpoint inhibitors (ICIs) are monoclonal antibodies that block immune inhibitory pathways. Administration of ICIs augments T cell-mediated immune responses against tumor, resulting in improved overall survival in cancer patients. It has emerged that the intestinal microbiome can modulate responses to ICIs via the host immune system and that the use of antibiotics can lead to reduced efficacy of ICIs. Recently, reports that fecal microbiota transplantation can lead to ICI therapy responses in patients previously refractory to therapy suggest that targeting the microbiome may be a viable strategy to reprogram the tumor microenvironment and augment ICI therapy. Intestinal microbial metabolites may also be linked to response rates to ICIs. In addition to response rates, certain toxicities that can arise during ICI therapy have also been found to be associated with the intestinal microbiome, including in particular colitis. A key mechanistic question is how certain microbes can enhance anti-tumor responses or, alternatively, predispose to ICI-associated colitis. Evidence has emerged that the intestinal microbiome can modulate outcomes to ICI therapies via two major mechanisms, including those that are antigen-specific and those that are antigen-independent. Antigen-specific mechanisms occur when epitopes are shared between microbial and tumor antigens that could enhance, or, alternatively, reduce anti-tumor immune responses via cross-reactive adaptive immune cells. Antigen-independent mechanisms include modulation of responses to ICIs by engaging innate and/or adaptive immune cells. To establish microbiome-based biomarkers of outcomes and specifically modulate the intestinal microbiome to enhance efficacy of ICIs in cancer immunotherapy, further prospective interventional studies will be required.

scholarly journals P042 CHARACTERIZATION OF INNATE AND ADAPTIVE IMMUNE CELLS INVOLVED IN THE FOREIGN BODY REACTION TO POLYPROPYLENE MESHES IN THE HUMAN ABDOMEN

2021 ◽  
Vol 108 (Supplement_8) ◽  
Author(s):  
Axel Dievernich ◽  
Pascal Achenbach ◽  
Luke Davies ◽  
Uwe Klinge
Keyword(s):  
T Cells ◽  
Foreign Body ◽  
Immune Cells ◽  
Foreign Body Reaction ◽  
Immune Cell ◽  
Cell Types ◽  
Specific Cell ◽  
T Helper ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Abstract Aim Polypropylene (PP) mesh is widely used to reinforce tissues. The foreign body reaction (FBR) to the implant is dominated by innate immune cells, especially macrophages. However, considerable numbers of adaptive immune cells have also been regularly observed, which appear to play a crucial role in the long-term host response. This study investigated the FBR to seven human PP meshes, which were removed from the abdomen for recurrence after a median of one year. Material and Methods Using immunofluorescence microscopy and distance maps, the FBR was spatially analyzed for various innate (e.g., CD68+ macrophages, CD56+ NK) and adaptive immune cells (CD3+ T, CD4+ T-helper, CD8+ cytotoxic, FoxP3+ T-regulatory, CD20+ B) as well as “conventional” immune cells (defined as cells expressing their specific immune cell marker without co-expressing CD68). Results T-helper cells (19%) and regulatory T-cells (25%) were present at comparable rates to macrophages, and clustered significantly toward the mesh fibers. For all cell types the lowest proportions of “conventional” cells (< 60%) were observed at the mesh–tissue interface, but increased considerably at about 50–100 µm, indicating reduced stimulation with rising distance to the mesh fibers. Conclusions Both innate and adaptive immune cells participate in the chronic FBR to PP meshes with T cells and macrophages being the predominant cell types, respectively. Furthermore, many cells present a “hybrid” pattern near the mesh fibers. The complexity of the local immune reaction may explain why approaches focusing on specific cell types have not been very successful in reducing the chronic FBR.

scholarly journals Characterization of innate and adaptive immune cells involved in the foreign body reaction to polypropylene meshes in the human abdomen

Hernia ◽  
2021 ◽  
Author(s):  
A. Dievernich ◽  
P. Achenbach ◽  
L. Davies ◽  
U. Klinge
Keyword(s):  
T Cells ◽  
Foreign Body ◽  
Immune Cells ◽  
Foreign Body Reaction ◽  
Immune Cell ◽  
Cell Types ◽  
Specific Cell ◽  
T Helper ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

Abstract Background Polypropylene (PP) mesh is widely used to reinforce tissues. The foreign body reaction (FBR) to the implant is dominated by innate immune cells, especially macrophages. However, considerable numbers of adaptive immune cells, namely T cells, have also been regularly observed, which appear to play a crucial role in the long-term host response. Methods This study investigated the FBR to seven human PP meshes, which were removed from the abdomen for recurrence after a median of one year. Using immunofluorescence microscopy, the FBR was examined for various innate (CD11b+ myeloid, CD68+ macrophages, CD56+ NK) and adaptive immune cells (CD3+ T, CD4+ T-helper, CD8+ cytotoxic, FoxP3+ T-regulatory, CD20+ B) as well as “conventional” immune cells (defined as cells expressing their specific immune cell marker without co-expressing CD68). Results T-helper cells (19%) and regulatory T-cells (25%) were present at comparable rates to macrophages, and clustered significantly toward the mesh fibers. For all cell types the lowest proportions of “conventional” cells (< 60%) were observed at the mesh–tissue interface, but increased considerably at about 50–100 µm, indicating reduced stimulation with rising distance to the mesh fibers. Conclusion Both innate and adaptive immune cells participate in the chronic FBR to PP meshes with T cells and macrophages being the predominant cell types, respectively. In concordance with the previous data, many cells presented a “hybrid” pattern near the mesh fibers. The complexity of the immune reaction seen within the foreign body granuloma may explain why approaches focusing on specific cell types have not been very successful in reducing the chronic FBR.

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