Infection and immunity

2021 ◽  
pp. 853-920
Keyword(s):  
Major Histocompatibility Complex ◽  
Immune System ◽  
Cell Types ◽  
The Body ◽  
Acquired Immunity ◽  
Histocompatibility Complex ◽  
Repair Mechanisms ◽  
Antigen Presenting ◽  
Different Cell Types

‘Infection and immunity’ considers the response of the body to pathogens, such as bacteria, viruses, prions, fungi, and parasites, which are discussed in terms of their nature, life cycle, and modes of infection. The role of the immune system in defence against infection is discussed, including innate and adaptive (acquired) immunity, antigens, the major histocompatibility complex, and the different cell types involved (antigen-presenting cells, T-cells, and B-cells). The mechanisms and cellular basis of inflammation are considered, as are post-infection repair mechanisms, and pathologies of the immune system such as hypersensitivity, autoimmunity and transplantations, and immunodeficiency (both primary and secondary to other diseases).

scholarly journals The Role of MicroRNAs in Repair Processes in Multiple Sclerosis

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1711 ◽  
Author(s):  
Conor P. Duffy ◽  
Claire E. McCoy
Keyword(s):  
Multiple Sclerosis ◽  
Autoimmune Disorder ◽  
Cell Types ◽  
Repair Process ◽  
Rna Molecules ◽  
Current State ◽  
Non Coding Rna ◽  
Repair Mechanisms ◽  
Different Cell Types

Multiple sclerosis (MS) is an autoimmune disorder characterised by demyelination of central nervous system neurons with subsequent damage, cell death and disability. While mechanisms exist in the CNS to repair this damage, they are disrupted in MS and currently there are no treatments to address this deficit. In recent years, increasing attention has been paid to the influence of the small, non-coding RNA molecules, microRNAs (miRNAs), in autoimmune disorders, including MS. In this review, we examine the role of miRNAs in remyelination in the different cell types that contribute to MS. We focus on key miRNAs that have a central role in mediating the repair process, along with several more that play either secondary or inhibitory roles in one or more aspects. Finally, we consider the current state of miRNAs as therapeutic targets in MS, acknowledging current challenges and potential strategies to overcome them in developing effective novel therapeutics to enhance repair mechanisms in MS.

scholarly journals Presentation of Toxoplasma gondii Antigens via the Endogenous Major Histocompatibility Complex Class I Pathway in Nonprofessional and Professional Antigen-Presenting Cells

2007 ◽  
Vol 75 (11) ◽  
pp. 5200-5209 ◽  
Author(s):  
Florence Dzierszinski ◽  
Marion Pepper ◽  
Jason S. Stumhofer ◽  
David F. LaRosa ◽  
Emma H. Wilson ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Antigen Processing ◽  
Cell Types ◽  
T Cell Response ◽  
Complex Class ◽  
Mhc I ◽  
Histocompatibility Complex ◽  
Antigen Presenting

ABSTRACT Challenge with the intracellular protozoan parasite Toxoplasma gondii induces a potent CD8+ T-cell response that is required for resistance to infection, but many questions remain about the factors that regulate the presentation of major histocompatibility complex class I (MHC-I)-restricted parasite antigens and about the role of professional and nonprofessional accessory cells. In order to address these issues, transgenic parasites expressing ovalbumin (OVA), reagents that track OVA/MHC-I presentation, and OVA-specific CD8+ T cells were exploited to compare the abilities of different infected cell types to stimulate CD8+ T cells and to define the factors that contribute to antigen processing. These studies reveal that a variety of infected cell types, including hematopoietic and nonhematopoietic cells, are capable of activating an OVA-specific CD8+ T-cell hybridoma, and that this phenomenon is dependent on the transporter associated with antigen processing and requires live T. gondii. Several experimental approaches indicate that T-cell activation is a consequence of direct presentation by infected host cells rather than cross-presentation. Surprisingly, nonprofessional antigen-presenting cells (APCs) were at least as efficient as dendritic cells at activating this MHC-I-restricted response. Studies to assess whether these cells are involved in initiation of the CD8+ T-cell response to T. gondii in vivo show that chimeric mice expressing MHC-I only in nonhematopoietic compartments are able to activate OVA-specific CD8+ T cells upon challenge. These findings associate nonprofessional APCs with the initial activation of CD8+ T cells during toxoplasmosis.

Immunological changes accompanying the development of experimental neoplastic process

2015 ◽  
Vol 6 (2) ◽  
pp. 96-108
Author(s):  
Elena Aleksandrovna Dementeva ◽  
Olga Petrovna Gurina
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Genome Stability ◽  
Cell Types ◽  
Transformation Process ◽  
The Body ◽  
Expression Of Genes ◽  
Neoplastic Process ◽  
And Control ◽  
Different Cell Types

The key immunology problem remains the understanding of the mechanisms for the effective protection of the body against various pathogens with simultaneous suppression of the immune response to autoantigens. The pathogenesis of neoplastic pathological processes includes violations of the mechanisms of normal cell growth and cell proliferation. Antitumor immune response is a complex event, involving many different cell types. But despite the ability of the immune system to recognize and respond to a variety of tumor-associated antigens, the neoplastic process overcomes the protective forces of the organism, grows and spreads. For cancer cells characterized by independence from antiproliferative signals, autocrine stimulation of growth disturbances in the system, induction of apoptosis and control of genome stability. As a result of accumulation of genetic and epigenetic changes in tumor cells differ significantly from the normal range and the level of expression of genes involved in the transformation process, the accumulation of mutations in key genes promoters and suppressors of tumorigenesis. This creates the opportunity for recognition by cells of the immune system. The study of changes in value and operation of the various elements of the immune system in the development of experimental neoplastic process allows you to identify the mechanisms of interaction in the system «malignant tumor-immune system, to assess patterns of interaction with other organs and tissues, to create a theoretical pathogenetically reasonable premise for the development of anticancer therapy.

scholarly journals Role of BoLA-DRB3 genetic diversity against resistance to mastitis in cattle: Review

2019 ◽  
pp. 30-36 ◽  
Author(s):  
Namita Kumari ◽  
Shubham Loat ◽  
Shallu Saini ◽  
Nitika Dhilor ◽  
Anurag Kumar ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Immune Response ◽  
Major Histocompatibility Complex ◽  
Immune Regulation ◽  
Peptide Antigens ◽  
Mhc Molecules ◽  
Histocompatibility Complex ◽  
Antigen Presenting ◽  
Jawless Fish

The major histocompatibility complex (MHC) is an organized cluster of tightly linked genes, present in all vertebrates, playing an important role in the immune system, except the jawless fish [1]. MHC was first identified during tissue transplantation studies in mice [2] and was first known for its role in histocompatibility. Consequently, the role of MHC was discovered in immune regulation [3] and several other functions [4,5]. The important function of the MHC is to code for specialized antigen-presenting receptor glycoproteins, also called as MHC molecules. The products of these genes are involved in the induction and regulation of immune response. These molecules bind processed peptide antigens and present them to T-lymphocytes, thereby triggering immune response.

scholarly journals Healthy lungs maintain a young and energetic body

2021 ◽  
Vol 12 (8) ◽  
pp. 2117-2139
Author(s):  
Florian Ion Tiberiu Petrescu ◽  
Relly Victoria Virgil Petrescu
Keyword(s):  
Cell Types ◽  
The Body ◽  
Pipeline System ◽  
Piping System ◽  
Main Task ◽  
Basal Cells ◽  
Inhaled Particles ◽  
Multiple Cell ◽  
Different Cell Types

In general, life is only possible in the presence of oxygen in a form that can be easily absorbed by the body. In the case of humans, the lungs have as their main task the provision of the oxygen necessary for the body to carry out daily activities. The lung is a paired organ located in the chest cavity, a fibro-elastic organ capable of altering your volume during breathing (inspire and expire). The weight of a lung varies between 800 and 1,000 grams, of which more than 50% is blood. The air reaches the lungs through a pipeline system consisting of Nazo-pharynx, larynx, trachea, bronchi, and bronchiole. The role of the piping system is to heat and dampen the air or to capture and remove foreign inhaled particles. The channel system decreases in diameter after each branch - from the trachea and the large bronchi to the bronchiole with a diameter of less than one millimeter. The lung consists of over 30 different cell types. Trachea and large bronchi are taped by a mucous layer containing multiple cell types: ciliary cells - provides mucus movement, caliciform cells - secretes mucus, basal cells - plays a role in regeneration and neuro-ectodermic cells - ensures the secretory function of the lungs. In the chorion (the deep layer beneath the mucosa) there are cells involved in the defense processes - lymphocytes, mast cells, eosinophils or neutrophils.

scholarly journals Distinct mechanisms of neonatal tolerance induced by dendritic cells and thymic B cells.

1991 ◽  
Vol 173 (3) ◽  
pp. 549-559 ◽  
Author(s):  
M Inaba ◽  
K Inaba ◽  
M Hosono ◽  
T Kumamoto ◽  
T Ishida ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
B Cells ◽  
Cell Types ◽  
Cell Sorter ◽  
Histocompatibility Complex ◽  
Different Types ◽  
Induced Tolerance ◽  
Antigen Presenting

To assess the role of different types of antigen-presenting cells (APC) in the induction of tolerance, we isolated B cells, macrophages, and dendritic cells from thymus and spleen, and injected these into neonatal BALB/c mice across an Mls-1 antigenic barrier. One week after injection of APC from Mls-1-incompatible mice or from control syngeneic mice, we measured the number of thymic, Mls-1a-reactive, V beta 6+ T cells and the capacity of thymocytes to induce a graft-vs.-host (GVH) reaction in popliteal lymph nodes of Mls-1a mice. Injection of thymic but not spleen B cells deleted thymic, Mls-1a-reactive V beta 6+ T cells and induced tolerance in the GVH assay. The thymic B cells were primarily of the CD5+ type, and fluorescence-activated cell sorter-purified CD5+ thymic B cells were active. Injection of dendritic cells from spleen or thymus also induced tolerance, but the V beta 6 cells were anergized rather than deleted. Macrophages from thymus did not induce tolerance. Dendritic cells and thymic B cells were also effective in inducing tolerance even when injected into Mls-, major histocompatibility complex-incompatible, I-E- mice, but only thymic B cells depleted V beta 6-expressing T cells. Therefore, different types of bone marrow-derived APC have different capacities for inducing tolerance, and the active cell types (dendritic cells and CD5+ thymic B cells) can act by distinct mechanisms.

scholarly journals Viruses Teaching Immunology: Role of LCMV Model and Human Viral Infections in Immunological Discoveries

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 106 ◽  
Author(s):  
Mohamed Abdel-Hakeem
Keyword(s):  
Major Histocompatibility Complex ◽  
Immune System ◽  
Essential Role ◽  
Viral Infections ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocytic Choriomeningitis Virus ◽  
Viral Escape ◽  
Escape Mutation ◽  
Histocompatibility Complex

Virology has played an essential role in deciphering many immunological phenomena, thus shaping our current understanding of the immune system. Animal models of viral infection and human viral infections were both important tools for immunological discoveries. This review discusses two immunological breakthroughs originally identified with the help of the lymphocytic choriomeningitis virus (LCMV) model; immunological restriction by major histocompatibility complex and immunotherapy using checkpoint blockade. In addition, we discuss related discoveries such as development of tetramers, viral escape mutation, and the phenomenon of T-cell exhaustion.

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