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Questions and Answers
What is autoimmunity?
What is autoimmunity?
What is self-tolerance in the context of autoimmunity?
What is self-tolerance in the context of autoimmunity?
What is central tolerance?
What is central tolerance?
Where does thymic maturation of T cells take place?
Where does thymic maturation of T cells take place?
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What is a proposed factor in the development of canine nasal CLE (cutaneous lupus erythematosus)?
What is a proposed factor in the development of canine nasal CLE (cutaneous lupus erythematosus)?
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Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
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What is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
What is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
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What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
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Which animals are more susceptible to autoimmune diseases according to the text?
Which animals are more susceptible to autoimmune diseases according to the text?
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What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
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What is the primary cause of ACAID in the eye according to the text?
What is the primary cause of ACAID in the eye according to the text?
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What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
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What is a proposed factor in the development of autoimmunity in the testes after puberty?
What is a proposed factor in the development of autoimmunity in the testes after puberty?
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What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
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Which age group of animals is more susceptible to autoimmune diseases according to the text?
Which age group of animals is more susceptible to autoimmune diseases according to the text?
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What is a proposed factor contributing to the development of autoimmune diseases in animals?
What is a proposed factor contributing to the development of autoimmune diseases in animals?
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What is the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
What is the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
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What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
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Which cells mainly inhibit immune reactions against self-antigens through immunosuppressive cytokines like IL-10 and TGF-β?
Which cells mainly inhibit immune reactions against self-antigens through immunosuppressive cytokines like IL-10 and TGF-β?
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What is the process through which deletion of mature T cells may occur?
What is the process through which deletion of mature T cells may occur?
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What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
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Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
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What is the primary mechanism used to control autoreactive cells that escape to the periphery?
What is the primary mechanism used to control autoreactive cells that escape to the periphery?
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What is the term for the process undergone by immature T cells to prove their TCR is incapable of responding to self-antigens with high affinity?
What is the term for the process undergone by immature T cells to prove their TCR is incapable of responding to self-antigens with high affinity?
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Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
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What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
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What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
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What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
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Where do T cells undergo their final development and maturation?
Where do T cells undergo their final development and maturation?
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What is the fate of immature T cells that recognize self-antigens during their maturation in the thymus?
What is the fate of immature T cells that recognize self-antigens during their maturation in the thymus?
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What is the primary mechanism used to control autoreactive B cells during their maturation in the bone marrow?
What is the primary mechanism used to control autoreactive B cells during their maturation in the bone marrow?
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What is the first change to an early thymic immigrant (immature T cell) upon entering the thymus?
What is the first change to an early thymic immigrant (immature T cell) upon entering the thymus?
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Which of the following is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
Which of the following is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
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What is the proposed mechanism through which infectious agents can trigger autoimmune responses?
What is the proposed mechanism through which infectious agents can trigger autoimmune responses?
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What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
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What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
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What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
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What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
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What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
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What is the term for the process through which deletion of mature T cells may occur?
What is the term for the process through which deletion of mature T cells may occur?
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What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
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Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
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What is the term for the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
What is the term for the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
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Which age group of animals is more susceptible to autoimmune diseases according to the text?
Which age group of animals is more susceptible to autoimmune diseases according to the text?
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What is the term for the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
What is the term for the process undergone by immature T cells in the thymus to ensure their TCR can interact with MHC-peptide complex with moderate affinity?
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What is the term for the process undergone by immature T cells to prove their TCR is incapable of responding to self-antigens with high affinity?
What is the term for the process undergone by immature T cells to prove their TCR is incapable of responding to self-antigens with high affinity?
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Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
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What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
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What is the primary mechanism used to control autoreactive cells that escape to the periphery?
What is the primary mechanism used to control autoreactive cells that escape to the periphery?
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What is the proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
What is the proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
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Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
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What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
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What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
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What is the term for the process through which deletion of mature T cells may occur?
What is the term for the process through which deletion of mature T cells may occur?
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What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
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What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
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Study Notes
Autoimmunity and Autoimmune Diseases in Veterinary Medicine
- Autoimmunity may occur in the testes after puberty, due to the appearance of new antigens long after T cell tolerance has developed.
- The anterior chamber-associated immune deviation (ACAID) in the eye is caused by inhibitory cytokines produced by iris and ciliary body cells.
- Most autoimmune diseases in veterinary medicine are organ-specific, with autoimmune diseases being most prevalent in dogs.
- Examples of autoimmune diseases in veterinary medicine include autoimmune haemolytic anaemia, thrombocytopaenia, neutropaenia, pemphigus disorders, polyarthritis, myasthenia gravis, thyroiditis, diabetes mellitus, and SLE.
- Autoimmunity is a multifactorial process involving self-tolerance dysfunction, genetic predisposition, and triggering factors.
- Genetic predisposition to autoimmune diseases is linked to particular dog breeds and certain genes, especially those of the MHC.
- Predisposing factors for autoimmune diseases in animals include age, gender, lifestyle, and diet, with middle to older age animals being more susceptible.
- Environmental factors such as UV irradiation, chemicals, infectious agents, and other triggers can contribute to the development of autoimmune diseases in animals.
- UV light exposure is proposed to modify the antigenic structure of autoantigens in the skin, leading to the development of canine nasal CLE (cutaneous lupus erythematosus).
- Trimethoprim-sulphonamides are recognized as triggers of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals.
- Infectious agents can trigger autoimmune responses through various mechanisms, including upregulating the expression of costimulators on APCs and causing bystander activation.
- Factors contributing to the loss of self-tolerance and the development of autoimmunity include inheritance of susceptibility genes, infections, immunological imbalance, tissue injury, and environmental factors like UV light and drugs.
Immune Tolerance Mechanisms
- Immature T cells in the thymus undergo positive selection, proving their TCR can interact with MHC-peptide complex with moderate affinity and negative selection, proving their TCR is incapable of responding to self-antigens with high affinity.
- Thymic epithelial cells present a wide range of normal tissue antigens to immature T cells for testing their TCR.
- Immature bone marrow B cells undergo a process similar to negative selection of T cells, with self-antigen contact leading to apoptosis or receptor editing.
- Central tolerance is imperfect, allowing self-reactive lymphocytes to escape into the periphery.
- Peripheral tolerance mechanisms include anergy, suppression by regulatory T cells, and deletion by apoptosis to control autoreactive cells that escape to the periphery.
- Regulatory T cells, mainly CD4+ cells expressing high levels of CD25 and FOXP3, inhibit immune reactions against self-antigens through immunosuppressive cytokines like IL-10 and TGF-β.
- Deletion of mature T cells may occur through the Bim pathway or the Fas-Fas ligand system, which induces apoptosis of activated T cells and self-reactive B cells.
- Antigen sequestration in immunologically privileged sites, such as the blood-brain barrier or sites with limited MHC expression, may prevent exposure to self-antigens and the induction of a self-reactive immune response.
Immune Tolerance Mechanisms
- Immature T cells in the thymus undergo positive selection, proving their TCR can interact with MHC-peptide complex with moderate affinity and negative selection, proving their TCR is incapable of responding to self-antigens with high affinity.
- Thymic epithelial cells present a wide range of normal tissue antigens to immature T cells for testing their TCR.
- Immature bone marrow B cells undergo a process similar to negative selection of T cells, with self-antigen contact leading to apoptosis or receptor editing.
- Central tolerance is imperfect, allowing self-reactive lymphocytes to escape into the periphery.
- Peripheral tolerance mechanisms include anergy, suppression by regulatory T cells, and deletion by apoptosis to control autoreactive cells that escape to the periphery.
- Regulatory T cells, mainly CD4+ cells expressing high levels of CD25 and FOXP3, inhibit immune reactions against self-antigens through immunosuppressive cytokines like IL-10 and TGF-β.
- Deletion of mature T cells may occur through the Bim pathway or the Fas-Fas ligand system, which induces apoptosis of activated T cells and self-reactive B cells.
- Antigen sequestration in immunologically privileged sites, such as the blood-brain barrier or sites with limited MHC expression, may prevent exposure to self-antigens and the induction of a self-reactive immune response.
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Test your knowledge of autoimmunity and immune tolerance mechanisms in veterinary medicine with this quiz. Learn about organ-specific autoimmune diseases, genetic predisposition, environmental triggers, immune tolerance mechanisms, and more.