Podcast Beta
Questions and Answers
What is autoimmunity?
What is self-tolerance in the context of autoimmunity?
What is central tolerance?
Where does thymic maturation of T cells take place?
Signup and view all the answers
What is a proposed factor in the development of canine nasal CLE (cutaneous lupus erythematosus)?
Signup and view all the answers
Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
Signup and view all the answers
What is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
Signup and view all the answers
What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
Signup and view all the answers
Which animals are more susceptible to autoimmune diseases according to the text?
Signup and view all the answers
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
Signup and view all the answers
What is the primary cause of ACAID in the eye according to the text?
Signup and view all the answers
What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
Signup and view all the answers
What is a proposed factor in the development of autoimmunity in the testes after puberty?
Signup and view all the answers
What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
Signup and view all the answers
Which age group of animals is more susceptible to autoimmune diseases according to the text?
Signup and view all the answers
What is a proposed factor contributing to the development of autoimmune diseases in animals?
Signup and view all the answers
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?
Signup and view all the answers
What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
Signup and view all the answers
Which cells mainly inhibit immune reactions against self-antigens through immunosuppressive cytokines like IL-10 and TGF-β?
Signup and view all the answers
What is the process through which deletion of mature T cells may occur?
Signup and view all the answers
What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
Signup and view all the answers
Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
Signup and view all the answers
What is the primary mechanism used to control autoreactive cells that escape to the periphery?
Signup and view all the answers
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?
Signup and view all the answers
Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
Signup and view all the answers
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
Signup and view all the answers
What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
Signup and view all the answers
What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
Signup and view all the answers
Where do T cells undergo their final development and maturation?
Signup and view all the answers
What is the fate of immature T cells that recognize self-antigens during their maturation in the thymus?
Signup and view all the answers
What is the primary mechanism used to control autoreactive B cells during their maturation in the bone marrow?
Signup and view all the answers
What is the first change to an early thymic immigrant (immature T cell) upon entering the thymus?
Signup and view all the answers
Which of the following is a recognized trigger of immune-mediated haemolytic anaemia, thrombocytopaenia, and neutropaenia in animals?
Signup and view all the answers
What is the proposed mechanism through which infectious agents can trigger autoimmune responses?
Signup and view all the answers
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
Signup and view all the answers
What is the term for the process through which immature T cells prove their TCR can interact with MHC-peptide complex with moderate affinity?
Signup and view all the answers
What is the term for the process through which self-reactive lymphocytes are inhibited from causing immune reactions against self-antigens?
Signup and view all the answers
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
Signup and view all the answers
What is a proposed factor contributing to genetic predisposition to autoimmune diseases in animals?
Signup and view all the answers
What is the term for the process through which deletion of mature T cells may occur?
Signup and view all the answers
What is a proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
Signup and view all the answers
Which cells are responsible for causing the anterior chamber-associated immune deviation (ACAID) in the eye?
Signup and view all the answers
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?
Signup and view all the answers
Which age group of animals is more susceptible to autoimmune diseases according to the text?
Signup and view all the answers
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?
Signup and view all the answers
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?
Signup and view all the answers
Which cells express high levels of CD25 and FOXP3 and inhibit immune reactions against self-antigens?
Signup and view all the answers
What is the term for the imperfect central tolerance that allows self-reactive lymphocytes to escape into the periphery?
Signup and view all the answers
What is the primary mechanism used to control autoreactive cells that escape to the periphery?
Signup and view all the answers
What is the proposed factor contributing to the loss of self-tolerance and the development of autoimmunity?
Signup and view all the answers
Which mechanism involves the induction of a self-reactive immune response by preventing exposure to self-antigens?
Signup and view all the answers
What is the mechanism used by immature bone marrow B cells when they come into contact with self-antigens?
Signup and view all the answers
What is a proposed mechanism through which infectious agents can trigger autoimmune responses?
Signup and view all the answers
What is the term for the process through which deletion of mature T cells may occur?
Signup and view all the answers
What is the term for the process similar to negative selection of T cells undergone by immature bone marrow B cells?
Signup and view all the answers
What is a proposed environmental factor contributing to the development of autoimmune diseases in animals?
Signup and view all the answers
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.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
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.
