Immunology CD4 and CD8 T Cells Quiz

False

True

False

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>Class I MHC molecules present peptides from proteins synthesized within the cell, while class II MHC molecules present peptides from proteins that have been ingested and processed by the cell.</p> Signup and view all the answers

<p>The α-chain gene is polymorphic and encodes for three extracellular domains, specifically α1, α2, and α3.</p> Signup and view all the answers

<p>Class I MHC molecules are composed of a polymorphic α-chain and a non-polymorphic β2-microglobulin, forming a heterodimer on the cell surface.</p> Signup and view all the answers

<p>The TCR binds to both the antigenic peptide and the flanking α-helices of the MHC molecule, enabling T cell antigen recognition.</p> Signup and view all the answers

<p>MHC restriction refers to the phenomenon where T cells can only recognize their specific antigen when presented with a specific self-MHC molecule.</p> Signup and view all the answers

<p>The genes for HLA class I molecules are located within the MHC region on chromosome 6.</p> Signup and view all the answers

<p>The groove allows for the binding of antigenic peptides, which is essential for T cell recognition.</p> Signup and view all the answers

<p>The specific type of class I MHC molecule is determined by the polymorphic α-chain encoded by distinct genes.</p> Signup and view all the answers

<p>The α3 domain consists of 5 antiparallel β-strands that create an immunoglobulin-type fold, reinforcing the MHC structure.</p> Signup and view all the answers

<p>CD8+ T cells are associated with class I MHC molecules, while CD4+ T cells are associated with class II MHC molecules.</p> Signup and view all the answers

<p>The HLA class I molecule is composed of a polymorphic α-chain and a non-polymorphic β2-microglobulin, which allows it to present a diverse array of peptide fragments to T cells, thus influencing immune response.</p> Signup and view all the answers

<p>The three major HLA class I molecules are HLA-A, HLA-B, and HLA-C, and they are structurally similar as they all consist of a heterodimer of an α-chain and β2-microglobulin.</p> Signup and view all the answers

<p>The α1 and α2 domains create a groove that allows for the binding of antigenic peptides, facilitating the interaction with T cell receptors.</p> Signup and view all the answers

<p>The MHC molecules present peptides that the TCR recognizes; the specific combination of peptide and MHC molecule influences T cell activation.</p> Signup and view all the answers

<p>The β2-microglobulin enhances the stability of the class I MHC structure, allowing it to form a stable heterodimer with the α-chain.</p> Signup and view all the answers

<p>The intracellular domain of the α-chain anchors the class I MHC protein to the cell membrane, ensuring its proper localization for function.</p> Signup and view all the answers

<p>MHC restriction means T cells can only recognize their specific antigens when presented by a corresponding MHC molecule, impacting their activation.</p> Signup and view all the answers

<p>Class I MHC molecules present endogenous peptides to CD8+ T cells, while class II MHC molecules present exogenous peptides to CD4+ T cells.</p> Signup and view all the answers

<p>The polymorphism of the HLA class I α-chain allows for a wide range of peptides to be presented, enhancing the immune system's ability to combat various pathogens.</p> Signup and view all the answers

<p>The TCR has no measurable affinity for the peptide alone and low affinity for MHC molecules with other peptides, highlighting its dependence on the specific MHC-peptide complex for activation.</p> Signup and view all the answers

<p>The immune system detects structural features that mark pathogens or toxins as distinct from host cells, enabling it to eliminate threats while preserving host tissues.</p> Signup and view all the answers

<p>The two categories are i) innate responses encoded by germ line genes that recognize shared molecular patterns, and ii) adaptive responses that result from somatic rearrangement for specific antigen recognition.</p> Signup and view all the answers

<p>Obligate pathogens are microbes that can cause disease in the host, while commensal organisms are typically non-pathogenic and can provide beneficial functions to the host.</p> Signup and view all the answers

<p>The immune system must carefully regulate its responses to eliminate pathogens without causing harm to its own cells and tissues.</p> Signup and view all the answers

<p>Recognizing unique molecular patterns allows the immune system to identify and target pathogens for elimination while distinguishing them from host molecules.</p> Signup and view all the answers

<p>The immune system must identify and neutralize these substances without overreacting to them, as excessive responses could damage normal tissues or lead to allergies.</p> Signup and view all the answers

<p>Homeostasis refers to the host's ability to maintain stability in physiological functions despite the constant challenge posed by pathogenic microbes.</p> Signup and view all the answers

<p>It is essential for the immune system to tolerate commensal organisms to support normal gut health, prevent infections, and promote beneficial interactions.</p> Signup and view all the answers

<p>They bind molecular patterns expressed on the surfaces of invading microbes.</p> Signup and view all the answers

<p>The adaptive immune system has exquisite specificity for its target antigens, unlike the innate immune system which utilizes germ-line-encoded receptors.</p> Signup and view all the answers

<p>Clonal expansion refers to the rapid multiplication of antigen-specific T and B cells in response to an antigen.</p> Signup and view all the answers

<p>CD antigens are cell phenotype-determining markers that help distinguish different leukocyte subsets.</p> Signup and view all the answers

<p>Hematopoietic stem cells are pluripotent cells that can differentiate into various types of blood cells.</p> Signup and view all the answers

<p>The innate immune response serves as the first line of defense and activates the adaptive response for enhanced specificity.</p> Signup and view all the answers

<p>The assembly of antigen receptors employs a rearrangement of germ-line gene elements, followed by a selection process for functional receptors.</p> Signup and view all the answers

<p>New CD molecules are defined and registered during workshops organized by Human Leukocyte Differentiation Antigen workshops.</p> Signup and view all the answers

<p>Monoclonal antibodies bind to specific CD antigens, allowing for the detection and analysis of different leukocyte types.</p> Signup and view all the answers

<p>B cells, T cells, natural killer (NK) cells, and NK-T cells.</p> Signup and view all the answers

<p>By their expression of the B cell receptor for antigen, specifically anchored Ig.</p> Signup and view all the answers

<p>Neutrophils clear microbial pathogens and assist in tissue repair through phagocytosis and cytokine production.</p> Signup and view all the answers

<p>T cells are defined by the presence of the T cell receptor (TCR), which binds to processed antigens presented by APCs.</p> Signup and view all the answers

<p>They are highly phagocytic and produce cytokines that regulate immune responses.</p> Signup and view all the answers

<p>They give rise to granulocytes, megakaryocytes, platelets, and erythrocytes.</p> Signup and view all the answers

<p>NK cells use a collection of activating and inhibitory cell surface receptors to identify virus-infected or tumor cells.</p> Signup and view all the answers

<p>Macrophages primarily utilize the production of nitric oxide and phagocytosis to kill pathogens.</p> Signup and view all the answers

<p>Granulocytes, such as neutrophils and eosinophils, have distinct granules in their cytoplasm, while agranulocytes, like lymphocytes, do not.</p> Signup and view all the answers

<p>Neutrophils produce reactive oxygen species which are cytotoxic to bacterial pathogens.</p> Signup and view all the answers

<p>Neutrophils primarily function in the clearance of microbial pathogens through phagocytosis and the production of reactive oxygen species.</p> Signup and view all the answers

<p>Monocytes and macrophages are highly phagocytic and are mobilized to sites of infection, where they play a crucial role in both acute and chronic inflammatory responses.</p> Signup and view all the answers

<p>Macrophages differentiate based on the activating signals they receive, adopting either pro-inflammatory or anti-inflammatory phenotypes depending on the cytokines present.</p> Signup and view all the answers

<p>Eosinophils are primarily active against helminths and other parasites and play a significant role in allergic responses through their cytotoxic granules.</p> Signup and view all the answers

<p>Basophils and mast cells, although morphologically similar, represent distinct lineages and have different roles in the immune response.</p> Signup and view all the answers

<p>Neutrophils produce significant amounts of cytokines like TNF and IL-12, supporting their role beyond direct pathogen clearance to include immunoregulatory functions.</p> Signup and view all the answers

<p>Macrophages kill microbial pathogens primarily through the production of nitric oxide and by phagocytosis.</p> Signup and view all the answers

<p>Granulocytes, including neutrophils, eosinophils, and basophils, contribute to the immune response by releasing active substances that target pathogens and modulate inflammation.</p> Signup and view all the answers

<p>NK-T cells share characteristics of both NK cells and T cells, recognizing infected or tumor cells through a unique set of receptors.</p> Signup and view all the answers

<p>Neutrophils produce reactive oxygen species and various enzymes that facilitate tissue remodeling and repair following injury.</p> Signup and view all the answers

<p>IL-4, IL-10, and IL-13 are involved in inducing alternatively activated macrophages.</p> Signup and view all the answers

<p>Eosinophils are enhanced by IL-5 and play a prominent role in mediating most allergic responses.</p> Signup and view all the answers

<p>Basophils and mast cells initiate immediate hypersensitivity by releasing histamine and other mediators upon IgE binding.</p> Signup and view all the answers

<p>Dendritic cells are potent antigen-presenting cells (APCs) that activate T cell responses by presenting processed antigens.</p> Signup and view all the answers

<p>Plasmacytoid dendritic cells are known for producing high levels of type I interferon and have a distinct histological morphology.</p> Signup and view all the answers

<p>The release of IL-4 by mast cells and basophils is significant for the induction of allergic immune responses.</p> Signup and view all the answers

<p>They engulf microbial antigens, process them, and present peptide fragments to activate T cells.</p> Signup and view all the answers

<p>The cytokine IL-5 enhances the production and survival of eosinophils in peripheral tissues.</p> Signup and view all the answers

<p>Langerhans cells are antigen-presenting cells located in the epidermis.</p> Signup and view all the answers

<p>Eosinophil granules contain toxic molecules and enzymes that are particularly active against helminths and parasites.</p> Signup and view all the answers

<p>The innate immune system acts rapidly and broadly to recognize and respond to invading pathogens or toxins.</p> Signup and view all the answers

<p>The adaptive immune response is specific to individual pathogens, relying on a small number of cells that must proliferate upon encountering an antigen.</p> Signup and view all the answers

<p>Self-tolerance refers to the immune system's ability to prevent damage to its own tissues by avoiding reactions against self-antigens.</p> Signup and view all the answers

<p>A key feature is the generation of long-lived memory cells that can rapidly re-express effector functions upon re-encounter with their specific antigen.</p> Signup and view all the answers

<p>Physical barriers include epithelial cell layers, mucus layers, and cilia that help to prevent pathogen entry and clear contaminants.</p> Signup and view all the answers

<p>T cells maintain self-tolerance by recognizing foreign antigens in conjunction with self-antigens, ensuring they target infected cells without damaging normal tissues.</p> Signup and view all the answers

<p>Soluble proteins and small molecules, such as complement proteins and cytokines, facilitate communication and activities of immune cells in response to pathogens.</p> Signup and view all the answers

<p>The ability to mount a rapid response is vital for containing infections early, preventing pathogens from establishing and spreading.</p> Signup and view all the answers

<p>The innate immune system provides immediate defense against pathogens, while the adaptive immune system develops a specific response that can enhance future defenses.</p> Signup and view all the answers

<p>Memory cells persist after an initial infection and enable a quicker and more effective immune response upon re-exposure to the same pathogen.</p> Signup and view all the answers

<p>T cells identify and destroy infected cells, playing a crucial role in adaptive immunity.</p> Signup and view all the answers

<p>T cells require recognition of both a self-component and a microbial structure via MHC molecules.</p> Signup and view all the answers

<p>The α1 and α2 domains form a groove that allows binding of antigenic peptides.</p> Signup and view all the answers

<p>It provides diversity in antigen presentation, enhancing the immune system's ability to recognize various pathogens.</p> Signup and view all the answers

<p>β2-microglobulin stabilizes the structure of class I MHC molecules on the cell surface.</p> Signup and view all the answers

<p>The common myeloid progenitor differentiates into myeloid cells while the common lymphoid progenitor gives rise to lymphocytes.</p> Signup and view all the answers

<p>T cells recognize specific antigens through the T cell receptor (TCR) that binds to processed antigens presented by MHC molecules.</p> Signup and view all the answers

<p>MHC restriction means that T cells can only respond to their specific antigen when presented on matching self-MHC.</p> Signup and view all the answers

<p>NK cells are large granular lymphocytes that play a critical role in the innate immune response.</p> Signup and view all the answers

<p>Phagocytosis allows antigen-presenting cells to process and present microbial antigens to T cells.</p> Signup and view all the answers

<p>Mast cells release histamine and other mediators that initiate immediate hypersensitivity responses.</p> Signup and view all the answers

<p>Dendritic cells process microbial antigens and present them as peptide fragments to activate T cells.</p> Signup and view all the answers

<p>Flt3 is essential for the development of both conventional and plasmacytoid dendritic cells from stem cells.</p> Signup and view all the answers

<p>T cells recognize infected cells by detecting peptide fragments bound to MHC molecules.</p> Signup and view all the answers

<p>Plasmacytoid dendritic cells are recognized for their ability to produce high levels of type I interferon.</p> Signup and view all the answers

<p>Identifying infected cells helps the immune system to destroy them and contain microbial infections effectively.</p> Signup and view all the answers

<p>Macrophages contribute to both innate and adaptive immune responses through antigen uptake and presentation.</p> Signup and view all the answers

<p>MHC class I and II expression allows antigen-presenting cells to present antigens to CD8+ and CD4+ T cells, respectively.</p> Signup and view all the answers

<p>The immune system recognizes specific molecular patterns associated with pathogens, enhancing pathogen identification.</p> Signup and view all the answers

<p>Mast cells and basophils release IL-4, which is critical for the induction of allergic immune responses.</p> Signup and view all the answers

<p>The β2-microglobulin stabilizes the structure of class I MHC molecules by forming a heterodimer with the polymorphic α-chain.</p> Signup and view all the answers

<p>The three extracellular domains (α1, α2, α3) form a groove for peptide binding, with α1 and α2 specifically allowing the presentation of antigenic peptides to TCR.</p> Signup and view all the answers

<p>The specific type is determined by the polymorphic α-chain encoded by distinct genes for HLA-A, HLA-B, and HLA-C.</p> Signup and view all the answers

<p>MHC restriction ensures that T cells can only recognize specific antigens when presented by compatible MHC molecules.</p> Signup and view all the answers

<p>The antiparallel β-strands form an immunoglobulin-type fold in the α3 domain, contributing to the structural integrity and stability of class I MHC.</p> Signup and view all the answers

<p>The α1 and α2 domains associate with their β-strands, creating a binding groove that accommodates antigenic peptides.</p> Signup and view all the answers

<p>The α-chain genes are located on chromosome 6, while the β2-microglobulin gene is found on chromosome 15, highlighting the genetic diversity and organization of MHC molecules.</p> Signup and view all the answers

<p>The TCR interacts with both the antigenic peptide and the adjacent α-helices of the MHC, which is critical for T cell activation.</p> Signup and view all the answers