T cells
Antigen challenge and clonal selection are most likely to occur in the secondary lymphoid organs, such as the lymph nodes and spleen. These organs are where antigens encounter immune cells, triggering an immune response and the selection of specific immune cell clones.
Antigen-presenting cells (APCs) are nonlymphocyte cells that play a central role in clonal selection. They present antigens to T cells, triggering the immune response and selection of specific clones of T cells that can recognize and respond to the antigen.
B cells are activated in the immune response when they encounter a specific antigen that matches their receptors. This triggers the B cells to multiply and differentiate into plasma cells, which produce antibodies to target and neutralize the antigen.
Clonal selection is responsible for the production of a large population of identical B or T cells that specifically recognize and target a particular antigen. This process is critical for the adaptive immune system's ability to mount a targeted immune response against pathogens.
Neither. Alloreactivity has to do with a lymphocytes reacting to a foreign antigen. Positive and negative selection are processes of central tolerance which is to say that they deal with a T cell's ability to bind self-antigen.
Antigen presentation is essential for the activation and clonal selection of T cells, particularly CD4+ helper T cells and CD8+ cytotoxic T cells. Antigen-presenting cells (APCs), such as dendritic cells, macrophages, and B cells, process and present antigens on their surface using major histocompatibility complex (MHC) molecules. This interaction, along with co-stimulatory signals, initiates T cell activation, leading to proliferation and differentiation into effector cells. This process is crucial for the adaptive immune response against pathogens.
neutralization of the antigen, agglutination or precipitation, and complement activation.
antigen processing and presentation
Yes. The first signal that a T cell receives from an antigen presenting cell (dendritic cell) is MHC presenting an antigen (foreign peptide). This gives the T cell specificity to this antigen.
Activated B cells are immune cells that have undergone a process of activation in response to an antigen, typically following interaction with helper T cells. Upon activation, these B cells proliferate and differentiate into plasma cells, which produce antibodies specific to the encountered antigen. They also form memory B cells that provide long-lasting immunity by remaining in the body to respond more rapidly upon future encounters with the same antigen. This process is essential for the adaptive immune response and the development of immunological memory.
When a B cell recognizes an antigen, it will undergo activation and differentiation into plasma cells, which produce antibodies specific to that antigen. Some B cells may also differentiate into memory cells that provide long-lasting immunity to the antigen. This process is essential in the adaptive immune response to eliminate pathogens and prevent future infections.
The first step in the activation of naive B cells is the binding of an antigen to the B cell receptor (BCR) on the surface of the B cell. This interaction leads to receptor clustering and internalization of the antigen-BCR complex, initiating a signaling cascade that promotes B cell activation. Additionally, for optimal activation, naive B cells often require help from T helper cells, which provide necessary co-stimulatory signals and cytokines.
Antigen challenge and clonal selection are most likely to occur in the secondary lymphoid organs, such as the lymph nodes and spleen. These organs are where antigens encounter immune cells, triggering an immune response and the selection of specific immune cell clones.
Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies.
when a antigen enters the body then the body would send antibodies to get rid of them. The antibody doesn't get rid of the antigen they tag it by binding to it so that a cell..a white blood cell can come and destroy by phagi.
Antigen-presenting cells (APCs) are nonlymphocyte cells that play a central role in clonal selection. They present antigens to T cells, triggering the immune response and selection of specific clones of T cells that can recognize and respond to the antigen.
The glycoprotein CD4 is a co-receptor. A co-receptor is "a cell surface receptor, which, when bound to its respective ligand, modulates antigen receptor binding or affects cellular activation after antigen-receptor interactions." (MediLexicon)