Hey,
I do have some immunologic questions:
1. Thymus-independent antigens can activate B cells without the help of T cells. Does this mean that a naive B cell can undergo class switching, affinity maturation, and antibody production as a plasma cell without the typical cytokines? If not, what is meant by "activating B cells"?
2. Memory B cells are, as I've understood it, a specific type of cell meaning it has differentiated from a naive B cell (the other path this B cell could have taken was plasma cell) and is NOT just an "inactivated" plasma cell. Do these memory cells differentiate later on into plasma cells and cytotoxic, helper or regulatory T cells if they're T memory cells?
3. Memory cells yield a stronger, quicker immune response. I'm assuming this is due to B memory cells being inactivated forms of those B cells mutated and made for the specific antigen A and T memory cells being copies of that T cell that (lets say it was a helper T cell) secreted cytokines to determine class switching of B cell. The memory T cell remembers what exact cytokines was secreted from its parent Th cell and thus can secrete those exact to hurry up the elimination of a pathogen. Is this correct (simplified realism, I know, but the principle)?.
And in the case of the memory B cell, it simply just differentiates into a plasma cell and secrete the high affinity immunoglobulins the initial plasma cells secreted (those that differentiated directly to plasma from naive B cells)?
4. It is said that when a B cell gets activated receptor-mediated endocytosis occurs (one of the initial steps). B cells have Igs on their surfaces; do these get involved in that receptor-mediated endocytosis?
5. Naive B cells express IgM and IgD on their surface. Can they as just naive B cells produce and secrete these antibodies? Plasma cells can only secrete A,E or G so that has to be true. This would mean that plasma cells are not the only antibody-secreting cell...
6. How can naive B cells express two different antibodies? I thought each B cell expressed only one type of antigen specificty on their antibodies.
I'd greatly appreciate the help to any question (i.e., if you only can answer one but not the rest then do that!)
Thanks,
I do have some immunologic questions:
1. Thymus-independent antigens can activate B cells without the help of T cells. Does this mean that a naive B cell can undergo class switching, affinity maturation, and antibody production as a plasma cell without the typical cytokines? If not, what is meant by "activating B cells"?
2. Memory B cells are, as I've understood it, a specific type of cell meaning it has differentiated from a naive B cell (the other path this B cell could have taken was plasma cell) and is NOT just an "inactivated" plasma cell. Do these memory cells differentiate later on into plasma cells and cytotoxic, helper or regulatory T cells if they're T memory cells?
3. Memory cells yield a stronger, quicker immune response. I'm assuming this is due to B memory cells being inactivated forms of those B cells mutated and made for the specific antigen A and T memory cells being copies of that T cell that (lets say it was a helper T cell) secreted cytokines to determine class switching of B cell. The memory T cell remembers what exact cytokines was secreted from its parent Th cell and thus can secrete those exact to hurry up the elimination of a pathogen. Is this correct (simplified realism, I know, but the principle)?.
And in the case of the memory B cell, it simply just differentiates into a plasma cell and secrete the high affinity immunoglobulins the initial plasma cells secreted (those that differentiated directly to plasma from naive B cells)?
4. It is said that when a B cell gets activated receptor-mediated endocytosis occurs (one of the initial steps). B cells have Igs on their surfaces; do these get involved in that receptor-mediated endocytosis?
5. Naive B cells express IgM and IgD on their surface. Can they as just naive B cells produce and secrete these antibodies? Plasma cells can only secrete A,E or G so that has to be true. This would mean that plasma cells are not the only antibody-secreting cell...
6. How can naive B cells express two different antibodies? I thought each B cell expressed only one type of antigen specificty on their antibodies.
I'd greatly appreciate the help to any question (i.e., if you only can answer one but not the rest then do that!)
Thanks,
