How do T cells activate B cells?

Armed helper T cells activate B cells when they recognize the appropriate peptide:MHC class II complex on the B-cell surface (Fig. 9.5). Binding of CD40 by CD40L helps to drive the resting B cell into the cell cycle and is essential for B-cell responses to thymus-dependent antigens.

What does T and B stand for in lymphocytes?

T cells (thymus cells) and B cells (bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies).

What is the difference between T and B lymphocytes?

Both T cells and B cells are produced in the bone marrow. The T cells migrate to the thymus for maturation. The main difference between T cells and B cells is that T cells can only recognize viral antigens outside the infected cells whereas B cells can recognize the surface antigens of bacteria and viruses.

Do B cells need T cells activation?

In a T-dependent immune response the B cells need assistance from T cells in order to respond.

How are the T and B lymphocytes involved in the immune response?

The T and B lymphocytes (T and B Cells) are involved in the acquired or antigen-specific immune response given that they are the only cells in the organism able to recognize and respond specifically to each antigenic epitope. The B Cells have the ability to transform into plasmocytes and are responsible for producing antibodies (Abs).

How are T and B lymphocytes multipotent?

The ETP are multipotent and can generate T Cells, B Cells, Natural killer cells (NK), myeloid cells, and dendritic cells (DC). ETP represent a small and heterogenous subset, have the ability to proliferate massively, and can be identified by the phenotype Lin low , CD25 − , Kit high as well as by their expression of Flt3, CD24, and CCR9 ( 1 ).

How are B cells activated by T dependent antigens?

B cell activation by T dependent antigens require contact dependent help delivered by the interaction between CD40 on B cells and CD40L on activated T H cells. Soluble protein antigens which bind to membrane bound immunoglobulin on the surface of B Cell are internalized, processed and are displayed as peptide-MHC-II complexes.

How are the B and T cells related?

The B Cells have the ability to transform into plasmocytes and are responsible for producing antibodies (Abs). Thus, humoral immunity depends on the B Cells while cell immunity depends on the T Cells.