Given the low likelihood of a B cell and T cell having the same antigen specificity, what is one mechanism that regulates thisinteraction?Ο Ο Ο Οthe proximity of the T-cell and B-cell zonesthe expression of complement receptors on B cellsthe expression of CCR7 by B cells and CXCR5 by T cellsthe presentation of antigens to T cells by macrophages

The interaction between B and T cells is a crucial part of the immune response. B cells are responsible for producing antibodies that can neutralize pathogens, while T cells can directly kill infected cells or help other immune cells in their functions. The specificity of B and T cells for a particular antigen is determined by the receptors they express on their surface.The likelihood of a B and T cell having the same antigen specificity is low due to the vast diversity of these receptors. Despite this, B and T cells need to interact for an effective immune response. This interaction is regulated by several mechanisms.The interaction between B and T cells is facilitated by the expression of specific chemokine receptors on their surface. B cells express CCR7, which attracts them to the T cell zones in the lymph nodes where they can interact with T cells. On the other hand, T cells express CXCR5, which attracts them to the B cell zones. This reciprocal expression of chemokine receptors ensures that B and T cells can find each other in the lymph nodes despite their different antigen specificities. Therefore, the expression of CCR7 by B cells and CXCR5 by T cells is one mechanism that regulates the interaction between B and T cells.Hence, the one mechanism that regulates the interaction is the expression of CCR7 by B cells and CXCR5 by T cells.