What are the differences between B-cells and T-cells in the immune response?

What are the differences between B-cells and T-cells in the immune response?

• A. B-cells produce antibodies (humoral immunity); T-cells mediate cell-mediated immunity; helper T-cells activate B-cells and cytotoxic T-cells; cytotoxic T-cells kill infected cells.
• B. B-cells are attacker cells, T-cells are antibody producers.
• C. B-cells store memory, T-cells produce antibodies.
• D. B-cells only function in innate immunity.

Answer: (A)

B cells and T cells carry out different arms of the adaptive immune response. B cells drive humoral immunity by producing antibodies that circulate in body fluids and target extracellular pathogens. When B cells meet their specific antigen and receive help from helper T cells, they differentiate into plasma cells that secrete antibodies and memory B cells that remember the encounter for faster future responses. Antibodies neutralize pathogens, block their entry, tag them for destruction through opsonization, and activate the complement system. T cells, on the other hand, mediate cell-mediated immunity and do not produce antibodies. They recognize peptide antigens presented on MHC molecules by other cells. Helper T cells (CD4+) coordinate the immune response by activating B cells, assisting cytotoxic T cells, and boosting macrophage activity. Cytotoxic T cells (CD8+) directly kill infected or abnormal cells by releasing molecules that induce target cell death. This separation of labor—B cells making antibodies and T cells handling infected cells and coordination—best captures the cooperative roles described. The other statements mix up these functions or reduce the roles to incorrect ones (for example, antibody production by T cells or antibody production being the sole role of T cells; or B cells functioning in innate immunity).

B cells and T cells carry out different arms of the adaptive immune response. B cells drive humoral immunity by producing antibodies that circulate in body fluids and target extracellular pathogens. When B cells meet their specific antigen and receive help from helper T cells, they differentiate into plasma cells that secrete antibodies and memory B cells that remember the encounter for faster future responses. Antibodies neutralize pathogens, block their entry, tag them for destruction through opsonization, and activate the complement system.

T cells, on the other hand, mediate cell-mediated immunity and do not produce antibodies. They recognize peptide antigens presented on MHC molecules by other cells. Helper T cells (CD4+) coordinate the immune response by activating B cells, assisting cytotoxic T cells, and boosting macrophage activity. Cytotoxic T cells (CD8+) directly kill infected or abnormal cells by releasing molecules that induce target cell death.

This separation of labor—B cells making antibodies and T cells handling infected cells and coordination—best captures the cooperative roles described. The other statements mix up these functions or reduce the roles to incorrect ones (for example, antibody production by T cells or antibody production being the sole role of T cells; or B cells functioning in innate immunity).