Which immune cells are involved in fighting specific pathogens in the body?

Which immune cells are involved in fighting specific pathogens in the body?

• A. T lymphocytes
• B. B lymphocytes
• C. Natural Killer Cells
• D. Monocytes

Answer: (A)

Fighting specific pathogens relies on the adaptive immune system’s ability to recognize and respond to particular antigens. T lymphocytes drive this targeted response through cell-mediated immunity. When infected cells present pathogen-derived peptide fragments on MHC molecules, T cells that are specific for those antigens become activated. Cytotoxic T cells (CD8+) then kill the infected cells to halt pathogen replication, while helper T cells (CD4+) coordinate and amplify the overall immune response by releasing cytokines that activate other immune cells, including macrophages and B cells. Memory T cells remain ready to respond more quickly if the same pathogen appears again, providing lasting specificity. B lymphocytes also contribute to targeted defense by producing antibodies that neutralize pathogens and mark them for destruction, but the direct elimination of infected cells and orchestration of the immune response described above are hallmarks of T cell–mediated immunity. Natural Killer cells and monocytes are important components of innate immunity and provide rapid, nonspecific responses rather than antigen-specific, targeted actions.

Fighting specific pathogens relies on the adaptive immune system’s ability to recognize and respond to particular antigens. T lymphocytes drive this targeted response through cell-mediated immunity. When infected cells present pathogen-derived peptide fragments on MHC molecules, T cells that are specific for those antigens become activated. Cytotoxic T cells (CD8+) then kill the infected cells to halt pathogen replication, while helper T cells (CD4+) coordinate and amplify the overall immune response by releasing cytokines that activate other immune cells, including macrophages and B cells. Memory T cells remain ready to respond more quickly if the same pathogen appears again, providing lasting specificity.

B lymphocytes also contribute to targeted defense by producing antibodies that neutralize pathogens and mark them for destruction, but the direct elimination of infected cells and orchestration of the immune response described above are hallmarks of T cell–mediated immunity. Natural Killer cells and monocytes are important components of innate immunity and provide rapid, nonspecific responses rather than antigen-specific, targeted actions.