IMMUNOLOGY

Detailed explanation-1: -Dendritic Cells: These cells instruct T cells on what to attack, also known as antigen-presenting cells. Central to both categories of immune responses is the ability to distinguish foreign invaders (germs), which need to be attacked, versus our own tissues, which need to be protected.

Detailed explanation-2: -Helper T cells are arguably the most important cells in adaptive immunity, as they are required for almost all adaptive immune responses. They not only help activate B cells to secrete antibodies and macrophages to destroy ingested microbes, but they also help activate cytotoxic T cells to kill infected target cells.

Detailed explanation-3: -T cells can detect the presence of an intracellular pathogen because infected cells display on their surface peptide fragments derived from the pathogen’s proteins. These foreign peptides are delivered to the cell surface by specialized host-cell glycoproteins.

Detailed explanation-4: -There are two main classes of T cells-cytotoxic T cells and helper T cells. Effector cytotoxic T cells directly kill cells that are infected with a virus or some other intracellular pathogen.

Detailed explanation-5: -Human Immunodeficiency Virus (HIV) specifically attacks Helper T cells. Without an adequate supply of Helper T cells, the immune system cannot signal B cells to produce antibodies or Cytotoxic T cells to kill infected cells.