BAIER: Now, does Secretary Clinton factor into this? SCHWEIZER: For that deal to go through, it needs federal government approval and one of those people that has to approve that deal is Secretary of State Hillary Clinton.
An antigen is any foreign substance which invades the body of an organism, while a pathogen is a living antigen (such as viruses or bacteria) which invade an organism. Many different kinds of white blood cells exist which are able to help the body fight foreign invaders in various ways.
Natural killer cells, or NK cells, are a part of the innate immune system which does not directly attack invading microbes. Instead, NK cells destroy compromised host cells, such as tumor cells or virus-infected cells. It recognises such cells by a condition known as missing self.hese are immune cells that engulf, i.e. phagocytose, pathogens or particles. To engulf a particle or pathogen, a phagocyte extends portions of its plasma membrane, wrapping the membrane around the particle until it is enveloped (i.e. the particle is now inside the cell).