A bacteria has entered the body. it 's probably a pathogen! The first line of defence has to start attacking immediately . The first line of defence tries to kill the pathogen with it's acid and mucus but the first line fails to kill the pathogen.
Since the first line of defence has failed we will have to rely on the second line of defence . The second line of defence has to identify which cells belong and which don't. Oh no ! The second line of defence has failed to catch the pathogen. Now it's all up to the third line of defence or otherwise known as the innate immune response.
The innate response must kill the pathogen. This has caused inflammation in the area of the infection. You might get red and swollen because of this. Phagocytes are very important white blood cells that have to kill the infection. A virus has entered the body but we don't know what it means so it's probably a antigen.
Now it's the acquired immune response . that has to invade and destroy the pathogen and the antigen. It might take the acquired immune response some time to attack. So the B cells have to produce newly made antibodies so they can recognize the antigens and the B cells have to make sure they cant enter the cells.
The pathogen and the antigen have entered a cell . The helper T cells tell the B cells to attack, they produce antibodies to kill the pathogen and the antigen. The killer T cells try to kill the pathogen and the antigen without any help because their independent warriors but sadly the killer T cells have lost.
we've done it cells ,organelles and others. The immune system has finally won. Next time any antigen or pathogen attacks us we will know what to do and best believe we will win once again.