Life of An Antibody
Hi! My name is Gigi and I am an antibody. I come from a family of warriors, called Gamma hence called IgG). We constitute about 70–80-% of total immunoglobulins in the blood stream; and 15% of the total serum proteins. We live independently as monomers. Life is not very easy for us here. We are specialized to defend the body against different pathogens. When there is an invasion, we fight with foreign particles and often die in the process.
Our arms have specific sequence of amino acids, called the Fab region. This amino acid sequence is variable, and specific for each type of pathogen. We use these arms to attach ourselves to any foreign particles. On our tails, specific sequence of amino acids constitute our FC region. Amino acid sequence in this region is constant and is recognized by phagocytic cells of the body. These phagocytic cells bind with our Fc region, and eat us alive, thus killing the pathogen we have captured.
I am a little weak right now. I weight about 120 kDa. I need to put on some weight, around 30 kDa in order to function properly. My grandma says there is nothing to worry about. My grandpa was also a little weak when he was young, but when he grew up, he became pride of the whole family and died like a hero. My grandma tells me his story every night before I go to sleep.
Many years ago, there was a bacterial invasion. My grandpa and his friends were coming back home from their office, when they encountered a bacterium. Grandpa, along with his friends attacked that cell. He attached himself with an antigen on the bacterial cell, by the help of Fab region on his arms. All his friends did the same with other antigens on the surface of the bacterial cell. They then sent signals to the phagocytes on patrolling. One of the macrophage nearby cached their signal. It immediately responded by engulfing the whole bacteria-antibody complex. Grandpa and his friends died that day, but they will live forever in our hearts.
My uncle George along with his whole family, followed the footsteps of my grandpa. Not very long after grandpa was opsonized, Uncle George, Aunt Georgina and their three kids were agglutinated. It was a dark day, when many bacterial cells invaded the body. Uncle George’s family was going to the mall for shopping, when they encountered a gang of aggressive bacteria. All of them bound to antigens on different bacterial cells, but the whole family never left each other in the process. That is what Uncle George had taught his family his whole life; to always remain by each other’s side and never let go, no matter what happens. The bacterial cells were captured, but the agglutinate thus formed was blocking the flow of blood, so a team of macrophages had to clear that debris. A memoir was built along the road side, in the honor of Uncle George’s family. Such memoirs are often built after an intense fight. Humans refer to these memoirs as pimples.
Nowadays, I badly miss my cousin Gina. She is my first cousin. She used to live with us, along with her parents; Uncle Gavin, Aunt Grace and her siblings. Gina and I were best friends. We used to play together all the time, until recently when Uncle Gavin received the orders that he had been recruited by the newly formed receptors in the Fetus. That’s right! We are the only family of immunoglobulins who can cross the placental barrier. When the person we live in, gets pregnant, our receptors are expressed in the fetus in about three months. Some of us then have to migrate through the placenta and reside there. In this way, some of our family members are separated from us permanently. Although we miss them, but we know it’s for the greater good. We never forget the purpose of our life; protecting humans generation after generation.
We not only fight with foreign invaders, but we also defend the body against its own cells, who have gone rouge. A few months ago, our neighbors; the Griffins went undercover and detected the cells that were involved in some criminal activities (i.e. tumor production). They handcuffed them, using their Fab region, and reported to the authorities. Natural killer (NK) cells arrived at the scene, recognized and bound to the Fc region of the Griffins. In response, the NK cells released cytotoxins which dissolved those tumor cells. In this way, once again, the day was saved; thanks to the antibodies.
We also defend the body against different toxins, such as Tetanus, Botulism, and snake and scorpion Venom. A few years ago, whole family of my distant Uncle Gale, was consumed in this way. The person we reside in, was stung by a snake. Venom was released in the blood stream. It could have destroyed everything, but Uncle Gale along with his family stepped forward, attached their Fab regions to the active sites of toxins; and destroyed them and got martyred themselves.
That’s all for now. Next time I will introduce you to my friends, belonging to other families of Immunoglobulins.
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