Question

Which of the immune cells can perform phagocytosis?

• A. neutrophils
• B. cytotoxic T cells
• C. natural killer cells
• D. basophils

Which of the following antibody function can enhance phagocytosis?

• A. complement activation
• B. opsonization
• C. neutralization
• D. ADCC

High level of ___ in patient blood indicates it’s the early stage during a primary infection.

• A. IgM
• B. IgG
• C. IgA
• D. IgE

Answer 1

Q1.........................................................

Ans. Neutrophils.

It is a type of WBC or white blood cell. The WBC content of blood contributed by the neutrophils is approx.40-60%. These are among the different immune cells and are known for their quick response at the site of infection. When a person gets infected in that case the neutrophil count in the body increases. Neutrophil comes into action by eating foreign invader or ingesting them. This process is known as phagocytosis. During phagocytosis, the body's immune cell can recognize the type of pathogen and can easily destroy the pathogen.

Q2.........................................................

Ans. Opsonization

Opsonization is process in which a foreign pathogen is coated with opsonins or plasma proteins. By this process attachment and internalization of the pathogen is carried out which facilitate the process of phagocytosis by a phagocytic cell.

The presence of the plasma protein as a coating over the pathogen facilitate the interaction of the pathogen to the surface of the phagocytic cell. This is the action of binding of antibodies to the surface of the pathogen or the invader. Plasma proteins like IgG and C3b are recognized as opsonins.

Q3..................................................

Ans. IgM is one of the largest antibodies in the body. IgM comes into action at the initial stages of infection or to the initial exposure to the antigen. IgM is present on B-cells. It is the first antibody which builds during the body's immune response. Due to their big structure, they can easily identify the pathogen which can be marked for phagocytosis and lead to the cell agglutination. structurally it is made of 5 or 6 chains with two heavy and two light chains. Monomers of IgM are bound by a disulfide bond.