Q.1 (a) Production of which of the following types of proteins during an innate
ID: 69985 • Letter: Q
Question
Q.1 (a) Production of which of the following types of proteins during an innate immune response would directly lead to the lysis of a microbe?
- Membrane Attack Complex
- Perforin
- Immunoglobulin
- Interferon
Q 1. (b) Swelling due to bulk flow from the plasma into the interstital fluid is the result of decreased protein permeability in the capillaries. (True or False?)
Q.1 (c) Both inflammation and fever result in an increase in the temperature set point of the body. (True or False?)
Q.1 (d) Indicate which of the following statements describe Class I MHC molecules, describe Class II MHC molecules or decribe both Class I MHC & Class II MHC molecules?
-This molecule is expressed on all nucleated cells.
- This molecule interacts with proteins expressed on the surface of Cytotoxic T cells.
- This molecule is expressed on the surface of Antigen presenting cells.
- This molecule is important for activating helper T cells.
- This molecule is expressed on the surface of B cells
- This molecule binds to antigens that come from primarily intracellular pathogens.
Q.1 (e) What type of B cell does not secrete many antibodies during a primary immune response, but is very important for a secondary immune response?
Q.1 (f)If an individual failed to develop any mature lymphocytes, they would have lessened innate responses to infection and lessened adaptive responses to infection. (True or False?)
Q.1 (g) Which of the following statements about the late stages of HIV infection/AIDS are true? Choose all of the correct answers.
A person in the late stages of AIDS is more susceptible to infection with bacteria, fungi and viruses than a person in the asymptomatic stage of HIV infection.
The number of CD4-expressing T cells in the blood is high during the late stages of HIV infection
The number of Killer T cells in the blood can be high during the late stages of HIV infection.
Innate immune responses may be weakened during the late stages of HIV infection because of the weakened adaptive responses during these stages.
A person in the late stages of AIDS is more susceptible to infection with bacteria, fungi and viruses than a person in the asymptomatic stage of HIV infection.
The number of CD4-expressing T cells in the blood is high during the late stages of HIV infection
The number of Killer T cells in the blood can be high during the late stages of HIV infection.
Innate immune responses may be weakened during the late stages of HIV infection because of the weakened adaptive responses during these stages.
Explanation / Answer
Answer
1a. Innate immunity is the natural defense mechanism adopted by the body right from birth. It protects the host from infections. The immune cells (macrophages) recognizes the antigen, engulf and digests with the enzyme and simply eliminates it from the body. The lysis of the microbe or pathogen is done by interferons, proteins required for the degradation of the antigen.
Therefore, option 4 is correct.
1b. In general, large proteins cannot enter the capillaries resulting in the increased pressure. Due to this, the fluid is pulled out of the capillaries. In some conditions, the plasma proteins are expelled out through urine, where there is a decreased pressure in the capillaries. This makes the fluids filter more through the capillaries and accumulate in the tissues itself.
This results in edematous condition.
Therefore, the statement is true.
1c. Inflammation occurs due to infections. These infections are caused by pathogens which release chemicals. These chemicals may show pyrogenic effect, which results in the increased temperature. Anyhow, fever is a condition of elevated body temperature.
Therefore, the statement is true.
1d. Major histocompatibility molecules are the detective molecules used to recognize foreign substances. This MHC complex is present in all vertebrates and is classified as I and II. MHC-I is present in all nucleated cells, and aids in immune cell activation. MHC-II is present on the antigen presenting cells such as macrophages or dendritic cells.
From the above explanation, the given statements can be related as follows:
Class I MHC molecules: expressed on all nucleated cells.
Binds to antigens that come from primarily intracellular
Pathogens.
Class II MHC molecules: expressed on the surface of antigen presenting cells.
Important for activating T-helper cells.
Expressed on the surface of B-cells.
Both molecules: interacts with proteins expressed on the surface of cytotoxic T cells
1e. Lymphocytes or white blood cells are the cells responsible for protection in the body. If they are produced from thymus, they are T-cells and if they are produced in bone marrow, they are B-cells. B-cells produce antibodies in the presence of antigen. During this process these B-cells undergo clonal selection and produce matured cells or plasma cells. These cells have memory to recognize the pathogen for the second time. They are called memory cells.
These memory cells do not have function in primary response and are functional during secondary response.
1f. Whenever an antigen is recognized, the lymphocytes activate and develop mature lymphocytes that secretes antibodies in response to the antigen. If these mature lymphocytes are not developed then innate or adaptive response is lessened.
Therefore, given statement is true.
1g. During the late changes of HIV infection, the immune response is largely reduced. This makes an individual susceptible to many infectious diseases due to the weakened innate or adaptive response. This results in lower levels of immune cells in the body.
From the above explanation, option 1 and 4 are correct.
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