Question

1. Identify the two ways chemokines affect the trafficking of lymphocytes from the blood vessel into the infected tissue.

   a. Strengthen the binding between the integrin and ICAM
   b. Directly mediate diapedesis
   c. Facilitate the start of the rolling process by binding to carbohydrates

   expressed on the immune cell
   d. Create a gradient for the immune cell to follow after moving through the blood

   vessel

2. True or False: Macrophages migrate in response to inflammation faster than neutrophils.

3. Which of the following is a main contributor for systemic production of TNF-α causing sepsis and possibly death?

   a. Liver produces acute phase proteins
   b. The hypothalamus increases the body temperature
   c. Blood vessels collapse because of decreased blood volume and too much

   clotting
   d. Too many neutrophils are mobilized from the bone marrow and enter the

   tissues

4. True or False: Fibrosis occurs when inflammation is sustained and tissues are not properly remodeled.

5. Which of the following is NOT a mechanism of the innate immune response to decrease inflammation and promote tissue repair?

   1. Secretion of cytokines and growth factors that promote proliferation of non- immune cells

   2. High production of interferons by dendritic cells

   3. Macrophages activating angiogenesis by secreting prostaglandin E2

   4. Halting recruitment and inducing apoptosis of neutrophils

6. True or False: An antibody proteolytically cleaved by pepsin yields a fragment with higher affinity to the cognate antigen than an antibody cleaved by papain.

Answer 1

Answer 1: d. Create a gradient for the immune cell to follow after moving through the blood Vessel.

Comments: Chemokines are small molecules or signalling proteins secreted by immune cells to help in the migration of other immune cells at the site of infection. The immune cells migrate to the infected site based on the gradient of chemokine (means at the site of infection there is the highest concentration of chemokines so more and more number of immune cells are attracted their).   

Answer 2: False

Comments: Both neutrophils and macrophages are migrated in response to inflammation. The migration rate of neutrophils is more than the migration rate of macrophages

Answer 3: d. Too many neutrophils are mobilized from the bone marrow and enter the tissues

Comments: In severe inflammation (sepsis) too many neutrophils are migrated from the bone marrow into the circulation and these macrophages are activated to produce the TNF-α, the produced these cytokines or storm of pro-inflammatory cytokines leads to septic shock.

Answer 4: True

Comments: In chronic inflammation development of fibrosis takes place in the lungs/ bronchi of lungs that lead to damage of lungs tissue. The lungs tissue loses its capability to regenerate.

Answer 5: Secretion of cytokines and growth factors that promote the proliferation of non- immune cells

Comments: To induce the tissue repair by the immune system, the inflammation should be decreased and it is possible by decreasing pro-inflammatory cytokine and proliferation of non-immune cells.

Answer 6: True

Comments: Pepsin produces (Fab)₂ however, papain produces Fab. The affinity of (fab)₂ is more than the affinity of fab.