MHC class II proteins: A. present exogenous antigen to the immune system B. both are found on antigen presenting cells and present exogenous C. antigen to the immune system are found on antigen presenting cells

C4a     A. functions as an opsonin   B. binds to the surface of an antigen   C. is immediately inactivated once formed   D. binds to the surface of immune cells   E. is the large subunit of C4

You are studying SARS-COV2. You identify a viral protein that results in the decrease of MHC class I, a cell surface receptor, on the cell surface. You are trying to determine the mechanism for how the virus is decreasing cell surface MHC I. You decide to do an experiment to determine whether the receptor is making it all of the way through the secretory pathway. You take two samples of cells. 1. Uninfected 2. Infected with SARS-CoV2 You treat them with EndoH and analyze MHC I on a western blot and get the following results: 1. Uninfected cells - 50% of protein is endo H sensitive and 50% is Endo H resistant 2. SARS-COV2 infected cells - 100% of protein is Endo H sensitive How would you best interpret these results? Is MHC I going all the way through the secretory pathway in infected cells? A. No, MHC I is not going all the way through the secretory pathway. 100% of the protein is EndoH sensitive in infected cells, this means that the virus is somehow inhibiting the protein from making…

Which of the following cells demonstrate MHC II molecules on their surface membrane? 1.  B lymphocyte 2.  macrophage 3.  erythrocyte 4.  neuron 5.  smooth muscle cell Choose from the following: (A) 1 and 2 (B) 1, 2 and 3 (C) 1, 2, 4, and 5 (D) 1, 2, 3, 4, and 5

Somatic cells can display antigen [small peptides] and present them to the body’s immunesystem via their MHC/HLA receptor displays. Discuss the paths for MHC/HLA1 vs. MHC/HLA2display. How do these two paths fit into the health of the body, and the response of theimmune system to normal/disease/infection?

Explain why each choice (a-d) is correct or incorrect.  In order for an antigen to activate or sensitize a T helper cell, the antigen must be a. coated with antibodies b. displayed on the surface of an APC along with MHC antigens c. displayed on the surface of another T cell with IgD antibodies d. partly digested by a natural killer cell

Identify which of the following statements regarding naive T cells is incorrect. a. Naive T cells have the capacity to survive for many years as nondividing circulating cells in the absence of specific antigen. b. Naive T cells express LFA-1 molecules that change their conformation after encountering a specific peptide:MHC complex. c. Naive T cells exit from lymph nodes using the same route as effector T cells. d. Naive T cells express ICAM-3, which binds to DC-SIGN on dendritic cells with high affinity. e. Naive T cells express high levels of S1P receptors on their surface.

B lymphocytes require which of the following to become activated and to form plasma cells? 1. recognition and binding of an antigen to the B cell receptor 2. presentation of antigen fragments on the B cell surface by MHC I molecules 3. binding of the B cell to an activated T helper cell Choose one from the following: (A) 1 and 2 (B) 1 and 3 (C) 2 and 3 (D) 1,2 and 3

The followings are functions of antibody eliminating unknown particles or cells which enter into the body, except... A. Attach to the active side of particle or cell that enters into the body B. Make easier of macrophage to phagositosize unknown particle or cell that enters the body C. Precipitate the unknown particle that dissolves in body fluid  D. Initiate the working system of complement E. Eliminate bacteria that grows on endosome of macropahge