IMMUNOLOGY I

Which of the following is NOT a secondary lymphoid organ

• Thymus

• Spleen

• Mesenteric lymph node

• Peyers patch

Which of the following is NOT a characteristic of innate immunity?

• It provides an immediate response to foreign invaders.

• It  protects against bacteria and foreign cells

• It remembers specific foreign antigens. 

• It responds immediately to foreign antigens.

Which of the following is NOT a type of white blood cell that is involved in innate immunity?

• Monocytes 

• Platelets

• Neutrophils

• Eosinophils

NK cells recognise and kill

• Normal host cells

• Cells with increased expression of MHC-I molecules

• Cells with decreased expression of MHC-I molecule

• Intracellular pathogens

A 90-year-old man is infected with West Nile virus and develops an encephalitis. Astrocytes become infected by the virus. These astrocytes subsequently no longer express MHC 1 antigen. Which of the following inflammatory cells is most likely to destroy these infected astrocytes?

• B-cells

• T-cells

• Mast cells

• Natural killer cells

Pattern recognition structures found in the cytoplasm of host cells include

• TLR-4

• DC-SIGN and Dectin-1

• NLR and RLR receptors

• TLR9

A study is performed to determine the distribution of Class I and Class II MHC molecules displayed on cell surfaces. It is observed that all immunologically active inflammatory cells display MHC I molecules, but not all display MHC II molecules. Which of the following cell types is most likely to display only MHC I molecules?

• B cells

• Dendritic cells

• Macrophages

• Natural killer cells

In an experiment, mycobacterial organisms are added to a cell culture of macrophages. It is observed that the macrophages ingest the mycobacteria and then display peptides from those organisms on their cell surfaces. The peptides are displayed in conjunction with MHC molecules. Peptide antigens displayed in this manner are most likely to activate which of the following cells?

• B-cells

• Dendritic cells

• Natural killer cells

• Macrophages

• T cells

In an experiment, bacteria are introduced into human blood. It is observed that the complement system is activated and the bacterial cells are killed. Which of the following complement components generated by complement activation will most likely bind to bacteria and lead to either opsonization or phagocytosis?

• C3b

• C5a

• C2

• C4