Questions and Answers

What aer the two primary characteristics that distinguish hematopoietic stem cells and progenitor cells?

An individual is infected with — i Intracellular bacteria and ii) Extracellular bacteria. Which kind(s) of immune response will be expected in each case?

What are chemokines? Give one example.

Explain briefly whether the following statements are true or false : (i) Dendritic cells arise only from the lymphoid organ. (ii) All TH cells express CD4 and recognize only antigen associated with class II MHC molecule. (iii) A hapten can stimulate antibody formation but cannot combine with many different antibody molecules. (iv) In order for B cells to mature into plasma cells, they need help from T cells. (v) All antigens are immunogens but all immunogens are not antigens.

Most viruses and bacteria enter cells via specific receptors. Why would a cell have receptors that allow pathogens to enter?

Which region of the whole MHC molecule shows the highest amino acid variation? What roles do anchor residues play in peptide binding by MHC molecules?

What is the role of Mucosal-Associated Lymphoid Tissue (MALT) in host defence?

Compare and contrast the BCR and TCR in terms of the following characteristics : (i) Specificity for antigen (ii) Cellular expression (iii) Types of Ag recognized.

What is a major source of non-protein antigens?

What are sequential and non-sequential epitopes?