Which of the following statements is correct about antigen presentation by class

Question

Which of the following statements is correct about antigen presentation by class I and class I MHC molecules? Multiple Choice The class I MHC molecule is presented on the surface together with its endogenous antigen, enabling the host cell to present the antigen to a subset of T cells known as cytotoxic T lymphocytes. An antigen-presenting cell (APC), such as a macrophage, dendritic cell, or B cell, takes in the MHC molecule by receptor- mediated endocytosis or phagocytosis and produces MHC fragments by digestion in the phagolysosome. Class II MHC molecules bind to fragments that initially come from antigens outside the cell, thus they undergo endogenous antigen processing Class I MHC molecules bind to fragments that Initially come from antigens outside the cell, thus they undergo exogenous antigen processing.

Explanation / Answer

MHC class I and class II molecules were generally having similar functions such as they deliver short peptides to the cell surface which enables these peptides to be recognised by CD8+ (cytotoxic) and CD4+ (helper) T cells. MHC class I cell handshakes with CD8+ T cells where as MHC class II with CD4+ T cells.

The main difference lies in the origin and recognition of different peptide sources which is as follows

Exceptions: There is also so called cross-presentation which exists in which exogenous antigens can be presented by MHC class I molecules. Endogenous antigens can also be presented by MHC class II when they are degraded through autophagy.

So, Option 1 is the required answer for this question.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.