What is one of the differences between CD4+ and CD8+ T cells? a. CD4+ cells are immature, and CD8+ cells are mature. b. CD4+ cells are activated, and CD8+ cells are not. c. CD4+ cells interact with class II MHC proteins, and CD8+ cells interact with class I MHC proteins. d. CD4+ cells activate cell-mediated responses, and CD8+ cells activate humoral responses.

Verified step by step guidance

1. Identify the key terms in the question: CD4+ T cells and CD8+ T cells, and their interactions with MHC proteins.
2. Understand the roles of MHC proteins: Class I MHC proteins present antigens to CD8+ T cells, while Class II MHC proteins present antigens to CD4+ T cells.
3. Recall the functions of CD4+ and CD8+ T cells: CD4+ T cells help other cells of the immune system, while CD8+ T cells directly kill infected cells.
4. Evaluate the answer choices in relation to the roles and interactions of CD4+ and CD8+ T cells with MHC proteins.
5. Select the correct answer: c. CD4+ cells interact with class II MHC proteins, and CD8+ cells interact with class I MHC proteins.

Key Concepts

T Cell Subtypes

T cells are a type of lymphocyte that play a central role in the immune response. They are primarily classified into two subtypes: CD4+ T cells, also known as helper T cells, and CD8+ T cells, known as cytotoxic T cells. CD4+ T cells help activate other immune cells, while CD8+ T cells directly kill infected or cancerous cells.

MHC Class I and II

Major Histocompatibility Complex (MHC) molecules are essential for the immune system to recognize foreign molecules. MHC Class I molecules present antigens to CD8+ T cells, allowing them to identify and destroy infected cells. In contrast, MHC Class II molecules present antigens to CD4+ T cells, which help orchestrate the immune response by activating other immune cells.

Immune Response Activation

The activation of T cells is crucial for an effective immune response. CD4+ T cells, upon recognizing antigens presented by MHC Class II, stimulate B cells and other immune cells, enhancing the humoral response. Conversely, CD8+ T cells, activated by MHC Class I, are primarily involved in cell-mediated immunity, targeting and eliminating infected or malignant cells.