Why do we think we need two MHC class I and class II in our body?

Major histocompatibility complex (MHC) class I and class II proteins play a pivotal role in the adaptive branch of the immune system. Both classes of proteins share the task of presenting peptides on the cell surface for recognition by T cells.

Why is it important that CD8 positive T cells recognize antigen presented by class I MHC?

Once activated by pAPCs, effector CD8 T cells can recognize any infected cell expressing MHC I loaded with its cognate peptide. This results in the killing of the infected cell and/or the production of antiviral cytokines both being important to control or clear viral infections.

Why do T cells recognize antigens?

How do T cells recognize antigens? Each T cell has a unique T cell receptor (TCR) that recognizes a specific antigen. TCRs recognize an antigen when they bind with major histocompatibility complex (MHC) molecules on the surface of other cells.

What is MHC class I and MHC 2?

MHC class I glycoproteins present endogenous antigens that originate from the cytoplasm. MHC II proteins present exogenous antigens that originate extracellularly from foreign bodies such as bacteria. Present antigen to helper T cell lymphocytes; (CD4+ T cells).

How do helper T cells and cytotoxic T cells work together quizlet?

How do helper T-cells and cytotoxic T-cells work together? Helper T-cells produce cytotoxic T-cells. Cytotoxic T-cells produce cytokines to activate helper T-cells. Helper T-cells produce cytokines to activate other cells of the immune system.

Why do T cells need MHC?

T Cells Recognize Foreign Peptides Bound to MHC Proteins The recognition process depends on the presence in the antigen-presenting cell of MHC proteins, which bind these fragments, carry them to the cell surface, and present them there, along with a co-stimulatory signal, to the T cells.

How do T cells identify the difference between a MHC class I and MHC class II molecules?

The main difference between MHC class 1 and 2 is that MHC class 1 molecules present antigens to cytotoxic T cells with CD8+ receptors whereas MHC class 2 molecules present antigens to helper T cells with CD4+ receptors.