Question

________ is a protein on the surface of the cytotoxic T cell. It is a membrane bound variant of TNFa

Answer 1

The protein on the surface of cytotoxic T cells that is a variant of TNFa and involved in binding to antigens presented by MHC molecules on APCs is the T cell receptor (TCR).

Step-by-step explanation:

The protein on the surface of the cytotoxic T cell that is a membrane-bound variant of TNFa is known as the T cell receptor (TCR). The cytotoxic T cells, or Tc cells, are types of T lymphocytes that play a crucial role in the immune system by inducing apoptosis in target cells. These cells achieve this through the production of granzymes and perforins when they interact with the MHC I-epitope complex on an infected cell.

TNFa was initially recognized for its role in causing tumor necrosis but is now considered a vital mediator in acute inflammatory responses, especially in response to pathogens like Y. pestis. The TCRs have variable binding regions that project into the extracellular space, allowing them to bind processed antigens presented via MHC molecules on antigen-presenting cells (APCs).

Answer 2

The protein on the surface of the cytotoxic T cell that acts as a membrane-bound variant of TNFa is the T cell receptor (TCR). It plays a crucial role in the immune response by helping T cells recognize and respond to infected cells.

Step-by-step explanation:

The protein on the surface of the cytotoxic T cell that is a membrane-bound variant of TNFa is known as the T cell receptor (TCR).

This receptor is a protein dimer embedded in the plasma membrane and is crucial for T cell activation. When a cytotoxic T cell, also known as a Tc cell, interacts with the MHC I-epitope complex on an infected cell, it can produce granzymes and perforins that induce apoptosis in the target cells.

TNFa is a key cytokine involved in most acute inflammatory responses, acting as a soluble, short-range communication molecule between cells. The TCR plays a critical role by projecting variable binding regions into the extracellular space to bind processed antigens presented by MHC molecules on antigen-presenting cells (APCs).