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1) Indirect junctions between the T-cell and other cells are mediated by integri

ID: 173915 • Letter: 1

Question

1) Indirect junctions between the T-cell and other cells are mediated by integrin. Which extra-cellular matrix protein do cells and integrin likely bind to?

Actin

Fibronectin

SRP

Importin

2) Antigen-presenting cells make contact with T-cells via cellular junctions. Which of the following is likely to mediate this junction, if liquid can pass between the cells in the extra-cellular matrix but can not pass directly from cell to cell?

Claudin

Cadherin

Calnexin

Connexin

Actin

Fibronectin

SRP

Importin

Explanation / Answer

1) Fibronectin is involved in the development and migration of T cells and other leucocytes. But the integrin activation upon TCR stimuli involves alterations in actin cytoskeleton dynamics. So cells and integrin likely bind to Actin.

2) The assembly of APC with T cells is orchestrated by several factors including Calnexin. It majorly plays a role in binding of major histocompatibility complex (MHC) class I molecules with presenting endogenous antigens to cytotoxic T lymphocytes (CTLs).