Pathogen-associated molecular patterns (or PAMPs) are common foreign structures that characterize whole groups of pathogens. It is these unique antigenic structures that the immune system frequently recognizes first. Animals, both invertebrates and vertebrates, have evolved to express several types of cell surface and soluble proteins that quickly recognize many of these PAMPs; a form of pathogen profiling. For example, encapsulated bacteria possess a polysaccharide coat with a unique chemical structure that is not found on other bacterial or human cells. White blood cells naturally express a variety of receptors, collectively referred to as pattern recognition receptors (PRRs), that specifically recognize these sugar residues, sugar residues is recognised by?

TLS Online TPP Program

#Question id: 15848

#Unit 4. Cell Communication and Cell Signaling

viruses frequently expose unique chemical structures only during their replication inside host cells. Many of these can be detected via intracellular receptors that bind exposed chemical moieties while still inside the host cell. This can trigger an immediate antiviral response in the infected cell that blocks further virus replication. At the same time, this initiates the secretion of chemical warning signals sent to nearby cells to help them guard against infection (a neighborhood watch system!). virus is not recognised which receptor?

TLS Online TPP Program

#Question id: 15530

#Unit 4. Cell Communication and Cell Signaling

The activity of already differentiated effector and memory T cells is maintained by a receptor which are generally expressed on the memory and effector T cells. 

TLS Online TPP Program

#Question id: 15529

#Unit 4. Cell Communication and Cell Signaling

When does the T-cell anergy occur?

TLS Online TPP Program

#Question id: 15528

#Unit 4. Cell Communication and Cell Signaling

The B7 family of protein interact  with distinct receptor present on the T-cells, 

TLS Online TPP Program

#Question id: 15527

#Unit 4. Cell Communication and Cell Signaling

CD4 and CD8 T cells leave the thymus and enter the circulation as resting cells in which stage of the cell cycle?

TLS Online TPP Program

#Question id: 15526

#Unit 4. Cell Communication and Cell Signaling

If a thymocyte randomly generated a TCR with an affinity for MHC Class I, the TCR and CD8 would bind MHC Class I together, and generate a signal that specifically initiated a program that is 

a) silenced CD8 expression

b) silenced CD4 expression

c) induced expression of genes specific for helper T-cell lineage function

d) induced expression of genes specific for cytotoxic T-cell lineage function