The E. coli SSB is a tetramer; eukaryotic SSB (also known as RPA) is a trimer.

TLS Online TPP Program

#Id: 9933

#Unit 4. Cell Communication and Cell Signaling

Bacterial Infections

Bacteria enter the body through several natural routes.

TLS Online TPP Program

#Id: 9934

#Unit 4. Cell Communication and Cell Signaling

Cell wall endotoxins of some gram-negative bacteria activate macrophages, resulting in release of high levels of IL-1 and TNF-α, which can cause septic shock.

TLS Online TPP Program

#Id: 9935

#Unit 4. Cell Communication and Cell Signaling

In staphylococcal food poisoning and toxic shock syndrome, exotoxins produced by the pathogens function as superantigens, which can activate all T cells. 

TLS Online TPP Program

#Id: 9936

#Unit 4. Cell Communication and Cell Signaling

Extracellular Bacteria

TLS Online TPP Program

#Id: 9937

#Unit 4. Cell Communication and Cell Signaling

Intracellular bacterial

Intracellular bacterial infections tend to induce a cell-mediated immune response, specifically DTH. 

In this response, cytokines secreted by CD4+ T cells are important—most notably IFN-ϒ, which activates macrophages.

TLS Online TPP Program

#Id: 9938

#Unit 4. Cell Communication and Cell Signaling

Host immune responses and bacterial evasion mechanisms