Why does immune cell exhaustion occur in chronic infections and cancer?

💡 Explanation

Immune cell exhaustion occurs because of persistent antigen stimulation during chronic infections or in cancer, leading to prolonged antigen receptor signaling. This chronic signaling drives epigenetic and transcriptional changes, causing impaired effector function. Therefore, exhaustion ensues rather than a sustained immune response because the cells become desensitized.

• A cancer cell has a mutation causing constitutive activation of a growth factor receptor. If a drug inhibits a key protein in the apoptosis pathway, which consequence follows?
• A chronic Pseudomonas aeruginosa lung infection is treated with tobramycin. Which resistance mechanism most directly allows the bacteria to persist despite initially effective antibiotic concentrations?
• Why does skin elasticity decrease in elderly individuals more rapidly than in younger individuals after equivalent UV exposure?
• Why does severe dehydration lead to decreased cognitive function?
• Why does lung compliance decrease more significantly with age compared to a young adult, even when both experience similar levels of exposure to environmental pollutants?
• Why does digoxin, a drug with a narrow therapeutic index, exhibit variable plasma concentrations between patients even when administered at the same weight-normalized dose?