.jpg) NK cell |
Null cells, a subset of large circulatingwhite blood cells, mimic the appearance ofT orBlymphocytes but do not possess their defining surface receptors. Predominantly, these includenatural killer cells (NK cells), with a lesser portion beinghematopoietic stem cells traversing freely within thebloodstream.[1]
In the realm ofoncology, certainpathological null cells contribute to the development ofcancers, such as null celladenomas within thepituitary gland. These adenomas often grow slowly and secretehormones in patterns that are not well understood, potentially leading tonecrosis of surroundingbrain tissue, thereby affecting neurological functions.[2] The discovery of null cells in the benignadenohypophysis suggests that such adenomas might evolve from pre-existing benign null cells, shedding light on the tumors' origins and potential interventions.[3]
In relation toviral infections, the interaction betweenviruses and theimmune system can lead to the emergence of null cells with impaired functionality. For example,Cytomegalovirus (CMV) has been shown to induceT-lymphocytes to stop expressingCD28 and other critical surface molecules. This alteration essentially converts these T-cells into a form of null cell, lacking the additional properties ofNK cells and therefore failing to contribute to the immune response, which can result in conditions ofimmunodeficiency.[4]
Understanding the roles and mechanisms of null cells within the immune system and in pathological conditions such as cancer and viral infections not only provides insights into fundamentalbiological processes but also opens avenues for therapeutic interventions targeting these unique cell types.