Infectious mononucleosis is primarily caused by a pathogen that attaches to which type of cell?

Infectious mononucleosis is primarily caused by the Epstein-Barr virus (EBV), which specifically targets B lymphocytes. The virus has a preference for these cells because it uses the CD21 receptor, which is expressed on the surface of B lymphocytes, to gain entry into the cell. Once inside, the virus can manipulate the B cells for replication, leading to the characteristic symptoms associated with infectious mononucleosis, such as fatigue, fever, sore throat, and swollen lymph nodes.

B lymphocytes are central to the immune response, and the successful infection of these cells by EBV can lead to an increase in atypical lymphocytes seen in laboratory tests. This is a key indicator of infectious mononucleosis, underscoring the relationship between the pathogen and B cells. The other cell types mentioned, such as T lymphocytes, macrophages, and neutrophils, do not have the same structural mechanism or receptor interactions that facilitate EBV attachment and infection, making them less relevant to the pathogenesis of infectious mononucleosis.