Human Immunodeficiency Virus (HIV) attacks the body's immune system, in particular CD4+ T cells, with devastating effects. The virus spreads between these cells by forming a bridge called a virological synapse (VS), but exactly how is not clear. Two different magnifications of the same electron microscopy image help to answer this question. They show how a CD4+ cell’s organelles (structures within the cell), usually involved in secreting benign substances, are hijacked by the virus as a VS forms. Directed by the microtubule organising centre or centrosome (large dark grey blobs in right-hand image), diseased organelles huddle together near the point of contact with an uninfected neighbouring cell, thus herding the swarming virus (small grey spots in right-hand image) towards its next victim. This is an important step in determining the mechanisms that spread HIV, and could lead to better drugs for fighting the disease in the future.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.