Hall 123

How does identifying subsets of cells in the human blood help in understanding heterogeneity in the human population?

Vineeta Bal

National Institute of Immunology, Aruna Asaf Ali Road, New Delhi, India

Human blood is considered the easiest and ethically acceptable source to study human health and disease. Many types of white blood cells (WBCs) are present in the blood apart from red blood cells, platelets etc. Using antibodies labelled with chemicals which emit fluorescence, many cell surface molecules can be identified on WBCs thus providing an avenue for documentation of proportions and numbers of various subsets such as T cells, B cells, monocytes etc. We have used this method, called flow cytometry, to identify about 20 subsets in WBC populations from healthy adult volunteers and from umbilical cord blood from normal deliveries. Umbilical cord blood collected at the time of delivery represents outcome of ‘sterile’ environment because during its residence in the mother’s womb, the baby is almost free from any exposure to bacteria or viruses. In contrast, healthy adults have very large number of bacteria and viruses, described as microbiome, present inside them. Thus, blood from healthy adult volunteers is likely to show influences of microbial exposure unlike cord blood. On this backdrop we identify cellular subsets and analyse their distribution in adult and cord blood samples. We propose that this approach helps in identifying origins of heterogeneity in certain cellular subsets in adult and cord blood.