From a systems biology perspective, immunology is fascinating. To occupy ecological niches, vertebrates have evolved a strategy that hinges on longevity rather than a high reproduction rate. To survive in this context, we need to deal with viruses and bacteria which represent the dominant forms of life in the universe and have adopted the opposite strategy. This is made possible by the immune system whose evolution was marked by an immunological big bang 450 million years ago: the emergence of the adaptive immune system.
Our team’s main focus is on the cells that orchestrate the functioning of the adaptive immune system: T lymphocytes. Two examples illustrate how T cells are unique. First, in contrast to other terminally differentiated cells, the proliferation potential of T cells is similar to that of stem cells. Second, when confronted with the most complex entity in the universe, an eukaryotic cell, the exquisite sensitivity of T cells allow them to react to the presence of a single “non-self”’ peptide and to initiate complex signalling cascades with far-reaching consequences for the organism. These properties coupled to the fact that they are readily accessible (e.g., blood) and can migrate in all tissues and organs make T cells extremely instructive to address various cell biology issues.
The medical importance of immunology is considerable since infections represent the most common cause of death in human. The functioning of the adaptive immune system has been shaped by co-evolution with viruses and bacteria. This co-evolution represents 450 million years of clinical trials during which T lymphocyte have evolved strategies to recognize stressed cells with an abnormal proteome. Because cancer cells have much in common with infected cells, one goal of our team is to harness the potential of T lymphocytes to cure cancer.