T cell receptor diversity and T cell repertoire dynamics in an eco-evolutionary model species

• Applicant: Professor Dr. Tobias Lenz
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology)
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433116033

The recognition of antigens by T cells of the immune system is a central process of a pathogen-specific immune response in vertebrates. The ability of the adaptive immune system to continuously recognize novel antigens is based on a complex interaction of higly variable molecules in the body. The genetic basis for this variability has presumably evolved through the continuous interaction with diverse pathogens, but the exact factors and mechanism behind this evolutionary process are not yet fully understood. In this project, we examine the T-cell repertoire of the three-spined stickleback (Gasterosteus aculeatus) from an evolutionary perspective. The stickleback has become a model species for studying complex evolutionary processes, including the coevolution between hosts and their parasites. In principle, the stickleback’s immune system functions in the same way as the one in humans, so that the findings from our research can also provide insights into the evolution and complexity of the human immune system. Employing novel molecular techniques and sequencing technologies, we are able to study the variability of the T cell repertoire among individual sticklebacks as well as its development from birth to the end of life. Specifically, we investigate here the dynamic response of the T-cell repertoire to exposure with individual antigens, as well as the the full range of the natural parasite community that the stickleback is exposed to in its natural habitat. Furthermore, we investigate the relationship between the variability of the T cell repertoire and the microbiome of the stickleback, which is suspected to modulate T cell-driven immunity. The results of this project will provide new insights into the evolution of the T cell-based adaptive immune system, and ultimately lead to a better understanding of the genetic basis of differences in immune competence among individuals.

• DFG Programme: Research Grants