Loss of αβ but not γδ T cells in chickens causes a severe phenotype
Theresa von Heyl, Romina Klinger, Dorothea Aumann, Christian Zenner, Mohanned Naif Alhussien, Antonina Schlickenrieder, Kamila Lengyel, Hanna‐Kaisa Vikkula, Teresa Mittermair, Hicham Sid, Benjamin Schusser
Abstract
Abstract The availability of genetically modified mice has facilitated the study of mammalian T cells. No model has yet been developed to study these cells in chickens, an important livestock species with a high availability of γδ T cells. To investigate the role of γδ and αβ T cell populations in birds, we generated chickens lacking these T cell populations. This was achieved by genomic deletion of the constant region of the T cell receptor γ or β chain, leading to a complete loss of either γδ or αβ T cells. Our results show that a deletion of αβ T cells but not γδ T cells resulted in a severe phenotype in KO chickens. The αβ T cell KO chickens exhibited granulomas associated with inflammation of the spleen and the proventriculus. Immunophenotyping of αβ T cell KO chickens revealed a significant increase in monocytes and expectedly the absence of CD4 + T cells including FoxP3 + regulatory T cells. Surprisingly there was no increase of γδ T cells. In addition, we observed a significant decrease in immunoglobulins, B lymphocytes, and changes in the bursa morphology. Our data reveal the consequences of T cell knockouts in chickens and provide new insights into their function in vertebrates.