Cutting Edge: Eomesodermin Is Sufficient To Direct Type 1 Innate Lymphocyte Development into the Conventional NK...

Area of Science:

• Immunology
• Cell Biology
• Developmental Biology

Background:

• Type 1 innate lymphocytes (ILCs) encompass type 1 helper ILCs (hILC1s) and conventional NK cells (cNKs).
• Both lineages express T-bet, but cNKs uniquely express Eomesodermin (Eomes).
• The distinct roles of T-bet and Eomes in type 1 ILC development are not fully elucidated.

Purpose of the Study:

• To investigate the necessity of Eomes for conventional NK cell development.
• To determine if Eomes is sufficient to confer conventional NK cell characteristics onto type 1 helper ILCs.
• To explore the developmental plasticity of type 1 innate lymphoid cells.

Main Methods:

• Utilized NKp46-Cre mice to delete Eomes alleles during type 1 ILC maturation.
• Generated transgenic mice expressing Eomes under the control of the Tbx21 locus.
• Analyzed the lymphoid and nonlymphoid type 1 ILC compartments in genetically modified mice.

Main Results:

• Deletion of Eomes significantly blocked conventional NK cell development.
• The formation of the type 1 ILC compartment depends on the semiredundant functions of T-bet and Eomes.
• Ectopic Eomes expression induced conventional NK cell-like properties in both lymphoid and nonlymphoid type 1 ILCs.

Conclusions:

• Eomes is crucial for conventional NK cell lineage commitment.
• T-bet and Eomes act semiredundantly in the development of all type 1 ILCs.
• Type 1 innate lymphoid cells exhibit significant developmental plasticity post-lineage specification.