Lymphotactin: a Cytokine that Represents a New Class of Chemokine

TLDR

Lymphotactin resembles Cys‑Cys and Cys‑X‑Cys chemokines yet lacks two of the four cysteine residues typical of chemokines. The study aimed to characterize the cytokine profile of progenitor T cells. Lymphotactin was identified from a pro‑T cell cDNA library, is expressed in activated CD8⁺ T cells and CD4⁻CD8⁻ thymocytes, attracts lymphocytes but not monocytes or neutrophils, is encoded on chromosome 1, and represents a novel chemokine family member.

Abstract

In this study, the cytokine-producing profile of progenitor T cells (pro-T cells) was determined. During screening of a complementary DNA library generated from activated mouse pro-T cells, a cytokine designated lymphotactin was discovered. Lymphotactin is similar to members of both the Cys-Cys and Cys-X-Cys chemokine families but lacks two of the four cysteine residues that are characteristic of the chemokines. Lymphotactin is also expressed in activated CD8+ T cells and CD4-CD8- T cell receptor alpha beta + thymocytes. It has chemotactic activity for lymphocytes but not for monocytes or neutrophils. The gene encoding lymphotactin maps to chromosome one. Taken together, these observations suggest that lymphotactin represents a novel addition to the chemokine superfamily.