Human natural killer cells and mature T lymphocytes express identical CD3 zeta subunits as defined by cDNA cloning and sequence analysis.
In order to characterize the CD3 zeta-related protein found in human natural killer (NK) cells and compare it with CD3 zeta expressed in T lymphocytes, the present study was performed. A polyclonal CD3-CD16+NK population displaying a strong non-major histocompatibility complex-restricted cytotoxic activity against the NK target K-562 was isolated and a product corresponding to CD3 zeta amplified using the polymerase chain reaction method. This 0.6-kb product was present in similar amounts in NK cells and T cells. In contrast, a product corresponding to CD3 delta was amplified from T lymphocytes exclusively. Thus, the CD3 zeta product detected in NK cells did not originate from contaminating T cells. DNA sequence analysis of two independent polymerase chain reaction products from the NK cells demonstrates that human NK cells and mature T cells share a CD3 zeta subunit with an identical primary amino acid sequence. The nucleotide sequence of a third NK-derived cDNA revealed an insertion of a CAG triplet encoding an additional glutamine residue in the cytoplasmic domain. Since this residue is encoded by nucleotides at a putative RNA splice junction, it possibly results from a difference in pre-mRNA splicing. Taken together, these data show that CD3 zeta is not structurally distinct in NK cells and in T lymphocytes.
Moingeon
P
P
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA 02115.
Stebbins
C C
CC
D'Adamio
L
L
Lucich
J
J
Reinherz
E L
EL
D000595:Amino Acid Sequence; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis* / Q000235:genetics; D001483:Base Sequence; D017252:CD3 Complex; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011948:Receptors, Antigen, T-Cell / Q000096:biosynthesis* / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology*; D014158:Transcription, Genetic
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D004247:DNA