ISSN:
1432-0851
Keywords:
LAK cells
;
Daudi cells
;
γ/δ-TCR
;
Adhesion
;
Cytotoxicity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Effector-target conjugates, formed by coincubation of lymphokine-activated killer (LAK) cells with either K562 or Daudi cells, were separated from single cells by Percoll sedimentation. The occurrence of various CD molecules (CD3, CD56, CD57, CD16, γ/δ-TCR) was compared in both fractions. Only LAK cells expressing the γ/δ T cell receptor (TCR) were found in a significantly increased percentage in fractions containing conjugates indicating that γ/δ-TCR+ LAK cells were preferably bound to target cells at the time of separation. In order to determine whether γ/δ-TCR+ LAK cells also show a preferred killing activity against the targets, cultures enriched with or depleted of γ/δ-TCR+ cells were established. Against K562 cells, γ/δ-TCR+-enriched cultures showed a greatly reduced killing activity compared to LAK bulk cultures or cultures depleted of γ/δ-TCR+ cells. Using Daudi cells as targets the enriched fraction revealed a slightly increased killing activity compared to bulk cultures or depleted fractions. Preincubation of γ/δ-TCR+ LAK cells with anti-γ/δ or anti-CD3 mAb resulted in a distinct increase of the killing activity against K562 cells, but in only a slightly enhanced activity against Daudi cells. It is postulated that γ/δ-TCR+ LAK cells use the same adhesion mechanism for both targets but that only Daudi cells express a specific ligand for the γ/δ-TCR. Occupation of the γ/δ-TCR/CD3 complex by mAb, however, seems to substitute for the absent epitope on K562 cells by eliciting stimulatory signals in γ/δ-TCR+ LAK cells which, in combination with the binding stimulus, trigger cytolytic activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01741172
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