Faculty Collaboration Database

Kinetic analysis of cloned cytotoxic T lymphocyte reactivity against normal and leukaemic target cells. J Immunogenet 1986;13(2-3):275-85

Date

04/01/1986

Pubmed ID

3493298

DOI

10.1111/j.1744-313x.1986.tb01112.x

Scopus ID

2-s2.0-0022895122 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

The kinetics of unrestricted killing of normal and leukaemic lymphocyte target cells by a Qa-1b-specific murine cytotoxic T lymphocyte (CTL) clone were evaluated in a manner analogous to enzyme kinetic assays in which the effector and target cells corresponded to the enzyme and substrate, respectively. In order to apply the enzyme-substrate analogy to clonal cytolytic reactions, it was first established that the lytic reactions exhibited initial steady-state velocity of lysis at the effector and target cell concentrations used. The lytic reaction maintained linearity for velocity of lysis during the first 90 min of incubation, then plateaued. Vmax (the maximal rate of target cell lysis achieved by a given effector population) and Km (the target cell number resulting in 1/2Vmax) values were determined over a wide range of target and effector cell concentrations. Both parameters were found to be directly proportional to the number of effector cells. At a given concentration of cloned CTL, the lytic parameters of Vmax and Km were not significantly different for normal or leukaemic target cells that express Qa-1b. Additional kinetic parameters for lysis of normal and leukaemic target cells by a cloned CTL were also compared. The lytic efficiency of the CTL clone (i.e. maximal killing rate with an infinite number of targets) and the intrinsic affinity between effector and target cells were the same with either normal or leukaemic targets. However, the maximal lysis of target cells at an infinite number of effectors was significantly less for normal compared with leukaemic targets. This suggests that the normal target cells were more heterogeneous in their expression of the target (Qa-1b) antigen. Enzyme-like kinetic analysis of cell-mediated lysis reactions can be useful for comparing the relative affinities of effector and target cells obtained from various sources.

Author List

LeFever AV, Truitt RL

Author

Robert L. Truitt PhD Emeritus Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Clone Cells
Cytotoxicity, Immunologic
Kinetics
Leukemia, Experimental
Lymphocytes
Mice
T-Lymphocytes, Cytotoxic