Search

A quantitative model for the population distributions of the different types of conjugates formed between cytotoxic T lymphocytes and target cells has been developed. The comparison of the theoretical predictions with data of the literature reveals that the transit populations among the different types of conjugates depends on the lymphocyte-to-target ratio, R, and two constants, k and k1. These constants (where k greater than k1) govern, respectively, the transit populations among conjugates of the type LTi (LTn----LTn-1----...LT), and among LjT conjugates (LT----L2T----...----LmT). We have found that high ratios are necessary to obtain conjugates where multiple T lymphocytes are bound to one target cell, and that under these conditions the predominant conjugate, LjT, varies according to j = 1 + k1R. Conversely, for low values of R the predominant population is of the type LTi, where i also shows a linear dependence on R. Our model explains also why the conjugate LT is normally the predominant population under the experimental conditions reported in the literature. A discussion of the influence exerted by the population distributions of lymphocyte-target cell conjugates on the kinetic of the lytic process for these kinds of effector-target systems has also been made.

We developed a model for the kinetics of target cell lysis by cytotoxic T-lymphocytes which accounts for most facts observed at the population level. In contrast to previous models, the following facts: conjugate frequency of cytotoxic T-lymphocytes bound to target cell, dependence of this frequency on the lymphocyte-to-target ratio (R), variation of R with time as target cells are destroyed, and population distributions of the different types of conjugates formed between lymphocytes and target cells, which are involved in the kinetics of these kinds of effector-target systems have been contemplated in the model. The relationship with effector-kinetic analogy models for the lytic process has been discussed. Predictions of the model have been explored and compared with experimental observations about target cell lysis reported in the literature.