TY - JOUR
T1 - Antagonistic interactions among T cell subsets of old mice revealed by limiting dilution analysis
AU - Dozmorov, I. M.
AU - Kalinichenko, V. V.
AU - Sidorov, I. A.
AU - Miller, R. A.
PY - 1995
Y1 - 1995
N2 - When CD4 spleen cells from old (but not young) mice are tested for Con A- induced proliferation in limiting dilution assays, the dose response curve shows a nonlinear relationship. We interpret these observations using a two- cell model, in which proliferation of one cell type (LPC1) can be blocked by a second cell type (LPC2), which can itself generate detectable proliferation only at high multiplicities. The two-cell model accounts for several observations: 1) the variation in curve shape as a function of incubation time; 2) the skewed distribution of wells scored as 'negative' in cultures of old splenocytes; and 3) the initially antagonistic effects of old splenocytes titrated into cultures containing fixed numbers of young responders. To provide a further test of the two-cell model, ionomycin-resistant (Ca(R)) and ionomycin-sensitive (Ca(S)) cells were separated using a Percoll/ionomycin gradient. The Ca(R) preparation, shown previously to consist largely of memory T cells, showed the dose curve predicted for the LPC2 cell type, whereas the Ca(S) (naive) cells showed the single-hit kinetics postulated for LPC1 cells. Furthermore, mixtures of Ca(R) and Ca(S) cells from young mice reproduced the zigzag dose curve characteristically produced by unseparated cells from old mice. These data suggest that the spleens of both young and old mice contain two kinds of Con A-responsive CD4 cell: one that proliferates vigorously, and a second, calcium ionophore-resistant type that proliferates less well, that can interfere with proliferation of the first cell type, and whose frequency increases with age.
AB - When CD4 spleen cells from old (but not young) mice are tested for Con A- induced proliferation in limiting dilution assays, the dose response curve shows a nonlinear relationship. We interpret these observations using a two- cell model, in which proliferation of one cell type (LPC1) can be blocked by a second cell type (LPC2), which can itself generate detectable proliferation only at high multiplicities. The two-cell model accounts for several observations: 1) the variation in curve shape as a function of incubation time; 2) the skewed distribution of wells scored as 'negative' in cultures of old splenocytes; and 3) the initially antagonistic effects of old splenocytes titrated into cultures containing fixed numbers of young responders. To provide a further test of the two-cell model, ionomycin-resistant (Ca(R)) and ionomycin-sensitive (Ca(S)) cells were separated using a Percoll/ionomycin gradient. The Ca(R) preparation, shown previously to consist largely of memory T cells, showed the dose curve predicted for the LPC2 cell type, whereas the Ca(S) (naive) cells showed the single-hit kinetics postulated for LPC1 cells. Furthermore, mixtures of Ca(R) and Ca(S) cells from young mice reproduced the zigzag dose curve characteristically produced by unseparated cells from old mice. These data suggest that the spleens of both young and old mice contain two kinds of Con A-responsive CD4 cell: one that proliferates vigorously, and a second, calcium ionophore-resistant type that proliferates less well, that can interfere with proliferation of the first cell type, and whose frequency increases with age.
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M3 - Article
C2 - 7722287
AN - SCOPUS:0028997807
SN - 0022-1767
VL - 154
SP - 4283
EP - 4293
JO - Journal of Immunology
JF - Journal of Immunology
IS - 9
ER -