Differentiation of single populations in a bidirectional mixed lymphocyte culture using X and Y chromosome-specific FiSH markers.
OBJECTIVE
To validate a new combination of a viability assay and Fluorescence in Situ Hybridsation (FiSH) techniques using X- or Y-DNA probes to assay the viability of each single population within bidirectional mixed lymphocyte cultures (MLCs).


METHODS
We determined the absolute viable lymphocyte counts of each population in bidirectional maternal-fetal MLCs as well as in bidirectional MLCs between male and female unrelated adults using a combination of a viability assay and additional sex discrimination by FiSH, and compared the results with the classical tritiated thymidine incorporation assay and with sex discrimination by metaphase number.


RESULTS
The results of the total viability assay correlated with those of the tritiated thymidine incorporation assay. The differentiation of each single population by FiSH showed, as in the metaphase assay, that the relationship between viable maternal and neonatal cells was shifted significantly (p<0.05) towards the neonatal cells, while the relationship of the viable cells in the MLCs between unrelated adults was balanced.


CONCLUSIONS
Our results show that X/Y discrimination by FiSH would be a useful tool for analyzing the immunologic network by bidirectional MLCs. The main advantage over sex discrimination by metaphase counting is that not only the proliferating cells but all viable cells are taken into account. An additional aspect would be the possibility to sort the cells according to surface markers (e.g. CD8+ HLA DR+) before discrimination by X and Y chromosomes.
Department of Pediatrics, Otto-von-Guericke University, Wiener Strasse D-39112 Magdeburg, Germany. thbrune@muenster.de
Thomas
T
Brune
Felix G
FG
Riepe
Kirsten
K
Beier
Rita
R
Exeler
Frank
F
Louwen
Henk
H
Garritsen
D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007231:Infant, Newborn; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D007959:Lymphocyte Culture Test, Mixed / Q000379:methods*; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008677:Metaphase; D013936:Thymidine / Q000096:biosynthesis; D014960:X Chromosome; D014998:Y Chromosome
D005819:Genetic Markers; D013936:Thymidine