T and B cell collaboration: induction of motility in small, resting B cells by interleukin 4.
In this report we investigate if IL 4 can work as a chemoattractant factor by inducing locomotion in B cells. We found that murine recombinant IL 4 (rIL 4) induced motile morphology and migration through polycarbonate micropore filters of murine, splenic B cells at an optimal concentration of 3 ng/ml. Kinetic studies revealed optimal migration at 8-16 h, although a significant response could be detected already after 1 h. Flow cytometric studies confirmed that the migrated cells were indeed B cells. We also compared the activity of small, dense B cells and large, low-density B cells, based on Percoll gradient separation. We found no difference in IL 4-induced motility among the two groups. Furthermore, we looked at B cells activated in vitro by preculture in lipopolysaccharide (LPS) or IL 4. Our data indicate that both LPS and IL 4 can increase the general capacity for motility in B cells after preculture for 24 h. T and B cell collaboration requires close cell-cell contacts in order for T cell help to be administered to the B cell. One way of enhancing such cell contacts could be through directional cell migration induced by helper factors (chemotaxis). We suggest that IL 4 can play a role as a chemoattractant factor that enhances cell contacts between T helper cells and B cells.
Clinchy
B
B
Department of Immunology, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden.
Elenström
C
C
Severinson
E
E
Möller
G
G
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000502:physiology; D002450:Cell Communication; D002465:Cell Movement / Q000187:drug effects; D005260:Female; D015847:Interleukin-4 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010641:Phenotype; D013601:T-Lymphocytes / Q000502:physiology*
D008070:Lipopolysaccharides; D015847:Interleukin-4