Effects of chronic ethanol feeding on murine dendritic cell numbers, turnover rate, and dendropoiesis.
BACKGROUND
Chronic alcoholics have increased susceptibility to and severity of infection, which are likely to be a result of impaired immune defense mechanisms. The contribution of dendritic cells (DC) to these immune defense changes is not well understood. Alterations in DC numbers, dendropoiesis, and lifespan have not been specifically studied in vivo in chronic ethanol (EtOH) exposure models. As DC play an essential role in initiating immune responses, alterations in these DC characteristics would help explain changes observed in adaptive immune responses.


METHODS
Mice received 20% EtOH (w/v) in the drinking water for up to 28 weeks, with mouse chow ad libitum. In EtOH-fed and water control mice, DC were enumerated by flow cytometry. The effect of EtOH on DC precursor numbers was determined by differentiation in vitro in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4, and the effect of an EtOH environment on untreated DC differentiation was measured following bone marrow transfer to irradiated hosts. DC turnover rate was also examined by bromodeoxyuridine incorporation and loss.


RESULTS
The percentage and absolute numbers of DC were decreased in spleen and increased in thymus beginning as early as 4 weeks of EtOH feeding. In addition, the overall cellularity of spleen and thymus were altered by this regimen. However, chronic EtOH consumption did not adversely affect DC precursor numbers, differentiation abilities, or turnover rates.


CONCLUSIONS
Decreased splenic DC numbers observed following chronic murine EtOH consumption are not because of altered DC precursor numbers or differentiation, nor increased DC turnover rate. Similarly, increased thymic DC numbers are not the result of alterations in DC precursor differentiation or turnover rate. Compartment size plays a role in determining splenic and thymic DC numbers following chronic EtOH feeding. EtOH-induced alterations in total DC numbers provide several mechanisms to partially explain why chronic alcoholics have increased susceptibility to infections.
Department of Pathology, University of Iowa Carver College of Medicine, Iowa 52242, USA.
Michelle R
MR
Edsen-Moore
Ji
J
Fan
Kristin J
KJ
Ness
Jacquie R
JR
Marietta
Robert T
RT
Cook
Annette J
AJ
Schlueter
D000428:Alcohol Drinking / Q000276:immunology*; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects*; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D008221:Lymphoid Tissue / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D051379:Mice; D008815:Mice, Inbred Strains
D002492:Central Nervous System Depressants; D000431:Ethanol