Pivotal Advance: passively acquired membrane proteins alter the functional capacity of bovine polymorphonuclear cells.
We have previously shown that bovine polymorphonuclear cells (PMNs) have an impressive capacity to passively acquire membrane lipids and proteins from apoptotic cells. The present study used confocal microscopy to analyze the interaction between PMNs and a variety of donor cells, and assays were used to determine if passively acquired membrane proteins altered PMN biology. Confocal microscopy revealed that direct cell-cell contact and microparticles shed by donor cells may be a source of passively acquired membranes and integral membrane proteins, which then integrate into the PMN plasma membrane. Donor cells expressing green fluorescent protein in their cytoplasm were also used to demonstrate the transfer of cytoplasmic proteins from donor cells to PMNs. The functional consequences of passive membrane protein acquisition by PMNs were then investigated using two distinct systems. First, PMNs were incubated with membranes isolated from an adenovirus-permissive cell line, and this passive transfer of cell membranes significantly increased adenovirus infection of PMNs. Second, major histocompatibility complex (MHC) class II molecules were passively transferred from ovine B cells to bovine PMNs, and PMNs with ovine MHC class II on their surface were able to induce a proliferative response and increased cytokine gene expression in alloreactive bovine T cell lines. In conclusion, passively acquired membrane proteins integrated into the plasma membrane of bovine PMNs and altered the functional capacity of these cells.
Whale
Tyler A
TA
Vaccine and Infectious Disease Organization, VIDO, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK, S7N 5E3.
Wilson
Heather L
HL
Tikoo
Suresh K
SK
Babiuk
Lorne A
LA
Griebel
Philip J
PJ
D000818:Animals; D002417:Cattle; D002460:Cell Line; D005260:Female; D008297:Male; D008563:Membrane Lipids / Q000276:immunology; D008565:Membrane Proteins / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*
D008563:Membrane Lipids; D008565:Membrane Proteins