In vitro study of Listeria monocytogenes infection to murine primary and human transformed B cells.
Immunity to Listeria monocytogenes is largely mediated by T lymphocytes. Recently, B lymphocytes or their secreted products are implicated to provide immunity against L. monocytogenes infection. To understand whether L. monocytogenes can infect and kill B cells as a possible strategy to initiate an infection, we examined the effects of L. monocytogenes on a human B lymphoma (Ramos RA-1) and mouse primary B cells in vitro. L. monocytogenes infection resulted in significantly (p<or=0.05) high cytotoxicity (58-79%) for Ramos and 39-68% cytotoxicity for mouse primary B cells. In contrast, non-pathogenic L. innocua caused only 1.2% cytotoxicity for Ramos and 19% for primary B cells. Bacterial cells were found frequently adhered to the B cell surfaces; however, active invasion was not a prerequisite for infection. L. monocytogenes caused loss of B cell surface molecules, pore formations, cell swelling, membrane damages and apoptosis. This study demonstrates that L. monocytogenes can infect and kill B cells as a possible strategy to initiate a successful infection.
Menon
A
A
Food Microbiology and Immunochemistry Laboratory, Department of Food Science, Alabama A&M University, Normal, AL 35897, USA.
Shroyer
M L
ML
Wampler
J L
JL
Chawan
C B
CB
Bhunia
A K
AK
D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology / Q000382:microbiology* / Q000648:ultrastructure; D001422:Bacterial Adhesion; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D008087:Listeria / Q000276:immunology / Q000502:physiology; D008089:Listeria monocytogenes / Q000276:immunology / Q000502:physiology*; D008088:Listeriosis / Q000276:immunology / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D014407:Tumor Cells, Cultured