A novel factor isolated from Actinobacillus actinomycetemcomitans stimulates mouse B cells and human peripheral blood mononuclear cells.
A novel immunostimulating factor (ISTF) of Actinobacillus actinomycetemcomitans ATCC 29522 was isolated and characterized as inducing proliferation of mouse B cells and human peripheral blood mononuclear cells. This factor was isolated from the bacterial culture medium and purified by size exclusion chromatography, dye-ligand affinity chromatography, immunoaffinity chromatography using monoclonal antibodies, and preparative electrophoresis. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the purified ISTF migrated as a single band corresponding to a molecular mass of 13 kDa. ISTF was a proteinaceous material distinct from lipopolysaccharide; it directly induced the proliferation of B lymphocytes but had no effect on the proliferation of T lymphocytes, even in the presence of antigen-presenting cells. A B-lymphocyte-mitogenic activity of ISTF was also shown by flow cytometric analysis of responding cell subpopulations. Immunoblot analysis revealed that ISTF was a component of the outer membranes of bacteria, could exist as a soluble form, and was released by growing and/or lysed bacteria. These results suggest that ISTF produced by A. actinomycetemcomitans may play an important role in immunopathologic changes associated with A. actinomycetemcomitans infections.
Jeong
S J
SJ
The Institute of Medical Science, Pusan, Korea.
Yee
S T
ST
Jo
W S
WS
Yu
S H
SH
Lee
S H
SH
Lim
Y J
YJ
Yoo
Y H
YH
Kim
J M
JM
Lee
J D
JD
Jeong
M H
MH
D000276:Adjuvants, Immunologic / Q000302:isolation & purification* / Q000494:pharmacology; D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry*; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000502:physiology
D000276:Adjuvants, Immunologic; D008070:Lipopolysaccharides; D016693:Receptors, Antigen, T-Cell, alpha-beta