The heat shock proteins, Hsp70 and Hsp83, of Leishmania infantum are mitogens for mouse B cells.
Extending earlier studies, this report demonstrates that Leishmania infantum heat shock proteins (Hsps), Hsp70 and Hsp83, expressed as recombinant proteins fused to the Escherichia coil maltose-binding protein (MBP), are potent mitogens for murine splenocytes. The response was not due to lipopolysaccharide (LPS) because the stimulatory activity of Hsp preparations was sensitive to boiling and trypsin treatments, whereas the corresponding activity of LPS was resistant to both treatments. It was found that in vitro incubation of spleen cells with the Leishmania Hsps leads to the expansion of CD220-bearing populations, suggesting a direct effect of these proteins on B lymphocytes. In fact, splenocytes from B cell-deficient mice did not proliferate in response to the Leishmania Hsps. In contrast, spleen cells from athymic nude mice were significantly stimulated by these recombinant proteins as an indication that the MBP-Hsp70 and MBP-Hsp83 recombinant proteins behave as T cell-independent mitogens of B cells. Furthermore, both proteins were able to induce proliferation on B cell populations purified from BALB/c spleen.
Rico
Ana I
AI
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid 28049, Spain.
Gironès
Núria
N
Fresno
Manuel
M
Alonso
Carlos
C
Requena
Jose M
JM
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D018314:Leishmania infantum / Q000276:immunology / Q000378:metabolism*; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology*; D058619:Maltose-Binding Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008934:Mitogens / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D013154:Spleen / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
D002352:Carrier Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C490310:Hsp83 protein, protozoan; D058619:Maltose-Binding Proteins; D008934:Mitogens; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins