Rights statement: http://journals.cambridge.org/action/displayJournal?jid=PAR The final, definitive version of this article has been published in the Journal, Parasitology, 122 (5), pp 521-529 2001, © 2001 Cambridge University Press.
Final published version, 498 KB, PDF document
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Transformation of Leishmania mexicana metacyclic promastigotes to amastigote-like forms mediated by binding of human C-reactive protein
AU - Bee, A
AU - Culley, F J
AU - Alkhalife, I S
AU - Bodman-Smith, K B
AU - Raynes, J G
AU - Bates, P A
N1 - http://journals.cambridge.org/action/displayJournal?jid=PAR The final, definitive version of this article has been published in the Journal, Parasitology, 122 (5), pp 521-529 2001, © 2001 Cambridge University Press.
PY - 2001/5
Y1 - 2001/5
N2 - Infective metacyclic promastigote forms of Leishmania mexicana are introduced by the bite of sandfly vectors into their human hosts where they transform into the amastigote form. The kinetics of this process was examined in vitro in response to different combinations of temperature (26 degrees C or 32 degrees C), pH (7.2 or 5.5), and exposure to human serum. Little transformation occurred at 26 degrees C/pH 7.2, intermediate levels at 26 degrees C/pH 5.5 and 32 degrees C/pH 7.2, and the greatest response at 32 degrees C/pH 5.5. Transformation was stimulated by exposure to normal human serum, but was markedly reduced when serum previously incubated at 56 degrees C for 1 h was used (complement heat-inactivated). This stimulatory effect was reproduced by exposure to a single purified component of human serum, C-reactive protein (CRP). Binding of CRP to the whole surface of L. mexicana metacyclic promastigotes, including the flagella, was demonstrated by an indirect fluorescent antibody test. The effect of purified CRP was dose dependent and occurred using normal serum concentrations. The stimulatory effect of whole serum was oblated by CRP depletion and restored by addition of purified CRP. The effects of cAMP analogues indicated that transformation could be mediated via an adenylate cyclase cascade.
AB - Infective metacyclic promastigote forms of Leishmania mexicana are introduced by the bite of sandfly vectors into their human hosts where they transform into the amastigote form. The kinetics of this process was examined in vitro in response to different combinations of temperature (26 degrees C or 32 degrees C), pH (7.2 or 5.5), and exposure to human serum. Little transformation occurred at 26 degrees C/pH 7.2, intermediate levels at 26 degrees C/pH 5.5 and 32 degrees C/pH 7.2, and the greatest response at 32 degrees C/pH 5.5. Transformation was stimulated by exposure to normal human serum, but was markedly reduced when serum previously incubated at 56 degrees C for 1 h was used (complement heat-inactivated). This stimulatory effect was reproduced by exposure to a single purified component of human serum, C-reactive protein (CRP). Binding of CRP to the whole surface of L. mexicana metacyclic promastigotes, including the flagella, was demonstrated by an indirect fluorescent antibody test. The effect of purified CRP was dose dependent and occurred using normal serum concentrations. The stimulatory effect of whole serum was oblated by CRP depletion and restored by addition of purified CRP. The effects of cAMP analogues indicated that transformation could be mediated via an adenylate cyclase cascade.
KW - Leishmania mexicana
KW - metacyclic promastigote
KW - C-reactive protein
KW - lipophosphoglycan
KW - amastigote
KW - adenylate cyclase
U2 - 10.1017/S0031182001007612
DO - 10.1017/S0031182001007612
M3 - Journal article
C2 - 11393825
VL - 122
SP - 521
EP - 529
JO - Parasitology
JF - Parasitology
SN - 0031-1820
IS - 5
ER -