Amphotericin B regulates the host immune response in visceral leishmaniasis: reciprocal regulation of protein kinase C isoforms.
OBJECTIVE
Treatment of visceral leishmaniasis (VL) is marked by the failure of pentavalent antimonials which has brought amphotericin B (AmpB) to the forefront. In this study we have focused on signaling pathway regulating AmpB triggered effector response.


METHODS
AmpB triggered effector response in the form of free radicals and proinflammatory cytokines was determined by FACS, colorimetric estimation or Real-Time PCR (RT-PCR). Specific peptide inhibitors for classical and atypical protein kinase C (PKC) were used to investigate the role of PKC isoforms in the functioning of AmpB during VL.


RESULTS
In vitro studies with THP1 cells showed that 2 microg/ml dose of AmpB could mediate effective parasite clearance due to strong induction of free radicals and proinflammatory cytokines. This induction of proinflammatory response paralleled with antagonistic regulation of classical and atypical PKC. Further confirmation was provided by RT-PCR of (peripheral blood mononuclear cells) PBMC isolated from VL infected patients undergoing AmpB treatment.


CONCLUSIONS
Overall, our results suggest that classical and atypical PKC signaling pathways are involved in the modulation of proinflammatory response triggered by AmpB against Leishmania donovani. These observations may contribute to the understanding of the mechanism responsible for the initiation of protective response induced by AmpB during VL.
Mukherjee
Asok Kumar
AK
Div. of Molecular Medicine, Bose Institute, Kolkata, India.
Gupta
Gaurav
G
Bhattacharjee
Surajit
S
Guha
Subhasis Kamal
SK
Majumder
Saikat
S
Adhikari
Anupam
A
Bhattachrya
Parna
P
Majumdar
Suchandra Bhattacharyya
SB
Majumdar
Subrata
S
D000293:Adolescent; D000328:Adult; D000666:Amphotericin B / Q000008:administration & dosage*; D000981:Antiprotozoal Agents / Q000008:administration & dosage*; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D005260:Female; D005609:Free Radicals / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D009000:Monocytes / Q000276:immunology; D020033:Protein Isoforms / Q000096:biosynthesis; D011493:Protein Kinase C / Q000096:biosynthesis*; D055815:Young Adult
D000981:Antiprotozoal Agents; D016207:Cytokines; D005609:Free Radicals; D020033:Protein Isoforms; D000666:Amphotericin B; D011493:Protein Kinase C