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Leishmania donovani infection enhances lateral mobility of macrophage membrane protein which is reversed by liposomal cholesterol.

Ghosh M, Roy K, Das Mukherjee D, Chakrabarti G, Roy Choudhury K, Roy S - PLoS Negl Trop Dis (2014)

Bottom Line: The protozoan parasite Leishmania donovani (LD) reduces cellular cholesterol of the host possibly for its own benefit.To our knowledge this is the first direct demonstration that LD parasites during their intracellular life cycle increases lateral mobility of membrane proteins and decreases F-actin level in infected macrophages.Such defects may contribute to ineffective intracellular signaling and other cellular functions.

View Article: PubMed Central - PubMed

Affiliation: Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.

ABSTRACT

Background: The protozoan parasite Leishmania donovani (LD) reduces cellular cholesterol of the host possibly for its own benefit. Cholesterol is mostly present in the specialized compartment of the plasma membrane. The relation between mobility of membrane proteins and cholesterol depletion from membrane continues to be an important issue. The notion that leishmania infection alters the mobility of membrane proteins stems from our previous study where we showed that the distance between subunits of IFNγ receptor (R1 and R2) on the cell surface of LD infected cell is increased, but is restored to normal by liposomal cholesterol treatment.

Methodology/principal findings: We determined the lateral mobility of a membrane protein in normal, LD infected and liposome treated LD infected cells using GFP-tagged PLCδ1 as a probe. The mobility of PLCδ1 was computationally analyzed from the time lapse experiment using boundary distance plot and radial profile movement. Our results showed that the lateral mobility of the membrane protein, which is increased in infection, is restored to normal upon liposomal cholesterol treatment. The results of FRAP experiment lent further credence to the above notion. The membrane proteins are intimately linked with cellular actin and alteration of cellular actin may influence lateral mobility. We found that F-actin is decreased in infection but is restored to normal upon liposomal cholesterol treatment as evident from phalloidin staining and also from biochemical analysis by immunoblotting.

Conclusions/significances: To our knowledge this is the first direct demonstration that LD parasites during their intracellular life cycle increases lateral mobility of membrane proteins and decreases F-actin level in infected macrophages. Such defects may contribute to ineffective intracellular signaling and other cellular functions.

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Related in: MedlinePlus

Analysis of PLCδ1 movement.RAW264.7 cells were transfected with plcδ1-gfp plasmid. Average motions of the PLCδ1-GFP were measured by computational analysis as a function of distance from center of cell. Each line represents a particular cell. Motion is on a scale of 0–6 (arbitary unit, a.u.). A) N-MΦ; B) I-MΦ; and C) I-MΦ-CL.
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pntd-0003367-g004: Analysis of PLCδ1 movement.RAW264.7 cells were transfected with plcδ1-gfp plasmid. Average motions of the PLCδ1-GFP were measured by computational analysis as a function of distance from center of cell. Each line represents a particular cell. Motion is on a scale of 0–6 (arbitary unit, a.u.). A) N-MΦ; B) I-MΦ; and C) I-MΦ-CL.

Mentions: We studied the lateral mobility of PLCδ1 in LD infection using computational analysis. The radial profile of PLCδ1 movement showed that the movement is highest near the cell membrane irrespective of infection status of the cell. The highest movement at the cell boundary is denoted as peak movement or “P”. It was observed that peak movement is higher in the I-MΦ as compared to N-MΦ,whereas in I-MΦ-CL it was comparable to that in N-MΦ (Fig. 4). To confirm this result, we carried out an ANOVA analysis of PLCδ1 movement across cells, as described in equation (1.2). The fitted model indicates that movement of PLCδ1 at the cell membrane is significantly higher in I-MΦ as compared to N-MΦ (p-value = 0.04) and there was no significant difference between N-MΦ and I-MΦ-CL (p-value = 0.72) (Table 2).


Leishmania donovani infection enhances lateral mobility of macrophage membrane protein which is reversed by liposomal cholesterol.

Ghosh M, Roy K, Das Mukherjee D, Chakrabarti G, Roy Choudhury K, Roy S - PLoS Negl Trop Dis (2014)

Analysis of PLCδ1 movement.RAW264.7 cells were transfected with plcδ1-gfp plasmid. Average motions of the PLCδ1-GFP were measured by computational analysis as a function of distance from center of cell. Each line represents a particular cell. Motion is on a scale of 0–6 (arbitary unit, a.u.). A) N-MΦ; B) I-MΦ; and C) I-MΦ-CL.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256160&req=5

pntd-0003367-g004: Analysis of PLCδ1 movement.RAW264.7 cells were transfected with plcδ1-gfp plasmid. Average motions of the PLCδ1-GFP were measured by computational analysis as a function of distance from center of cell. Each line represents a particular cell. Motion is on a scale of 0–6 (arbitary unit, a.u.). A) N-MΦ; B) I-MΦ; and C) I-MΦ-CL.
Mentions: We studied the lateral mobility of PLCδ1 in LD infection using computational analysis. The radial profile of PLCδ1 movement showed that the movement is highest near the cell membrane irrespective of infection status of the cell. The highest movement at the cell boundary is denoted as peak movement or “P”. It was observed that peak movement is higher in the I-MΦ as compared to N-MΦ,whereas in I-MΦ-CL it was comparable to that in N-MΦ (Fig. 4). To confirm this result, we carried out an ANOVA analysis of PLCδ1 movement across cells, as described in equation (1.2). The fitted model indicates that movement of PLCδ1 at the cell membrane is significantly higher in I-MΦ as compared to N-MΦ (p-value = 0.04) and there was no significant difference between N-MΦ and I-MΦ-CL (p-value = 0.72) (Table 2).

Bottom Line: The protozoan parasite Leishmania donovani (LD) reduces cellular cholesterol of the host possibly for its own benefit.To our knowledge this is the first direct demonstration that LD parasites during their intracellular life cycle increases lateral mobility of membrane proteins and decreases F-actin level in infected macrophages.Such defects may contribute to ineffective intracellular signaling and other cellular functions.

View Article: PubMed Central - PubMed

Affiliation: Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.

ABSTRACT

Background: The protozoan parasite Leishmania donovani (LD) reduces cellular cholesterol of the host possibly for its own benefit. Cholesterol is mostly present in the specialized compartment of the plasma membrane. The relation between mobility of membrane proteins and cholesterol depletion from membrane continues to be an important issue. The notion that leishmania infection alters the mobility of membrane proteins stems from our previous study where we showed that the distance between subunits of IFNγ receptor (R1 and R2) on the cell surface of LD infected cell is increased, but is restored to normal by liposomal cholesterol treatment.

Methodology/principal findings: We determined the lateral mobility of a membrane protein in normal, LD infected and liposome treated LD infected cells using GFP-tagged PLCδ1 as a probe. The mobility of PLCδ1 was computationally analyzed from the time lapse experiment using boundary distance plot and radial profile movement. Our results showed that the lateral mobility of the membrane protein, which is increased in infection, is restored to normal upon liposomal cholesterol treatment. The results of FRAP experiment lent further credence to the above notion. The membrane proteins are intimately linked with cellular actin and alteration of cellular actin may influence lateral mobility. We found that F-actin is decreased in infection but is restored to normal upon liposomal cholesterol treatment as evident from phalloidin staining and also from biochemical analysis by immunoblotting.

Conclusions/significances: To our knowledge this is the first direct demonstration that LD parasites during their intracellular life cycle increases lateral mobility of membrane proteins and decreases F-actin level in infected macrophages. Such defects may contribute to ineffective intracellular signaling and other cellular functions.

Show MeSH
Related in: MedlinePlus