Limits...
An analysis of the binding characteristics of a panel of recently selected ICAM-1 binding Plasmodium falciparum patient isolates.

Madkhali AM, Alkurbi MO, Szestak T, Bengtsson A, Patil PR, Wu Y, Alharthi S, Jensen AT, Pleass R, Craig AG - PLoS ONE (2014)

Bottom Line: One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive.We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions.The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia.

ABSTRACT
The basis of severe malaria pathogenesis in part includes sequestration of Plasmodium falciparum-infected erythrocytes (IE) from the peripheral circulation. This phenomenon is mediated by the interaction between several endothelial receptors and one of the main parasite-derived variant antigens (PfEMP1) expressed on the surface of the infected erythrocyte membrane. One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive. The current study examined the cytoadherence patterns of lab-adapted patient isolates after selecting on ICAM-1. We investigated the binding phenotypes using variant ICAM-1 proteins including ICAM-1Ref, ICAM-1Kilifi, ICAM-1S22/A, ICAM-1L42/A and ICAM-1L44/A using static assays. The study also examined ICAM-1 blocking by four anti-ICAM-1 monoclonal antibodies (mAb) under static conditions. We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions. The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.

Show MeSH

Related in: MedlinePlus

Static adhesion assay, 2 µl spots at 50 µg/ml protein concentration were placed onto 6 cm dishes and standard protein static binding assays carried out with IE suspended in binding buffer at a parasitaemia of 3% and a haematocrit of 1%.The results show the mean of binding (IE/mm2) (Figure 1A) and %ICAM-1Ref binding (Figure 1B–E), and the bars represents SE (n≥3).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4216080&req=5

pone-0111518-g001: Static adhesion assay, 2 µl spots at 50 µg/ml protein concentration were placed onto 6 cm dishes and standard protein static binding assays carried out with IE suspended in binding buffer at a parasitaemia of 3% and a haematocrit of 1%.The results show the mean of binding (IE/mm2) (Figure 1A) and %ICAM-1Ref binding (Figure 1B–E), and the bars represents SE (n≥3).

Mentions: All isolates were genetically distinct as shown by genotyping (data not shown). Based on the level of binding to ICAM-1Ref, all the isolates were categorised into high and low-avidity parasites. ItG was previously defined as a high-avidity ICAM-1 binder whereas, A4 was characterised as low-avidity ICAM-1 binder from an earlier study [49]. Using the same criteria only two of the lab-adapted isolates were high-avidity ICAM-1 binders; 8146 and 8206. The rest of the isolates were assigned as low-avidity binders (Figure 1A).


An analysis of the binding characteristics of a panel of recently selected ICAM-1 binding Plasmodium falciparum patient isolates.

Madkhali AM, Alkurbi MO, Szestak T, Bengtsson A, Patil PR, Wu Y, Alharthi S, Jensen AT, Pleass R, Craig AG - PLoS ONE (2014)

Static adhesion assay, 2 µl spots at 50 µg/ml protein concentration were placed onto 6 cm dishes and standard protein static binding assays carried out with IE suspended in binding buffer at a parasitaemia of 3% and a haematocrit of 1%.The results show the mean of binding (IE/mm2) (Figure 1A) and %ICAM-1Ref binding (Figure 1B–E), and the bars represents SE (n≥3).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216080&req=5

pone-0111518-g001: Static adhesion assay, 2 µl spots at 50 µg/ml protein concentration were placed onto 6 cm dishes and standard protein static binding assays carried out with IE suspended in binding buffer at a parasitaemia of 3% and a haematocrit of 1%.The results show the mean of binding (IE/mm2) (Figure 1A) and %ICAM-1Ref binding (Figure 1B–E), and the bars represents SE (n≥3).
Mentions: All isolates were genetically distinct as shown by genotyping (data not shown). Based on the level of binding to ICAM-1Ref, all the isolates were categorised into high and low-avidity parasites. ItG was previously defined as a high-avidity ICAM-1 binder whereas, A4 was characterised as low-avidity ICAM-1 binder from an earlier study [49]. Using the same criteria only two of the lab-adapted isolates were high-avidity ICAM-1 binders; 8146 and 8206. The rest of the isolates were assigned as low-avidity binders (Figure 1A).

Bottom Line: One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive.We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions.The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom; Department of Medical Laboratories Technology, College of Applied Medical Sciences, Jazan University, Jazan, Kingdom of Saudi Arabia.

ABSTRACT
The basis of severe malaria pathogenesis in part includes sequestration of Plasmodium falciparum-infected erythrocytes (IE) from the peripheral circulation. This phenomenon is mediated by the interaction between several endothelial receptors and one of the main parasite-derived variant antigens (PfEMP1) expressed on the surface of the infected erythrocyte membrane. One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive. The current study examined the cytoadherence patterns of lab-adapted patient isolates after selecting on ICAM-1. We investigated the binding phenotypes using variant ICAM-1 proteins including ICAM-1Ref, ICAM-1Kilifi, ICAM-1S22/A, ICAM-1L42/A and ICAM-1L44/A using static assays. The study also examined ICAM-1 blocking by four anti-ICAM-1 monoclonal antibodies (mAb) under static conditions. We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions. The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.

Show MeSH
Related in: MedlinePlus