Step I Leukocyte extravasation

[Phloston]

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P. 247 of FA2012 gives a list of the order in which different molecules participate in the induction of leukocyte extravasation.

P-selectin is listed under E-selectin.

In contrast, University of Utah Webpath says, "P-selectin is expressed rapidly, while E-selectin is expressed within several hours."

Wikipedia is non-specific. I also can't be bothered to delve into PubMed for this detail.

Does anyone with a good immuno background know which one is actually expressed first (btw, I've caught plenty of errors in Utah's webpath, which is why I'm circumspect here).

Thanks a lot!

~Phloston

 

[MrBigglesworth]

I would suspect that P-selectin would be released first since histamine is what causes its release. (pre-formed and local)

Whereas E-selectin is released later because of TNF and Il-1 ?

Overall I don't think it matters. I haven't had a single question asking this, nor did it come up in immuno-class.

 

[JRjcu08]

P. 247 of FA2012 gives a list of the order in which different molecules participate in the induction of leukocyte extravasation.

P-selectin is listed under E-selectin.

In contrast, University of Utah Webpath says, "P-selectin is expressed rapidly, while E-selectin is expressed within several hours."

Wikipedia is non-specific. I also can't be bothered to delve into PubMed for this detail.

Does anyone with a good immuno background know which one is actually expressed first (btw, I've caught plenty of errors in Utah's webpath, which is why I'm circumspect here).

Thanks a lot!

~Phloston

I don't think FA was putting them in a particular order, just listing them as being involved.
P-selectin is released from the Weibel-Palade bodies, mediated by histamine.
E-selectin is induced by TNF and IL-1 from macrophages.

Since P selectin is stored I would say it is the first to appear because E selectin requires cytokines to induce its expression on the endothelial cells.

 

[JRjcu08]

I would suspect that P-selectin would be released first since histamine is what causes its release. (pre-formed and local)

Whereas E-selectin is released later because of TNF and Il-1 ?

Overall I don't think it matters. I haven't had a single question asking this, nor did it come up in immuno-class.

👍 what he said 👍

 

[Phloston]

I would suspect that P-selectin would be released first since histamine is what causes its release. (pre-formed and local)

Whereas E-selectin is released later because of TNF and Il-1 ?

That sounds right.

P-selectin is released from the Weibel-Palade bodies, mediated by histamine.
E-selectin is induced by TNF and IL-1 from macrophages.

Since P selectin is stored I would say it is the first to appear because E selectin requires cytokines to induce its expression on the endothelial cells.

I had completely forgotten about the Weibel-Palade bodies, but that makes a lot more sense now, given that P-selectin would quickly just be released from them.

Thanks a lot, guys.

 

[Morsetlis]

I believe my Immuno notes say the selectins slow down the leukocytes, the integrins form tight bonds, and then PECAM enables diapedesis. P-Selectin is definitely associated with Histamine, and E-Selectin with TNFa/IL-1.

http://www.ncbi.nlm.nih.gov/pubmed/8340753

"Thus, the process of leukocyte emigration can be dissected into three successive stages: rolling, mediated by the selectin class of adhesion molecules; tight adhesion, mediated by the leukocyte integrins and their endothelial cell counter-receptors; and now transmigration, which, based on these studies, requires PECAM-1."

 

[Phloston]

I believe my Immuno notes say the selectins slow down the leukocytes, the integrins form tight bonds, and then PECAM enables diapedesis. P-Selectin is definitely associated with Histamine, and E-Selectin with TNFa/IL-1.

Thanks again 🙂