Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Jun 24;18(12):R521-4.
doi: 10.1016/j.cub.2008.04.058.

Phagocytic signaling: you can touch, but you can't eat

Jason M Kinchen  1 , Kodi S Ravichandran
Affiliations

Phagocytic signaling: you can touch, but you can't eat

Jason M Kinchen et al. Curr Biol. .

Abstract

The ability of phagocytes to discriminate between viable/healthy and apoptotic/foreign/abnormal cells is of fundamental importance; a recent study provides new molecular insights into the function of CD47-SIRP alpha signaling in this discrimination.

PubMed Disclaimer

Figures

Figure 1
Figure 1. CD47/SIRPÎ block internalization of viable cells
Recognition of the apoptotic cells, either through exposed phosphatidylserine (PtdSer) or other opsonins results in the activation of the Rac GTPase, extension of lamellipodia around the target, and ultimately internalization. CD47/SIRPÎ is down-modulated during apoptosis, and inhibits the inappropriate internalization of viable cells.
See this image and copyright information in PMC

References

    1. Ravichandran KS, Lorenz U. Engulfment of apoptotic cells: signals for a good meal. Nat Rev Immunol. 2007;7:964–974. - PubMed
    1. Gardai SJ, McPhillips KA, Frasch SC, Janssen WJ, Starefeldt A, Murphy-Ullrich JE, Bratton DL, Oldenborg PA, Michalak M, Henson PM. Cell-surface calreticulin initiates clearance of viable or apoptotic cells through trans-activation of LRP on the phagocyte. Cell. 2005;123:321–334. - PubMed
    1. van Beek EM, Cochrane F, Barclay AN, van den Berg TK. Signal regulatory proteins in the immune system. J Immunol. 2005;175:7781–7787. - PubMed
    1. Brown S, Heinisch I, Ross E, Shaw K, Buckley CD, Savill J. Apoptosis disables CD31-mediated cell detachment from phagocytes promoting binding and engulfment. Nature. 2002;418:200–203. - PubMed
    1. Kinchen JM, Ravichandran KS. Journey to the grave: signaling events regulating removal of apoptotic cells. J Cell Sci. 2007;120:2143–2149. - PubMed