Expression of CD23 receptors on b chronic lymphocytic leukaemia cells

Autor: B.W. Ozanne, A. Doig, Gillian Borland, N. Lucie, Johanne Matheson, William Cushley, B. Kyle
Rok vydání: 2000
Předmět:
Zdroj: Experimental Hematology. 28:75
ISSN: 0301-472X
DOI: 10.1016/s0301-472x(00)00323-4
Popis: CD23, the low affinity receptor for IgE (FcϵRII), is a 45kDa cell surface glycoprotein which is proteolytically cleaved to form a range of soluble CD23 species (sCD23), which have cytokine-like activities and act via a number of cell surface receptors. The currently defined receptors are CD11b–CD18, CD11c–CD18, CD21 and the αvβ3 and αvβ5 vitronectin receptor isoforms. Elevated levels of serum sCD23 are often noted in B-CLL, with very high levels correlating with a poor prognosis, suggesting that sCD23 may play a role in B-CLL disease progression, possibly by inhibiting apoptosis. To address this hypothesis, we have determined patterns of expression of CD23 and its receptors on CLL B cells and normal B cells. FACS analysis showed low levels of expression of CD23 on normal, resting B cells, and consistently higher levels on CLL B cells. CD21 was present at low levels on both normal and CLL B cells, and CD11c was found on a proportion of B-CLL samples. No significant expression of CD11b, αvβ3 or αvβ5 was detected. Mild acid washing of the cells did not increase detection of CD23 receptors, indicating that the receptors were not masked by binding of CD23 or other ligand. The receptor expression patterns found by FACS analysis were reflected by RT-PCR of receptor transcripts. These results indicate that any possible effect of sCD23 in B-CLL is unlikely to be mediated via any of the known CD23 receptors with the exception of CD21. This does not, however, rule out the involvement of other, as yet unidentified receptors in B-CLL development.
Databáze: OpenAIRE
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