Lysated CLL Cells Yield Proteins of Unknown Significance

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Hematol J. 2003;4(4):271-6.

A study of the proteins responsible for stimulating B-CLL-specific T-

cell responses by autologous dendritic cells pulsed with tumour cell

lysate.

Goddard R, Prentice A, Copplestone A, Kaminski E.

1Derriford Combined Laboratory, Derriford Hospital, Plymouth, UK.

We have previously shown that autologous dendritic cells (DCs) pulsed

with tumour cell lysate and cultured with autologous T cells from

patients with B-cell chronic lymphocytic leukaemia (B-CLL) stimulate

significant increases in proliferation, IFN-gamma secretion and

specific HLA class II-restricted cytotoxicity to B-CLL targets.

In this study, normal and tumour cell lysates were analysed by

reducing SDS-PAGE, and protein bands of interest eluted from the

polyacrylamide gel by electroelution. The eluted protein fractions

and whole-cell lysate were then pulsed onto autologous DCs and

cocultured with autologous T cells. Finally, the stimulatory

fractions were sequenced.

B-CLL cell lysates revealed protein bands at 65, 42, 35 and 25 kDa,

while normal B-cell lysates only showed a single protein band at 65

kDa. Both the 65 kDa band and 42 kDa bands were capable of

stimulating comparable amounts of IFN-gamma secretion and specific

cytotoxicity as whole lysate, while the other protein bands were not.

Sequencing of the 65 kDa fraction showed a dominant peptide that

matched human serum albumin, while sequencing the 42 kDa fraction

showed three dominant peptides which matched human actin and another

unidentified protein.

The significance of these findings remains unclear.

The Hematology Journal (2003) 4, 271-276. doi:10.1038/sj.thj.6200254

PMID: 12872152 [PubMed - in process]