B-cell stimulation by T-cell-secreted proteoglycan

D Levitt1, L Olmstead

  • 1Guthrie Research Institute, Sayre, Pennsylvania 18840-1692.

Cellular Immunology
|December 1, 1987
PubMed

We have further characterized a recently described B-cell stimulatory factor that contains chondroitin sulfate proteoglycan and 70- to 75-kDa protein, both of which are secreted by T cells and coisolate (T-cell proteoglycan fraction, T-PGF). Using T-PGF isolated from a T-cell hybridoma (T14), it was observed that the association between B-cell stimulatory activity and CSPG is stable and comigrates on Sephacryl S-200 columns eluted at high salt concentrations (1.5 M NaCl) and on CsCl gradients. The T-PGF stimulated larger numbers of low-density (activated) B cells, but better relative PFC formation occurred in high-density (resting) B-cell fractions. It is proposed that the B-cell stimulatory activity of T-PGF is, in fact, chondroitin sulfate proteoglycan.

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