Fig. 4.

Western blot identification of MBP epitopes expressed by two non-neural cells using 1H6.2 MoAb. The reactivity of 1H6.2 MoAb against total cell lysates from Raji and CFPAC-1 cells is compared with that observed for 1H6.2 reacting against human brain white matter tissue extracts (hBWM). As a control, reactivity of 1H6.2 against total cell lysates of erythrocytes is also shown. Lane a, control anti-MBP MoAb (Serotec) recognizing the 84-89 MBP epitope; lane b, 1H6.2 MoAb; lane c, secondary anti-mouse IgM MoAb (Amersham, Aylesbury, UK). MBP has a reduced electrophoretic mobility due to its positive charge and runs at approximately the 21 kD level under these experimental conditions [24,25]. Bands at approximately 30 kD or at higher molecular weights are also stained by 1H6.2 and by anti-MBP MoAbs. These proteins might correspond to multimers of MBP and/or MBP epitopes.