Regulation of interferon receptor expression in XXXX blood lymphocytes in vitro and during interferon therapy.

@entity1 @entity778 @entity981 @entity4316 @entity4020
Interferons (IFN) elicit antiviral and antineoplastic activities by binding to specific receptors on the cell surface. The binding characteristics of IFN to @entity1 lymphocytes were studied using @entity4020 labeled with 125I to high specific activity. The specific binding curves generated were analyzed by the LIGAND program of Munson and Rodbard to determine receptor numbers. The number of receptors in peripheral blood lymphocytes (PBL) and tonsillar B-lymphocytes (TBL) from normal individuals were 505 +/- 293 (n = 10) and 393 +/- 147 (n = 3) respectively. When these cells were preincubated in vitro with unlabeled @entity4020 , the receptor number decreased to 82 +/- 45 and 61 +/- 16 respectively. Receptor binding activities recovered gradually over a period of 72 h when the cells were incubated in IFN-free medium. This recovery of receptors could be blocked by the addition of @entity4316 to the incubation medium. A similar decrease in receptor expression was observed in vivo in PBL from @entity1 being treated daily with 5 X 10(6) units/m2 per d of @entity4020 by subcutaneous injection, for @entity981 or @entity778 . Receptor numbers in PBL in vivo were further reduced concurrent with the progression of IFN therapy. Thus the reduction in IFN receptor expression observed in vitro can be demonstrated in vivo. These studies indicate that monitoring IFN receptor expression in vivo can provide information regarding the availability of IFN receptors at the cell surface for the mediation of IFN actions during the course of IFN therapy.
