7.3-01 Dialysable suppressive factor related to E-receptors(CD2)

67

Abstracts

7.2-07

ALTERED LYMPHOCYTE PHENOTYPE FREQUENCY PATTERNS IN HUMANS EXPOSED TO HALOGENATED AROMATIC HYDROCARBONS. P.R. McConnachie and A.C. Zahalsky, Immunotransplant Laboratory, Memorial Medical Center, Springfield, Il., and Immunox Research, Edwardsville, Il. Lymphocyte phenotype frequencies for 17 antigens of five major clusters were studied in three groups of subjects exposed respectively to polychlorinated biphenyls (PCB, n=12), chlordane/heptachlor (CHL, n=12) or pentachlorophenol (PCP, n=ll). Exposures were in the home environment. The tests were performed in Springfield, Il., on shipped blood samples drawn at various locations in the U.S.A. A reference range was developed for the same phenotype frequencies using blood samples from 56 normal control individuals, some local to Springfield and others shipped from out of state. All samples were tested within 16-20 hours of venipuncture. There were significant differences between the control and test group phenotype frequencies in all of the Additionally, there were significant differences antigen clusters. between the three test groups defining patterns of phenotype abnormalities specific to each toxin. The most striking differences were increased frequencies of CD1,2,3,4, and 10 and decreased CD16 and 56 in the PCB group, increased CD14,16 and 24 frequencies in the CHL group and; increased CD1,16,56 and lambda light chains and decreased CD24 frequencies in the PCP group. That these abnormal patterns were detected up to eight years after exposure strongly suggests long term presistance of the toxic effects of halogenated aromatic hydrocarbons both in bone marrow and peripheral lymphocyte compartments.

7.3-01

DIALYSABLE SUPPRESSIVE FACTOR RELATE:, TO E-RECEP'JORS(CD2). CC Musatti, FV Fonseca, IIB Nader and MG DeLina,Escola Paulista de Medicina, Sao Paulo, Brazil. . Early data showed that human serum dialysate(HSD) had an inhibitory effect upon T cell proliferation.This inhibition was abolished by absorption with E or by passing MSD across a column sensitized with an anti-E-receptor serum. In the present study such dialysable suppressive factor related to C-receptor (dSER) has been partially characterized. . HSD fractionated on Sephadex was tested for inhibition

upon lymphocyte proliferation and E-rosetting. The dSER activity was in a fraction of apparent size less than 3kDa. . dSER appears to act on T cell activation mainly in the phase of interaction of IL2 to IL2 receptors(IL2-R). A kinetic analysis indicated, however, that dSER interferes with T lymphoblast proliferation induced by IL2 without directly competing with IL2 for binding to IL2-R. . Lymphocyte incubation with dSER inhibited E-resetting similarly to anti-CD2 monoclonal antibodies.Differe:ltly from anti-CD2,incubation of dSER with E,instead of lymphocytes,also affected E-rosettes.Interestingly,simultaneous incubation df T cells with dSER and anti-CD2 reverted t.he inhibitory effect observed with each alone. These results

further

emphasized

the

relationship

between

dSER and CD2.