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Biomedical subjects

G Shu

Publications and source records attributed to G Shu.

25 records · Page 2Linked to original sources
PubMed1987

Activation of human B cell proliferation through surface Bp35 (CD20) polypeptides or immunoglobulin receptors.

Human B cells can be activated with monoclonal antibodies (mAb) to surface IgM receptors or mAb to a 35-kilodalton B cell differentiation antigen, Bp35 (CD20). We compared anti-Ig-induced B cell activation with B cell triggering by anti-Bp35. Both anti-Ig- and anti-Bp35-dependent proliferation were augmented by the same co-stimulants, including a partially purified BCGF, recombinant IL 1, TPA, or each other. When anti-Bp35 and anti-Ig were used together to induce proliferation of tonsillar B cells, the strongest response was observed when anti-Bp35 was added 12 to 24 hr before anti-Ig. Anti-Bp35 also was found to act most effectively when added before the BCGF. Blood and tonsillar B cells differed in their proliferative response to anti-Ig or anti-Bp35: unlike dense tonsillar B cells, which consistently proliferated in response to either stimulus, blood B cells from many donors proliferated in response to anti-Ig but not to anti-Bp35 even in the presence of other co-stimuli. Dense tonsillar B cells that proliferate in response to anti-Bp35 appeared to be at a more activated stage than unresponsive blood B cells because they expressed higher levels of HLA class II molecules than blood B cells. Pretreatment of blood B cells with anti-Bp35 converted them to an HLA-DR(bri) phenotype and made them more responsive to anti-Ig-induced proliferation. These results suggest that B cells at different stages of differentiation differ in their response to anti-Bp35 and anti-Ig. The Bp35 surface polypeptide may play an early role in the activation of B cells prior to antigen or other signals.

Antibodies↗
PubMed1987

Augmentation of normal and malignant B cell proliferation by monoclonal antibody to the B cell-specific antigen BP50 (CDW40).

We recently described a 50,000 dalton polypeptide Bp50 (CDw40) that is expressed on human B cells and plays a role in regulating B cell proliferation. Here we additionally characterize the functional signal given by antibody binding to Bp50 on both normal and malignant B cells. A monoclonal anti-Bp50 antibody could augment the proliferation of B cells activated by anti-IgM, anti-CD20, or 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulation, but was not co-stimulatory with B cell growth factor (BCGF), interleukin 1, or interleukin 2. The signal did not depend on the Fc portion of the antibody, because F(ab')2 fragments of anti-Bp50 were still functionally active. Both anti-Bp50 and a low m.w. BCGF preparation were similar in that both were co-stimulatory with the same agents and both anti-Bp50 and BCGF affected activated B cells but not resting B cells. However, a panel of B cell malignancies differed in their responsiveness to anti-Bp50 vs BCGF: some tumors proliferated in response to anti-Bp50 but not BCGF, whereas other tumors had the opposite pattern. Bp50 was found to have several properties in common with HLA class II molecules: both Bp50 and class II were expressed at lower levels on blood B cells than on tonsillar B cells; the expression of both Bp50 and class II was increased after activation of blood B cells with TPA or anti-IgM; and the expression of both Bp50 and class II was increased after activation of non T, non-B acute leukemias with BCGF. Thus class II and Bp50 expression may be under common regulatory control. The fact that BCGF modulated the expression of Bp50 on leukemic cells suggests that BCGF and Bp50-mediated signals may be coordinately regulated.

Animals↗
PubMed1986

Polypeptides on human B lymphocytes associated with cell activation.

Two monoclonal antibodies (MoAbs), designated BB-1 and LB-2, react with distinct polypeptides expressed on activated human B cells. The BB-1 MoAb reacted with a 37,000-dalton polypeptide (Bp37) restricted to pre-B and B-cell blasts and B-cell malignancies. The LB-2 MoAb reacted with a 76,000-dalton polypeptide (p76) found on resting B cells but at higher levels on activated B cells and T cells. Buoyant tonsillar lymphoid cells with a germinal center phenotype express higher levels of Bp37 and p76 than do dense B cells of the mantle zone. Furthermore, the expression of Bp37 and p76 on tonsillar B-cell subsets was distinct from other B-cell antigens such as Bp39, Bp95, Bp135, the C3d receptor and surface IgM. Based on biochemical, cross-blocking, and tissue distribution analyses, these antigens appear to be distinct from previously described B cell and B-cell-blast markers.

Animals↗
PubMed1985

Role of the Bp35 cell surface polypeptide in human B-cell activation.

A 35-kDa polypeptide, Bp35, expressed on the surface of all B cells, plays a role in B-cell activation. Monoclonal antibodies to Bp35 stimulate human tonsillar B cells to proliferate. The activation induced by anti-Bp35 is similar to anti-Ig-mediated in several ways: the activation does not require T cells but is augmented by T-cell-derived allogeneic factors; monovalent Fab fragments to Bp35 do not trigger proliferation but instead block activation by whole antibody, indicating that cross-linking is required; and induction by anti-Bp35, like the induction by anti-Ig, is inhibited by monoclonal anti-IgM via an Fc domain-dependent mechanism. However, several features of anti-Bp35-mediated proliferation are clearly different from activation by anti-Ig: anti-Bp35 monoclonal antibodies do not require attachment to beads to function, the proliferation induced by anti-Bp35 and anti-Ig is additive, and Fab fragments of anti-Bp35 augment proliferation induced by anti-Ig. Models for the possible function of the Bp35 polypeptide as either a "bridge" or a "second signal" with surface Ig in B-cell activation are discussed.

Antibodies, Anti-Idiotypic↗
PubMedDate not supplied

The ability of disease modifying antirheumatic drugs to induce and maintain improvement in patients with rheumatoid arthritis. epidemiology of DMARDs treatment in Japan.

OBJECTIVE: The effectiveness of the disease-modifying antirheumatic drugs (DMARDs) methotrexate (MTX), bucillamine (BUC), salazosulphapyridine (SASP) and gold sodium thiomalate (GST) over two courses of treatment with a follow-up period of at least 12 months was evaluated in 425 patients with rheumatoid arthritis. METHODS: Clinical efficacy was evaluated on the basis of the numbers of painful and swollen joints, morning stiffness, grip strength, erythrocyte sedimentation rate, C-reactive protein and rheumatoid factor levels before and after treatment. Results were evaluated on the basis of the survival rate (Kaplan-Meier method) and the incidence and types of adverse drug reactions (ADR) following single and combined therapies. RESULTS: In the first course of treatment, the survival rates for MTX, GST, BUC and SASP were 52.3%, 40.4%, 33.0% and 24.8%, respectively. The rates of development of ADR were 22.9%, 23.5%, 26.3% and 30.0% for BUC, SASP, GST and MTX, respectively. In the second course, the survival rates for MTX, BUC and SASP were 36.6%, 14.1% and 10%, respectively. CONCLUSION: DMARDs used in the first course of treatment improved the clinical parameters until the 6th month after initiation of treatment. Combination treatments showed some effectiveness, but because of the high incidence of ADR the survival rate was low. DMARDs used in the second course of treatment were not efficacious and there was no improvement in the survival rate compared to the first course of treatment.

Adolescent↗