C-terminal mutations of CD20 constitute part of the mechanisms that resist rituximab therapy. Most CD20 having a C-terminal mutation was not recognized by L26 antibody. As the exact epitope of L26 has not been determined, expression and localization of mutated CD20 have not been completely elucidated. In this study, we revealed that the binding site of L26 monoclonal antibody is located in the ...

We have engineered an anti-CD20-interleukin 2 (IL-2) immunocytokine (ICK) based on the Leu16 anti-CD20 antibody and have deimmunized both the variable (V) regions as well as the junction between the heavy (H) chain constant region and IL-2. Mutations were made to remove potential T-cell epitopes identified by in silico binding to major histocompatibility complex (MHC) class II molecules. The re...

We investigated the impact of rhesus macaque (RM) B-cell depletion before inoculation with the isolate SIVsmmD215. Seven RMs were treated every 3 weeks with 50 mg/kg of an anti-CD20 antibody (rituximab) starting 7 days before inoculation for 2 (n = 4) and 5 (n = 3) months. Four control animals received no antibody. Three animals were completely depleted of CD20(+) B cells, but 4 were only parti...

The lower expression of CD20 antigen molecules on the B cell membrane is the primary characteristic of B-chronic lymphocytic leukemia (B-CLL). In this paper, we combined laser scanning confocal microscopy (LSCM) and quantum dots labeling to detect the expression and distribution of CD20 molecules on CD20+B lymphocyte surface. Simultaneously, we investigated the morphology and ultrastructure of ...

We examined the expression of CD20 in normal canine peripheral blood mononuclear cells, normal canine spleen, and canine non-Hodgkin lymphoma (NHL) to determine the feasibility of using this antigen as a diagnostic aid and as a possible target for therapy. An antibody generated against a C-terminal (intracytoplasmic) epitope of human CD20 recognized proteins of 32-36 kd in normal and malignant ...

The anti-CD20 antibody rituximab is useful in the treatment of certain B-cell malignancies, most notably non-Hodgkin's lymphoma. Its efficacy has been increased when used in combination with chemotherapy, yet anti-CD20 monoclonal antibodies (mAbs) directly conjugated with drugs such as doxorubicin (Dox) have failed to deliver drug or to demonstrate antitumor activity. We have produced anti-CD20...

CD20 is a B cell surface marker that is expressed in various stages in B lymphocytes and certain lymphomas. Clinical administration of CD20 antibody, such as rituximab, is used widely to treat human B-cell lymphomas and other diseases. However, CD20 antibody failed to treat systemic lupus erythematosus (SLE or lupus). The reason for the failure is currently unknown. Type I interferons (IFN) are...

Multiple sclerosis is a common leading cause of disability worldwide. CD20-expressing B cells play major role in multiple pathogenesis. Hence, anti-CD20 monoclonal antibodies effectively deplete mainly by complement-dependent cytotoxicity, antibody-dependent cell-mediated phagocytosis, and cellular cytotoxicity. While the precise etiology remains unknown, it now recognized that environment...

BACKGROUND CD20 monoclonal antibodies are widely used in clinical practice. Antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity and direct cell death have been suggested to be important effector functions for CD20 antibodies. However, their specific contributions to the in vivo mechanism of action of CD20 immunotherapy have not been well defined. DESIGN AND METHODS Her...

CD20 is a 33-kD B-cell antigen that is expressed from the early pre-B-cell stage of development and is lost on differentiation of B cells into plasma cells. Because CD20 is expressed strictly by B cells, it is an attractive target for B-cell lymphoma therapy. Monoclonal antibodies to CD20 have been used successfully in the treatment of B-cell lymphomas. We hypothesized that a vaccine consisting...