B cell follicular

CD21 130 (soluble), 145 (membrane-bound) B cells, follicular dendritic cells Receptors for various antigens. Involved in signal transduction... 

CD23 45 B cells, follicular dendritic cells, monocytes IgE synthesis regulation, induction of inflammatory cytokines... 

CD19 B-cell lymphoma/ AML (MO), blast phase B-cells, follicular... 

CD35 C3b receptor CD36 Known to be z macrophage thrombospondin receptor CD40 Present on B cells and follicular dendritic cells CD41 Known to be z platelet glycoprotein... 

Breitfeld D, Ohl L, Kremmer E, et al. Follicular B helper T cells express CXC chemokine receptor 5, localize to B cell follicles, and support immunoglobulin production. J Exp Med 2000 192 1545-1552. 

Schaerli P, Willimann K, Lang AB, Lipp M, Loetscher P, Moser B. CXC chemokine receptor 5 expression defines follicular homing T cells with B cell helper function. J Exp Med 2000 192 1553-1562. 

Hardtke S, Ohl L, Forster R. Balanced expression of CXCR5 and CCR7 on follicular T helper cells determines their transient positioning to lymph node follicles and is essential for efficient B-cell help. Blood 2005 106 1924-1931. 

Rituxan Rituximab Genentech Treatment of relapsed or refractory low-grade or follicular CD20-positive B-cell non-Hodgkins lymphoma... 

Rituximab, a chimeric monoclonal antibody directed at the CD20 molecule on B cells, has become one of the most widely used therapies for follicular lymphoma. Rituximab is approved for first-line therapy either alone or combined with chemotherapy and as maintenance therapy for patients with stable disease or with partial or complete response following induction chemotherapy. 

As compared to DCs, B cells are very poor APCs and play a major role as source for antibodies. Upon stimulation by antigens and in the presence of T cells at the border of the T-cell-B-cell area, adjacent to follicles, B cells become antibody-secreting cells and eventually form a germinal center (GC) response. GCs are specialized follicles for B-cell expansion, somatic hypermutation, and class switch recombination, processes that are regulated by T cells, follicular DCs, and other cells. In this process of B-cell maturation, Tregs seem to play a critical role, as in several immune diseases, which are characterized by aberrant antibody... 

M8. McDonnell, T. J., Deane, N., Platt, E M., Ntmez, G., Jaeger, U., McKeam, J. P., and Korsmeyer, S. J., bcl-2-inununoglobulin transgenic mice demonstrate extended B cell survival and follicular lymphoproUferation Cell 57, 79—88 (1989). 

MM = multiple myeloma ATL = adult T-cell leukemia ALL = acute lymphoblastic leukemia CLL = chronic lymphocytic leukemia FCC = follicular center cell lymphoma DLC = diffuse large cell lymphoma TRB = T-cell rich B-cell lymphoma ALCL = anaplastic large cell lymphoma MALT = mucosa-associated lymphoid tissue-type lymphoma LC = lung cancer CMM = cutaneous malignant melanoma TCC = transitional cell carcinoma CSCC = cutaneous squamous cell carcinoma. 

B. Indications and use Rituxan is the first FDA-approved monoclonal antibody for the treatment of cancer. Several clinical trials have demonstrated efficacy of this chimeric antibody against NHL. Rituxan is indicated for the treatment of patients with relapsed or refractory low-grade or follicular B-cell non-Hodgkin s lymphoma (indolent lymphoma). 

E Role in therapy Rituxan is recommended for low-grade or follicular B-cell lymphoma in patients relapsing after or refractory to conventional chemotherapy. Complete responses are infrequent but partial responses appear durable. 

Treatment of patients with relapsed or refractory low-grade, follicular, or transformed B-cell non-FIodgkin s lymphoma, including patients with Rituximab (Rituxan) refractory follicular non-Flodgkin s lymphoma. The therapeutic regimen includes Rituximab, Indium-111 Ibritumomab Tiuxetan, and Yttrium-90 Ibritumomab Tiuxetan... 

A major breakthrough in the treatment of lymphoid malignancies was the discovery of monoclonal antibody activity, especially that of rituximab. Rituximab was the first monoclonal antibody approved by the U.S., FDA for the treatment of relapsed follicular lymphoma (1), and it has now been extensively used for the treatment of various lymphoid neoplasm which express CD20 antigen. Its efficacy has been also demonstrated against diffuse large B-cell lymphoma when administered as a combination regimen such as rituximab plus CHOP (R-CHOP) chemotherapy (2). 

This chapter reviews our current understanding of the mechanism of action of monoclonal antibody (especially rituximab), as well as the role of Fey receptor and Fey receptor gene polymorphisms, and their impact on treatment outcomes in hematologic malignancies including follicular lymphoma (FL), diffuse large B-cell lymphoma (DL-BCL), Waldenstrom s macroglobulinemia (WM), and chronic lymphocytic leukemia (CLL). 

CD40 48 monomer B lineage cells, follicular dendritic cells, endothelial cells, macrophages B-ceh growth, differentiation, isotype switching. Induction of cytokine release and adhesion molecules... 

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