The bovine leukemia virus (BLV) is an oncogenic retrovirus that is associated with the development of persistent lymphocytosis (PL) and lymphoma in cattle. While B lymphocytes have been shown to be the primary cellular target of BLV, recent studies suggest that some T lymphocytes and monocytes may be infected by the virus. Because virally altered functions of monocytes and/or T cells could cont...

IL-10-competent subset within CD1d(hi)CD5(+) B cells, also known as B10 cells, has been shown to regulate autoimmune diseases. Whether B10 cells can prevent or suppress the development of experimental autoimmune myasthenia gravis (EAMG) has not been studied. In this study, we investigated whether low-dose GM-CSF, which suppresses EAMG, can expand B10 cells in vivo, and whether adoptive transfer...

Human B lymphocytes expressing the CD5 surface antigen (CD5+ B cells) constitute a subset capable of producing polyspecific antibodies recognizing a variety of selfantigens . The repertoire of antibodies produced by CD5+ and CD5 B cells is different . However, it is not yet established whether this distribution is reflected in different immunoglobulin variable region gene (IgV) use. Rearrangeme...

The function of thymic B cells in several standard in vitro assays was investigated. Thymic B cells, 75% of which were CD5+, showed a poor responsiveness to the mitogens LPS or anti-mu plus IL-4. Both proliferation and antibody formation were much lower in thymic than splenic B cell cultures. However, CD5- B cells purified using a cell sorter responded well to B cell stimulants, whereas purifie...

Previous studies in our laboratory suggested that there was positive selection of B cells during early development in the appendix of normal and V(H) mutant (ali/ali) rabbits. Preferential expansion and survival of B lymphocytes was affected by the Ig V(H) frameworks 1 and 3 sequences expressed on the cell surface. We demonstrated a specific interaction between rabbit CD5 and the V region of ra...

The cellular origin of chronic lymphocytic leukemia (CLL) is still debated, although this information is critical to understanding its pathogenesis. Transcriptome analyses of CLL and the main normal B cell subsets from human blood and spleen revealed that immunoglobulin variable region (IgV) gene unmutated CLL derives from unmutated mature CD5(+) B cells and mutated CLL derives from a distinct,...

Hepatitis C virus (HCV) infection is associated with immune-mediated abnormalities and B-cell lymphoproliferation. Recently, CD81 was identified as an HCV receptor on B lymphocytes, providing a mechanism by which B cells are infected and activated by the virus. It has recently been shown that peripheral B-cell CD81 overexpression and CD5(+) subpopulation expansion correlate with HCV viral load ...

De novo CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) is a highly aggressive subtype of DLBCL with a high incidence of misdiagnosis when spinal cord compression is the initial symptom. We report a case of a 45-year old man with de novo CD5+ DLBCL primarily presenting as spinal cord compression. Unfortunately, this patient was resistant to rituximab-based therapy, which indicated a p...

CD5-expressing B lymphocytes from patients with selected chronic lymphoproliferative disorders were used to determine whether monoclonal populations of CD5+ human B cells produce autoantibodies. CD5+ B cells from 19 patients with chronic lymphocytic leukemia (CLL) and one with diffuse well-differentiated lymphocytic lymphoma (DWDL) were cultured, with and without mitogenic stimulation, to obtai...

Recent studies have demonstrated that mature natural killer (NK) cells can be grown from human triple negative (TN; CD3-, CD4-, CD8-) thymocytes, suggesting that a common NK/T cell precursor exists within the thymus that can give rise to both NK cells and T cells under appropriate conditions. In the present study, we have investigated human fetal and postnatal thymus to determine whether NK cel...