The pan-B and B cell-specific sIg and CD19 antigens are functionally and physically associated in the presence of anti-Ig mAb. Incubation of B cells with anti-Ig antibodies causes rapid, specific, reversible, concentration-dependent, and unidirectional comodulation of CD19 on every mature B cell studied. Comodulation is produced by mAbs specific for the gamma, mu, kappa, and lambda chains of Ig...

Immunoglobulin (Ig) class switching is a process by which B lymphocytes shift from production of IgM to other Ig classes and subclasses via Ig class switch recombination (CSR). Multiple cellular and molecular processes are involved in CSR. Induction of a given IgH germline transcription initiates CSR processes. Ig germline transcription is selectively activated and induced by specific cytokine(...

The study of the free idempotent generated semigroup IG(E) over a biordered set E began with the seminal work of Nambooripad in the 1970s and has seen a recent revival with a number of new approaches, both geometric and combinatorial. Here we continue the study of the free idempotent generated semigroup IG(E) over the biordered set E of a wreath product G ≀ Tn. The latter monoid is isomorphic t...

The inducible costimulator protein (ICOS) was recently identified as a costimulatory molecule for T cells. Here we analyze the role of ICOS for the acquired immune response of mice against the intracellular bacterium Listeria monocytogenes. During oral L. monocytogenes infection, low levels of ICOS expression were detected by extracellular and intracellular Ab staining of Listeria-specific CD4(...

The effect of specific immunoglobulin (Ig) on specific binding of antigen to cells has been studied in a model system consisting of nurine myeloma cells (MOPC 315), MOPC 315 serum, and DNP conjugates. MOPC 315 serum, which has IgA specific for DNP, specifically inhibited the binding of DNP conjugates to these cells. Using this model it was found that cells have a marked advantage over free spec...

The study of the free idempotent generated semigroup IG(E) over a biordered set E began with the seminal work of Nambooripad in the 1970s and has seen a recent revival with a number of new approaches, both geometric and combinatorial. Here we study IG(E) in the case E is the biordered set of a wreath product G ≀ Tn, where G is a group and Tn is the full transformation monoid on n elements. This...

S e e in g t h e B ig P ic t u r e (w it h a S m a ll D e v ic e)

Understanding the regulation of cell surface expression of specific peptide-major histocompatibility complex (MHC) complexes is hindered by the lack of direct quantitative analyses of specific peptide-MHC complexes. We have developed a direct quantitative biochemical approach by engineering soluble divalent T cell receptor analogues (TCR-Ig) that have high affinity for their cognate peptide-MHC...

It has becom e increasingly apparen t that B lymphomas provide clonal models for antigen-specific lymphocytes and for the analysis o f both positive and negative signalling in B cells. In addit ion, ant i Ig reagents have been used to mimic an t igen / to le rogen in their interact ion with B cell receptors at a polyclonal level (1-3). We have been studying the effects o f ant i-Ig on a g roup ...