Following the binding of B cell receptors (BCR) to cognate antigens exposed on presenting cells, B cells rapidly spread over antigen-containing surface. During B cell spreading, antigen-BCR microclusters are continually assembled at the periphery of the contact area between the cells. The initial spreading response is followed by a contraction phase, which results in the accumulation of antigen...

Antigen-specific B cells are implicated as antigen-presenting cells in memory and tolerance responses because they capture antigens efficiently and localize to T cell zones after antigen capture. It has not been possible, however, to visualize the effect of specific B cells on specific CD4+ helper T cells under physiological conditions. We demonstrate here that rare T cells are activated in viv...

B cells are capable of mounting responses to a bewildering range of potentially pathogenic antigens through the production of high-affinity antibodies and the establishment of immunological memory. Thus, regulated B-cell activation is critical for protection against a variety of bacterial and viral infections, as well as cancers. Here, we discuss a number of recent imaging studies that have pro...

exposure (Prince, Hargrove, Szmuness, Cherubin, Fontana, and Jeffries, 1970; Papaevangelou, Kourea, and Tsoukas, 1971; Fulford, Dane, Catterall, Woof, and Denning, 1973). A high frequency of HB Ag-positive hepatitis cases was also found among homosexuals (Vahrman, 1973) and evidence has been presented that hepatitis B may spread between sexual partners (Hersh, Melnick, Goyal, and Hollinger, 197...

in the recent issue of middle east journal of digestive diseases, we read with great interest the article by bahari et al. 1 , “significance of response to hepatitits b vaccine in subjects with isolated antibody to hepatitis b core antigen”. we wanted to specify some important matters related to the article.