There is a growing trend to use antibodies coupled to insoluble support materials to facilitate the separation of antigen-antibody complexes from antigen in radioimmunoassay (RIA) procedures. Materials most widely employed are polymers, such as polystyrene and agarose. Usually a suspension of fine beads is used. Alternatively, antibodies may be attached to the walls of the polystyrene tubes in ...

Probiotic bacteria, including Lactobacillus acidophilus and Bifidobacterium bifidum, have been shown to enhance antibody responses in mammals. The objective of this study was to examine the effects of a probiotic product containing the above bacteria in addition to Streptococcus faecalis on the induction of the chicken antibody response to various antigens, both systemically and in the gut. The...

Feedback regulation of the primary humoral immune response to sheep erythrocytes (SRBC) was studied in vitro. Whole spleen cells or spleen cell subpopulations were incubated with antigen for 4 d under Mishell-Dutton conditions (education) and the surviving cells tested for regulatory activity in fresh anti-SRBC spleen cell cultures assayed by measuring plaque-forming cells on day 4. The data in...

An explanation was sought for the fact that delayed-type hypersensitivity (DTH) does not normally occur in response to T-cell-dependent antigens unless an adjuvant is used. But when sheep red blood cells (SRBC) were administered intravenously DTH did appear, provided that the dose of antigen was less than that required to give a maximum antibody response. Animals in which T-cell activity had be...

Spleen cells educated in vitro with sheep red blood cells (SRBC) suppressed the plaque-forming cell response of Mishell-Dutton assay cultures challenged with optimal doses of SRBC. Changing conditions in the assay cultures changed the effect educated cells had on the assay culture responses. For example, educated cells helped rather than suppressed assay cultures of suboptimal numbers of spleen...

Thoracic duct cells and spleen cells were tested for their ability to restore the primary antibody response of X-irradiated rats to bovine serum albumin (BSA), sheep red blood cells (SRBC), horse spleen femtin (HSF), and Salmonella typhi flagella. Spleen cells were at least as efficient as thoracic duct cells in restoring the response to BSA, HSF, and Salmonella typhi flagella. In further exper...

Anti-D can prevent immunization to the RhD Ag on RBCs, a phenomenon commonly termed Ab-mediated immune suppression (AMIS). The most accepted theory to explain this effect has been the rapid clearance of RBCs. In mouse models using SRBC, these xenogeneic cells are always rapidly cleared even without Ab, and involvement of epitope masking of the SRBC Ags by the AMIS-inducing Ab (anti-SRBC) has be...

By using the two criteria (a) high density of immunoglobulin determinants on the cell surface and (b) presence of receptors for C'3 on the cell surface for defining bone marrow-derived lymphocytes, it is indirectly shown that all or at least a major population of human thymus-derived lymphocytes under certain conditions will form nonimmune rosettes with sheep red blood cells (SRBC). Almost all ...

The functional role of the T cell (Tv) which can replicate vesicular stomatitis virus (VSV) on activation by the antigen was investigated in antibody response in vitro. By the inoculation of VSV into the culture, marked augmentation of antibody response to sheep erythrocytes (SRBC) was observed in the culture of spleen cells taken more than 3 days after the immunization with SRBC, suggesting th...

The IgM and IgG response of mice to sheep erythrocytes (SRBC) and bluetongue virus (BTV) was determined by means of haemolytic plaque assays. Maximum primary IgM response to SRBC occurred after 4 days but declined rapidly to 4% of the maximum by Day 9. A lag period of about 2 days was observed in the appearance of IgG haemolytic plaque-forming cells (PFC) but they reached a maximum after 6-9 da...