Immune response deficiency of BSVS mice. II. Generalized deficiency to thymus‐dependent antigens

Abstract

BSVS mice gave abnormally low IgG responses to 5 thymus-dependent antigens as well as a weak delayed-type hypersensitivity (DTH) response to sheep red blood cells. In contrast to IgG, the IgM antibody responses of these mice were normal to three T-independent antigens as well as to all five T-dependent antigens. The low immune responsiveness of BSVS mice was also reflected in the low levels of IgG(2)a, IgG(2)b and IgG(3) in their normal serum. The low T-dependent immune responses may result from BSVS mice having been selectively bred for susceptibility to infection with St. Louis encephalitis virus and Salmonella. C57BL/6J mice, which are also highly susceptible to Salmonella, gave low immune responses similar to, but genetically distinct from, those of BSVS mice. The levels of Ig-positive and theta-positive cells were normal in BSVS and C57BL/6J mice.

Protection of mice from infection with Streptococcus pneumoniae by anti-phosphocholine antibody

“…Anti-type 3 antibodies (IgM, CA3-1; IgG3, 16.3) (14) obtained from K. Schroer (National Cancer Institute, Bethesda, Md.) and anti-Salmonella antibody (IgM, ST-1) (3a) were used as diluted ascites fluid and quantitated by isotype-specific radioimmunoassays (5).…”

Antiphosphocholine antibodies found in normal mouse serum are protective against intravenous infection with type 3 streptococcus pneumoniae.

“…The amount of antibody in these fluids was estimated by determining the total levels of IgM (30) in the ascites fluids. The concentrations of antibody in these ascites fluids ranged from 5-20 mg/ml.…”

PspA Family Fusion Proteins Delivered by AttenuatedSalmonella entericaSerovar Typhimurium Extend and Enhance Protection againstStreptococcus pneumoniae

“…It causes respiratory infections, otitis media, sinusitis, and invasive diseases such as pneumonia, meningitis, and bacteremia. S. pneumoniae causes more than 1 million deaths worldwide every year among children under 5 years of age (8,11,20). The current 23-valent capsular polysaccharide vaccine elicits immunity in individuals greater than 2 years of age, and the current conjugate polysaccharide-protein pneumococcal vaccine provides protection for those under the age of 2 years (23,26,33).…”