IMMUNIZATION OF EXPERIMENTAL ANIMALS WITH A SOLUBLE ANTIGEN EXTRACTED FROM PNEUMOCOCCI

Immunization of Experimental Animals with a Soluble Antigen Extracted from Pneumococci

Pneumococci killed by acetic acid at pH 4.2, then allowed to become Gram-negative at pH 7.0, under conditions such that no cellular disintegration takes place, release in solution small amounts of a substance which is precipitable by acetic acid, and soluble at neutral reaction. This soluble fraction injected into rabbits by the intravenous route causes the production of antibodies which afford...

A Study of Pneumococci Isolated from Horses Undergoing Pneumococcus Immunization

IT HAS BEEN SHOWN THAT THE PNEUMOCOCCUS MULTIPLYING IN THE TISSUES OF THE IMMUNIZED ANIMAL (HORSE) BECOMES ATTENUATED: loses, in varying degrees, its virulence, capacity of capsule formation, susceptibility to phagocytosis, and type specificity. The antigenic activity as an immunizing agent and the production of "soluble specific substance" are also altered. In some instances, the typical pneum...

Preparation and characterization of a soluble precipitating antigen from African horsesickness virus propagated in cell cultures

Immunization against experimental murine salmonellosis with liposome-associated O-antigen.

Partially delipidated Salmonella typhimurium (O-1,4,5,12) lipopolysaccharide was incorporated into small multilamellar liposomes composed of either naturally occurring or synthetic phospholipids. Vaccination of mice with the liposome-lipopolysaccharide complexes induced a cellular response specific for O-1,4,5,12 determinants, as determined by the development of a delayed-type hypersensitivity ...

T Regulatory Cell Responses to Immunization with a Soluble Egg Antigen in Schistosoma mansoni-Infected Mice

The aim of the study is to characterize the phenotypes of CD4(+) CD25(+) T regulatory cells within the liver granulomas and association with both Foxp-3 gene expression and splenic cytokines. Naïve C57BL/6 mice were intravenously injected with multiple doses of the soluble egg antigen (SEA) 7 days before cercarial infection. The immunized and infected control groups were sacrificed 8 and 16 wee...