Antigenic modification, rosette-forming cells, and Salmonella typhimurium resistance in outbred and inbred mice

A report of an outbreak of Salmonella oranienburg in a hybrid mouse colony

Mice in a hybrid breeding colony developed symptoms compatible with a diagnosis of salmonellosis. Salmonella oranienburg was recovered from feces by conventional bacteriological techniques. Active salmonellosis appeared to be precipitated by the stress of pregnancy among breeder female BALB/c mice. Necropsy examination of the BALB/c breeder females revealed diarrhea, roughened hair coats, enlarged spleens, white foci in the liver, and skin abscesses. S. oranienburg was recovered from the spleen, cecum, oropharynx, uterus, and skin abscesses of affected mice. DBA/2N breeder males were asymptomatic and S. oranienburg was recovered from the cecum only. Breeding productivity indices dropped to unacceptable levels in rooms containing infected animals. Relatively normal production was observed among uninfected animals of the same strains in adjacent rooms, thus demonstrating the detrimental effect S. oranienburg had on this breeder colony.

In vitro effect of murine-derived transfer factor on Salmonella-specific rosette formation

The splenic lymphocytes from Salmonella-immune ICR Swiss or C3H/HeJ mice formed greater than 0.2% antigen-specific rosettes with sheep erythrocytes coated with a spent-medium protein antigen of Salmonella typhimurium. These rosette-forming lymphocytes were found to be sensitive to the effects of antithymocyte serum plus complement. Transfer factor prepared from the Salmonella-immune splenic lymphocytes of ICR Swiss mice was active in sensitizing nonimmune ICR Swiss or C3H/HeJ lymphocytes to form greater than or equal to 0.2% rosettes with salmonella antigen-coated sheep erythrocytes. These rosettes were also sensitive to antithymocyte serum and complement. Few rosettes were formed between the transfer factor-treated lymphocytes and sheep erythrocytes coated with a Listeria protein antigen. A nonimmune dialysate preparation was inactive in sensitizing nonimmune lymphocytes, as indicated by a lack of rosette formation. Neither the immune transfer factor nor the nonimmune dialysate had any enhancing or abrogating effect upon rosette formation by splenic lymphocytes from Salmonella-immune mice. The enumeration of antigen-specific rosettes may be a useful means of assaying for transfer factor activity.

Transfer of Salmonella resistance and delayed hypersensitivity with murine-derived transfer factor

Protective host immunity and delayed hypersensitivity were transferred to nonimmune ICR and C3H/HeJ mice with transfer factor prepared from the splenic lymphocytes of ICR Swiss mice immune to Salmonella typhimurium. Only mice injected with the "immune" dialysate exhibited significant footpad swelling (P less than 0.01) to a spent medium antigen of S. typhimurium, but not Listeria monocytogenes. Host survival to a lethal Salmonella challenge infection was seen only in transfer factor-injected mice. Also, these challenged animals had fewer numbers of bacteria present in their spleens (P less than 0.01) than did challenged mice previously injected with either control dialysates or commercial endotoxin. Neither the Salmonella antigens nor endotoxin present in the sterile transfer factor preparation was responsible for the transfer of host protection and delayed hypersensitivity, since none of the control dialysates resulted in any positive responses when injected into either the ICR Swiss or endotoxin-resistant C3H/HeJ mice.