Six breeding groups of chickens, each characterized by a different haplotype of the B blood group system, were challenged with different classes of antigens, namely Newcastle disease vaccine (ND), infectious bronchitis vaccine (IB), infectious bursal disease viral agent (IBD), Salmonella pullorum antigen (P), and sheep red blood cells (SRBC). Parents were challenged at 20 weeks of age, and their offspring were challenged at 3 weeks of age. Blood samples were taken from the parents at 1 week after challenge, and from the offspring at 1, 2, 3, and 4 weeks after challenge for determination of antibody titers to each antigen. The offspring were also challenged at 8 weeks of age in the wing-web with Rous sarcoma virus (RSV). Tumor scores were taken weekly on individual chickens for the next 10 weeks. There were significant differences (P less than .01) between breeding groups of parents for antibody titer responses to ND, IB, P, and SRBC. There were significant differences (P less than .05) between the breeding groups of offspring for antibody titer responses to ND, IB, IBD, P, and SRBC. There were significant (P less than .01) differences between the breeding groups in the accumulative tumor scores over the 10-week period. The lines that cause regression of Rous sarcomas (R-lines) were significantly (P less than .01) superior in resisting tumor growth to those lines that allow progressive growth of tumors (Pr-lines). The only antigen to which the R-lines gave significantly (P less than .01) higher titers of antibody responses than the Pr-lines was SRBC.
The relationship between the level of C-reactive protein (CRP) in the sera of mice and resistance to Staphylococcus aureus infection after the injection of Escherichia coli endotoxin was studied. The CRP level was essentially unchanged at 6 hr after endotoxin, and resistance was slightly decreased. At 24 hr after endotoxin, both CRP levels and resistance were increased. Since the increase in the CRP level and resistance appeared to be associated, it was of interest that, when mouse CRP was tested for in vitro reactions with several strains of bacteria, cells of all species of gram-positive bacteria tested (including S. aureus) were agglutinated by CRP. E. coli was not agglutinated under the conditions of the test. It is proposed that mouse CRP is an opsonin, and possibly a lysin, and is involved in nonspecific resistance to infection with S. aureus. Results of a recent study on staphylococcal arthritis in chickens suggested that the early production of C-reactive protein (CRP) is associated with resistance to Staphylococcus aureus (Patterson and Mora, 1965). The production of CRP in humans and Cx-reactive protein (CxRP) in rabbits can be induced by a variety of stimuli, including endotoxins (Hedlund, 1961). It is of interest, therefore, that many of these agents also can enhance resistance of mice to infection with S. aureus (Shilo and Wolman, 1958; Springer et al., 1961; Higginbotham, 1964) as well as with gram-negative bacteria (Rowley, 1964). Considerable attention has been given to the possible role of both cellular and humoral factors in the endotoxin-induced nonspecific resistance in mice (Rowley, 1964; Shilo, 1959). However, there appear to have been no studies relating CRP to resistance in this species. The present study was conducted to determine whether the endotoxininduced increase in resistance of mice to S. aureus infection was associated with the appearance of CRP-like substance in the sera of these animals. Evidence is presented that a substance that reacts with Cx-polysaccharide and antisera to human CRP was elevated in sera of mice during the early stage of increased resistance to infection. It was of interest that this protein caused the agglutination of cells of S. aureus as well as several other species of gram-positive bacteria.
A technique for staining avian blood smears using combined Wright's-Giemsa's stain is described. This procedure is very easy to perform and is suitable for routine avian hematology. (
Several immunological, hematological, and pathological responses associated with Marek's disease were determined. Four-week-old Marek's disease-infected and control chickens were injected with Salmonella pullorum antigen. About one-half of all infected chickens tested were unresponsive to antigenic challenge. Antibody titers in responsive infected chickens were significantly depressed at 1 and 2 weeks postinoculation when compared to controls. Total white blood cell counts of control and control-antigen chickens were significantly lower than counts in infected chickens. Based on response to antigenic challenge, 24% of the responsive group had leukemia compared to 54% of the unresponsive chickens. The predominant cell
The response of rabbits and mice to treatment with Escherichia coli endotoxin, as measured by C-reactive protein (CRP) and leukocyte levels, and resistance to Staphylococcus aureus infection was studied to evaluate the significance of these responses and their associations. In both species, there was an initial leukopenia without early recovery of normal lymphocyte levels. This was followed by an increase in polymorphonuclear leukocytes and a return to near the normal range. The CRP level was slightly altered during the stage of decreased resistance and increased throughout the remainder of the period of observation. The resistance level was decreased initially, recovered to normal levels, and continued to increase. The changes in CRP and resistance levels were closely associated. It would appear that this association between CRP and resistance, the antibacterial activity of CRP, and its action on the polysaccharides obtained from bacterial cell walls are evidence for the participation of CRP in nonspecific resistance to infection.
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