Immunization with ribosomal preparations from Haemophilus influenzae type b elicited protective immunity in mice. Ribosomes from disrupted cells where isolated by differential centrifugation using sodium dodecyl sulfate. The washed ribosomes contained 25% protein and 75% ribonucleic acid and sedimented as a single peak on sucrose density gradient analysis with a sedimentation coefficient of 67S, using Escherichia coli ribosomes as a 70S marker. Immunodiffusion tests with antipolyribose phosphate serum showed that the ribosomes were free from capsular material. Mice immunized subcutaneously with ribosomes, with or without adjuvant, were challenged intraperitoneally with 100 to 1,000 mean lethal doses of H. influenzae type b suspended in gastric mucin. Significant protection was induced by ribosomes and was compared to that obtained after sublethal infection with live cells. The protection was greatly enhanced after incorporation of ribosomes into adjuvants. Maximum protection (90 to 95%) was observed at 1 to 2 weeks after immunization. Ribosomes from a nonencapsulated strain of H. influenzae were as immunogenic as those from the encapsulated strain, demonstrating that the capsular material is not responsible for immunogenicity of Haemophilus ribosomes.

This investigation was designed to characterize the immunoprotective antigen of ribosomal preparations from Haemophilus influenzae. The ribosomes that elicited 80 to 90% protection contained 25% protein and 75% ribonucleic acid but did not contain any detectable hexoses. The immunodiffusion and hemagglutination inhibition tests also failed to demonstrate that the capsular material (polyribose phosphate) was in ribosomal preparations. Treatment of ribosomes with ribonuclease degraded 78% ribonucleic acid but did not affect the immunogenicity of such preparations. The proteolytic enzymes reduced the immunogenicity of ribosomes corresponding to the amount of protein degraded. The protection elicited by ribosomal protein extracted with 2-chloroethanol was comparable to that induced by intact ribosomes. In contrast, the low levels of protection observed by immunization with phenol-extracted ribonucleic acid were dependent on the amounts of contaminating protein. Finally, immunogenicity of ribosomal ribonucleic acid and protein was abrogated by treatment with proteolytic enzymes. These results clearly indicate that the protein associated with Haemophilus ribosomes is the major immunoprotective antigen.

Intraperitoneal injection of slime glycolipoprotein (GLP) from Pseudomonas aeruginosa induced leukopenia and death of mice, similar to the effect of infection with viable organisms. Differential counts established that the leukopenia was characterized by a decrease in the number of polymorphonuclear leukocytes, followed by death of mice. Mice immunized with GLP survived challenge and responded with a leukocytosis that had a substantial increase in circulating polymorphonuclear leukocytes. Leukocytes from GLP-injected mice were agglutinated by anti-GLP serum, indicating an association between GLP and leukocytes. Other results indicated that 14C-labeled GLP is deposited mainly in the liver. Normal leukocytes labeled with 51Cr were injected intravenously into mice receiving an intraperitoneal injection of GLP. As with GLP, the 5'Crlabeled leukocytes were sequestered in the liver. These results indicate that GLP enters the blood stream and becomes associated mainly with neutrophils, and that the neutrophil-GLP complex is deposited in the liver, possibly accounting for the leukopenia in mice.Although infections resulting from Pseudomonas aeruginosa have been studied for many years, relatively little is known about its pathogenesis. Several possible virulence factors have been characterized, such as: proteases (11), exotoxin or toxin A (4, 12), leukocidin (13-16), and slime (1,8,18,19). The glycolipoprotein (GLP) fraction, extracted from the slime layer, has been observed to induce leukopenic and lethal effects in mice, much the same as infection with viable organisms. Active and passive immunization against highly purified GLP protected mice from leukopenia and death after challenge with live organisms (18). The production of GLP has been detected in vivo after injection of live organisms, as well as its dissemination via the peripheral blood circulation to become associated with erythrocytes (8).In this study, the GLP-induced leukopenic effect was further characterized, and the relationship between GLP and blood leukocytes was examined. The distribution of GLP in mouse organs was also determined. MATERIALS AND METHODSOrganism. The bacterium used in this study, P. aeruginosa strain BI, was originally isolated from a clinical specimen and was described previously (2). GLP. The GLP fraction was obtained from the extracellular slime layer of strain BI and was purified by the method described by Sensakovic and Bartell (18). Purified GLP was injected into mice intraperitoneally at a concentration of 50 pugIg as a challenge. This concentration represented 2 mean lethal doses and was usually lethal to 100% of the mice injected.Mice. Young, white, male Swiss mice, weighing 18 to 20 g, were used in this study. They were housed 10 per cage and supplied Purina Mouse Chow and water ad libitum. All mice were weighed immediately before injection.Mouse leukocyte counts were performed using blood samples from the tail vein. Standard techniques of dilution using 0.1 M HOl were employed followed by enumeration of the total leukocyte ...

Bovine serum albumin promotes the growth of small inocula ofMycobacterium tuberculosis in media containing unesterified fatty acids. Albumin binds fatty acids present in concentrations toxic for the organisms. In the present study, additional roles of albumin were investigated. When present in a basal medium, fatty acid-free albumin could be utilized by M. tuberculosis as a sole source of carbon. Since albumin could not substitute for the amino acids in basal medium as a nitrogen source, it was concluded that the protein component in albumin was not utilized as a nutrient by the organisms. An ether extract of fatty acid-free albumin supported a small but significant amount of growth. Analysis of the lipids in fatty acid-free albumin by gas chromatography revealed the presence of 686 ytg of fatty acid per g of albumin. Although a small amount of growth occurred

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