Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Competent bacteria of Haemophilus influenzae strain Rd were exposed to various kinds of radioactive deoxyribonucleic acid (DNA) for short periods of time and at relatively low temperature. The fate of phage HP1 DNA was studied most extensively. Adsorbed DNA was partially acid solubilized by lysogens and by nonlysogens with very similar kinetics. The biological activity of the DNA decreased extensively in both lysogenic and nonlysogenic recipients. 2,4-Dinitrophenol had no effect on the acid solubilization but largely abolished the biological inactivation. Inactivation kinetics for three different markers and for the triple combination were roughly the same. The presence of 2,4-dinitrophenol in the medium, or the HP1 prophage in the chromosome, did not alter this observation. This suggests that acid solubilization involves the destruction of whole DNA molecules. In view of the absence of DNA homology between phage and host, it is concluded that acid-soluble breakdown of adsorbed transforming DNA is not an integral part of the donor DNA integration process. Behavior of mutant bacteria indicates that neither exonuclease III nor exonuclease V is involved.
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PMID:Acid-soluble breakdown of homologous deoxyribbonucleic acid adsorbed by Haemophilus influenzae: its biological significance. 454 63

The high-molecular-weight (HMW) immunoglobulin binding proteins (IgBPs) of Haemophilus somnus and a 76-kDa surface protein (p76) are found in serum-resistant virulent strains but not in several serum-sensitive strains from asymptomatic carriers. For the first time, p76 was shown to be an IgBP also. This was done by competitive inhibition studies with affinity-purified antidinitrophenol (anti-DNP) and DNP to ensure that binding was not antigen specific. The HMW IgBPs, but not the p76 IgBP, were partially purified from concentrated culture supernatant in detergent by fluid-phase liquid chromatography with a gel filtration column. Membrane extraction studies showed that p76 predominated in the Sarkosyl-soluble fraction of the bacterial cell pellet. Since integral outer membrane (OM) proteins are Sarkosyl insoluble, this is consistent with our previous finding that implicated p76 as a peripheral OM protein. The HMW IgBPs were found predominantly in the Sarkosyl-soluble fraction of the culture supernatant. This suggests that they were not integral membrane proteins and that their presence in the supernatant was not due to OM blebbing. We then showed that two IgBP-positive serum-resistant virulent strains have a surface fibrillar network but that two IgBP-negative serum-sensitive H. somnus strains from asymptomatic preputial carriers do not. Fibrils on the surfaces of IgBP+ strains bound gold-labelled bovine immunoglobulin G2 (IgG2) anti-DNP, indicating that these fibrils have IgG2 binding activity. Therefore, this study shows that H. somnus has two IgBPs, including a peripheral membrane protein and a fibrillar surface network.
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PMID:Haemophilus somnus immunoglobulin binding proteins and surface fibrils. 931 34

Glomerular IgA deposits were eluted from biopsied kidney tissues of patients with IgA nephritis and the antibody specificity was analyzed. The IgA was successfully eluted with combined use of citrate buffer and collagenase. The elution procedure did not attenuate antibody activity which was confirmed by the preliminary experiment that mouse IgA monoclonal anti-DNP antibody similarly treated did not cause any decline of antigen-binding ability. Because of the limited amounts ranging from 80-800 ng/ml, the eluted IgA did not react with respective lysates of the kidney tissues from which the IgA had derived. Moreover, kidney tissues from 9 biopsies yielded 5 micrograms/ml of IgA, when mixed together as source of IgA; nevertheless, the eluted IgA did not react with the kidney lysates, either. The eluted IgA, however, did react with several bacterial antigens, among which the 34-kDa antigen from Haemophilus influenzae (34-kDa H. influenzae) was most clearly detected with IgA eluted from pooled 10 kidney samples of IgA nephritis, which was confirming by Western blot analysis. The reactivity of the eluted IgA with the 34-kDa H. influenzae antigen was seen in 3/5 of IgA nephritis and 3/9 of non IgA nephritis patients with glomerular IgA deposits, respectively. The reactivity of serum IgA with the bacterial antigen was also investigated, which revealed that the serum IgA reacted with the 34-kDa antigen in 2/12 of IgA nephritis, 4/10 of liver cirrhosis patients and 3/10 of healthy control individuals, respectively. The surerum IgA from the IgA nephritis patients appeared to react with 34-kDa antigen more intensively than did healthy control IgAs. These results suggest that the 34-kDa H. influenzae plays an important role in the pathogenesis of at least certain IgA nephritis cases.
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PMID:[Isolation of glomerular IgA deposits from biopsied kidney tissues of patients with IgA nephritis and analysis of the antibody specificity of IgA]. 1042 65

Immunoglobulin binding proteins (IgBPs) are thought to be virulence factors which enable pathogens to evade the host's immune response. Since bovine IgG2 is important in protection against pyogenic infections, the binding characteristics of Staphylococcus aureus protein A (PrA), streptococcal protein G (PrG), or Haemophilus somnus high molecular weight IgBPs to the two bovine IgG2 allotypes were examined. For PrA or PrG binding of IgG2, guinea pig red blood cells coated with specific IgG2a or IgG2b antibodies were used in a competitive binding inhibition assay with unlabeled and horseradish peroxidase-labeled PrA or PrG. To determine which sizes of H. somnus. IgBPs bind to the two IgG2 allotypes, immunoblots with H. somnus culture supernatant were probed with anti-DNP IgG2a and IgG2b. This detects only Fc binding because anti-DNP does not cross-react with H. somnus antigens. Both IgG2 allotypes bound equally well to PrA and PrG. However, IgG2b but not IgG2a bound to H. somnus high molecular weight IgBPs. The lack of differential binding of bovine IgG2 allotypes to PrA and PrG means that these IgBPs can be considered to be unbiased reagents in assays for detection of bovine IgG2 or for immunoaffinity purification. The differential binding of H. somnus IgBPs to the IgG2 allotypes indicates that animals having one allotype may be more resistant to H. somnus infection than animals having the other allotype.
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PMID:Binding of bovine IgG2a and IgG2b allotypes to protein A, protein G, and Haemophilus somnus IgBPs. 1053 3

The relationship of the 76kDa immunoglobulin binding, surface antigen (p76) of Haemophilus somnus to the high molecular weight immunoglobulin binding proteins (HMW IgBPs) was investigated. The kanamycin resistance gene from pLS88 was used via homologous recombination with allelic exchange to replace a portion of the gene encoding IgBPs of H. somnus strain 8025. Recombinants were shown by Western immunoblotting to express and secrete truncated antigens of approximately 200kDa and not to produce p76. The truncated HMW IgBP variants retained the ability to bind bovine IgG2 by the Fc portion as demonstrated by Western immunoblotting against IgG2 anti-DNP. This data indicated that the deleted 1.8kb BglII fragment was not required for secretion or immunoglobulin Fc binding by the HMW IgBPs but was required for expression of the downstream p76 gene. Functional studies showed that, in addition to Fc binding of IgG2 to truncated HMW IgBPs, the mutant strain 8025 Kan1 was equally resistant to killing by mouse complement but less virulent than the wild type parent (8025) in a mouse septicemia model of H. somnus infection. However, mutant strain 8025 Kan1 did adhere less well than the wild type to bovine pulmonary artery endothelial cells. It is probable that p76 and the missing peptides of the HMW IgBPs play a role in this aspect of virulence and perhaps other aspects.
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PMID:Genetic manipulation of immunoglobulin binding proteins of Haemophilus somnus. 1263 74