A strong, preferential response of mice to polymorphic antigenic determinants of the chicken MHC, analyzed with mouse hybridoma (monoclonal) antibodies

Longenecker, B. M.; Mosmann, Timothy R.; Shiozawa, C

doi:10.1007/bf01570404

Cited by 56 publications

(21 citation statements)

References 17 publications

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“…Subsequently, the mouse was sacrificed and the spleen was removed for fusion. The fusion was performed as described by Longenecker et al (32) by using the NS1 myeloma cell line. Monoclonal antibody MCA A-20:D-8 was identified by reaction with protein G on Western (immuno-) blot (described below).…”

Section: Methodsmentioning

confidence: 99%

Characterization of mechanisms of quinolone resistance in Pseudomonas aeruginosa strains isolated in vitro and in vivo during experimental endocarditis

Chamberland

Bayer

Schollaardt

et al. 1989

Antimicrob Agents Chemother

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Mechanisms of resistance to quinolones were characterized in Pseudomonas aeruginosa strains isolated after Tn5 insertional mutagenesis and in resistant strains that emerged during pefloxacin therapy of experimental aortic endocarditis. Quinolone resistance achieved in in vitro-selected mutants Qr_1 and Qr-2 was associated with cross-resistance to several groups of antimicrobial agents, including ,-lactams, tetracycline, and chloramphenicol. A significant reduction of norfloxacin uptake was also observed. After ether permeabilization of the cells, DNA synthesis of these two isolates was as susceptible to norfloxacin as DNA synthesis of the parent strain (PAO1). These results indicate that alteration of outer membrane permeability is the primary determinant of resistance in these isolates. This altered cell permeability was correlated with reduction of outer membrane protein G (25.5 kilodaltons) and loss of a 40-kilodalton outer membrane protein in strain Qr_l. Resistance to quinolones that emerged during experimental endocarditis therapy was associated with both modification of outer membrane permeability (decreased uptake of norfloxacin) and decreased susceptibility of DNA synthesis to norfloxacin. Resistance was limited to quinolones and chloramphenicol. For these strains, norfloxacin inhibitory doses (50%) for DNA synthesis were identical to the drug MICs, suggesting that despite the identification of a permeability change, perhaps due to changes of lipopolysaccharide, the alteration of the quinolone intracellular target(s) susceptibility constitutes the primary determinant of resistance. Also, two distinct levels of norfloxacin resistance of DNA synthesis were found in these isolates, indicating that at least two distinct alterations of the drug target(s) are possible in P. aeruginosa.New fluoroquinolones, such as ciprofloxacin and norfloxacin, have potent antimicrobial activity against gram-positive and gram-negative bacteria, including Pseudomonas aeruginosa (48). Biochemical and genetic evidence has designated the DNA gyrase (subunit A) as the intracellular target of these drugs. Bacterial DNA gyrase is a tetramer of two of each of the subunits, A and B, encoded by the gyrA and gyrB genes, respectively. DNA gyrase catalyzes DNA supercoiling, which serves important functions in DNA replication, recombination, and repair (12). Inhibition of DNA gyrase activities by quinolones leads to inhibition of DNA synthesis, but the mechanisms by which quinolones induce cell death and the exact molecular interactions existing between quinolones, DNA gyrase, and DNA are not clear (24).Mutational resistance to fluoroquinolones in gram-negative bacteria such as Escherichia coli and P. aeruginosa has been associated with modification of the intracellular target of the drug (DNA gyrase) or alteration of outer membrane permeability (21,25,42,48).In E. coli, mutations that affect both gyrase subunits, leading to various levels of resistance to fluoroquinolones and nalidixic acid, have been described (24), while in P. aeruginos...

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Section: Methodsmentioning

confidence: 99%

Characterization of mechanisms of quinolone resistance in Pseudomonas aeruginosa strains isolated in vitro and in vivo during experimental endocarditis

Chamberland

Bayer

Schollaardt

et al. 1989

Antimicrob Agents Chemother

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“…The biological functions of these molecules are unknown, but the serologically polymorphic ones may have some role in specific recognition of foreign antigens by cells of the immune system (4,6), based on the high polymorphism, location in the MHC, distinctive tissue distribution, and two interesting phenomena: polymorphic B-G epitopes are recognized by so-called "natural antibodies" in a variety of species (7,8) and B-G molecules are responsible for the "adjuvant effect" for humoral responses to other molecules on erythrocytes and in liposomes (refs. 9 and 10; J.S., H.…”

mentioning

confidence: 99%

Size polymorphism of chicken major histocompatibility complex-encoded B-G molecules is due to length variation in the cytoplasmic heptad repeat region.

Kaufman

Salomonsen

Skjødt

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

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B-G antigens are cell-surface molecules encoded by a highly polymorphic multigene family located in the chicken major histocompatibility complex (MHC). Rabbit antisera to B-G molecules immunoprecipitate 3-6 bands from iodinated erythrocytes by sodium dodecyl sulfate (SDS) gels under reducing conditions. These are all B-G molecules because they all map to the B-G region of the chicken MHC in congenic and recombinant chickens, most are directly recognized by the antisera, most form disulfide-linked dimers, and none bear N-linked carbohydrate. Both apparent homodimers and heterodimers are found, which bear intrachain disulfide bonds. All 3-6 bands have different mobilities in SDS gels between different haplotypes, ranging from 30 to 55 kDa. This size polymorphism is not affected by glycosidase treatment or addition of protease inhibitors. Partial proteolysis of cell surface-iodinated B-G molecules generates extremely similar patterns of spots, both within and between haplotypes. These surface-iodinated peptides bear either interchain or intrachain disulfide bonds. Additional peptides are generated by proteolysis of B-G molecules iodinated after isolation. Thus, it appears that the extracellular regions of these molecules are very similar and that the length polymorphism is due to variations in the cytoplasmic regions. Inspection of the cDNAderived protein sequence in this region shows many heptad repeats, which may allow variation in length by step deletion and alternative splicing. The repeats indicate an a-helical coiled-coil structure, which could form an interaction between subunits of the dimer or with the cytoskeleton or both.

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“…human bloodstream, as shown in Table 1, may seem disproportionately greater than might be expected a priori from nonimmune donors, although the CRBC-binding frequency of nonimmunized murine spleen cells has been shown to range between 0.04 and 1.19% (21,22). It is important to recognize, moreover, that each of the antigen systems described here constitutes a family of antigenic determinants, as opposed to individual haptens, such that individual clonotype frequencies should be additive in each family.…”

Section: Discussionmentioning

confidence: 99%

“…Thus, we have been able to determine that precursors specific for antigens present on CRBC, NeHuRBC, DNA, and sperm, (re)circulate in the nonimmune human blood stream. Antigens under the control of the major histocompatibility complex and blood group loci of the chicken are expressed on CRBC and recognized by human peripheral blood B cells, as they are by murine splenic B cells (21,22). This recognition of polymorphically expressed determinants confirms earlier work on human "natural" antibody specificities (23) and may indicate a strategy of the mammalian immune system to cope with major histocompatibility complex antigen mimicry by parasites.…”

Section: Discussionmentioning

confidence: 99%

Efficient generation in vitro, from human peripheral blood cells, of monoclonal Epstein-Barr virus transformants producing specific antibody to a variety of antigens without prior deliberate immunization.

Winger¹,

Winger²,

Shastry³

et al. 1983

Proc. Natl. Acad. Sci. U.S.A.

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This paper describes a simple protocol for the efficient generation of large numbers of human monoclonal antibody-producing cells. This system is based on initial limiting-dilution culture after Epstein-Barr virus exposure of highly enriched precursors selected from peripheral blood mononuclear cells. Precursors can be enriched by using rosetting or panning approaches. Antibodies to erythrocytes, a mouse mammary carcinoma, DNA, and sperm antigens, produced without any deliberate immunization, are described. Large-scale human monoclonal antibody production may be facilitated by a combination of this protocol with a human cellular fusion system. For efficient precursor analysis and short-term (2 months or more) monoclonal antibody production, however, the system described here may be sufficient.Two general systems-the hybridoma approach (1-3), and the Epstein-Barr virus (EBV) transformation approach (4-6)-have been used for immortalizing human antibody-producing cells. A major obstacle to date, however, to the efficient production of human monoclonal antibodies of predetermined specificity, using either of these techniques, has been the problem of procuring a sufficient number of cells of the desired specificity for statistically probable immortalization.Thus, for either the hybridoma approach (7,8) or the EBV approach (6), relatively heroic in vivo immunization schedules and time constraints after priming have been considered necessary to yield sufficient (re)circulating precursors. Alternatively, tonsillar cells have been the tissue of choice for in vitro immunization prior to fusion (9); also, draining lymph nodes from solid cancer-compromised patients (10) or mononuclear cell infiltrates of the tumor mass (11)

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A strong, preferential response of mice to polymorphic antigenic determinants of the chicken MHC, analyzed with mouse hybridoma (monoclonal) antibodies

Cited by 56 publications

References 17 publications

Characterization of mechanisms of quinolone resistance in Pseudomonas aeruginosa strains isolated in vitro and in vivo during experimental endocarditis

Characterization of mechanisms of quinolone resistance in Pseudomonas aeruginosa strains isolated in vitro and in vivo during experimental endocarditis

Size polymorphism of chicken major histocompatibility complex-encoded B-G molecules is due to length variation in the cytoplasmic heptad repeat region.

Efficient generation in vitro, from human peripheral blood cells, of monoclonal Epstein-Barr virus transformants producing specific antibody to a variety of antigens without prior deliberate immunization.

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