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rdf:type |
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lifeskim:mentions |
umls-concept:C0003319,
umls-concept:C0003320,
umls-concept:C0014780,
umls-concept:C0017262,
umls-concept:C0024530,
umls-concept:C0037993,
umls-concept:C0085324,
umls-concept:C0185117,
umls-concept:C0205419,
umls-concept:C1514873,
umls-concept:C1522642,
umls-concept:C2911684
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pubmed:issue |
3
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pubmed:dateCreated |
1983-7-15
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pubmed:abstractText |
Variant antigens appear on the surface of Plasmodium knowlesi-infected erythrocytes as the asexual parasite matures and are detected by antibody-mediated schizont-infected cell agglutination (SICA). We now show that cloned parasites can undergo antigenic variation in nonsplenectomized monkeys. In addition, we previously described a new P. knowlesi phenotype in which uncloned parasites passaged in splenectomized monkeys were no longer agglutinable by immune sera. We have designated this new phenotype SICA[-] and the one expressing the variant antigen SICA[+]. Cloned parasites can also switch from SICA[+] to SICA[-] in splenectomized monkeys. The switch from SICA[+] to SICA[-] is a gradual process that requires sequential subpassage in several monkeys. After passage in one monkey, the agglutination titer decreased 4- to 16-fold. Decreased agglutination was associated with decreased antibody binding on all infected erythrocytes as measured by fluorescein-conjugated anti-rhesus monkey immunoglobulin. The asexual malaria parasite can therefore alter its expression of variant antigen in response to the host environment (antivariant antibody or splenectomy). When cloned SICA[-] parasites were inoculated into intact monkeys, two courses of parasitemia were observed: fulminant parasitemia (greater than 20%) and parasitemia that was controlled. Fulminant infections were associated with conversion of the parasite from SICA[-] to SICA[+], i.e., from nonexpression to expression of the variant antigen on the erythrocyte surface. Parasitized erythrocytes remained SICA[-] in those infections that were controlled. It appears, therefore, that the expression of the variant antigen on the erythrocyte surface may influence parasite virulence.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-14297353,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-14332847,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-388448,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-401854,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4141372,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4628462,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4632834,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4958335,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4965829,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4994112,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-4999241,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-5026166,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-514362,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-5504485,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-5821272,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-6172478,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-6243753,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-661969,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-7017935,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-74212,
http://linkedlifedata.com/resource/pubmed/commentcorrection/6189787-980109
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0019-9567
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
40
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
985-94
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:6189787-Animals,
pubmed-meshheading:6189787-Antigens,
pubmed-meshheading:6189787-Epitopes,
pubmed-meshheading:6189787-Erythrocyte Membrane,
pubmed-meshheading:6189787-Erythrocytes,
pubmed-meshheading:6189787-Female,
pubmed-meshheading:6189787-Genetic Variation,
pubmed-meshheading:6189787-Hemagglutination,
pubmed-meshheading:6189787-Macaca mulatta,
pubmed-meshheading:6189787-Malaria,
pubmed-meshheading:6189787-Male,
pubmed-meshheading:6189787-Phenotype,
pubmed-meshheading:6189787-Plasmodium,
pubmed-meshheading:6189787-Spleen,
pubmed-meshheading:6189787-Splenectomy,
pubmed-meshheading:6189787-Virulence
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pubmed:year |
1983
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pubmed:articleTitle |
Splenic requirement for antigenic variation and expression of the variant antigen on the erythrocyte membrane in cloned Plasmodium knowlesi malaria.
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pubmed:publicationType |
Journal Article
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