Triple Immunochromatographic System for Simultaneous Serodiagnosis of Bovine Brucellosis, Tuberculosis, and Leukemia

An immunochromatographic test system has been developed for the simultaneous rapid multiplex serodiagnostics of bovine brucellosis, tuberculosis, and leukemia. The test system is based on the use of a conjugate of gold nanoparticles with the chimeric protein Cysteine-A/G and three analytical zones with immobilized pathogen antigens: Brucella abortus lipolysaccharide, recombinant proteins MPB64 and MPB83-MPB63 of Mycobacterium bovis, and recombinant protein p24 of the bovine leukemia virus. Prototypes of the test system were tested on 98 samples of sera from healthy and infected animals. The diagnostic sensitivity of the developed test system was 92% for brucellosis, 92% for tuberculosis, and 96% for leukemia. False positive test results were not observed.

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Growth agglutination and growth inhibition tests in the diagnosis of brucellosis

Journal of Hygiene ◽

10.1017/s0022172400026097 ◽

1979 ◽

Vol 83 (2) ◽

pp. 295-304 ◽

Cited By ~ 1

Author(s):

K. R. Mittal ◽

I. R. Tizard

Keyword(s):

Guinea Pig ◽

Growth Inhibition ◽

Brucella Abortus ◽

Bovine Serum ◽

Agglutination Test ◽

Inhibition Test ◽

Test Results ◽

Bovine Brucellosis ◽

Growth Inhibition Test ◽

Living Organisms

summaryGrowth agglutination and growth inhibition tests were established for the diagnosis ofBrucella abortusinfection. The former involves the agglutination of living organisms while the latter is a bactericidal test. Using mouse, guinea-pig, rabbit and bovine serum it was shown that the growth agglutination test is approximately ten times, and the growth inhibition test one hundred times, more sensitive than the conventional tube agglutination test. It is suggested that these techniques may be of assistance in diagnosing bovine brucellosis in situations in which the tube agglutination test results are suspected of being falsely negative.

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Dileucine and YXXL Motifs in the Cytoplasmic Tail of the Bovine Leukemia Virus Transmembrane Envelope Protein Affect Protein Expression on the Cell Surface

Journal of Virology ◽

10.1128/jvi.78.15.8301-8311.2004 ◽

2004 ◽

Vol 78 (15) ◽

pp. 8301-8311 ◽

Cited By ~ 8

Author(s):

Sinisa Novakovic ◽

Earl T. Sawai ◽

Kathryn Radke

Keyword(s):

Cell Surface ◽

Bovine Leukemia Virus ◽

Leukemia Virus ◽

Surface Display ◽

Chimeric Protein ◽

Surface Expression ◽

Terminal Segment ◽

Cell Surface Expression ◽

Chimeric Proteins ◽

Env Protein

ABSTRACT Several retroviruses downmodulate the cell surface expression of envelope (Env) proteins through peptide sequences located in the cytoplasmic tail of the transmembrane (TM) subunit. We investigated whether cell surface expression of a chimeric protein containing the cytoplasmic domain of the TM protein (CTM) of bovine leukemia virus (BLV) was regulated by two membrane-proximal dileucine motifs or by tyrosine Y487 or Y498 in YXXL motifs. A chimeric protein composed of the extracellular and membrane-spanning portions of human CD8-α plus a wild-type (wt) BLV CTM was detectable on the surface of only 40% of the cells in which it was transiently expressed. Replacement of either dileucine pair with alanines increased the level of surface display of chimeric proteins. Nearly all cells became surface positive when both dileucine motifs were altered simultaneously and when either an N-terminal segment containing both dileucine motifs or a C-terminal segment containing all YXXL motifs was deleted. In contrast, replacement of Y487 or Y498 with alanine or phenylalanine enabled only small increases in surface display compared with wt levels. Chimeric proteins had similar stabilities but were downmodulated from the cell surface at three different rates. Point mutants segregated into each of the three groups of proteins categorized according to these different rates. Interestingly, Y487 mutants were downmodulated less efficiently than Y498 mutants, which behaved like wt. CD8-CTM chimeric proteins were phosphorylated on serine residues, but the native BLV Env protein was not phosphorylated either in transfected cells or in a lymphoid cell line constitutively producing BLV. Thus, both dileucine and YXXL motifs within the BLV CTM contribute to downmodulation of a protein containing this domain. Interactions with other proteins may influence surface exposure of Env protein complexes in virus-infected cells, assisting in viral evasion of adaptive immunity.

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