[Nucleotide sequence of two exons of the human T-lymphocyte CD4 receptor gene]. / Nukleotidnaia posledovatel'nost' dvukh ékzonov gena CD4-retseptora T-limfotsitov cheloveka]

Genome DNA encoding the N-part of human CD4 gene located in the 15 kilobase (kb) Sau3a restriction fragment was cloned and nucleotide sequence of a part (3430 b.p.) of this fragment determined. Exons 2 and 3, intron 2, and partially introns 2 and 3 of this gene were located in the sequenced fragment. Six Alu repeats and open reading frames (ORFs) coding for proteins very close to C5 and C3 components of the complement were detected in this fragment.

[The antiviral action of recombinant forms of the human T-lymphocyte CD4 receptor]. / Protivovirusnoe deistvie rekombinantnykh form CD4-retseptora T-limfotsita cheloveka.

A recombinant protein containing the first 179 N-terminus amino acids of human T-lymphocyte CD4-receptor was synthesized in E. coli cells. This recombinant protein was shown to interact with OKT4A and Leu3a monoclonal antibodies competing with HIV gp120 glycoprotein for binding with the native CD4 receptor. Experiments in vitro in human T-lymphocyte cultures showed that the recombinant CD4-protein in concentrations of 1 to 10 micrograms/ml inhibited the virus-induced syncytium formation, HIV replication in cell culture, synthesis of HIV reverse transcriptase and other virus-specific proteins, that is, behaved as a HIV inhibitor.

[The antiviral action of recombinant receptorotoxins based on the diphtheria toxin and the human T-lymphocyte CD4-receptor]. / Protivovirusnoe deistvie rekombinantnykh retseptorotoksinov na osnove difteriinogo toksina i CD4-retseptora T-limfotsitov cheloveka.

A number of vectors expressing in E. coli hybrid proteins (receptorotoxins) composed of diphtheria toxin lacking the C-terminal region and CD4-receptor fragment including N-terminal region of the natural protein have been constructed. The receptorotoxins consisting of the CD4 fragment in their N-terminal region were more stable. These recombinant receptorotoxins were cultured with HIV-infected Hut-78 cells and were shown to block HIV infection in vitro.

[The isolation and characteristics of monoclonal antibodies to recombinant proteins of HIV-1 and HIV-2--the env and gag gene products]. / Poluchenie i kharakteristika monoklonal'nykh antitel k rekombinantnym belkam VICh-1 i VICh-2--produktam genov env i gag.

Ten hybridomas secreting monoclonal antibodies (Mab) against recombinant HIV-1 and HIV-2 antigens were produced (3 Mab anti-gag protein, 2 anti-env1, and 5 anti-env2). In the immunoblotting assay all the anti-gag Mabs reacted with HIV capsid protein p24, whereas one of them reacted also with p55 protein and with 7 other polypeptides. Another anti-gag Mab cross-reacted with the antigen of subpopulation of human peripheral blood lymphocytes. The third one interacted with the antigen of both HIV-1 and HIV-2. All the 10 Mabs interacted with natural HIV antigens and can be used for identification and differentiation of HIV-1 and HIV-2.

[Cloning and expression of the CD4 receptor gene from human T-lymphocytes in Escherichia coli cells]. / Klonirovanie i ékspressiia v kletkakh Escherichia coli fragmentov gena CD4-retseptora T-limfotsitov cheloveka.

The gene for the CD4-membrane glycoprotein-receptor for HIV has been cloned. The 179 amino acids fragment of the CD4-receptor responsible for binding of gp120 HIV glycoprotein has been fused with beta-galactosidase and shown to be expressed in Escherichia coli cells. The recombinant protein in ELISA and immunoblotting techniques reacts with the monoclonal antibodies OKT4A and Leu3A known to block the interaction between the CD4 and gp120 HIV glycoprotein. The recombinant protein can be used for different scientific and practical purposes including studying of the mechanisms for HIV interaction with the sensitive cells as well as for viral gp120 protein purification, etc.