Biomedical subjects

Reetakshi Arora

Publications and source records attributed to Reetakshi Arora.

3 recordsLinked to original sources

PubMed2006

A nonneutralizing anti-HIV Type 1 antibody turns into a broad neutralizing antibody when expressed on the surface of HIV type 1-susceptible cells. II. Inhibition of HIV type 1 captured and transferred by DC-SIGN.

Previously, we demonstrated that the expression of a nonneutralizing human anti-HIV-1 gp41 scFv on the surface of HIV-1-susceptible cells markedly inhibits HIV-1 replication and HIV-1 envelope-mediated cell-cell fusion. The inhibition is at the level of viral entry, specific for the HIV-1 envelope, and independent of virus tropism. In the previous studies, cell-free viruses of laboratory-adapted HIV-1 strains from subtype B were used to infect human CD4 T cell lines. To further test the effectiveness of this membrane-bound scFv (m-scFv) on HIV-1 infection, in this study, we carried out experiments to determine whether the m-scFv can neutralize infection of primary isolates from various HIV-1 subtypes and whether the m-scFv can neutralize HIV-1 captured and transferred by DC-SIGN on the surface of monocytic cell lines or DCs. We demonstrated that the m-scFv markedly inhibits primary isolates derived from various subtypes and significantly blocks HIV-1 captured and transferred by DC-SIGN on monocytic cell lines and on human DCs. Therefore, a nonneutralizing antibody acts as a broad neutralizing antibody when expressed on the cell surface, which significantly inhibits infection of both cell-free and DC-SIGN-captured and transferred virus. Our studies further point out the potential use of m-scFv as a inhibitor against HIV-1 transmission as well as a tool to dissect the mechanism of HIV-1 entry via DC-SIGN capture and transfer to CD4 T cells.

Antibody Formation↗

PubMed2006

Integration of human immunodeficiency virus type 1 in untreated infection occurs preferentially within genes.

Previous analyses of human immunodeficiency virus type 1 (HIV-1) integration sites generated in infections in vitro or in patients in whom viral replication was repressed by antiviral therapy have demonstrated a preference for integration within protein-coding genes. We analyzed integration sites in peripheral blood mononuclear cells (PBMCs), spleen, lymph node, and cerebral cortex from patients with untreated HIV-1 infections. The great majority of integration sites in each tissue were within genes. Statistical analyses of the frequencies of integration in genes in PBMCs and lymph tissue demonstrated a strong preference for integration within genes. Although the sample size for brain tissue was too small to demonstrate a clear statistical preference for integration in genes, four of the five integration sites identified in brain were within genes. Taken together, our data indicate that HIV-1 preferentially integrates within genes during untreated infection.

Cerebral Cortex↗

PubMed2005

Gel-based nonradioactive single-strand conformational polymorphism and mutation detection: limitations and solutions.

Single-strand conformation polymorphism (SSCP) for screening mutations/single-nucleotide polymorphisms (SNPs) is a simple, cost-effective technique, saving an expensive exercise of sequencing each and every PCR reaction product and assisting in choosing only the amplicons of interest with expected mutation. The principle of detection of small changes in DNA sequences is based on the changes in single-strand DNA conformations. The changes in electrophoretic mobility that SSCP detects are sequence-dependent. The limitations faced in SSCP range from the routine polyacrylamide gel electrophoresis (PAGE) problems to the problems of resolving mutant DNA bands. Both these problems could be solved by controlling PAGE conditions and by varying physical and environmental conditions such as pH, temperature, voltage, gel type and percentage, addition of additives or denaturants, and others. Despite much upgrading of the technology for mutation detection, SSCP continues to remain the method of choice to analyze mutations and SNPs in order to understand genomic variations, spontaneous and induced, and the genetic basis of diseases.

Animals↗