Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously demonstrated that acidic medium inhibits the replication of HIV-1. The present study was designed to examine the effects of other growth conditions and infection of fibroblasts by coculture with HIV infected lymphoid cells. Several lymphoblastoid cell lines normally grown in RPMI-1640 were grown in Eagle's MEM. These cells supported virus replication to higher titres than did RPMI-1640. Peak viral titres were achieved within 24-48 h after newly infected or chronically infected cells were placed in fresh medium. When virus was stored in liquid medium either frozen or at higher temperatures, virus titres were retained for several months while frozen but decreased upon storage at 4 degrees C or higher. If cells were passaged after trypsinization in Ca(++)-depleted medium, then a decreased susceptibility of cells for HIV-1 by 2 log10 at 24 h post infection was observed. Infectivity of cell-free and cell-associated HIV-1 was measured using syncytium formation, reverse transcriptase activity and p24 antigen. No fusion between HIV-1 infected CD4+ lymphoblasts and CD4- fibroblasts was observed but HIV-1 infected lymphoid cells, even in the absence of syncytium formation, exerted a strong toxic effect on fibroblasts. This study extends previous findings that medium acidity was inhibitory to virus replication and survival. Thus, conditions for study of HIV must be well controlled in buffered medium so that misleading results are not obtained regarding virus multiplication and possibly regarding transmission to and pathogenesis in CD4- cells.
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PMID:The influence of cell culture and storage conditions on HIV-1 infectivity and fusogenic activity. 128 37

Sensitivity of the cell-free human immundeficiency virus type 1 (HIV-1) and its producer cells was Studied in acidic media between pH 7.4 and 4.9 vitro. The cytopathic effect, reverse transcriptase activity and p24 antigen production by survived viruses were monitored in indicator cell cultures. It was established that, the cell-free HIV-1 particles are very sensitive to acidity. Between pH 7.4 and 6.0 they loose infectivity gradually, but this process is irreversible under pH 6.0 and subsequent neutralization cannot restore lost infectivity. However, viability, of virus producer cells is hardly affected between pH 7.4 and 4.9, but their ability to release infectious particles is lost gradually, similarly to the case of cell-free viruses. Neutralization of the media after treatment results in gradual restoration of releasing infectious viruses. These data explain that, cell-free HIV-1 looses infectivity in the acidic vagina or does on the skin, but infectivity is preserved in the blood, semen, rectum and breast milk being neutral or slightly alcalic. Virus carrier or producer lymphocytes by any route of infection can survive such protective mechanism of the body.
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PMID:[Different sensitivity to acid reaction of the AIDS virus and virus-producing cells: clinical conclusions]. 221 19