Barbara Keys

Karolinska Institutet, Сольна, Stockholm, Sweden

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Publications (6)21.84 Total impact

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    ABSTRACT: The spread of HIV-1 to the nervous system occurs early during infection in a large number of asymptomatic virus carriers. In order to address the question whether the brain is targeted by a group of HIV-1 variants with increased neurotropic properties we have obtained 20 paired isolates from the blood and cerebrospinal fluid (CSF) of patients with varying severity of HIV-1 infection. We determined the nucleotide sequence of variable region 3 (V3) of the gp 120 envelope protein and studied the growth capacity of the virus isolates in primary monocyte/macrophage cultures. Blood and CSF V3 sequences could be grouped according to the host, whereas particular amino acid sequences related to tissue specificity were not identified. Moreover, the majority of HIV-1 isolates, independently of the tissue source, replicated in macrophage cultures. The isolates derived from the brain and blood compartments thus appeared genetically similar and could not be grouped according to their replicative capacities. The genetic distance between paired CSF and blood sequences was more pronounced in the group of patients with AIDS than in asymptomatic virus carriers. These observations indicate that the viruses present in the blood and CSF in the early stage of infection are genetically similar. Different mechanisms of adaptation or immunomodulation of the virus in CSF and blood may account for the increased intra-patient variability observed in the AIDS group.
    No preview · Article · Nov 1993 · Virology
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    ABSTRACT: Cerebrospinal fluid (CSF) specimens from 63 patients with different severities of human immunodeficiency virus (HIV-1) infection, including asymptomatic virus carriers, were examined for the presence of HIV-1 by using polymerase chain reaction (PCR) and virus isolation. Polyadenylated RNA, presumably associated with virus particles, was extracted and reverse transcribed, and the pol region was amplified in a nested PCR. Virus could be detected in 90% of the CSF specimens examined by PCR, and data on isolation of virus from CSF were in agreement with these figures. In fact, when several CSF specimens from the same individual were studied, HIV-1 could be isolated from 80% of the patients. The presence of the viral RNA in CSF was independent of the clinical stage of infection and of neurological symptoms. These results show that the spread of HIV-1 to the brain represents an early event during infection and occurs in the majority of asymptomatic individuals.
    Full-text · Article · Aug 1992 · Journal of Clinical Microbiology
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    ABSTRACT: The cerebrospinal fluids (CSF) and sera from HIV-1-infected individuals at different clinical stages were monitored for neutralizing activity against CSF-derived HIV-1 isolates. None of the CSF samples and only one of seven serum samples could neutralize the autologous CSF isolate. CSF samples collected one to two years later from the same patients also lacked autologous neutralizing antibodies against these isolates. However, some CSF samples were able to neutralize heterologous CSF isolates albeit in low titers. HIV antibody positive control sera could readily neutralize all of the CSF isolates demonstrating that these isolates were not resistant to neutralization per se. IgG antibodies against the HIV-1 envelope protein and, specifically, against the V3 loop of HIV-1 gp120 (MN) were present in some CSF samples, although the samples lacked neutralizing activity. In summary, this study demonstrates a lack of autologous neutralizing antibodies in CSF samples when assayed against CSF-derived HIV-1 isolates.
    No preview · Article · Jul 1992 · AIDS Research and Human Retroviruses
  • Barbara Keys · Jan Albert · Jan Kövamees · Francesca Chiodi
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    ABSTRACT: HIV type 1 and 2 isolates derived from brain and blood of infected individuals were used to infect astrocytic cells of tumor origin. Infection was monitored by polymerase chain reaction. The majority of the isolates infected the glioma cells, independently of the source of isolation. Added to the fact that the majority of primary HIV isolates infect cells of the monocyte/macrophage lineage, these results indicate that primary blood and brain HIV strains have similar target cells. The production of virus from infected astrocytes was detected only upon infection with two macrophage-adapted strains. Also in this case, the number of infected cells was very low and only one in 5000 cells carried the proviral HIV genome.
    No preview · Article · Sep 1991 · Virology
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    ABSTRACT: The possibility of using simian immunodeficiency virus (SIV)-infected macaques to study pathogenic events linked to HIV infection of the brain prompted us to investigate some of the virological features in SIV-infected macaques. Nine cynomolgus macaques were inoculated with SIVsm and killed at different times. We successfully isolated virus from the blood of all the animals and from the brains of eight. These results point to the early and regular spread of this lentivirus to the brain. Neutralizing activity was studied in the serum and cerebrospinal fluid specimens obtained from these macaques against a selected group of isolates. Cerebrospinal fluid did not show any neutralizing activity. Our findings integrate the observations from HIV-1 infection in man and indicate that SIV infection of macaques is a useful model for studying pathogenic events of brain infection.
    No preview · Article · May 1991 · AIDS
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    ABSTRACT: Virus has been isolated from the blood and cerebrospinal fluid (CSF) of eight subjects with varying severity of human immunodeficiency virus type 1 (HIV-1) infection and from the frontal lobe of one patient with AIDS. The five patients with AIDS-related complex (ARC) and AIDS also showed neurological/psychiatric complications. With the exception of one isolate from the CSF of an asymptomatic carrier, all isolates replicated in peripheral blood mononuclear cells and monocytes after cell-free transmission. Isolates obtained from the blood of patients in late stages of HIV infection replicated in 3 (of 4) cases in H9 cells, whereas none of the blood isolates from patients in the early stages did so. The capacity of CSF isolates to replicate in H9 cells was low (only 2 of 12). Paired virus isolates from blood and CSF of the same patient could be distinguished by their replicative capacity in different cell lines, type of cytopathic effect, and protein profile as tested by radioimmunoprecipitation. The results indicate that variant viruses with distinct biological characteristics may be isolated from the blood and CSF of the same patient.
    No preview · Article · Dec 1989 · Virology