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T Folks

Publications and source records attributed to T Folks.

At least 19 recordsLinked to original sources
PubMed2003

Human infection with foamy viruses.

Virtually all nonhuman primate species investigated thus far including prosimians, New World and Old World monkeys and apes all harbor distinct and species-specific clades of simian foamy virus (SFV). However, evidence supporting the existence of a human-specific foamy virus (FV) is not yet available. Early reports describing widespread infection of healthy and sick humans with FV could not be confirmed. In contrast, all FV infections documented in humans are of zoonotic origin and are identified in persons occupationally exposed to nonhuman primates. The introduction of SFV into humans raises several public health questions regarding disease outcomes and potential for human-to-human transmissibility. The available data from a very limited number of SFV-infected humans suggest that these infections are nonpathogenic and are not easily transmissible. Additional studies are needed to better define the prevalence and natural history of SFV in humans.

Animals↗
PubMed1997

Immune stimulation may contribute to enhanced progression of SIV induced disease in rhesus macaques.

A number of rhesus macaques experimentally infected with SIV isolates such as SIVmac251, fail to seroconvert, develop high plasma viremia and die rapidly (within 6-7 months p.i.). We hypothesized that such rapid progression is a result of a state of hyperimmune activation and concomitant immune suppression of these animals at the time of virus challenge. In efforts to test the hypothesis that immune activation leads to rapid progression of lentivirus-induced disease, adult rhesus macaques were infected with SIV mac251 and received an alternate monthly schedule of repeated immunization with allogeneic cells, keyhole limpet hemocyanin and tetanus toxoid (group I). For purposes of controls, a group of monkeys was infected with the same pool and dose of virus but were not immunized (group II) and a group was immunized with the same schedule of multiple antigens as group I but were not infected with SIV (group III). All the animals in group I (n = 3) either failed to seroconvert or developed very low levels of SIV antibodies, had high plasma p27 defined antigenemia, and died within 8 months (2/3 died within 4 months). Of the animals in group II (n = 8), two patterns emerged as we had noted before. One subgroup (3 animals), displayed the same profile as group I (failure to fully seroconvert, high p27 levels and death by 8 months), whereas the other subgroup (5 animals) seroconverted, had low plasma p27 levels, and survived past 11 months (2/5 still alive past 22 months). All 3 animals in group III remained healthy. The data provided herein suggest that either experimental or natural (due to factors not clear at present) immune stimulation may lead to accelerated lentivirus induced disease progression most likely due to immune suppression and has implications for the understanding of the mechanisms for the rate of disease progression in human HIV-1 infection.

Animals↗
PubMed1991

A monocyte-derived factor interferes with detection of reverse transcriptase in HIV-1 infection.

Culture supernatants from the rabbit macrophage cell line 6083 infected with a retrovirus, human immunodeficiency virus type 1 (HIV-1), were negative for reverse transcriptase (RT) expression although the line was shown to be productively infected by all other criteria tested. Supernatants from uninfected cultures of 6083, the human monocyte line U937, and from freshly isolated peripheral human monocytes, were found to contain a monocyte-derived inhibitory factor (MDIF) which interferes with a standard assay for RT. MDIF is a heat-labile activity of approximately of 40 kD. Both substrates and products of the reverse transcriptase assay are degraded by MDIF which is not affected by reduction and alkylation of disulfide bonds. MDIF is inhibited by the addition of a particular thioated oligonucleotide (S-dG30) to the reaction mixture but this addition also inhibits RT. The optimum method to minimize MDIF interference in the RT assay is by addition of ethylene glycol bis-(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA); MDIF requires divalent cations for activity and has a strong preference for calcium which is preferentially chelated by EGTA. The potential presence of this inhibitory activity should be considered when using RT levels as a measure of retroviral infection.

Animals↗
PubMed1989

Infection of rabbits with human immunodeficiency virus 1. A small animal model for acquired immunodeficiency syndrome.

Injection of rabbits with a human T cell line infected with HIV-1 caused seroconversion within 6 wk, and HIV-1 could be isolated from PBL cultures of infected rabbits. Identity of the isolated virus with HIV-1 was shown by analysis of products amplified by the polymerase chain reaction. HIV-1 infection was seen in rabbits injected with HIV-1-infected cells alone as well as in those that were first infected with HTLV-1 and subsequently with HIV-1. There were no consistent signs of disease in the rabbits infected with HIV-1 alone but HTLV-1/HIV-1-infected rabbits showed signs of illness including diarrhea and weight loss, transient neurologic impairment and, in one animal, a rapidly progressing mammary adenocarcinoma. Examination of organs taken at necropsy from both HIV-1- and HTLV-1/HIV-1-infected animals showed splenic hyperplasia and lymphocyte infiltration of the lungs, as well as moderate damage to liver and kidney in some cases.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Sera from HTLV-III/LAV antibody-positive individuals mediate antibody-dependent cellular cytotoxicity against HTLV-III/LAV-infected T cells.

The causative agent of the acquired immunodeficiency syndrome (AIDS) has been shown to be a human retrovirus called human T lymphotropic virus (HTLV)-III or lymphadenopathy-associated virus (LAV). The nature of the protective immune response against this virus is currently unknown. We report here results using an antibody-dependent cellular cytotoxicity (ADCC) assay which has been developed for measuring a specific immune response against HTLV-III/LAV. Forty-four sera were examined for their ability to mediate ADCC against HTLV-III/LAV-infected T cells. Sera from healthy HTLV-III/LAV seropositive individuals in the presence of mononuclear cells from healthy HTLV-III/LAV seronegative donors exhibited significantly higher levels of ADCC activity compared to sera from patients with AIDS. Western blot analysis of serum samples indicated that antibody reactivity with the p24 protein of HTLV-III/LAV correlated with higher levels of ADCC activity than did reactivity with Gp120/160. The observation that sera from healthy HTLV-III/LAV seropositive individuals mediated higher levels of ADCC activity than did sera obtained from subjects with AIDS suggests that ADCC may represent a protective immune response to infection with HTLV-III/LAV.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Direct polyclonal activation of human B lymphocytes by the acquired immune deficiency syndrome virus.

When B lymphocytes from normal human peripheral blood were incubated for 1 hour with the retrovirus that causes the acquired immune deficiency syndrome (AIDS), the B cells showed marked proliferation and differentiation. Proliferative responses to the virus peaked on day 4 and appeared to be independent of accessory cells. This finding was repeated with three separate viral isolates, one of which was from a patient from Zaire. The magnitude of the observed responses was comparable to that seen with standard polyclonal B-cell activators. This phenomenon may be at least partially responsible for the polyclonal B-cell activation seen in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Susceptibility of normal human lymphocytes to infection with HTLV-III/LAV.

Normal human peripheral blood lymphocytes were tested for their susceptibility to infection with retroviruses isolated from patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex. Of 10 normal individuals tested, lymphocytes from all subjects became infected and produced virus as detected by assay for Mg+2-dependent reverse transcriptase. Lymphocytes from different individuals were demonstrated to be either high or low producers of reverse transcriptase after infection. The kinetics of virus production were similar in cells from both high- and low-producing individuals. A significant correlation was observed between high and low viral-producing lymphocytes and expression of the Leu-3/T4 (CD4) surface molecule. Mitogen-stimulated peripheral blood lymphocytes exposed to HTLV-III/LAV manifested productive viral infection, as reflected by the appearance of early syncytia, followed by reverse transcriptase. Unstimulated peripheral blood lymphocyte cultures displayed late syncytia but no detectable reverse transcriptase upon exposure to virus. The addition of anti-human interferon-alpha did not appear to have an appreciable effect on viral production in normal peripheral blood lymphocytes exposed to the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Induction of HTLV-III/LAV from a nonvirus-producing T-cell line: implications for latency.

When the human T-cell line A3.01 is infected with HTLV-III/LAV, the virus associated with the acquired immune deficiency syndrome (AIDS), most of the cells are killed. However, a small number of cells that lack the Leu-3 surface marker survive. Under normal conditions these surviving cells do not produce virus, nor can they be infected by the virus, but they can be induced to produce virus by treatment with 5-iodo-2'-deoxyuridine. This response can be induced for as long as 3 months after the initial infection, suggesting that the cells may harbor a latent form of HTLV-III/LAV.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Identification of conserved and divergent domains within the envelope gene of the acquired immunodeficiency syndrome retrovirus.

The nucleotide sequences of the envelope genes of an African and a North American acquired immunodeficiency syndrome (AIDS) viral isolate have been determined. When their deduced amino acid sequences were aligned with the envelopes of the lymphoadenopathy and AIDS-associated retrovirus isolates, conserved and divergent regions were readily identified. Hypervariable stretches of 28-74 amino acids, exhibiting 20-30% amino acid identity at each position and characterized by reciprocal insertions and deletions, were confined to the gp120 external envelope protein. The origin and clinical implications of the AIDS viral env gene diversity are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Production of acquired immunodeficiency syndrome-associated retrovirus in human and nonhuman cells transfected with an infectious molecular clone.

We constructed an infectious molecular clone of acquired immunodeficiency syndrome-associated retrovirus. Upon transfection, this clone directed the production of infectious virus particles in a wide variety of cells in addition to human T4 cells. The progeny, infectious virions, were synthesized in mouse, mink, monkey, and several human non-T cell lines, indicating the absence of any intracellular obstacle to viral RNA or protein production or assembly. During the course of these studies, a human colon carcinoma cell line, exquisitely sensitive to DNA transfection, was identified.

Animals↗
PubMed1986

Risk of nosocomial infection with human T-cell lymphotropic virus type III/lymphadenopathy-associated virus in a large cohort of intensively exposed health care workers.

To assess the risk of nosocomial transmission of human T-cell lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), we prospectively evaluated a cohort of 531 health care workers. One hundred fifty of these employees reported percutaneous or mucous membrane exposures to blood or body fluids from a patient with the acquired immunodeficiency syndrome (AIDS) during the treatment of 238 such patients since 1981. None of these 150 employees had serologic evidence of HTLV-III/LAV infection on follow-up from 6 to 46 months after exposure. Of the 150, 46 were studied immunologically and 29 had lymphocytes cultured for HTLV-III/LAV. Results of all studies were normal. Of the 531 employees, 3 (0.56%) had serologic evidence of HTLV-III/LAV infection. All were seropositive at the time of study entry; none reported adverse nosocomial exposures. All acknowledged membership in one or more established risk groups for AIDS. This study provides strong evidence that the risk of nosocomial transmission of HTLV-III/LAV is extremely low.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Genomic heterogeneity of AIDS retroviral isolates from North America and Zaire.

In an analysis of the genomic variation of AIDS retroviral isolates from patients living in New York, Alabama, and Zaire, restriction maps were constructed by using seven enzymes, each known to cleave the proviral DNA more than once, in conjunction with Southern blot analysis. The maps of LAV, HTLV-III, and ARV-2 as deduced from their published nucleotide sequences were included in this analysis. The results demonstrated that (i) several "signature" restriction sites were common to all isolates; (ii) with the exception of LAV and HTLV-III, the North American and European isolates were all different from one another and showed no geographical specificity; (iii) the African isolates as a group were more diverse than those from North America and Europe; and (iv) the genomic variability was concentrated within the env gene.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Characterization of a continuous T-cell line susceptible to the cytopathic effects of the acquired immunodeficiency syndrome (AIDS)-associated retrovirus.

We have developed a continuous human T-cell line (A3.01) for the study of acquired immunodeficiency syndrome (AIDS)-associated retrovirus that mimics normal peripheral blood lymphocytes in susceptibility to viral cytopathic effect without the need for cell activation or conditioned medium. Following infection, substantial quantities of virus are produced during a 3- to 5-day period; the associated killing of cells can be monitored in a microtiter assay as a function of virus input. Southern blot hybridization of infected cellular DNAs indicated that no gross alteration occurred in the restriction maps of the proviral DNA during the transfer of virus to and its passage in A3.01 cells. This cell system offers an alternative to other AIDS retrovirus cell systems because it permits the monitoring of viral cytopathic effects.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Therapeutic cytapheresis in chronic lymphocytic leukemia.

The role of therapeutic reductive lymphapheresis in 59 patients with chronic lymphocytic leukemia (CLL) was reviewed. Reduction in lymphocytosis, lymphadenopathy and hepatosplenomegaly was noted in 50%-60% of the patients studied. In addition to mobilization of the lymphoid tumor load, 40% of the patients showed an improvement in their hemogram. Although apheresis-induced anemia can occur, reported complications were minimal. These studies suggest that a majority of CLL patients might benefit from therapeutic lymphapheresis.

Aged↗