Asher Dm

Experimental hantavirus infection in nonhuman primates

SummaryMild, transient proteinuria and azotemia were produced in three cynomolgus monkeys (Macaca fascicularis) and a chimpanzee (Pan troglodytes) following intravenous inoculation with Prospect Hill virus, a hantavirus isolated from meadow voles in the United States. This is the first demonstration of an acute nephropathy in nonhuman primates with the viruses causing hemorrhagic fever with renal syndrome.

Widespread, restricted low-level measles virus infection of brain in a case of subacute sclerosing panencephalitis

In situ reverse transcriptase-polymerase chain reaction amplification with labeled-probe hybridization (in situ RT-PCR/LPH) was used to detect measles virus RNA within formalin-fixed, paraffin-embedded brain tissue sections from a patient who died with subacute sclerosing panencephalitis (SSPE). Many more infected neurons and oligodendrocytes were detected by in situ RT-PCR/LPH than by immunohistochemistry or by in situ hybridization alone. In addition, infection of vascular endothelial cells was demonstrated only by in situ RT-PCR/LPH. The observation that many cells contained only a few copies of viral RNA without detectable antigen is consistent with a persistent viral infection of the central nervous system. In situ RT-PCR/LPH, combining the sensitivity of PCR with the tissue localization of in situ hybridization, should prove useful in further studies to detect nucleic acids in situ in the central nervous system.

Simultaneous isolation of simian foamy virus and HTLV-III/LAV from chimpanzee lymphocytes following HTLV-III or LAV inoculation

SummaryRe-isolation of virus from HTLV-III B and LAV-infected chimpanzee also yielded a simian foamy virus. This virus, replicated in HTLV-III B and LAV-producing H 9 cells, had identical reverse transcriptase activity and caused similar cytopathic effects in H 9 cells.

Attempts to establish cell cultures infected with the viruses of subacute spongiform encephalopathies.

Abstract Attempts to establish cell cultures infected with the viruses of scrapie, kuru, and Creutzfeldt—Jakob disease (CJD) were of limited success. Seven cultures of normal cell lines inoculated with brain suspensions containing kuru or CJD virus and nearly half (16134) of the primary cell cultures derived from brains of humans and experimental animals with subacute spongiform encephalopathies were infectious. However, following prolonged maintenance or serial passages, cultures lost infectivity. Further, of 10 rapidly growing cell lines produced by SV40 transformation of cultures derived from eight scrapie-infected mice, one CJD-infected chimpanzee, and one kuru-infected chimpanzee, only one, a transformed scrapie mouse brain cell line, maintained infectivity. In all infectious cultures, a minimum of 104 cells were required to transmit 1 LD50 to an assay animal.

Low-incidence latent infection with variant B or roseola type human herpesvirus 6 in leukocytes of healthy adults

SummaryNested primer-based polymerase chain reaction was employed to determine the frequency of latent infection with human herpesvirus 6 (HHV-6) among healthy adults from Bratislava, Slovak Republic. A 592-bp region, upstream from the gene encoding the putative large tegument protein of HHV-6, was amplified from DNA extracted from peripheral blood mononuclear cells (PBMC) of only one of 29 seropositive adults, suggesting that as few as 1 in 105 PBMC may be infected with the virus. Direct sequencing of the 592-bp fragment indicated that the virus harbored by the seropositive Slovak subject (designated B38) differed by only 3 nucleotides from an HHV-6 variant B strain (R-147) isolated from an American infant with a roseola-like illness and by 32 bases from the variant A strain GS isolated from a patient with lymphadenopathy (5.4% sequence divergence). None of these strains had a deoxyadenosine at base position 1251, when compared to the published sequence of strain GS clone pZVH14. Although this discrepancy did not affect the large tegument protein gene, it altered the predicted amino acid sequences of two putative proteins coded by open-reading frames 1 and 2 (ORF 1 and ORF 2) located upstream from this gene.

High prevalence of human T-lymphotropic virus type I infection in isolated populations of the Western Pacific region confirmed by Western immunoblot

High prevalences of antibodies against human T‐lymphotropic virus type I (HTLV‐I), as confirmed by Western immunoblot, were found in several remote indigenous populations of the Solomon Islands and Vanuatu and in some isolated populations of New Guinea that had no contact with Japanese or Africans and little contact with Caucasians prior to our bleedings. By contrast, zero or very low prevalences of HTLV‐I infection were found in Guamanians and Carolinians, despite more than 30 years of intense contact with the Japanese. A total of 1,601 sera, collected between 1963 and 1981 from 21 population groups in the Western Pacific, was tested by enzyme‐linked immunosorbent assay (ELISA) for IgG antibodies to HTLV‐I. By ELISA, prevalences of antibodies against HTLV‐I ranged from zero to 50%. Seropositivity could be confirmed in only 12.5% of 48 ELISA‐positive sera selected for testing by Western immunoblot. However, the confirmed HTLV‐I seroprevalences in some Melanesian populations were still as high as those found in HTLV‐I‐endemic regions, such as southwestern Japan and the Caribbean basin. HTLV‐I prevalences were similar among males and females, and acquisition of antibodies increased with age. Our data indicate that infections with HTLV‐I or a related retrovirus have been widespread in the southwestern Pacific for over 25 year in populations with minimal outside contact, while some populations which had extensive Japanese contact have no evidence of infection. Furthermore, based on the high frequency of indeterminate Western immunoblots, we conclude that in Melanesia this may represent either incomplete specific reactivity to HTLV‐I or the existence of an antigenic variant of HTLV‐I, distinct from prototype Japanese, American, and European HTLV‐I strains.

Transmission of human T-cell leukemia virus type I from a patient with HTLV-I associated myelopathy/tropical spastic paraparesis and an asymptomatic carrier to rabbits

SummaryRabbits were infected successfully with two strains of human T-cell leukemia virus type I (HTLV-I), one isolated from a Colombian patient with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) and the other from an asymptomatic carrier. HTLV-I was repeatedly demonstrated in peripheral blood mononuclear cells (PBMNC) of infected rabbits, and the rabbits had elevated antibodies against the various structural proteins of HTLV-I. Four rabbits inoculated with HTLV-I-infected autologous lymphoid cells intravenously (i.v.) and intracerebrally (i.c.) had virus present in their PBMNC for more than 40 weeks, while those that were inoculated either with HTLV-I-infected human lymphoid cells or with autologous rabbit lymphoid cells intraperitoneally (i.p.) had episodes during which virus was not recovered from their PBMNC. The one rabbit inoculated i.p. developed antibodies to viral envelope glycoproteins earlier than did those inoculated i.v. and i.c. Rabbit lymphoid cell lines persistently infected with HTLV-I were established by cocultivating the rabbit PBMNC with HTLV-I-infected human lymphoid cells that had been irradiated or by inoculation with cell-free supernatant fluids of HTLV-I infected non-irradiated lymphoid cell cultures. HTLV-I-infected rabbit cell lines were of T-cell origin and expressed HTLV-I antigens by immunofluorescence. Electron microscopy revealed type-C retrovirus particles.