Novel Arenavirus Sequences in Hylomyscus sp. and Mus (Nannomys) setulosus from Côte d'Ivoire: Implications for Evolution of Arenaviruses in Africa

This study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in Africa. During 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of Côte d'Ivoire. Specimens were screened by pan-Old World arenavirus RT-PCRs targeting S and L RNA segments as well as immunofluorescence assay. Sequences of two novel tentative species of the family Arenaviridae, Menekre and Gbagroube virus, were detected in Hylomyscus sp. and Mus (Nannomys) setulosus, respectively. Arenavirus infection of Mus (Nannomys) setulosus was also demonstrated by serological testing. Lassa virus was not found, although 60% of the captured animals were Mastomys natalensis. Complete S RNA and partial L RNA sequences of the novel viruses were recovered from the rodent specimens and subjected to phylogenetic analysis. Gbagroube virus is a closely related sister taxon of Lassa virus, while Menekre virus clusters with the Ippy/Mobala/Mopeia virus complex. Reconstruction of possible virus–host co-phylogeny scenarios suggests that, within the African continent, signatures of co-evolution might have been obliterated by multiple host-switching events

CD34+ hematopoietic progenitor cells are not a major reservoir of the human immunodeficiency virus

Hematologic abnormalities occur in the majority of patients with acquired immunodeficiency syndrome (AIDS). Infection of the hematopoietic progenitor cells has been proposed as a potential explanation. In this study, different bone marrow cell populations, including the CD34+ hematopoietic progenitor cells, were purified by a fluorescence-activated cell sorter (FACS) and analyzed for the presence of human immunodeficiency virus-1 (HIV-1) proviral DNA using the polymerase chain reaction. A group of 14 patients with AIDS or AIDS- related complex (ARC) was studied (11 with peripheral blood cytopenias). The CD4+ helper cells in the bone marrow were found positive for HIV-1 DNA in all patients. In contrast, CD34+ progenitor cells were positive in only one patient. Two monocyte samples and two samples of CD4-/CD34- lymphocytes/blasts (mainly B and CD8 lymphocytes) were positive. Proviral DNA could not be detected in granulocytes. FACS analysis showed that the percentage of CD34+ hematopoietic progenitor cells was not altered in the bone marrow of AIDS patients in comparison with the HIV-1 seronegative controls. In contrast, the number of CD4+ lymphocytes was markedly reduced in the bone marrow of AIDS patients. These results show that the hematologic abnormalities in AIDS patients are neither explained by direct infection of the hematopoietic progenitor cells with HIV-1 nor by a depletion of progenitor cells.</jats:p

CD34+ hematopoietic progenitor cells are not a major reservoir of the human immunodeficiency virus

Abstract Hematologic abnormalities occur in the majority of patients with acquired immunodeficiency syndrome (AIDS). Infection of the hematopoietic progenitor cells has been proposed as a potential explanation. In this study, different bone marrow cell populations, including the CD34+ hematopoietic progenitor cells, were purified by a fluorescence-activated cell sorter (FACS) and analyzed for the presence of human immunodeficiency virus-1 (HIV-1) proviral DNA using the polymerase chain reaction. A group of 14 patients with AIDS or AIDS- related complex (ARC) was studied (11 with peripheral blood cytopenias). The CD4+ helper cells in the bone marrow were found positive for HIV-1 DNA in all patients. In contrast, CD34+ progenitor cells were positive in only one patient. Two monocyte samples and two samples of CD4-/CD34- lymphocytes/blasts (mainly B and CD8 lymphocytes) were positive. Proviral DNA could not be detected in granulocytes. FACS analysis showed that the percentage of CD34+ hematopoietic progenitor cells was not altered in the bone marrow of AIDS patients in comparison with the HIV-1 seronegative controls. In contrast, the number of CD4+ lymphocytes was markedly reduced in the bone marrow of AIDS patients. These results show that the hematologic abnormalities in AIDS patients are neither explained by direct infection of the hematopoietic progenitor cells with HIV-1 nor by a depletion of progenitor cells.</jats:p

Detection of cytomegalovirus DNA in CD34+ cells from blood and bone marrow

Infection of hematopoietic progenitor cells with the human cytomegalovirus (HCMV) has been proposed as an explanation for the cytopenias associated with HCMV-related disease. To test this hypothesis, CD34+ cells, which include the hematopoietic progenitors, as well as mature leukocyte populations were purified on a fluorescence- activated cell sorter and analyzed for HCMV DNA by polymerase chain reaction (PCR). A total of 33 samples from 31 immunosuppressed as well as immunocompetent HCMV-seropositive individuals were studied. CD34+ cells were PCR-positive in four of seven bone marrow aspirates from allogeneic bone marrow transplant recipients, in three of eight aspirates from patients with acquired immunodeficiency syndrome, and in the first of two bone marrow samples from an immunocompetent patient with primary HCMV disease. CD34+ cells purified from peripheral blood for autologous and allogeneic transplantation were also analyzed, and 4 of 13 samples were HCMV DNA-positive. Interestingly, two of the four HCMV-positive samples were from healthy allogeneic donors. Among the mature leukocyte populations, the monocytes were most frequently found to be HCMV DNA-positive. No HCMV DNA was detected in the total bone marrow leukocytes of 13 healthy seropositive bone marrow donors or in the CD34+ cell fraction of three further seropositive donors. In conclusion, the data provide strong evidence that CD34+ hematopoietic progenitor cells can be infected with HCMV in immunosuppressed patients, while this cell population was not identified as a major viral reservoir in healthy HCMV-seropositive individuals.</jats:p