Mark A. Beilke

Adult T-cell leukemia/lymphoma development in HTLV-1–infected humanized SCID mice

The molecular and genetic factors induced by human T-lymphotropic virus type-1 (HTLV-1) that initiate adult T-cell leukemia/lymphoma (ATLL) remain unclear, in part from the lack of an animal model that accurately recapitulates leukemogenesis. HTLV-1-infected humanized nonobese diabetic severe combined immunodeficiency (HU-NOD/SCID) mice were generated by inoculation of NOD/SCID mice with CD34(+) hematopoietic progenitor and stem cells (CD34(+) HP/HSCs) infected ex vivo with HTLV-1. HTLV-1-HU-NOD/SCID mice exclusively developed CD4(+) T-cell lymphomas with characteristics similar to ATLL and elevated proliferation of infected human stem cells (CD34(+)CD38(-)) in the bone marrow were observed in mice developing malignancies. Purified CD34(+) HP/HSCs from HTLV-1-infected patient peripheral blood mononuclear cells revealed proviral integrations suggesting viral infection of human bone marrow-derived stem cells. NOD/SCID mice reconstituted with CD34(+) HP/HSCs transduced with a lentivirus vector expressing the HTLV-1 oncoprotein (Tax1) also developed CD4(+) lymphomas. The recapitulation of a CD4(+) T-cell lymphoma in HU-NOD/SCID mice suggests that HSCs provide a viral reservoir in vivo and act as cellular targets for cell transformation in humans. This animal model of ATLL will provide an important tool for the identification of molecular and cellular events that control the initiation and progression of the lymphoma and potential therapeutic targets to block tumor development.

Antiretroviral antibodies : Implications for schizophrenia, schizophrenia spectrum disorders, and bipolar disorder

BACKGROUNDnSome retroviral antigens share structural homology within a group of related retroviruses. It is possible that antibodies directed against one virus may cross-react with antigens from a different virus in the group.nnnMETHODSnUsing this principle, the human immunodeficiency virus 1 (HIV-1) Western blot assay was used as an available source of human retroviral antigens to screen serum samples from an archived collection to ascertain whether there was an association between serum antiretroviral antibodies and mental illnesses.nnnRESULTSnA statistically significant proportion (28/54, 52%) of patients suffering from psychiatric disorders had serum antibodies that recognized at least one antigen present on the blot, culminating in indeterminate HIV-1 tests. The majority of the reactive samples were directed against the HIV-1 group antigens p24 and p17. These findings contrast with those of nonpsychiatric patients, who had 4/16 (25%) indeterminate blots.nnnCONCLUSIONSnThe results suggest exposure to retroviral antigens related to those of HIV-1 in subpopulations of schizophrenic, schizophrenic spectrum disorder, and bipolar disorder patients.

Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

BACKGROUNDnWe aimed to derive and validate a risk score that identifies adults with cerebrospinal fluid (CSF) pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause.nnnMETHODSnPatients with CSF pleocytosis and a negative CSF Gram stain were stratified into a prospective derivation (n = 193) and a retrospective validation (n = 567) cohort. Clinically related baseline characteristics were grouped into three composite variables, each independently associated with a set of predefined urgent treatable causes. We subsequently derived a risk score classifying patients into low (0 composite variables present) or high (≥ 1 composite variables present) risk for an urgent treatable cause. The sensitivity of the risk score was determined in the validation cohort and in a prospective case series of 214 adults with CSF-culture proven bacterial meningitis, CSF pleocytosis and a negative Gram stain.nnnFINDINGSnA total of 41 of 193 patients (21%) in the derivation cohort and 71 of 567 (13%) in the validation cohort had an urgent treatable cause. Sensitivity of the dichotomized risk score to detect an urgent treatable cause was 100.0% (95% CI 93.9-100.0%) in the validation cohort and 100.0% (95% CI 97.8-100.0%) in bacterial meningitis patients.nnnINTERPRETATIONnThe risk score can be used to identify adults with CSF pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause.

Human T-cell Lymphotropic Virus Type I-Associated Uveitis in an African American

PURPOSE/METHODSnIn an African American woman with the human T-cell lymphotropic virus type I associated with uveitis, clinical and ocular findings were correlated with detection of viral genome by polymerase chain reaction, and by viral antigen detection in cultured peripheral blood mononuclear cells.nnnRESULTS/CONCLUSIONSnHigh levels of human T-cell lymphotropic virus type I gene expression in multiple samples over a two-year period strongly support the diagnosis of human T-cell lymphotropic virus type I uveitis. Systemic corticosteroid therapy resulted in partial remission.

Detection of HTLV-I in clinical specimens

The American Red Cross, which collects 50% of blood for transfusion in the United States, now tests all prospective blood donors for HTLV-I and HTLV-II antibodies. It will therefore be important to recognize the significance and clinical spectrum of diseases associated with these viruses, and to become familiar with the current methods used to diagnose infection. This review summarizes the techniques currently in use to screen for HTLV-I/II antibodies, as well as methods to detect viral genome and/or gene products in blood and tissue specimens.

Human T Cell Leukemia Virus Type 1 Up-Regulation after Simian Immunodeficiency virus-1 Coinfection in the Nonhuman Primate

The effects that human T cell leukemia virus (HTLV) type 1 and simian immunodeficiency virus (SIV) coinfection have on HTLV-1 dynamics and disease progression were tested in a nonhuman primate model. Seven rhesus macaques were experimentally inoculated with HTLV-1, and a persistent infection was established. Coinfection with SIV/smB670 resulted in increased HTLV-1 p19 antigens in peripheral blood mononuclear cells and HTLV-1 proviral loads. Circulating CD2(+) and CD8(+) T lymphocytes increased over preinoculation levels, along with a progressive decrease in CD4(+) T cells, typical for terminal SIV disease. Finally documented was the striking emergence of up to 19% of HTLV-associated flower cell lymphocytes in the circulation, as seen in patients with adult T cell leukemia/lymphoma. CD8(+)CD25(+) T cell subpopulation increases were positively correlated with flower cell appearance and suggested their possible role in this process. We conclude that SIV may have the potential to up-regulate HTLV-1 and disease expression.

High levels of CC‐chemokine expression and downregulated levels of CCR5 during HIV‐1/HTLV‐1 and HIV‐1/HTLV‐2 coinfections

The human T‐cell lymphotropic virus type 1 (HTLV‐1) and HTLV‐2 are common copathogens among Human Immunodeficiency Virus (HIV)‐infected individuals. HTLV‐2 may confer a survival benefit among patients with HIV‐1/HTLV‐2 coinfections, along with lower plasma HIV‐1 levels and delayed rates of CD4+ T‐cell decline. These effects have been attributed to the ability of the HTLV‐2 viral transactivating Tax2 protein to induce the production of high levels of antiviral CC‐chemokines and to downregulate expression of the CCR5 receptor, resulting in impaired entry of HIV‐1 into CD4+ T‐cells. This study investigated the innate immunity of coinfected HIV/HTLV individuals by testing the ability of patient PBMCs to produce CC‐chemokines in association CCR5 receptor modulation. The cellular proliferative responses of HIV/HTLV coinfected versus HIV monoinfected individuals were also evaluated. Higher levels of MIP‐1α, MIP‐1β, and RANTES (Pu2009<u20090.05) were found in HIV‐1/HTLV‐2 coinfected group compared to HIV‐1 monoinfected population. Upregulated levels of RANTES were shown in HIV‐1/HTLV‐1 after 1 and 3 days of culture (Pu2009<u20090.05). Lymphocytes from HIV‐1/HTLV‐2 coinfected individuals showed significant CCR5 downregulation after 1 and 3 days of culture compared to lymphocytes from HIV‐1 and uninfected groups (Pu2009<u20090.05). Lower percentages of CCR5‐positive cells were found in HIV‐1/HTLV‐1 coinfected after 3 days of incubation (Pu2009<u20090.05). Levels of proliferation were significantly higher in the HIV‐1/HTLV‐1 group compared to HIV‐1 alone (Pu2009<u20090.05). HTLV‐2 and HTLV‐1 infections may induce the involvement of innate immunity against HIV‐1 via stimulation of CC‐chemokines and receptors, potentially modifying CCR5/HIV‐1 binding and HIV‐1 progression in coinfected individuals. J. Med. Virol. 87:790–797, 2015.

Human T cell leukaemia virus type 2 tax protein mediates CC-chemokine expression in peripheral blood mononuclear cells via the nuclear factor kappa B canonical pathway

Retroviral co‐infections with human immunodeficiency virus type‐1 (HIV‐1) and human T cell leukaemia virus type 1 (HTLV‐1) or type 2 (HTLV‐2) are prevalent in many areas worldwide. It has been observed that HIV‐1/HTLV‐2 co‐infections are associated with slower rates of CD4+ T cell decline and delayed progression to AIDS. This immunological benefit has been linked to the ability of Tax2, the transcriptional activating protein of HTLV‐2, to induce the expression of macrophage inflammatory protein (MIP)‐1α/CCL3, MIP‐1β/CCL4 and regulated upon activation normal T cell expressed and secreted (RANTES)/CCL5 and to down‐regulate the expression of the CCR5 co‐receptor in peripheral blood mononuclear cells (PBMCs). This study aimed to assess the role of Tax2‐mediated activation of the nuclear factor kappa B (NF‐κB) signalling pathway on the production of the anti‐viral CC‐chemokines MIP‐1α, MIP‐1β and RANTES. Recombinant Tax1 and Tax2 proteins, or proteins expressed via adenoviral vectors used to infect cells, were tested for their ability to activate the NF‐κB pathway in cultured PBMCs in the presence or absence of NF‐κB pathway inhibitors. Results showed a significant release of MIP‐1α, MIP‐1β and RANTES by PBMCs after the activation of p65/RelA and p50. The secretion of these CC‐chemokines was significantly reduced (Pu2009<u20090·05) by canonical NF‐κB signalling inhibitors. In conclusion, Tax2 protein may promote innate anti‐viral immune responses through the activation of the canonical NF‐κB pathway.

Prolonged oral antibiotic suppression in osteomyelitis and associated outcomes in a Veterans population

OBJECTIVEnProlonged oral antimicrobial suppression has been suggested as an alternative treatment for patients with prosthetic joint infections who are unable or unwilling to undergo surgical intervention; however, little data exists for utilizing this approach in patients with chronic osteomyelitis and no artificial hardware.nnnMETHODSnWe retrospectively reviewed the medical records of all patients over a 5-year time frame who were treated with chronic oral antibiotic suppression for osteomyelitis and who had no artificial hardware. Clinical outcomes, risk factors for treatment failure, and adverse drug reactions were evaluated.nnnRESULTSnA total of 20 patients were included for evaluation, of which 12 (60%) were able to achieve successful suppression of disease for a mean duration of 778 ± 408 days after discontinuation. Diabetic patients were found to be at higher risk for treatment failure (p = 0.0281). We also identified a high rate of adverse events (25%) attributable to suppressive medications. Despite elevated inflammatory markers contributing to the decision to initiate antibiotic suppression in the majority of patients, few were able to achieve normal values throughout suppressive therapy.nnnCONCLUSIONnFurther randomized, controlled studies are needed to determine the utility of antibiotic suppression. However, prolonged oral antibiotic suppression may be a reasonable last-line treatment alternative for chronic osteomyelitis, even in the absence of artificial hardware, for patients who are unwilling or unable to undergo optimal surgical intervention.

Recombinant Tax1 and Tax2 proteins inhibit HIV-1 replication in peripheral blood mononuclear cells

Patients with HIV-1 and HTLV-2 coinfections often exhibit a clinical course similar to HIV-1 infected long-term nonprogressors. This observation has been attributed in part to the ability of the HTLV Tax2 protein to activate production of antiviral chemokines and to downregulate the CCR5 co receptor on lymphocytes. Therefore we investigated the possibility that a recombinant Tax2 protein could suppress HIV-1 viral replication in vitro. R5-tropic HIV-1 (NLAD8)-infected-PBMCs were treated daily with recombinant Tax1 and Tax2 proteins (dosage range 1-100 pM). Culture supernatants were collected at intervals for 22 days post-infection and assayed for levels of HIV-1 p24 antigen. Treatment of PBMCs with Tax2 protein resulted in significant reduction in HIV-1 p24 antigen levels (p<0.05) at days 10, 14, and 18 post-infection compared to HIV-1-infected or mock-treated PBMCs. This was preceded by the detection of increased levels of CC-chemokines MIP-1α/CCL3, MIP-1β/CCL4, and RANTES/CCL5, on days 1-7 of infection (p<0.05). Similar, but less robust inhibition was determined in Tax1 treated PBMCs. Addition of Tax2 proteins starting 48 hours previous to infection resulted in a significant inhibition of HIV-1 p24 levels (p<0.05 at days 7 to 14 compared to the untreated, R5 infected PBMCs. In contrast, when addition of Tax2 began two days after R5 infection, significant HIV-1 p24 levels were only determined at days 7 and 10 for 1 pM and at day 7 for 10 pM (p<0.05). These results support the contention that Tax1 and Tax2 play a role in generating antiviral responses against HIV-1 in vivo and in vitro.