Masako Moriuchi

Exposure to bacterial products renders macrophages highly susceptible to T-tropic HIV-1.

Microbial coinfections variably influence HIV-1 infection through immune activation or direct interaction of microorganisms with HIV-1 or its target cells. In this study, we investigated whether exposure of macrophages to bacterial products impacts the susceptibility of these cells to HIV-1 of different cellular tropisms. We demonstrate that () macrophages exposed to bacterial cell wall components such as lipopolysaccharide (LPS) (Gram-negative rods), lipoteichoic acid (Gram-positive cocci), and lipoarabinomannan (Mycobacteria) become highly susceptible to T cell (T)-tropic HIV-1 (which otherwise poorly replicate in macrophages) and variably susceptible to macrophage (M)-tropic HIV-1; () LPS-stimulated macrophages secrete a number of soluble factors (i.e., chemokines, interferon, and proinflammatory cytokines) that variably affect HIV infection of macrophages, depending on the virus phenotype in question; and () LPS-stimulated macrophages express CCR5 (a major coreceptor for M-tropic HIV-1) at lower levels and CXCR4 (a major coreceptor for T-tropic HIV-1) at higher levels compared with unstimulated macrophages. We hypothesize that a more favorable environment for T-tropic HIV-1 and a less favorable or even unfavorable environment for M-tropic HIV-1 secondary to exposure of macrophages to those bacterial products may accerelate a transition from M- to T-tropic viral phenotype, which is indicative of disease progression.

A Milk Protein Lactoferrin Enhances Human T Cell Leukemia Virus Type I and Suppresses HIV-1 Infection

Human T cell leukemia virus type I (HTLV-I) and HIV-1, causative agents of adult T cell leukemia/lymphoma and AIDS, respectively, are transmitted vertically via breast milk. Here we demonstrate that lactoferrin, a milk protein that has a variety of antimicrobial and immunomodulatory activities, facilitates replication of HTLV-I in lymphocytes derived from asymptomatic HTLV-I carriers and transmission to cord blood lymphocytes in vitro. Transient expression assays revealed that lactoferrin can transactivate HTLV-I long terminal repeat promoter. In contrast, lactoferrin inhibits HIV-1 replication, at least in part, at the level of viral fusion/entry. These results suggest that lactoferrin may have different effects on vertical transmission of the two milk-borne retroviruses.

Cathepsin G, a Neutrophil-Derived Serine Protease, Increases Susceptibility of Macrophages to Acute Human Immunodeficiency Virus Type 1 Infection

ABSTRACT Neutrophils dominate acute inflammatory responses that generally evolve into chronic inflammatory reactions mediated by monocyte/macrophages and lymphocytes. The latter cell types also serve as major targets for human immunodeficiency virus type 1 (HIV-1). In this study we have investigated the role of neutrophil products, particularly cathepsin G, in HIV infection. Cathepsin G induced chemotaxis and production of proinflammatory cytokines by macrophages but not CD4+ T cells. Pretreatment with cathepsin G markedly increased susceptibility of macrophages but not CD4+ T cells to acute HIV-1 infection. When macrophages were exposed to pertussis toxin prior to cathepsin G treatment, the cathepsin G-mediated effect was almost abrogated, suggesting that enhancement of HIV-1 replication by cathepsin G requires Gi protein-mediated signal transduction. Although prolonged exposure to cathepsin G suppressed HIV infection of macrophages, serine protease inhibitors, which are exuded from the bloodstream later during inflammatory processes, neutralized the inhibitory effect. Neutrophil extracts or supernatants from neutrophil cultures, which contain cathepsin G, had effects similar to purified cathepsin G. Thus, cathepsin G, and possibly other neutrophil-derived serine proteases, may have multiple activities in HIV-1 infection of macrophages, including chemoattraction of monocyte/macrophages (HIV-1 targets) to inflamed tissue, activation of target cells, and increase in their susceptibility to acute HIV-1 infection.

Severe postnatal cytomegalovirus infection in a very premature infant.

Several studies have reported that postnatally acquired cytomegalovirus (CMV) infection can cause sepsis-like syndrome in premature infants. We here report a 622-gram birth weight male infant of 23 weeks’ gestation who had sepsis-like syndrome and pneumonia. Substantial CMV loads were detected in peripheral blood cells, plasma, and urine when the patient was in crisis, but was decreased in parallel to clinical improvement without using ganciclovir. CMV DNA was not detected from his umbilical cord or Guthrie card, even by highly sensitive real-time PCR. Molecular profiles were indistinguishable between the CMV strain isolated from his urine and that from maternal breast milk, indicating postnatal acquisition of CMV through breast milk. Although he had transient hearing impairment, his neurodevelopmental outcome of 30 months of corrected age was normal. Further accumulation of clinical and virological data in postnatal CMV infection is necessary for evaluating the severity and selecting patients requiring antiviral therapy.

Reciprocal Interactions between Human T-Lymphotropic Virus Type 1 and Prostaglandins: Implications for Viral Transmission

ABSTRACT Human T-lymphotropic virus type 1 (HTLV-1), the etiologic agent of adult T-cell leukemia/lymphoma, is transmitted through breast milk and seminal fluid, which are rich in prostaglandins (PGs). We demonstrate that PGE2 upregulates the HTLV-1 long terminal repeat promoter through the protein kinase A pathway, induces replication of HTLV-1 in peripheral blood mononuclear cells (PBMC) derived from asymptomatic carriers, and enhances transmission of HTLV-1 to cord blood mononuclear cells (CBMC). Furthermore, HTLV-1 Tax transactivates a promoter for cyclooxygenase 2, a PG synthetase, and induces PGE2 expression in PBMC or CBMC. Thus, HTLV-1 interacts with and benefits from PGs, constituents of its own vehicle for transmission.

Retrospective diagnosis of congenital cytomegalovirus infection in children with autism spectrum disorder but no other major neurologic deficit

AIM Congenital cytomegalovirus (CMV) infection can cause a variety of neurological deficits of delayed onset in infants who are asymptomatic at birth. The aim of this study was to investigate the prevalence of congenital CMV infection among children with autism spectrum disorder (ASD) in Nagasaki, Japan. METHODS Twenty-nine children with ASD who were born in Nagasaki and had no other major neurological deficits were recruited. Two of the patients were excluded due to significant perinatal events. The remaining 27 children were investigated retrospectively for congenital CMV infection by analyzing dried blood spot samples or dried umbilical cords for CMV DNA using real-time PCR. RESULTS CMV DNA was detected in two (7.4%) of the 27 children. Neither of the patients had perinatal histories suggestive of congenital CMV disease or other neurological deficits, including hearing impairment and epilepsy. The severity of their autistic disorders varied considerably. CONCLUSIONS The rate of congenital CMV infection in this study (two of 27 children with ASD), which was significantly (p=0.004) higher than the incidence of congenital CMV infection in Nagasaki (0.31%, 10/3230 live births), suggests the involvement of congenital CMV infection in a portion of children with ASD, although definite diagnosis was not obtained due to limited clinical data of the study subjects.

Persistent hepatitis associated with chronic active Epstein-Barr virus infection.

A previously healthy boy developed persistent hepatitis without fever or lymphoproliferative disorder. Although serologic tests were not indicative, Epstein-Barr virus (EBV) genome and transcripts were detected from the liver tissue, and real time PCR detected extremely high levels of EBV viremia. EBV infection should be included in the differential diagnoses of hepatitis of unknown etiology, even with unremarkable serologic data.

No Association of Mouse Mammary Tumor Virus-Related Retrovirus With Japanese Cases of Breast Cancer

Mouse mammary tumor virus (MMTV) is the causative agent of breast tumors in mice. Recently, DNA sequences homologous or closely related to MMTV env gene have been specifically detected in breast cancer tissue from significant numbers of American, Australian, and Tunisian women, suggesting a viral etiology for at least a part of human breast cancer. However, the viral sequences have not been detected from any of breast cancer samples in several subsequent studies. Thus, whether MMTV‐related retrovirus is a causative agent of human breast cancer remains controversial. To demonstrate if MMTV‐related retrovirus is involved in Japanese cases of breast cancer, breast tissue specimens from 46 breast cancer patients and 3 patients with benign mammary tumors were investigated. Extensive analysis using PCR and Southern blot hybridization, however, could not detect the MMTV env gene‐like sequence in any of the samples tested as well as in MCF7 cells that has previously been described as a positive control. Thus, MMTV itself or MMTV‐related retrovirus is not associated with breast carcinogenesis in Japanese women, and it is unclear whether this conclusion is merely a reflection of regional differences in its epidemics. J. Med. Virol. 80:1447–1451, 2008.

Human T-cell leukemia virus type I–associated myelopathy following living-donor liver transplantation

This report describes a patient who developed human T‐cell leukemia virus type I–associated myelopathy (HAM) following a living‐donor liver transplantation (LDLT) for liver cirrhosis due to hepatitis C virus (HCV) infection. Both the recipient and the living donor (his sister) were human T‐cell leukemia virus type I (HTLV‐I) carriers. Since the LDLT, he had been treated with immunosuppressive drugs such as tacrolimus and steroids as well as interferon‐α to prevent rejection and a recurrence of the HCV infection, respectively. Even though the HTLV‐I proviral load had decreased upon interferon treatment, he developed a slowly progressive gait disturbance with urinary disturbance 2 years after the LDLT and was diagnosed with HAM. This appears to be the first report of HAM development in an HLTV‐I–infected LDLT recipient. Liver Transpl 14:647–650, 2008.

Short Communication HTLV Type I Tax Activation of the CXCR4 Promoter by Association with Nuclear Respiratory Factor 1

Human T lymphotropic virus type I trans-activator Tax protein regulates expression of several cellular genes that are involved in cellular activation, proliferation, and transformation. Tax mediates its regulatory activity through interaction with cellular transcription factors such as members of the cAMP-responsive elementbinding factors/ATF family or the NF-kappa B/Rel family. In this study we have demonstrated that Tax trans -activates the promoter for CXCR4, a coreceptor for T cell-tropic HIV-1 through its association with nuclear respiratory factor 1 (NRF1). The promoter region for CXCR4 contains an NRF1-binding site, which is crucial for basal and Tax-induced activity. Glutathione S-transferase (GST) pull-down experiments showed association of GST-Tax fusion protein with NRF1 in vitro. Expression of Tax, in addition to stimulation with phorbol myristate acetate and ionomycin, increased formation of the NRF1 complex in a gel-mobility shift assay, indicating that Tax association with NRF1 in vivo faci...