Kaposi's sarcoma-associated herpesvirus infection of bone marrow dendritic cells from multiple myeloma patients

Iatrogenic Kaposi's sarcoma from induction therapy for myeloma: to transplant or not to transplant?

We present the case of an HIV-negative man in his 50s who developed a generalised nodular rash while having first-line bortezomib-cyclophosphamide-dexamethasone chemotherapy for multiple myeloma. The rash was biopsied and proven to be Kaposi's sarcoma. The patient's treatment was interrupted at the sixth cycle of chemotherapy, by which time the rash had also spread to the oral mucosa and eyelid. The rash regressed spontaneously on stopping treatment. We were reluctant to restart myeloma treatment, but on the other hand, we wished to consolidate the very good partial response achieved. An autologous marrow transplant was done months later without any recurrence of his Kaposi's with the initiation of bortezomib maintenance. Bortezomib has putative activity against Kaposi's. The patient could benefit from imid-based (thalidomide, lenalidomide, pomalidomide) combination chemotherapy once his myeloma progresses or if there is a recurrence of Kaposi's sarcoma.

Virus–Host Interplay Between Poly (ADP-Ribose) Polymerase 1 and Oncogenic Gammaherpesviruses

The gammaherpesviruses, include the Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, and murine gammaherpesvirus 68. They establish latent infection in the B lymphocytes and are associated with various lymphoproliferative diseases and tumors. The poly (ADP-ribose) polymerase-1 (PARP1), also called ADP-ribosyltransferase diphtheria-toxin-like 1 (ARTD1) is a nuclear enzyme that catalyzes the transfer of the ADP-ribose moiety to its target proteins and participates in important cellular activities, such as the DNA-damage response, cell death, transcription, chromatin remodeling, and inflammation. In gammaherpesvirus infection, PARP1 acts as a key regulator of the virus life cycle: lytic replication and latency. These viruses also develop various strategies to regulate PARP1, facilitating their replication. This review summarizes the roles of PARP1 in the viral life cycle as well as the viral modulation of host PARP1 activity and discusses the implications. Understanding the interactions between the PARP1 and oncogenic gammaherpesviruses may lead to the identification of effective therapeutic targets for the associated diseases.

Immunomodulation: An immune regulatory mechanism in carcinoma therapeutics

Cancer has been generally related to the possession of numerous mutations which interrupt important signaling pathways. Nevertheless, deregulated immunological signaling is considered as one of the key factors associated with the development and progression of cancer. The signaling pathways operate as modular network with different components interacting in a switch-like fashion with two proteins interplaying between each other leading to direct or indirect inhibition or stimulation of down-stream factors. Genetic, epigenetic, and transcriptomic alterations maintain the pathological conduit of different signaling pathways via affecting diverse mechanisms including cell destiny. At present, immunotherapy is one of the best therapies opted for cancer treatment. The cancer immunotherapy strategy includes harnessing the specificity and killing mechanisms of the immunological system to target and eradicate malignant cells. Targeted therapies utilizing several little molecules including Galunisertib, Astragaloside-IV, Melatonin, and Jervine capable of regulating key signaling pathways can effectively help in the management of different carcinomas.

[IAssociation between Kaposi´s sarcoma and multiple myeloma: is it caused by HHV-8?]

Kaposi´s sarcoma is a tumor characterized by purple or brownish lesions affecting the skin. It is most commonly associated with human herpes virus type 8 (HHV-8) infection and may be secondary to malignant hemopathy, including lymphomas. We here report a new case of a very rare combination: Kaposi´s disease-multiple myeloma. The study involved Mr. aged 67 years, treated for Kaposi´s disease in the Department of Dermatology. Serological test for HHV-8 was positive; it was associated with stage I multiple myeloma IgG Lambda with a poor prognosis. We here report this 21^st case of Kaposi-Kahler in order to highlight Kaposi-human herpes 8 virus variant involved in the pathophysiology of multiple myeloma. More studies are needed in order to establish this exceptional link.

Lymphocyte Subsets and Inflammatory Cytokines of Monoclonal Gammopathy of Undetermined Significance and Multiple Myeloma

Almost all multiple myeloma (MM) cases have been demonstrated to be linked to earlier monoclonal gammopathy of undetermined significance (MGUS). Nevertheless, there are no identified characteristics in the diagnosis of MGUS that have been helpful in differentiating subjects whose cancer may progress to a malignant situation. Regarding malignancy, the role of lymphocyte subsets and cytokines at the beginning of neoplastic diseases is now incontestable. In this review, we have concentrated our attention on the equilibrium between the diverse lymphocyte subsets and the cytokine system and summarized the current state of knowledge, providing an overview of the condition of the entire system in MGUS and MM. In an age where the therapy of neoplastic monoclonal gammopathies largely relies on drugs capable of acting on the immune system (immunomodulants, immunological checkpoint inhibitors, CAR-T), detailed knowledge of the the differences existing in benign and neoplastic forms of gammopathy is the main foundation for the adequate and optimal use of new drugs.

Stem Cell Transplantation for Multiple Myeloma

BACKGROUND

Multiple myeloma (MM) is the second most common hematologic malignancy, affecting approximately 14,000 new patients in the United State per year. The median overall survival is 5 years, and cure is a realistic goal for only a small minority of patients.

METHODS

A review of the literature was conducted that focused on treatment strategies for MM involving administration of high doses of chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplant.

RESULTS

For over three decades, the standard treatment for MM has been a regimen of melphalan and prednisone (MP). Complete responses (CRs) have been rare, and 50% of patients have had disease that was resistant to treatment with MP. Attempts have been made to improve the outcome of MM by administering other combinations of standard doses of chemotherapy, but these treatments are equivalent in terms of overall survival. For patients who are candidates, high-dose therapy followed by autologous stem cell transplantation results in higher CR rates and improved long-term survival compared to treatment with standard doses of chemotherapy alone. While this strategy represents an advance in the treatment of MM, evidence-based reviews indicate that there are a number of issues to consider regarding the induction therapy, the collection of stem cells, and the timing, type, and number of high-dose therapies to use in this type of treatment strategy.

CONCLUSIONS

Advances have been made in autologous transplantation, allogeneic transplantation, anti-MM agents, and immunotherapy for MM. Combining these different strategies to achieve synergistic responses is an exciting possibility.

Where we were, where we are, where we are going: progress in multiple myeloma

The celebration of the 50th anniversary of the founding of the American Society of Clinical Oncology provides the occasion to review the progress that has been made in the biology and treatment of multiple myeloma. With the advent of melphalan and cyclophosphamide in the early 1960s the median survival of patients with multiple myeloma more than doubled from 10 months to approximately 24 months. Throughout multiple clinical trials in the 1970s and 1980s, melphalan and prednisone remained the gold standard, with a 3-year survival of 42%. The use of high-dose melphalan with autologous hematopoietic stem cell support provided an incremental advance in the 1990s. The outlook for patients was dramatically improved in the 2000s with the introduction of thalidomide analogs and proteasome inhibitors, so that the 3-year survival of patients treated in 2008 with melphalan and prednisone had increased to 66%. The 2010s are dominated by studying the optimal combination, sequence, and duration of therapies. These clinical advances have occurred along with our evolving understanding of the molecular pathogenesis of myeloma. Myeloma can be divided into two main groups: hyperdiploid, with multiple trisomies of odd-numbered chromosomes, and nonhyperdiploid, with recurrent immunoglobulin heavy chain gene translocations. Disease progression is associated with rearrangements of MYC, the most common mutation in myeloma, present in nearly half of patients. Genomic studies have highlighted marked subclonal heterogeneity that poses one of the main challenges to successful control of the disease. This problem will be addressed in future studies in the 2020s, which will include a focus on immunologic approaches such as monoclonal antibodies, checkpoint inhibitors, engineered T-cells, and novel immunomodulators.

Oncogenic Virus Infections in the General Population and End-stage Renal Disease Patients With Special Emphasis on Kaposi's Sarcoma Associated Herpes Virus (KSHV) in Northeast of Iran

BACKGROUND

Globally, almost 20% of cancers are related to infectious agents that can be prevented. Oncogenicity refers to viruses that may cause cancers, more importantly in immunocompromised subjects such as transplant and hemodialysis patients. Therefore, epidemiological studies are the first line for understanding the importance of these agents in public health, particularly, in mobile populations, tourism and pilgrimage regions.

OBJECTIVES

Oncogenic viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV) and Epstein-barr virus (EBV) are the most common viral agents in immunocompromised patients. Furthermore, human T lymphocyte virus type I (HTLV-I), due to endemicity in Khorasan Razavi province located northeast of Iran as a pilgrimage region, and Kaposi's sarcoma associated herpes virus (KSHV), as an oncogenic herpesvirus in immunocompromised subjects have been investigated among the general population and those with end-stage renal diseases (ESRD).

PATIENTS AND METHODS

A cross-sectional study was carried out among 1227 randomly selected individuals; 25 donors and 195 patients with ESRD, including 60 kidney transplant recipients and 135 dialysis patients from the Khorasan Razavi province, Iran. Serological tests were carried out using commercial enzyme-immunoassay kits. To confirm positive serology tests, the extracted viral DNA or RNA was examined for the presence of KSHV, HTLV-I and HCV by conventional PCR.

RESULTS

The prevalence of KSHV infection in the general population was 1.71% (21/1227); 2.60% (10/384) males and 1.30% (11/843) females. In kidney transplants, viral infections occurred in 23.3% of subjects; including EBV, HTLV-I and HBV-HCV co-infection in 8.3%, 3.3% and 1.7%, respectively. In patients on hemodialysis, viral infections were present in 29.6% including EBV, HTLV-I and HBV-HCV co-infection in 2.2%, 5.9% and 16.3%, respectively. Seroprevalence of KSHV in patients with kidney transplants was 1.7% and in patients on dialysis was 3.0%. Furthermore, KSHV and HTLV-I genome was detected in 25% and 100% of seropositive subjects, respectively.

CONCLUSIONS

In conclusion, this study demonstrated that these tumor virus infections including HTLV-I, KSHV and particularly hepatitis viruses (HBV plus HCV) are prevalent in the general population and in patients on hemodialysis, which might be an important health concern in this region due to the mobile population.

Kaposi's sarcoma-associated herpesvirus genome programming during the early stages of primary infection of peripheral blood mononuclear cells

The early period of Kaposi’s sarcoma-associated herpesvirus (KSHV) infection involves the dynamic expression of viral genes, which are temporally and epigenetically regulated. KSHV can effectively infect and persist in endothelial as well as human B cells with different gene expression patterns. To understand the temporal epigenetic changes which occur when KSHV infects the lymphocytic compartment, we infected human peripheral blood mononuclear cells (PBMCs) and comprehensively analyzed the changes which occurred at the binding sites of virally encoded lytic as well as latent proteins along with epigenetic modifications across the KSHV genome during early primary infection. Using chromatin immunoprecipitation (ChIP) assays, we showed that the KSHV genome acquires a uniquely distinct histone modification pattern of methylation (H3K4me3, H3K9me3, and H3K27me3) and acetylation (H3Ac) during de novo infection of human PBMCs. This pattern showed that the epigenetic changes were temporally controlled. The binding profiles of KSHV latent protein LANA and the immediate early proteins RTA and K8 showed specific patterns at different times postinfection, which reflects the gene expression program. Further analysis demonstrated that KSHV can concurrently express lytic and latent genes which were associated with histone modifications at these specific regions on the viral genome. We identified three KSHV genes, K3, ORF49, and ORF64, which exhibited different profiles of histone modifications during the early stages of PBMC infection. These studies established a distinct pattern of epigenetic modification which correlates with viral gene expression temporally regulated during the first 7 days of PBMC infection and provides clues to the regulatory program required for successful infection by KSHV of human PBMCs.

Kaposi’s sarcoma-associated herpesvirus (KSHV) has been documented as one of the major contributors to morbidity and mortality in AIDS patients during the AIDS pandemic. During its life cycle, KSHV undergoes latent and lytic replication. Typically, KSHV maintains a stringent preference for latent infection in the infected B cells. However, 1 to 5% of infected cells undergo spontaneous lytic reactivation. KSHV lytic replication and infection of new cells are likely to be critical for maintaining the population of infected cells which drive virus-associated pathogenesis. Here, we explored the temporal changes of crucial histone marks on the KSHV genome during early infection of human primary peripheral blood mononuclear cells (PBMCs), which are a physiologically relevant system for monitoring primary infection. These results showed that KSHV possessed a distinct pattern of epigenetic marks during early infection of PBMCs. Further, KSHV concurrently expressed lytic and latent genes during this early period. These results now provide new evidence which contributes to understanding the molecular mechanism that regulates viral gene expression during early infection.

Dendritic cells: key players in human herpesvirus 8 infection and pathogenesis

Human herpesvirus 8 (HHV-8; Kaposi's sarcoma-associated herpesvirus) is an oncogenic gammaherpesvirus that primarily infects cells of the immune and vascular systems. HHV-8 interacts with and targets professional antigen presenting cells and influences their function. Infection alters the maturation, antigen presentation, and immune activation capabilities of certain dendritic cells (DC) despite non-robust lytic replication in these cells. DC sustains a low level of antiviral functionality during HHV-8 infection in vitro. This may explain the ability of healthy individuals to effectively control this virus without disease. Following an immune compromising event, such as organ transplantation or human immunodeficiency virus type 1 infection, a reduced cellular antiviral response against HHV-8 compounded with skewed DC cytokine production and antigen presentation likely contributes to the development of HHV-8 associated diseases, i.e., Kaposi's sarcoma and certain B cell lymphomas. In this review we focus on the role of DC in the establishment of HHV-8 primary and latent infection, the functional state of DC during HHV-8 infection, and the current understanding of the factors influencing virus-DC interactions in the context of HHV-8-associated disease.

An important role for mitochondrial antiviral signaling protein in the Kaposi's sarcoma-associated herpesvirus life cycle

Kaposi's sarcoma-associated herpesvirus (KSHV) has been shown to be recognized by two families of pattern recognition receptors (PRRs), Toll-like receptors (TLRs) and NOD-like receptors (NLRs). Here we show that MAVS and RIG-I (retinoic acid-inducible gene 1), an RLR family member, also have a role in suppressing KSHV replication and production. In the context of primary infection, we show that in cells with depleted levels of MAVS or RIG-I, KSHV transcription is increased, while beta interferon (IFN-β) induction is attenuated. We also observed that MAVS and RIG-I are critical during the process of reactivation. Depletion of MAVS and RIG-I prior to reactivation led to increased viral load and production of infectious virus. Finally, MAVS depletion in latent KSHV-infected B cells leads to increased viral gene transcription. Overall, this study suggests a role for MAVS and RIG-I signaling during different stages of the KSHV life cycle.

IMPORTANCE

We show that RIG-I and its adaptor protein, MAVS, can sense KSHV infection and that these proteins can suppress KSHV replication following primary infection and/or viral reactivation.

Impact of interleukin-6 in hematological malignancies

Almost 3 decades have passed since the discovery and cloning of IL-6, and a tremendous amount of work has contributed to the current knowledge of the biological functions of this cytokine, its receptor, and the signaling pathways that are activated. The understanding of the role of IL-6 in human disease has led to the development of novel therapeutic strategies that block the biological functions of IL-6. In clinical studies, IL-6 and IL-6 receptor antibodies have proven efficacy in rheumatoid arthritis, systemic juvenile idiopathic arthritis, and Castleman's disease, conditions that are known to be driven by IL-6. The focus of this overview is the role of IL-6 in the pathophysiology of hematological malignancies.

Professional antigen presenting cells in human herpesvirus 8 infection

Professional antigen presenting cells (APC), i.e., dendritic cells (DC), monocytes/macrophages, and B lymphocytes, are critically important in the recognition of an invading pathogen and presentation of antigens to the T cell-mediated arm of immunity. Human herpesvirus 8 (HHV-8) is one of the few human viruses that primarily targets these APC for infection, altering their cytokine profiles, manipulating their surface expression of MHC molecules, and altering their ability to activate HHV-8-specific T cells. This could be why T cell responses to HHV-8 antigens are not very robust. Of these APC, only B cells support complete, lytic HHV-8 infection. However, both complete and abortive virus replication cycles in APC could directly affect viral pathogenesis and progression to Kaposi's sarcoma (KS) and HHV-8-associated B cell cancers. In this review, we discuss the effects of HHV-8 infection on professional APC and their relationship to the development of KS and B cell lymphomas.

Molecular and immunohistochemical detection of Kaposi sarcoma herpesvirus/human herpesvirus-8

Kaposi sarcoma herpesvirus/human herpesvirus-8 (KSHV/HHV-8) is etiologically related to the development of several human diseases, including Kaposi sarcoma, primary effusion lymphoma (PEL)/extra-cavitary (EC) PEL, multicentric Castleman disease (MCD), and large B-cell lymphoma arising in KSHV/HHV-8-associated multicentric Castleman disease. Although serologic studies can identify persons infected with this virus, molecular genetics, specifically PCR (polymerase chain reaction) and immunohistochemical techniques, are rapid, sensitive, and specific, and are able to more closely link KSHV/HHV-8 to a given disease process. As these KSHV/HHV-8-related diseases cause significant morbidity and mortality in affected individuals, the identification of the virus within lesional tissue will allow for more targeted therapy.

Aquaporin 1-positive stromal niche-like cells directly interact with N-cadherin-positive clusters in the basal limbal epithelium

Stem cells have a specialized microenvironment for maintaining self-renewal and multipotent capacities. It is believed that a cornea epithelial stem cell niche exists in the limbus. To characterize the niche of limbal epithelial stem cells, we observed the limbal basal epithelial layer by histological analysis. Cell clusters or cell suspensions from limbal tissue were prepared with collagenase or dispase II and fixed for cytospin sections. Adhesion assays were done to quantitate calcium-dependent cell adhesion. Limbal tissue and cytospin sections were analyzed by immunohistochemistry, transmission electron microscopy and confocal microscopy. AQP1 positive (AQP1(+)) cells were observed as non-epithelial cells in the subepithelial stroma. AQP1 expression did not co-localize with CD31, podoplanin, MART-1 positive cells, but were observed in vimentin positive stromal cells. When we made a thorough search of limbal basal cells by confocal microscopy, AQP1(+) were observed in the proximity of N-cad, K15 and p63 positive limbal basal epithelial cells. Furthermore, electron microscope revealed stromal cells penetrating the epithelial basal membrane and forming calcium-dependent cellular adhesions with N-cad(+) limbal basal epithelial cells. Although we could not clearly detect the expression of N-cad in the AQP1(+) cells, AQP1(+) cells immediately beneath the epithelial basement membrane may be stromal niche-like cells that directly interact with N-cad(+) limbal basal epithelial progenitor cells.

Multiple myeloma and its therapies: to what extent do they contribute to the increased incidence of second malignant neoplasms?

BACKGROUND

The high risk of another cancer once one has been diagnosed is well known. Furthermore, a clear association exists between the use of some cytotoxic agents and chemotherapy-induced malignancies.

METHODS

This review is set to explore the relationship between multiple myeloma, its modern therapies and the development of second cancers due to various genetic, immune, and environmental (including iatrogenic) factors. Most relevant publications were identified through the PubMed database and by reviewing the drug information released by the US Federal Drug Administration.

FINDINGS

Our comprehensive analysis identified several retrospective population studies, cohort group analyses and a number of case reports linking myeloma with other cancers in the world literature. A majority of these studies suggest that incidence of second solid and hematologic malignancies is significantly increased in patients with multiple myeloma and its precursor lesion, monoclonal gammopathy of unknown significance. In addition, incidence of second malignancies has been found increased in the family members of these individuals, especially in their first-degree relatives.

CONCLUSIONS

Analysis of the existing literature cohorts does not discriminate between the burden of second cancers in treated myeloma patients as opposed to the patients followed with the wait-and-watch approach. Notably, the rate of second malignant neoplasms in multiple myeloma may be further increased by certain myeloma therapies. These cancers include, for the most part, hematologic malignancies such as acute leukemias and certain lymphomas. While there is no question about the role of alkylating agents and topoisomerase II inhibitors in this regard, further research is necessary to determine whether the excess of second cancers represents a direct consequence of lenalidomide use.

β-HHVs and HHV-8 in Lymphoproliferative Disorders

Similarly to Epstein-Barr virus (EBV), the human herpesvirus-8 (HHV-8) is a γ-herpesvirus, recently recognized to be associated with the occurrence of rare B cell lymphomas and atypical lymphoproliferations, especially in the human immunodeficiency virus (HIV) infected subjects. Moreover, the human herpesvirus-6 (HHV-6), a β-herpesvirus, has been shown to be implicated in some non-malignant lymph node proliferations, such as the Rosai Dorfman disease, and in a proportion of Hodgkin’s lymphoma cases. HHV-6 has a wide cellular tropism and it might play a role in the pathogenesis of a wide variety of human diseases, but given its ubiquity, disease associations are difficult to prove and its role in hematological malignancies is still controversial. The involvement of another β-herpesvirus, the human cytomegalovirus (HCMV), has not yet been proven in human cancer, even though recent findings have suggested its potential role in the development of CD4⁺ large granular lymphocyte (LGL) lymphocytosis. Here, we review the current knowledge on the pathogenetic role of HHV-8 and human β-herpesviruses in human lymphoproliferative disorders.

Antibodies against lytic and latent Kaposi's sarcoma-associated herpes virus antigens and lymphoma in the European EpiLymph case-control study

Background:

Kaposi's sarcoma-associated herpes virus is associated with primary effusion lymphoma and multicentric Castleman's disease.

Methods:

Seropositivity to lytic and latent Kaposi's sarcoma herpes virus (KSHV) antigens were examined in 2083 lymphomas and 2013 controls from six European countries.

Results:

Antibodies against KSHV latent and lytic antigens were detectable in 4.5% and 3.4% of controls, respectively, and 3.6% of cases (P>0.05). The KSHV seropositivity was associated with splenic marginal zone lymphoma (SMZL) (odds ratio (OR)=4.11, 95% confidence interval (CI)=1.57–10.83) and multiple myeloma (OR=0.31, 95% CI=0.11–0.85).

Conclusion:

The KSHV is unlikely to contribute importantly to lymphomagenesis among immunocompetent subjects. However, the observed association with SMZL may underline a chronic antigen mechanism in its aetiology.

CD28 expressed on malignant plasma cells induces a prosurvival and immunosuppressive microenvironment

Interactions between the malignant plasma cells of multiple myeloma and stromal cells within the bone marrow microenvironment are essential for myeloma cell survival, mirroring the same dependence of normal bone marrow-resident long-lived plasma cells on specific marrow niches. These interactions directly transduce prosurvival signals to the myeloma cells and also induce niche production of supportive soluble factors. However, despite their central importance, the specific molecular and cellular components involved remain poorly characterized. We now report that the prototypic T cell costimulatory receptor CD28 is overexpressed on myeloma cells during disease progression and in the poor-prognosis subgroups and plays a previously unrecognized role as a two-way molecular bridge to support myeloid stromal cells in the microenvironment. Engagement by CD28 to its ligand CD80/CD86 on stromal dendritic cell directly transduces a prosurvival signal to myeloma cell, protecting it against chemotherapy and growth factor withdrawal-induced death. Simultaneously, CD28-mediated ligation of CD80/CD86 induces the stromal dendritic cell to produce the prosurvival cytokine IL-6 (involving novel cross-talk with the Notch pathway) and the immunosuppressive enzyme IDO. These findings identify CD28 and CD80/CD86 as important molecular components of the interaction between myeloma cells and the bone marrow microenvironment, point to similar interaction for normal plasma cells, and suggest novel therapeutic strategies to target malignant and pathogenic (e.g., in allergy and autoimmunity) plasma cells.

Human γ-herpesviruses Epstein-Barr virus and human herpesvirus-8 are not detected in the lungs of patients with severe pulmonary arterial hypertension

BACKGROUND

In susceptible individuals, multiple events may trigger pulmonary vascular remodeling and pulmonary arterial hypertension (PAH). Human herpesvirus-8 (HHV-8), a γ-herpesvirus homologous with Epstein-Barr virus (EBV), was suggested to act as a "second hit" in the development of PAH in susceptible patients. Although there is indirect evidence from in vitro and animal studies in favor of a link between γ-herpesviruses and the pathophysiology of PAH, results remain controversial. Therefore, we investigated the presence of EBV and HHV-8 in the lungs of patients with PAH.

METHODS

Thirty-four lungs explanted from French patients with end-stage PAH (mean age, 38 ± 14 years; 19 women) were studied. Tissue samples were incorporated into tissue microarrays. Normal lung tissues served as negative controls. Kaposi sarcoma tissue served as a positive control for HHV-8, and EBV-associated lymphoma served as a positive control for EBV. The presence of HHV-8 was investigated with immunohistochemistry and polymerase chain reaction. The presence of EBV was investigated with immunohistochemistry and in situ hybridization.

RESULTS

For HHV-8, none of PAH lung samples showed a "stippling" nuclear pattern classically observed in HHV-8-positive Kaposi sarcoma lesions. When studied by polymerase chain reaction, all cases remained negative. For EBV, none of the PAH lung samples showed positive staining, whatever the technique applied.

CONCLUSIONS

HHV-8 and EBV cannot be detected in the lungs of patients with end-stage PAH. The role of these γ-herpesviruses in the pathophysiology of PAH is, therefore, unlikely.

Murine gammaherpesvirus 68 LANA is essential for virus reactivation from splenocytes but not long-term carriage of viral genome

ORF73, which encodes the latency-associated nuclear antigen (LANA), is a conserved gamma-2-herpesvirus gene. The murine gammaherpesvirus 68 (MHV68) LANA (mLANA) is critical for efficient virus replication and the establishment of latent infection following intranasal inoculation. To test whether the initial host immune response limits the capacity of mLANA-null virus to traffic to and establish latency in the spleen, we infected type I interferon receptor knockout (IFN-alpha/betaR(-/-)) mice via intranasal inoculation and observed the presence of viral genome-positive splenocytes at day 18 postinfection at approximately 10-fold-lower levels than in the genetically repaired marker rescue-infected mice. However, no mLANA-null virus reactivation from infected IFN-alpha/betaR(-/-) splenocytes was observed. To more thoroughly define a role of mLANA in MHV68 infection, we evaluated the capacity of an mLANA-null virus to establish and maintain infection apart from restriction in the lungs of immunocompetent mice. At day 18 following intraperitoneal infection of C57BL/6 mice, the mLANA-null virus was able to establish a chronic infection in the spleen albeit at a 5-fold-reduced level. However, as in IFN-alpha/betaR(-/-) mice, little or no virus reactivation could be detected from mLANA-null virus-infected splenocytes upon explant. An examination of peritoneal exudate cells (PECs) following intraperitoneal inoculation revealed nearly equivalent frequencies of PECs harboring the mLANA-null virus relative to the marker rescue virus. Furthermore, although significantly compromised, mLANA-null virus reactivation from PECs was detected upon explant. Notably, at later times postinfection, the frequency of mLANA-null genome-positive splenocytes was indistinguishable from that of marker rescue virus-infected animals. Analyses of viral genome-positive splenocytes revealed the absence of viral episomes in mLANA-null infected mice, suggesting that the viral genome is integrated or maintained in a linear state. Thus, these data provide the first evidence that a LANA homolog is directly involved in the formation and/or maintenance of an extrachromosomal viral episome in vivo, which is likely required for the reactivation of MHV68.

Kaposi's sarcoma-associated herpesvirus and innate immunity

Kaposi's sarcoma-associated herpesvirus (KSHV) is the most recently discovered human herpesvirus, first isolated and identified from a Kaposi's sarcoma lesion in 1994. It is the etiological agent of Kaposi's sarcoma, a vascular lesion that is the predominant cancer among AIDS patients. KSHV is also the primary etiological agent of two B-cell lymphomas, primary effusion lymphoma and multicentric Castleman's disease. KSHV can exist in either a lytic phase, in which the viral DNA is actively replicated and virions are assembled, or in a latent phase, in which the viral genome is tethered to the host chromosome via protein-protein interactions. The lytic cycle generally occurs following primary infection, and within 72-96 h in most cell types, the virus enters the latent state. Reactivation from latency also leads to the intiation of the lytic cycle, which is necessary for virus propagation and survival in the host. Several KSHV proteins have been implicated in modulation of the host immune response to viral infection. This article summarizes recent discoveries involving the innate immune response to KSHV infection.

Plasma cell tumors in HIV-positive patients: Report of a case and review of the literature

Plasma cell tumors show an increased incidence in HIV-positive patients. The cases reported in the literature suggest that plasma cell tumors occur in a younger age group than that encountered in the general population. Pathologically, many of these tumors show a plasmablastic morphology. Plasma cell tumors in HIV-positive patients may present at unusual sites and progress rapidly to involve multiple sites, including the soft tissues and viscera. The prognosis is generally poor. These features may be related to a combination of factors, including immunodeficiency, oncogenic viruses, and altered cytokine milieu in these patients. A case of plasma cell tumor in an HIV-positive patient is presented.

HYPOTHALAMIC DIGOXIN, HEMISPHERIC CHEMICAL DOMINANCE, AND ONCOGENESIS: EVIDENCE FROM MULTIPLE MYELOMA

This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with multiple myeloma were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Multiple myeloma occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

Complete absence of KSHV/HHV-8 in posttransplant lymphoproliferative disorders: an immunohistochemical and molecular study of 52 cases

Posttransplant lymphoproliferative disorders (PTLDs), a heterogeneous group of monoclonal or polyclonal lesions, occur in immunosuppressed patients after solid organ or bone marrow transplantation. Although most PTLDs are Epstein-Barr virus (EBV)+ and seem to represent EBV-induced proliferations of monoclonal (or less often polyclonal) B, T, or plasma cells, a subset of PTLDs is EBV-. Because Kaposi sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) has been described in association with the development of hematolymphoid and nonhematolymphoid neoplasms in HIV+ patients, we investigated whether there is an association between KSHV/HHV-8 and PTLDs. Formalin-fixed, paraffin-embedded tissue from 52 confirmed PTLD cases were analyzed immunohistochemically for expression of KSHV/HHV-8 latent nuclear antigen (LNA)-1 protein and by polymerase chain reaction-hybridization analysis for the KSHV/HHV-8 genome. The PTLD subtypes included 12 with early lesions (1 plasmacytic hyperplasia and 11 infectious mononucleosis-like), 10 polymorphic, 23 monomorphic (5 Burkitt, 14 diffuse large B-cell lymphoma, 1 plasmacytoma, 1 multiple myeloma, and 2 T-cell), 1 Hodgkin lymphoma (HL), 5 HL-like lesions, and 1 unclassified or other. None of the 51 tested specimens showed expression of KSHV/HHV-8 LNA-1. Furthermore, all 46 specimens tested demonstrated complete absence of the KSHV/HHV-8 genome. Our data clearly indicated that KSHV/HHV-8 is not associated with PTLDs.

Unraveling viral interleukin-6 binding to gp130 and activation of STAT-signaling pathways independently of the interleukin-6 receptor

Human herpesvirus 8 encodes a viral version of interleukin-6 (vIL-6) which shows 25% sequence homology with human IL-6. In contrast to human IL-6, which first binds to the IL-6 receptor (IL-6R) and only subsequently associates with the signal transducing receptor subunit gp130, vIL-6 has been shown to directly bind to gp130 without the need of IL-6R. As a functional consequence, vIL-6 can activate far more target cells in the body since all cells express gp130, but only cells such as hepatocytes and some leukocytes express IL-6R. We sought to understand which amino acid sequences within the vIL-6 protein were responsible for its ability to bind and activate gp130 independent of IL-6R. As a first approach, we constructed chimeric IL-6 proteins in which all known gp130 interacting sites (sites II and III) were sequentially transferred from vIL-6 into the human IL-6 protein. To our surprise, human IL-6 carrying all gp130 interacting sites from vIL-6 did not show IL-6R-independent gp130 activation. Even more surprisingly, the loop between helix B and C of vIL-6, clearly shown in the crystal structure not to be in contact with gp130, is indispensable for direct binding to and activation of gp130. This points to an IL-6R induced change of site III conformation in human IL-6, which is already preformed in vIL-6. These data indicate a novel activation mechanism of human IL-6 by the IL-6R that will be important for the construction of novel hyperactive cytokine variants.

A replication-defective gammaherpesvirus efficiently establishes long-term latency in macrophages but not in B cells in vivo

Murine gammaherpesvirus 68 (gammaHV68 or MHV68) is genetically related to the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), providing a useful system for in vivo studies of the virus-host relationship. To begin to address fundamental questions about the mechanisms of the establishment of gammaherpesvirus latency, we previously generated a replication-defective gammaHV68 lacking the expression of the single-stranded DNA binding protein encoded by orf6. In work presented here, we demonstrate that this mutant virus established a long-term infection in vivo that was molecularly identical to wild-type virus latency. Thus, despite the absence of an acute phase of lytic replication, the mutant virus established a chronic infection in which the viral genome (i) was maintained as an episome and (ii) expressed latency-associated, but not lytic replication-associated, genes. Macrophages purified from mice infected with the replication-defective virus harbored viral genome at a frequency that was nearly identical to that of wild-type gammaHV68; however, the frequency of B cells harboring viral genome was greatly reduced in the absence of lytic replication. Thus, this replication-defective gammaherpesvirus efficiently established in vivo infection in macrophages that was molecularly indistinguishable from wild-type virus latency. These data point to a critical role for lytic replication or reactivation in the establishment or maintenance of latent infection in B cells.

Classic Kaposi Sarcoma in the United States over the last two decades: a clinicopathologic and molecular study of 438 non-HIV-related Kaposi Sarcoma patients with comparison to HIV-related Kaposi Sarcoma

Classic Kaposi sarcoma is rare and occurs predominantly in Mediterranean and Middle Eastern men. Since the emergence of acquired immune deficiency syndrome (AIDS)-related Kaposi sarcoma, the incidence, clinicopathologic features, and molecular human herpesvirus 8 (HHV-8) association of American Classic Kaposi Sarcoma has not been fully explored. This study compares Classic Kaposi Sarcoma to AIDS-related Kaposi Sarcoma over the same two decade time period. There were 438 histologically and clinically confirmed Classic Kaposi Sarcoma patients. The ethnic/racial distribution included Caucasian/American (56%), Mediterranean (22%), South American Hispanic (18%), Black (10%), western European (4%), Middle East (4%), Scandinavian (2%), and other (2%). Classic Kaposi Sarcoma was more common in men, 7:1, with a mean age of 74 years. The lesions presented in the lower extremity (69%), in the nodular stage (83%), and HHV-8 was detected by PCR in 40/41 randomly selected cases. A second, non-Classic Kaposi Sarcoma, malignancy was present in 42% (n=45) of the 108 Classic Kaposi Sarcoma patients with complete clinical information, 73% (33 patients) with a higher incidence over the general population. Follow-up of <1-19 years (mean=4.8 years) revealed that 24% of patients died of second malignancy, 22% died of other medical conditions, 2% died of treatment-related complications, and 2% patients died of widespread disease. Thirty-five percent are alive with no evidence of disease and 15% with persistent disease. Human immunodeficiency virus-related Kaposi Sarcoma was observed in 354 cases. There was a male predominance and more aggressive behavior, with higher rates of visceral and disseminated disease. While Classic Kaposi Sarcoma in the United States is an indolent disease and rarely accounts for patient demise, predominantly affecting Caucasian/American males on the lower extremity in the nodular phase, it more importantly may denote an underlying other malignancy. Current PCR probes detect HHV-8 in 98% of Classic Kaposi Sarcoma cases. In comparison, AIDS-related Kaposi Sarcoma is predominately multicentric, visceral, and disseminated, with more aggressive behavior.

Interactions of tumor cells with dendritic cells: balancing immunity and tolerance

Dendritic cells (DCs) are antigen-presenting cells specialized to initiate and maintain immunity and tolerance. DCs initiate immune responses in a manner that depends on signals they receive from pathogens, surrounding cells and their products. Most tumors are infiltrated by DCs. Thus, interactions between DCs and dying tumor cells may determine the balance between immunity and tolerance to tumor cells. In addition, DCs also display non-immunologic effects on tumors and the tumor microenvironment. Therefore, improved understanding of the cross talk between tumor cells and DCs may suggest new approaches to improve cancer therapy.

Reflections on the interpretation of heterogeneity and strain differences based on very limited PCR sequence data from Kaposi's sarcoma-associated herpesvirus genomes

Ever since the original identification of fragments of KSHV DNA in Kaposi's sarcoma (KS) tissue by Chang et al. in 1994, PCR has been used successfully and extensively to detect the virus in clinical samples from the accepted etiological diseases of KS, PEL and MCD. However, a number of other clinical and epidemiological studies claiming evidence for KSHV in multiple myeloma or sarcoid and more recently in primary pulmonary hypertension, as well as claims about the biological significance of DNA sequence polymorphisms based just on small ORF26 PCR DNA fragments have not been convincing. Here, we evaluate the validity and interpretations of previous results in the context of both the observed rates and global patterns of sequence variability within an extended ORF26 locus, as well as from the perspective of the overall levels of KSHV variability found after sampling multiple loci across the complete KSHV genome. The results cast doubts on most claims for biological significance for these polymorphisms, which instead correlate with viral subtype clustering arising from geographic and ethnic divergence of the ancestral human hosts. In addition, we describe several observations that help to explain likely sources of the often either unexpectedly high or unexpectedly low levels of sporadic variability seen in the PCR DNA sequence data reported in some of those studies.

Type I interferon inhibition and dendritic cell activation during gammaherpesvirus respiratory infection

The respiratory tract is a major mucosal site for microorganism entry into the body, and type I interferon (IFN) and dendritic cells constitute a first line of defense against viral infections. We have analyzed the interaction between a model DNA virus, plasmacytoid dendritic cells, and type I IFN during lung infection of mice. Our data show that murine gammaherpesvirus 68 (gammaHV68) inhibits type I IFN secretion by dendritic cells and that plasmacytoid dendritic cells are necessary for conventional dendritic cell maturation in response to gammaHV68. Following gammaHV68 intranasal inoculation, the local and systemic IFN-alpha/beta response is below detectable levels, and plasmacytoid dendritic cells are activated and recruited into the lung with a tissue distribution that differs from that of conventional dendritic cells. Our results suggest that plasmacytoid dendritic cells and type I IFN have important but independent roles during the early response to a respiratory gammaHV68 infection. gammaHV68 infection inhibits type I IFN production by dendritic cells and is a poor inducer of IFN-alpha/beta in vivo, which may serve as an immune evasion strategy.

Morphogens, morphostats, microarchitecture and malignancy

Morphogenetic fields organize tissue morphology in the embryo. By analogy, morphostatic fields maintain normal cell behaviour and normal tissue microarchitecture in the adult. The most prominent feature of cancer is the disruption of tissue microarchitecture. Cancer occurs much more frequently when morphostatic influences fail (metaplasia) or at the junction of two different morphostatic fields. This Review will describe what we know about morphostats and morphostasis, discuss the evidence for the role of disruption of morphostasis in malignancy, and address some testable hypotheses.

CD28-mediated regulation of multiple myeloma cell proliferation and survival

Although interactions with bone marrow stromal cells are essential for multiple myeloma (MM) cell survival, the specific molecular and cellular elements involved are largely unknown, due in large part to the complexity of the bone marrow microenvironment itself. The T-cell costimulatory receptor CD28 is also expressed on normal and malignant plasma cells, and CD28 expression in MM correlates significantly with poor prognosis and disease progression. In contrast to T cells, activation and function of CD28 in myeloma cells is largely undefined. We have found that direct activation of myeloma cell CD28 by anti-CD28 mAb alone induces activation of PI3K and NFkappaB, suppresses MM cell proliferation, and protects against serum starvation and dexamethasone (dex)-induced cell death. Coculture with dendritic cells (DCs) expressing the CD28 ligands CD80 and CD86 also elicits CD28-mediated effects on MM survival and proliferation, and DCs appear to preferentially localize within myeloma infiltrates in primary patient samples. Our findings suggest a previously undescribed myeloma/DC cell-cell interaction involving CD28 that may play an important role in myeloma cell survival within the bone marrow stroma. These data also point to CD28 as a potential therapeutic target in the treatment of MM.

Multiple Myeloma: An Overview

Multiple myeloma (MM) is a malignant hematologic disorder involving plasma cells. In MM, immunoglobulin is overproduced, and patients can develop skeletal, hematologic, renal, and/or neurologic complications. The exact etiology of MM is unknown. The treatment for MM includes chemotherapy, antiangiogenic medications, and, most recently, a proteasome inhibitor. Nursing care for patients with MM requires close monitoring for infections and anemia, pain control, and education about the disease and treatment options. Further understanding of the pathophysiology of MM may lead to newer treatment options for the disease.

Detection of four lymphotropic herpesviruses in Hungarian Patients with multiple myeloma and lymphoma

It has been suggested that human herpesvirus 8 (HHV-8), also known as KSHV (Kaposi's sarcoma-associated human herpesvirus), might possess a promoting effect in the development and progression of monoclonal gammopathies. In this study, the presence of Epstein-Barr virus (EBV), human cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and human herpesvirus 8 (HHV-8) were tested in patients with multiple myeloma (MM) using both serologic and nucleic acid amplification techniques. The transient reactivation or continuous presence of EBV, CMV, HHV-6 and HHV-8 could be detected in, respectively, 36, eight, 13 and 29 of 69 MM patients; nine, one, four and six of 16 monoclonal gammopathy of unknown significance patients; and seven, four, zero and five of 10 Waldenström's macroglobulinemia patients. The total number of MM patients was 95. HHV-8 PCR-positivity was significantly more frequent in the MM group than in the control group of patients with non-Hodgkin's lymphoma (NHL). However, serologic testing did not reveal significant differences between the two patient groups. The number of MM patients with concomitant herpesvirus infections as detected by PCR was as follows: 15 double, seven triple and two quadruple virus nucleic acid positive. In 13/95 MM patients, the simultaneous presence of acute EBV infection and HHV-8 PCR-positivity was detected compared with none of the control group (P=0.009). These results indicate that in addition to HHV-8, the transitional reactivation of EBV may also play a role in the pathogenesis of MM.

Number of siblings and the risk of lymphoma, leukemia, and myeloma by histopathology

Epidemiologic evidence indicates that several markers of exposure to childhood infections are inversely associated with the risk of childhood leukemia and lymphomas. We used the Swedish Family-Cancer Database to assess the effects of number of siblings on the risk of non-Hodgkin's (n = 7,007) and Hodgkin's lymphomas (n = 3,115), leukemias (n = 7,650), and multiple myeloma (n = 1,492) by histopathology. Poisson regression models included terms for age, sex, family history, period, and socioeconomic index. Having four or more siblings compared with none was associated with an excess risk of childhood acute lymphoblastic leukemia [ALL; rate ratio (RR), 2.11; P(trend) = 0.001], acute monocytic leukemia (RR, 2.51; P(trend) = 0.002), and multiple myeloma (RR, 1.34; P(trend) = 0.006). Having three or more older siblings compared with none decreased the risk of acute monocytic leukemia (RR, 0.35; P(trend) = 0.001) and childhood ALL (RR, 0.69; P(trend) = 0.01). The risk of Hodgkin's lymphoma for five or more older siblings compared with none was 0.41 (P(trend) = 0.003). Acute myeloid leukemia, chronic lymphocytic leukemia, and other lymphoproliferative malignancies were not associated with number of siblings. In conclusion, we found an excess risk of childhood ALL and acute monocytic leukemia in large families. However, for ALL, acute monocytic leukemia, and Hodgkin's lymphoma, younger siblings were strongly protected compared with older siblings. The remarkable protective effect of number of older siblings on acute monocytic leukemia is a novel finding of potential interest. Possible interpretations of our findings in the context of a putative infectious etiology are discussed.