AIDS and associated malignancies

KSHV infection of B cells primes protective T cell responses in humanized mice

Kaposi sarcoma associated herpesvirus (KSHV) is associated with around 1% of all human tumors, including the B cell malignancy primary effusion lymphoma (PEL), in which co-infection with the Epstein Barr virus (EBV) can almost always be found in malignant cells. Here, we demonstrate that KSHV/EBV co-infection of mice with reconstituted human immune systems (humanized mice) leads to IgM responses against both latent and lytic KSHV antigens, and expansion of central and effector memory CD4+ and CD8+ T cells. Among these, KSHV/EBV dual-infection allows for the priming of CD8+ T cells that are specific for the lytic KSHV antigen K6 and able to kill KSHV/EBV infected B cells. This suggests that K6 may represent a vaccine antigen for the control of KSHV and its associated pathologies in high seroprevalence regions, such as Sub-Saharan Africa.

Oncoviruses: How do they hijack their host and current treatment regimes

Viruses have the ability to modulate the cellular machinery of their host to ensure their survival. While humans encounter numerous viruses daily, only a select few can lead to disease progression. Some of these viruses can amplify cancer-related traits, particularly when coupled with factors like immunosuppression and co-carcinogens. The global burden of cancer development resulting from viral infections is approximately 12%, and it arises as an unfortunate consequence of persistent infections that cause chronic inflammation, genomic instability from viral genome integration, and dysregulation of tumor suppressor genes and host oncogenes involved in normal cell growth. This review provides an in-depth discussion of oncoviruses and their strategies for hijacking the host's cellular machinery to induce cancer. It delves into how viral oncogenes drive tumorigenesis by targeting key cell signaling pathways. Additionally, the review discusses current therapeutic approaches that have been approved or are undergoing clinical trials to combat malignancies induced by oncoviruses. Understanding the intricate interactions between viruses and host cells can lead to the development of more effective treatments for virus-induced cancers.

Cathepsin B S-nitrosylation promotes ADAR1-mediated editing of its own mRNA transcript via an ADD1/MATR3 regulatory axis

Genetic information is generally transferred from RNA to protein according to the classic "Central Dogma". Here, we made a striking discovery that post-translational modification of a protein specifically regulates the editing of its own mRNA. We show that S-nitrosylation of cathepsin B (CTSB) exclusively alters the adenosine-to-inosine (A-to-I) editing of its own mRNA. Mechanistically, CTSB S-nitrosylation promotes the dephosphorylation and nuclear translocation of ADD1, leading to the recruitment of MATR3 and ADAR1 to CTSB mRNA. ADAR1-mediated A-to-I RNA editing enables the binding of HuR to CTSB mRNA, resulting in increased CTSB mRNA stability and subsequently higher steady-state levels of CTSB protein. Together, we uncovered a unique feedforward mechanism of protein expression regulation mediated by the ADD1/MATR3/ADAR1 regulatory axis. Our study demonstrates a novel reverse flow of information from the post-translational modification of a protein back to the post-transcriptional regulation of its own mRNA precursor. We coined this process as "Protein-directed EDiting of its Own mRNA by ADAR1 (PEDORA)" and suggest that this constitutes an additional layer of protein expression control. "PEDORA" could represent a currently hidden mechanism in eukaryotic gene expression regulation.

New Look of EBV LMP1 Signaling Landscape

Simple Summary

Epstein-Barr Virus (EBV) infection is associated with various lymphomas and carcinomas as well as other diseases in humans. The transmembrane protein LMP1 plays versatile roles in EBV life cycle and pathogenesis, by perturbing, reprograming, and regulating a large range of host cellular mechanisms and functions, which have been increasingly disclosed but not fully understood so far. We summarize recent research progress on LMP1 signaling, including the novel components LIMD1, p62, and LUBAC in LMP1 signalosome and LMP1 novel functions, such as its induction of p62-mediated selective autophagy, regulation of metabolism, induction of extracellular vehicles, and activation of NRF2-mediated antioxidative defense. A comprehensive understanding of LMP1 signal transduction and functions may allow us to leverage these LMP1-regulated cellular mechanisms for clinical purposes.

Abstract

The Epstein–Barr Virus (EBV) principal oncoprotein Latent Membrane Protein 1 (LMP1) is a member of the Tumor Necrosis Factor Receptor (TNFR) superfamily with constitutive activity. LMP1 shares many features with Pathogen Recognition Receptors (PRRs), including the use of TRAFs, adaptors, and kinase cascades, for signal transduction leading to the activation of NFκB, AP1, and Akt, as well as a subset of IRFs and likely the master antioxidative transcription factor NRF2, which we have gradually added to the list. In recent years, we have discovered the Linear UBiquitin Assembly Complex (LUBAC), the adaptor protein LIMD1, and the ubiquitin sensor and signaling hub p62, as novel components of LMP1 signalosome. Functionally, LMP1 is a pleiotropic factor that reprograms, balances, and perturbs a large spectrum of cellular mechanisms, including the ubiquitin machinery, metabolism, epigenetics, DNA damage response, extracellular vehicles, immune defenses, and telomere elongation, to promote oncogenic transformation, cell proliferation and survival, anchorage-independent cell growth, angiogenesis, and metastasis and invasion, as well as the development of the tumor microenvironment. We have recently shown that LMP1 induces p62-mediated selective autophagy in EBV latency, at least by contributing to the induction of p62 expression, and Reactive Oxygen Species (ROS) production. We have also been collecting evidence supporting the hypothesis that LMP1 activates the Keap1-NRF2 pathway, which serves as the key antioxidative defense mechanism. Last but not least, our preliminary data shows that LMP1 is associated with the deregulation of cGAS-STING DNA sensing pathway in EBV latency. A comprehensive understanding of the LMP1 signaling landscape is essential for identifying potential targets for the development of novel strategies towards targeted therapeutic applications.

Viral and immunological markers of HIV-associated Kaposi sarcoma recurrence

Kaposi sarcoma (KS) is an AIDS-defining angio-proliferative malignancy highly prevalent in Sub-Saharan Africa. The main objective of this study was to determine the factors associated with recurrence of HIV-associated KS. We recruited a cohort of individuals on antiretroviral therapy who were in remission for HIV-associated KS after undergoing cytotoxic cancer chemotherapy. Collected variables included sociodemographic and clinical parameters, cytokines and chemokines, HIV viral loads, and CD4 counts. Compared to individuals who had KS recurrence, IL-5 was significantly higher at time of follow-up in individuals who had sustained remission (22.7pg/ml vs. 2.4pg/ml; p = 0.02); IL-6 was significantly higher at baseline and time of follow-up in individuals who had sustained remission, (18.4pg/ml vs. 0pg/ml; p = 0.01) and (18.0pg/ml vs. 0.18pg/ml; p = 0.03) respectively; IP-10 was significantly lower at baseline and at time of follow-up in individuals who had sustained remission, (534pg/ml vs. 920pg/ml; p = 0.04) and (446pg/ml vs.1098pg/ml; p = 0.01) respectively; while HIV viral load was significantly lower at baseline and at time of follow-up in individuals who had sustained remission, (0copies/ml vs. 113copies/ml; p = 0.004) and (0copies/ml vs. 152copies/ml; p = 0.025) respectively. Plasma levels of IL-5, IL-6, and IP-10 are associated with recurrence of HIV-associated KS, while persistently detectable HIV viral loads increase the risk of KS recurrence.

Immune Checkpoint Inhibitor Therapy in Colorectal Cancer-The Role of Cellular Pathology

Colorectal cancer (CRC) is a common malignancy with a worldwide distribution. Despite bowel cancer screening programmes, the management of patients with metastatic disease is still an important and challenging problem. Immune checkpoint inhibitor (ICI) therapy is a well-established treatment in several cancers, eg, malignant melanoma and non-small cell lung carcinoma and is used in metastatic disease. The principle of this treatment is to use monoclonal antibodies to block the immune tolerance that commonly develops to tumor cells, therefore allowing host T-cell immunity to recognise and lyse cancer cells. The cellular receptors most commonly targeted by ICI therapy are cytotoxic T-lymphocyte-associated protein-4 and the programmed death 1/programmed death ligand 1 system. This review provides a scientific background to current ICI therapy and discusses the factors that predict response to this treatment. This is followed by a description of the emerging evidence for the use of ICI therapy in CRC and the utility of cellular pathology in stratifying patients for this treatment, especially when the systemic disease is present.

Neoplasms-associated deaths in HIV-1 infected and non-infected patients in Bahia, Brazil

BACKGROUND

HIV-infected patients are at a higher risk to develop malignancies than general population. Although AIDS-related malignancies are a common feature of late-stage disease, patients under successful antiretroviral therapy also have an increased risk for development of non-AIDS malignancies.

OBJECTIVE

To compare the frequency and characteristics of adults HIV-infected patients and general population who died of malignancies in Bahia, Brazil from January 2000 to December 2010.

METHODS

National Information System on Mortality (SIM) was searched to identify all deaths in the study period caused by malignancies in general population and in HIV patients. The frequency of malignancies in these two groups was compared. For HIV patients we also recorded the last HIV-1 RNA plasma viral load and CD4+ cells count, retrieved from oficial databases on laboratory monitoring for HIV patients.

RESULTS

In the study period 733,645 deaths were reported, 677,427 (92.3%) of them in individual older than 13 years. Malignancies were the cause of death in 77,174 (11.4%) of them, and 5156 (0.8%) were associated to HIV/Aids. Among deaths of HIV/Aids patients, Kaposi´s sarcoma was the most prevalent malignancy (OR: 309.7; 95% CI: 177-544), followed by non-Hodgkin lymphoma (OR: 10.1; 95% CI: 5.3-19.3), Hodgkin´s lymphoma (OR: 4.3; 95% CI: 2.2-8.4), and cranial nervous malignancies (OR: 3.3; 95% CI:1.6-7.0). HIV patients died at a significantly lower age (43.7 years), than general population (64.5 years, p < 0.0001). Patients who had a diagnosis of Aids-related malignancies had lower CD4+ cells count than those with non-AIDS relates malignancies (p = 0.04).

CONCLUSION

HIV infection is a clear risk fator for development of some malignancies, and is associated with early mortality, compared to general population. The level of CD4+ cells count predicts the type of malignancies causing death in this population.

Head and Neck Lymphomas in HIV Patients: a Clinical Perspective

Introduction  Because of the many HIV-related malignancies, the diagnosis and treatment of lymphoma in patients infected with human immunodeficiency virus are challenging. Objective  Here, we review current knowledge of the pathogenesis, epidemiology, symptomatology, diagnosis, and treatment of head and neck lymphomas in HIV patients from a clinical perspective. Data Synthesis  Although Hodgkin's lymphoma is not an AIDS-defining neoplasm, its prevalence is ten times higher in HIV patients than in the general population. NHL is the second most common malignancy in HIV patients, after Kaposi's sarcoma. In this group of patients, NHL is characterized by rapid progression, frequent extranodal involvement, and a poor outcome. HIV-related salivary gland disease is a benign condition that shares some features with lymphomas and is considered in their differential diagnosis. Conclusion  The otolaryngologist may be the first clinician to diagnose head and neck lymphomas. The increasing survival of HIV patients implies clinical and epidemiological changes in the behavior of this disease. Early diagnosis is important to improve the prognosis and avoid the propagation of HIV infection.

Clinical Analysis of Five Cases of AIDS-related Non-Hodgkin Lymphoma

Objective:

Secondary malignancy is a major life-threatening complication facing patients afflicted with acquired immunodeficiency syndrome (AIDS). This study aimed to retrospectively review clinical features and treatment course of five patients with AIDS-associated non-Hodgkin lymphoma (A-NHL) in Jilin Tumor Hospital.

Methods:

Five A-NHL patients were retrospectively and consecutively hospitalized at our oncological unit between January 2012 and June 2014. All patients received pre-emptive highly active antiretroviral therapy (HAART) and chemotherapy, and were subsequently followed up at the outpatient clinic. All five patients were male, aged 27–53 years, and afflicted with A-NHL involving upper jaw, right inguinal region, right-side gingiva, mediastinum, or right-side neck. Histology showed diffuse large B-cell lymphoma (n = 3) or plasmablastic lymphoma (n = 2).

Results:

Two patients achieved complete remission after HAART and chemotherapy, whereas other three patients required a second-line treatment, with two achieving stable disease and one dying within a follow-up period of 0.5−2 years.

Conclusion:

The findings of the present study showed that A-NHL is a disease often diagnosed in the middle-to-late stages, with diverse clinical manifestations and short overall survival. In the cases reviewed in this study, HAART in combination with standard dose or high-dose chemotherapy, HAART and molecular targeted chemotherapy was administered, and these treatments proved to be effective for improving the prognosis of these patients. Moreover, the CD4+ cell count was important for determining the prognosis of patients.

Characteristics and Outcome of Patients With AIDS in Dutch ICUs Between 1997 and 2014

OBJECTIVE

Knowledge on characteristics and outcome of ICU patients with AIDS is highly limited. We aimed to determine the main reasons for admission and outcome in ICU patients with AIDS and trends over time therein.

DESIGN

A retrospective study within the Dutch National Intensive Care Evaluation registry.

SETTING

Dutch ICUs.

PATIENTS

We used data collected between 1997 and 2014. Characteristics of patients with AIDS were compared with ICU patients without AIDS, matched for age, sex, admission type, and admission year. Joinpoint regression analysis was applied to study trends over time.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 1,127 patients with AIDS and 4,479 matched controls. The main admission diagnoses of patients with AIDS were respiratory infection (28.6%) and sepsis (16.9%), which were less common in controls (7.7% and 7.5%, respectively; both p < 0.0001). Patients with AIDS had increased severity of illness and in-hospital mortality (28.2% vs 17.8%; p < 0.0001) compared with controls, which was associated with a higher rate of infections at admission in patients with AIDS (58.4% vs 25.5%). Over time, the proportion of patients with AIDS admitted with an infection decreased (75% in 1999 to 56% in 2013). Mortality declined in patients with AIDS (39% in 1999 to 16% in 2013), both in patients with or without an infection. Mortality also declined in matched controls without AIDS, but to a lesser extent.

CONCLUSION

Infections are still the main reason for ICU admission in patients with AIDS, but their prevalence is declining. Outcome of patients with AIDS continued to improve during a time of widespread availability of combination antiretroviral therapy, and mortality is reaching levels similar to ICU patients without AIDS.

Infection of female primary lower genital tract epithelial cells after natural pseudotyping of HIV-1: possible implications for sexual transmission of HIV-1

The global AIDS pandemic continues to expand and in some regions of the world, such as southern Africa, the prevalence of HIV-1 infection exceeds 20%. The devastating spread of the virus in young women in these countries appears disproportional to overall risk of infection. Regions with high prevalence of HIV-1 are often also highly endemic for other pathogenic viruses including HSV, CMV and HTLV. We propose that acquisition by HIV-1 of the envelope glycoproteins of other viruses, in a process we call “natural pseudotyping,” expands the cellular tropism of HIV-1, enabling it to infect female genital epithelial cells directly and thereby dramatically increasing risk of infection during sexual intercourse. In this proof-of-concept study, we demonstrate that when HIV-1 co-infects T cells along with the gammaretrovirus xenotropic murine leukemia virus-related virus (XMRV), progeny HIV-1 particles are produced capable of infecting primary vaginal, ectocervical and endocervical epithelial cells. These cell types are normally resistant to HIV-1 infection. Infection of primary genital cells was neutralized by antisera against the XMRV glycoprotein, confirming that infection was mediated by the XMRV glycoprotein acquired through pseudotyping of HIV. Inhibition by AZT showed that active replication of HIV-1 occurred in these cells and ruled out non-specific endocytic uptake of the virus. These results demonstrate that natural pseudotyping can expand the tropism of HIV-1 to include genital epithelial cells and have potential implications for sexual transmission of the virus.

Fallen angels or risen apes? A tale of the intricate complexities of imbalanced immune responses in the pathogenesis and progression of immune-mediated and viral cancers

Excessive immune responses directed against foreign pathogens, self-antigens, or commensal microflora can cause cancer establishment and progression if the execution of tight immuno-regulatory mechanisms fails. On the other hand, induction of potent tumor antigen-specific immune responses together with stimulation of the innate immune system is a pre-requisite for effective anti-tumor immunity, and if suppressed by the strong immuno-regulatory mechanisms can lead to cancer progression. Therefore, it is crucial that the inevitable co-existence of these fundamental, yet conflicting roles of immune-regulatory cells is carefully streamlined as imbalances can be detrimental to the host. Infection with chronic persistent viruses is characterized by severe immune dysfunction resulting in T cell exhaustion and sometimes deletion of antigen-specific T cells. More often, this is due to increased immuno-regulatory processes, which are triggered to down-regulate immune responses and limit immunopathology. However, such heightened levels of immune disruption cause a concomitant loss of tumor immune-surveillance and create a permissive microenvironment for cancer establishment and progression, as demonstrated by increased incidences of cancer in immunosuppressed hosts. Paradoxically, while some cancers arise as a consequence of increased immuno-regulatory mechanisms that inhibit protective immune responses and impinge on tumor surveillance, other cancers arise due to impaired immuno-regulatory mechanisms and failure to limit pathogenic inflammatory responses. This intricate complexity, where immuno-regulatory cells can be beneficial in certain immune settings but detrimental in other settings underscores the need for carefully formulated interventions to equilibrate the balance between immuno-stimulatory and immuno-regulatory processes.

Survival and Prognostic Factors for AIDS and Non-AIDS Patients with Non-Hodgkin's Lymphoma in Bahia, Brazil: A Retrospective Cohort Study

Despite the benefits of HAART, HIV-infected patients are increasingly affected by different malignancies. We compared a 5-year-period survival time and prognostic factors for HIV-1-infected individuals diagnosed with non-Hodgkin lymphomas (NHL) in a nested case-control study, with non-HIV-infected individuals in Salvador, Brazil. Survival time and prognostic factors were compared to HIV-negative patients. 31 cases (versus 63 controls) had a significantly more advanced NHL at diagnosis and lower mean CD4 count (26 cells/mm³) than controls. Mean overall survival (OS) was 35.8 versus 75.4 months, for cases and controls, respectively (P < 0.001), while mean event-free survival time (EFS) was 34.5 months for cases, versus 68.8 for controls (P = 0.002). Higher IPI, increased LDH levels, bone marrow infiltration, lower absolute lymphocyte counts (<1,000 cells/mm³), and type B symptoms were associated with a shorter survival time for cases. Although patients without poorer prognostic factors at baseline had an OS comparable to controls, the mean CD4 cell count for cases was similar for patients with favorable and nonfavorable response to therapy. Our findings suggest that HIV-1 infection is significantly associated with a shorter survival time for patients with NHL, independently of other predictive factors and of disease stage.

Impact of Epstein-Barr virus load, virus genotype, and frequency of the 30 bp deletion in the viral BNLF-1 gene in patients harboring the human immunodeficiency virus

Patients infected with the human immunodeficiency virus (HIV) are at higher risk of developing Epstein-Barr Virus (EBV)-associated lymphomas. The usefulness of monitoring EBV in peripheral blood mononuclear cells (PBMCs) of patients infected with HIV has not been established. The aim of this study was to evaluate the EBV viral load in PBMCs, the frequency of viral genotypes, and the presence of the 30-bp deletion in the BNLF-1 gene. DNA samples from 156 patients attending the HIV/AIDS Day Clinic at Botucatu School of Medicine, Sao Paulo State University were evaluated. The EBV viral load was detectable by real time PCR in 123/156 (78.8%) cases and was higher in patients not receiving antiretroviral treatment or under therapeutic failure than in patients under successful highly active antiretroviral therapy (HAART) (P = 0.0076). Overall, the profile of patients with high EBV viral load included elevated HIV viremia (P = 0.0005), longer time of HIV diagnosis (P = 0.0026), and increased levels of T CD8 (+) lymphocytes (P = 0.0159). The successful amplification of the EBNA-2 gene by nested-PCR was achieved in 95 of 123 (77.2%) cases, of which 75.8% were EBV-1, 9.5% EBV-2, and 14.7% were co-infected with both EBV-1 and -2. The analysis of the BNLF-1 gene was possible in 99 of 123 (80.5%) cases, of which 50.5% had the 30-bp deletion. EBV-1 was more common than EBV-2, which may reflect the fact that the cohort was predominantly Caucasian and heterosexual.

Protein kinase C-beta inhibition induces apoptosis and inhibits cell cycle progression in acquired immunodeficiency syndrome-related non-hodgkin lymphoma cells

INTRODUCTION

Acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (NHL) constitutes an aggressive variety of lymphomas characterized by increased extranodal involvement, relapse rate, and resistance to chemotherapy. Protein kinase C-beta (PKCβ) targeting showed promising results in preclinical and clinical studies involving a wide variety of cancers, but studies describing the role of PKCβ in AIDS-NHL are primitive if not lacking.

METHODS

In the present study, 3 AIDS-NHL cell lines were examined: 2F7 (AIDS-Burkitt lymphoma), BCBL-1 (AIDS-primary effusion lymphoma), and UMCL01-101 (AIDS-diffuse large B-cell lymphoma).

RESULTS

Immunoblot analysis demonstrated expression of PKCβ1 and PKCβ2 in 2F7 and UMCL01-101 cells, and PKCβ1 alone in BCBL-1 cells. The viability of 2F7 and BCBL-1 cells decreased significantly in the presence of PKCβ-selective inhibitor at half-maximal inhibitory concentration of 14 and 15 μmol/L, respectively, as measured by tetrazolium dye reduction assay. In contrast, UMCL01-101 cells were relatively resistant. As determined using flow cytometric deoxynucleotidyl transferase dUTP nick-end labeling assay with propidium iodide staining, the responsiveness of sensitive cells was associated with apoptotic induction and cell cycle inhibition. Protein kinase C-beta-selective inhibition was observed not to affect AKT phosphorylation but to induce a rapid and sustained reduction in the phosphorylation of glycogen synthase kinase-3 beta, ribosomal protein S6, and mammalian target of rapamycin in sensitive cell lines.

CONCLUSIONS

The results indicate that PKCβ plays an important role in AIDS-related NHL survival and suggest that PKCβ targeting should be considered in a broader spectrum of NHL. The observations in BCBL-1 were unexpected in the absence of PKCβ2 expression and implicate PKCβ1 as a regulator in those cells.

Assessment of immunovirological features in HIV related non-Hodgkin lymphoma patients and their impact on outcome

BACKGROUND

Despite the era of highly active antiretroviral therapy, non-Hodgkin lymphoma (NHL) remains one of the main causes of death in HIV-infected patients, with a wide variation on the outcome.

OBJECTIVES

We investigated immunological status and EBV, HHV8, HIV viral load in a group of HIV-infected patients at diagnosis of NHL to evaluate their prognostic significance.

STUDY DESIGN

Eighty-one consecutive HIV+ NHL patients were studied. CD4 and CD8 cell counts, HHV8 DNA, EBV DNA, HIV RNA and HIV DNA were assessed at diagnosis and at 3 months after chemotherapy initiation. Hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of disease free survival (DFS) and overall survival (OS) were computed according to CD4 and CD8 cell counts, EBV DNA, HIV RNA and HIV DNA. HRs were, thereafter, computed also for continuous variation of CD4, CD8 cell counts and EBV DNA.

RESULTS

In the multivariate analysis, CD4<160 and CD8<590 cell/μl and EBV DNA≥300 c/ml were independently associated to DFS (HR=2.98; 95%CI: 1.26-7.03; HR=2.65, 95%CI: 1.13-6.19; HR=4.01; 95%CI: 1.81-8.91) and OS (HR=3.32; 95%CI: 1.41-7.83; HR=4.62, 95%CI: 1.91-11.19; HR=3.11, 95%CI: 1.42-6.80). HRs for DFS and OS decreased continuously with increasing CD4 and CD8 cell counts, while they increased continuously with increasing EBV DNA levels.

CONCLUSIONS

The association with survival of low CD4 and CD8 cell counts and detectable EBV viremia, measured at lymphoma's diagnosis, identified three independent prognostic biomarkers that might help in the management of NHL HIV+ patients, offering complementary information in the ascertainment of their outcome.

Infectious agents and lymphoma

In the past 25 years revelations on the genesis of human cancer have come at an increasing pace. Research on oncogenic infectious agents, especially viruses, has helped us to understand the process of malignant transformation of cells because the cellular events in viral-driven transformation mirror, often brilliantly, basic cellular processes that culminate in cancer, even those not associated with viruses. Infectious agents, especially viruses, account for several of the most common malignancies-up to 20% of all cancers. Some of these cancers are endemic, with a high incidence in certain geographic locations, but sporadic/lower incidence in other parts of the world. Lymphomas arise frequently in association with infectious agents such as Epstein-Barr virus, human immunodeficiency virus, human herpes virus 8, Helicobacter pylori, and hepatitis C virus. In this review, we will focus on the association between infectious agents and lymphomas, with a look at the molecular mechanisms they use to disturb cell regulation and eventually result in cancer.

Therapeutic interventions for Burkitt lymphoma in children

BACKGROUND

Burkitt lymphoma (BL) is an important cancer found mostly in children but uncertainty remains as to the most effective form of management. In endemic areas, late-stage presentation as a result of delayed access to treatment compounds the situation.

OBJECTIVES

To assess the evidence for chemotherapy, surgery, radiotherapy and immunotherapy in the treatment of children with endemic BL.

SEARCH STRATEGY

We updated and re-ran the searches in the following electronic databases from the time of the first publication; the Cochrane Controlled Trials Register (CENTRAL) (Issue 1, 2011); MEDLINE (January 2011); EMBASE (January 2011); and the clinical trials registry (up to January 2011) to identify relevant trials. In addition, we also updated the search of the US clinical trials register for on-going and completed trials up to January 2011. We also updated the search terms and used the Cochrane filter for identifying randomised trials in MEDLINE.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of any duration. We included studies conducted in children with a confirmed diagnosis of BL. We did not restrict studies by geographical location or by language of publication. We considered any therapeutic intervention. The primary outcome was overall survival.

DATA COLLECTION AND ANALYSIS

Two review authors assessed studies for relevance. We assessed studies that met the entry criteria for study quality. We independently extracted data and entered the data into Review Manager (RevMan). In this update, two review authors independently assessed citations from the updated search and reviewed abstracts for relevance.

MAIN RESULTS

We included one new study in this update. In total, 13 trials involving 1824 participants met the inclusion criteria for this review however, data in usable format were only available in 10 trials (732 participants). Inadequate reporting of study methodology was a common feature of the trials preventing thorough assessment of study quality. We were unable to pool data for any of the outcomes due to the differences between the interventions assessed in the studies. Eight studies aimed to induce remission; overall survival did not differ significantly between treatment groups. Five studies aimed to maintain remission. In two out of three studies reporting survival, this was substantial but the difference was not statistically significant between treatment groups. Less aggressive treatment schedules appear to produce similar effects with less adverse event profiles.

AUTHORS' CONCLUSIONS

This review notes a preference in more recent studies for less aggressive care options for treatment of BL. However, the evidence for the relative effectiveness of interventions to treat BL is not strong as studies were small, underpowered and prone to both systematic and random error. We included one additional trial without change of conclusions.

mTOR as a multifunctional therapeutic target in HIV infection

Patients undergoing long-term highly active antiretroviral therapy treatment are probably at a higher risk of various HIV-related complications. Hyperactivation of The mammalian target of rapamycin (mTOR) has been found to contribute to dysregulated apoptosis and autophagy which determine CD4(+)-T-cell loss, impaired function of innate immunity and development of neurocognitive disorders. Dysregulated mTOR activation has also been shown to play a key part in the development of nephropathy and in the pathogenesis of HIV-associated malignancies. These studies strongly support a multifunctional key role for mTOR in the pathogenesis of HIV-related disorders and suggest that specific mTOR inhibitors could represent a novel approach for the prevention and treatment of these pathologies.

Genetic background and lymphocyte populations after total-body exposure to iron ion radiation

PURPOSE

Particle radiations could significantly impact astronaut health during space missions. This study quantified the effects of iron ion radiation on lymphocytes in two strains of mice differing in susceptibility to radiation-induced acute myeloid leukemia (AML) and thymic lymphoma (TL): C57BL/6 (AML resistant, TL sensitive) and CBA/Ca (AML sensitive, TL resistant).

MATERIALS AND METHODS

The animals (n = 60/strain) were irradiated with ⁵⁶Fe(26+) (1 GeV) to total doses of 0, 0.5, 2 and 3 Gray (Gy) at an average dose rate of 1 Gy/min and euthanised on days 4 and 30 thereafter; blood, spleen, and bone marrow were collected for flow cytometry analyses. Cells expressing the following molecules were quantified: Cluster of differentiation (CD) 4, CD8, CD25, CD34, CD71, B220 (isoform of CD45 on B cells), NK1.1 (marker on natural killer or NK cells, C57B mice), panNK (marker on NK cells, CBA mice), and Sca1 (stem cell antigen 1).

RESULTS

Exposure to radiation resulted in different distribution patterns in lymphocyte populations and leukocytes expressing activation and progenitor markers in the two mouse strains. Significant main effects were dependent upon strain, as well as radiation dose, body compartment, and time of assessment. Especially striking differences were noted on day 4 after 3 Gy irradiation, including in the CD4:CD8 ratio [blood, C57 (2.83 ± 0.25) vs. CBA (6.19 ± 0.24); spleen, C57 (2.29 ± 0.12) vs. CBA (4.98 ± 0.22)], %CD25(+) mononuclear cells in bone marrow [C57 (5.62 ± 1.19) vs. CBA (12.45 ± 0.93)] and %CD34(+)Sca1(+) cells in bone marrow [CD45¹° gate, C57 (2.72 ± 0.74) vs. CBA (21.44 ± 0.73)].

CONCLUSION

The results show that genetic background, as well as radiation dose and time post-exposure, had a profound impact on lymphocyte populations, as well as other leukocytes, after exposure to iron ion radiation.

Dysfunctional B-cell responses during HIV-1 infection: implication for influenza vaccination and highly active antiretroviral therapy

Although HIV-1 infection does not directly target B cells, B-cell numbers are reduced and their function is impaired during HIV infection. Antibody titres against antigens previously encountered through vaccination or natural infection are low in patients with HIV. Intrinsic B-cell defects might be involved in the impairment of humoral immunity during early HIV infection. Abnormal T-cell activation and the altered expression of molecules involved in the B-cell homing process cause dysfunctional interaction between T and B cells in the germinal centres of lymphoid tissues, which might impair B-cell responses during HIV infection. Class-switch recombination is also impaired in individuals with HIV. Protective immune responses against T-cell-dependent antigens, including influenza antigens, rely on the production of neutralising antibodies. Impaired B-cell responses during HIV infection could therefore hamper the effectiveness of vaccinations against seasonal influenza or the new pandemic influenza A H1N1 vaccines in individuals with HIV. By maintaining B-cell responses, highly active antiretroviral therapy might improve the efficacy of influenza vaccines in individuals with HIV.

Human tumor-associated viruses and new insights into the molecular mechanisms of cancer

The study of acute-transforming retroviruses and their oncogenes and of the multiple mechanisms deployed by DNA viruses to circumvent the growth-suppressive and proapoptotic function of tumor suppressor genes has provided the foundation of our current understanding of cancer biology. Unlike acute-transforming animal viruses, however, human tumor-associated viruses lead to malignancies with a prolonged latency and in conjunction with other environmental and host-related cooperating events. The relevance of viral infection to human cancer development has often been debated. We now know that at least six human viruses, Epstein-Barr virus (EBV), hepatitis B virus (HBV), hepatitis C virus (HCV), human papilloma virus (HPV), human T-cell lymphotropic virus (HTLV-1) and Kaposi's associated sarcoma virus (KSHV) contribute to 10-15% of the cancers worldwide. Hence, the opportunity exists to fight cancer at the global scale by preventing the spread of these viruses, by the development and distribution of effective and safe antiviral vaccines, and by identifying their oncogenic mechanism. Here, we discuss the molecular events underlying the neoplastic potential of the human tumor-associated viruses, with emphasis on the enigmatic KSHV and its numerous virally hijacked proangiogenic, immune-evasive and tumor-promoting genes. The emerging information may facilitate the development of new molecular-targeted approaches to prevent and treat virally associated human malignancies.

Activation of mTORC1 signaling pathway in AIDS-related lymphomas

Using immunohistochemistry with antibodies against the phosphoserine residues in both S6rp and 4E binding protein 1, we identified the activation of the mammalian target of rapamycin (mTORC)1 pathway in 29 cases of AIDS-related lymphoma. These cases represented a diverse spectrum of histological types of non-Hodgkin lymphoma (24 cases) and classic Hodgkin lymphoma (five cases). mTORC1 was also activated in the hyperplastic but not involuted follicles of HIV-associated lymphadenopathy in eight cases, supporting the notion that mTORC1 activation is a common feature of transformed lymphocytes irrespective of either their reactive or malignant phenotype. We also found that in B-cell lines that represent diffuse large B-cell lymphoma, Burkitt lymphoma, Epstein-Barr virus-infected lymphocytes, and human herpesvirus 8-positive primary effusion lymphoma, inhibitors of Syk, MEK, and, seemingly, phosphoinositide 3 kinases suppressed mTORC1 activation, in particular when these inhibitors were used in combination. These findings indicate that AIDS-related lymphoma and other histologically similar types of lymphomas that are derived from transformed B lymphocytes may display clinical responses to inhibitors that directly target mTORC1 or, possibly, upstream activators of the mTORC1 pathway.

Treatment-dependent loss of polyfunctional CD8+ T-cell responses in HIV-infected kidney transplant recipients is associated with herpesvirus reactivation

Antiretroviral-therapy has dramatically changed the course of HIV infection and HIV-infected (HIV(+)) individuals are becoming more frequently eligible for solid-organ transplantation. However, only scarce data are available on how immunosuppressive (IS) strategies relate to transplantation outcome and immune function. We determined the impact of transplantation and immune-depleting treatment on CD4+ T-cell counts, HIV-, EBV-, and Cytomegalovirus (CMV)-viral loads and virus-specific T-cell immunity in a 1-year prospective cohort of 27 HIV(+) kidney transplant recipients. While the results show an increasing breadth and magnitude of the herpesvirus-specific cytotoxic T-cell (CTL) response over-time, they also revealed a significant depletion of polyfunctional virus-specific CTL in individuals receiving thymoglobulin as a lymphocyte-depleting treatment. The disappearance of polyfunctional CTL was accompanied by virologic EBV-reactivation events, directly linking the absence of specific polyfunctional CTL to viral reactivation. The data provide first insights into the immune-reserve in HIV+ infected transplant recipients and highlight new immunological effects of thymoglobulin treatment. Long-term studies will be needed to assess the clinical risk associated with thymoglobulin treatment, in particular with regards to EBV-associated lymphoproliferative diseases.

Altered expression of the receptor-ligand pair CXCR5/CXCL13 in B cells during chronic HIV-1 infection

HIV-1 infection is associated with B-cell abnormalities, such as hypergammaglobulinemia, poor immunization responses, and loss of serologic memory. To determine whether altered expression of chemokine receptors and their ligands may play a role in B-cell dysfunctions during HIV-1 infection, the expression of CXC chemokine receptor 4 (CXCR4), CXCR5, and CC chemokine receptor 7 (CCR7) and their respective ligands on CD19(+) B cells were examined in HIV-1-infected patients and controls. We report a decreased CXCR5 expression on B cells from patients (P < .05), a phenomenon associated with a low CD4 T-cell count (< 350 cells/microL). Interestingly, an increased expression of CXC chemokine ligand 13 (CXCL13), the ligand for CXCR5, was found in peripheral B cells from HIV-1-infected patients. Moreover, on B-cell activation in vitro, CXCL13 was secreted in culture. CXCL13(+) B cells were also found in the lymph nodes of HIV-1-infected patients, but not in control tissue. B-cell migration toward CXCL13, CXCL12, and CC chemokine ligand 21 (CCL21), ligands for CXCR5, CXCR4, and CCR7 was also evaluated. In patients with a low CD4 T-cell count, migration toward all ligands was increased. Our findings indicate that altered expression of the chemokine receptor-ligand pair, CXCR5/CXCL13, may participate in the establishment of B-cell dysfunctions during HIV-1 infection.

Dose-reduced busulfan, cyclophosphamide, and autologous stem cell transplantation for human immunodeficiency virus-associated lymphoma: AIDS Malignancy Consortium study 020

Intensive chemotherapy for human immunodeficiency virus (HIV)-associated non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) has resulted in durable remissions in a substantial proportion of patients. High-dose chemotherapy and autologous stem cell transplantation (AuSCT), moreover, has resulted in sustained complete remissions in selected patients with recurrent chemosensitive disease. Based on a favorable experience with dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT for older patients with non-HIV-associated aggressive lymphomas, an AIDS Malignancy Consortium multicenter trial was undertaken using the same dose-reduced busulfan and cyclophosphamide preparative regimen with AuSCT for recurrent HIV-associated NHL and HL. Of the 27 patients in the study, 20 received an AuSCT. The median time to achievement of an absolute neutrophil count (ANC) of >or= 0.5 x 10(9)/L was 11 days (range, 9-16 days). The median time to achievement of an unsupported platelet count of >or= 20 x 10(9)/L was 13 days (range, 6-57 days). One patient died on day +33 posttransplantation from hepatic veno-occlusive disease (VOD) and multiorgan failure. No other fatal regimen-related toxicity occurred. Ten of 19 patients (53%) were in complete remission at the time of their day +100 post-AuSCT evaluation. Of the 20 patients, 10 were alive and event-free at a median of 23 weeks post-AuSCT. Median overall survival (OS) was not reached by 13 of the 20 patients alive at the time of last follow-up. This multi-institutional trial demonstrates that a regimen of dose-reduced high-dose busulfan, cyclophosphamide, and AuSCT is well tolerated and is associated with favorable disease-free survival (DFS) and OS probabilities for selected patients with HIV-associated NHL and HL.

Update on HIV lymphoma

In industrialized nations people infected with HIV remain at increased risk for malignancies despite highly active antiretroviral therapy. In these countries, lymphoma is the most common HIV-associated malignancy. This review summarizes progress from January 2005 to February 2007. The majority of investigation has been in diffuse large B cell lymphoma, with infusional therapy remaining promising but cumbersome. Rituximab likely improves complete response rates, and, possibly overall survival, but is likely associated with increased infections in a subset of patients with very low CD4 counts. Biologic insights have been attained in the spectrum of HIV-associated non-Hodgkin's lymphoma, Hodgkin's lymphoma, and virologic coinfections. Overall, the outcome for non-Hodgkin's lymphoma and Hodgkin's lymphoma in the setting of HIV continues to improve as insights into the pathophysiology and treatment advance.

Interventions for treating AIDS-associated Hodgkin s lymphoma in treatment-naive adults

BACKGROUND

Hodgkin's disease (HD) is the most common non-AIDS-defining malignancy in HIV-infected patients. Its unusually aggressive tumour behaviour includes a higher frequency of unfavourable histologic subtypes, high-stage and extranodal involvement by the time of presentation (anal canal, stomach), and poor therapeutic outcome, in comparison with HD outside the HIV setting. The optimal therapeutic strategy is still controversial, and median overall survival is short, ranging from 12 to 18 months. Thus, there is a need to identify the efficacy and safety of different interventions for AIDS-associated HD on overall survival and disease-free survival in treatment-naive adults with AIDS.

OBJECTIVES

To assess the effects of different interventions for treating AIDS-associated Hodgkin's disease including chemotherapy, bone marrow transplantation (BMT), and gene therapy on overall survival and disease-free survival in treatment-naive adults with AIDS.

SEARCH STRATEGY

We searched The Cochrane HIV/AIDS Group Trials Register (September 2006), which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 3, 2006), MEDLINE (1966 to September 2006), EMBASE (1974 to September 2006) LILACS (1982 to September 2006), ISI Web of Knowledge (1993 to September 2006), and AIDSearch (1980 to December 2006). Date of most recent search: December 2006.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials.

DATA COLLECTION AND ANALYSIS

We intended to summarise data by standard Cochrane Collaboration methodologies, but no eligible randomised controlled trials were identified.

MAIN RESULTS

We were unable to find any randomised controlled trials of interventions for treating AIDS-associated HD in treatment-naive adults with AIDS.

AUTHORS' CONCLUSIONS

Randomised controlled trials are needed to establish the efficacy and safety of interventions for treating AIDS-associated HD in treatment-naive adults with AIDS.

Growth regulation of simian and human AIDS-related non-Hodgkin's lymphoma cell lines by TGF-beta1 and IL-6

Background

AIDS-related non-Hodgkin's lymphoma (AIDS-NHL) is the second most frequent cancer associated with AIDS, and is a frequent cause of death in HIV-infected individuals. Experimental analysis of AIDS-NHL has been facilitated by the availability of an excellent animal model, i.e., simian Acquired Immunodeficiency Syndrome (SAIDS) in the rhesus macaque consequent to infection with simian immunodeficiency virus. A recent study of SAIDS-NHL demonstrated a lymphoma-derived cell line to be sensitive to the growth inhibitory effects of the ubiquitous cytokine, transforming growth factor-beta (TGF-beta). The authors concluded that TGF-beta acts as a negative growth regulator of the lymphoma-derived cell line and, potentially, as an inhibitory factor in the regulatory network of AIDS-related lymphomagenesis. The present study was conducted to assess whether other SAIDS-NHL and AIDS-NHL cell lines are similarly sensitive to the growth inhibitory effects of TGF-beta, and to test the hypothesis that interleukin-6 (IL-6) may represent a counteracting positive influence in their growth regulation.

Methods

Growth stimulation or inhibition in response to cytokine treatment was quantified using trypan blue exclusion or colorimetric MTT assay. Intracellular flow cytometry was used to analyze the activation of signaling pathways and to examine the expression of anti-apoptotic proteins and distinguishing hallmarks of AIDS-NHL subclass. Apoptosis was quantified by flow cytometric analysis of cell populations with sub-G1 DNA content and by measuring activated caspase-3.

Results

Results confirmed the sensitivity of LCL8664, an immunoblastic SAIDS-NHL cell line, to TGF-beta1-mediated growth inhibition, and further demonstrated the partial rescue by simultaneous treatment with IL-6. IL-6 was shown to activate STAT3, even in the presence of TGF-beta1, and thereby to activate proliferative and anti-apoptotic pathways. By comparison, human AIDS-NHL cell lines differed in their responsiveness to TGF-beta1 and IL-6. Analysis of a recently derived AIDS-NHL cell line, UMCL01-101, indicated that it represents immunoblastic AIDS-DLCBL. Like LCL-8664, UMCL01-101 was sensitive to TGF-beta1-mediated inhibition, rescued partially by IL-6, and demonstrated rapid STAT3 activation following IL-6 treatment even in the presence of TGF-beta1.

Conclusion

These studies indicate that the sensitivity of immunoblastic AIDS- or SAIDS-DLBCL to TGF-beta1-mediated growth inhibition may be overcome through the stimulation of proliferative and anti-apoptotic signals by IL-6, particularly through the rapid activation of STAT3.

Rheumatic manifestations of human immunodeficiency virus infection

Rheumatic complaints are common in patients with HIV, and HIV positivity confers an increased susceptibility in populations with similar risk factors for HIV infection. With the advent of the modern combined antiretroviral treatment, HAART has had a profound beneficial effect on survival in HIV-infected patients, with lifelong control of HIV infection and normalization of life expectancy; but it has also contributed to both an altered frequency and a different nature of rheumatic complications now being observed in this population, with new rheumatic complications, such as osteoporosis, osteonecrosis, gout, mycobacterial, mycotic osteoarticular infections, and neoplasia perhaps more prevalent. Rheumatologists, internists, and general physicians need to be aware of these changes to provide optimal diagnosis and how to disclose the results to their patients. They also need to be familiar with the management of HIV infection and to direct careful attention to the prevention of HIV transmission in health care facilities.

Molecular biology of KSHV in relation to AIDS-associated oncogenesis

KSHV has been established as the causative agent of KS, PEL, and MCD, malignancies occurring more frequently in AIDS patients. The aggressive nature of KSHV in the context of HIV infection suggests that interactions between the two viruses enhance pathogenesis. KSHV latent infection and lytic reactivation are characterized by distinct gene expression profiles, and both latency and lytic reactivation seem to be required for malignant progression. As a sophisticated oncogenic virus, KSHV has evolved to possess a formidable repertoire of potent mechanisms that enable it to target and manipulate host cell pathways, leading to increased cell proliferation, increased cell survival, dysregulated angiogenesis, evasion of immunity, and malignant progression in the immunocompromised host. Worldwide, approximately 40.3 million people are currently living with HIV infection. Of these, a significant number are coinfected with KSHV. The complex interplay between the two viruses dramatically elevates the risk for development of KSHV-induced malignancies, KS, PEL, and MCD. Although HAART significantly reduces HIV viral load, the entire T-cell repertoire and immune function may not be completely restored. In fact, clinically significant immune deficiency is not necessary for the induction of KSHV-related malignancy. Because of variables such as lack of access to therapy noncompliance with prescribed treatment, failure to respond to treatment and the development of drug-resistant strains of HIV, KSHV-induced malignancies will continue to present as major health concerns.

Update in HIV lymphoma

PURPOSE OF REVIEW

Despite the control of HIV infection in industrialized nations, individuals infected with HIV remain at increased risk of malignancies. Lymphoma is the most common HIV-associated malignancy in these countries. This review summarizes progress from January 2005 to March 2006.

RECENT FINDINGS

Investigators continue to demonstrate that HIV-associated non-Hodgkin's lymphoma remains a significant problem, even in the era of highly active antiretroviral therapy. The majority of work has been in diffuse large B-cell lymphoma, with infusional therapy remaining promising, and rituximab an area of investigation. The latter improves complete response rates, but is associated with an increased incidence of infections. Biological insights have been gained into the spectrum of HIV-associated non-Hodgkin's lymphoma and Hodgkin's disease, and include further work on virological co-infections.

SUMMARY

The outcome for individuals infected with HIV and developing non-Hodgkin's lymphoma and Hodgkin's disease continues to improve as insights into the pathophysiology and treatment advance.

High prevalence of multiple human herpesviruses in saliva from human immunodeficiency virus-infected persons in the era of highly active antiretroviral therapy

Human immunodeficiency virus (HIV) infection is associated with an increased risk for human herpesviruses (HHVs) and their related diseases. Methods for limiting the transmission of HHVs require a better understanding of the prevalence and infectiousness of oral HHVs in HIV-infected patients. We performed quantitative PCR to investigate the prevalence, quantity, risk, and correlates of salivary HHVs from 58 HIV-seropositive individuals in a case control study. HHVs were significantly more prevalent in the salivas of HIV-seropositive persons than in those of the controls (odds ratios [ORs], 4.2 to 26.2; P<or=0.008). In HIV-infected patients, Epstein-Barr virus (EBV), human herpesvirus 8 (HHV-8), cytomegalovirus (CMV), and herpes simplex virus type 1 (HSV-1) were detected in 90%, 57%, 31% and 16% of samples, respectively, compared with 48%, 24%, 2%, and 2%, respectively, of samples from controls. Multiple HHVs were observed in 71% of HIV-seropositive persons and only 16% of controls (OR, 13.0; 95% confidence interval, 5.29 to 32.56). HIV-positive patients had significantly higher EBV loads than HIV-negative persons (P<0.0001). HIV-infected patients with CD4 counts above 200 cells/microl had increased probability for having HHV-8 in saliva (P=0.009) compared with patients whose counts were less than 200. In contrast, HSV-1, EBV, and CMV were detected more often when CD4 counts were low. High salivary HHV loads were detected for those (n=7) with oral lesions. These findings suggest that saliva is a potential risk factor for the acquisition of multiple HHVs, and several host factors may function to accelerate HHV reactivation or replication in patients with HIV infection.