Effect of Statin Use on Inflammation and Immune Activation Biomarkers in HIV-Infected Persons on Effective Antiretroviral Therapy.

Immune activation and inflammation are hallmarks of chronic HIV infection and are etiologically linked to major causes of morbidity and mortality among HIV-infected persons, including coronary artery disease and cancer. Systemic immune activation is dampened, but not resolved, with use of combination antiretroviral therapy (cART). Statins are cardioprotective drugs that also appear to have immunomodulatory and anti-inflammatory properties. We sought to understand the association between statin use, cART, and levels of circulating immune markers in a longitudinal cohort study. From 2004 to 2009, statin use was ascertained in male participants of the Multicenter AIDS Cohort Study (MACS) using interviewer-administered questionnaires. Twenty-four circulating markers of immune activation and inflammation were measured in archived serial samples from a subset of cohort members using multiplex assays. Propensity-adjusted generalized gamma models were used to compare biomarkers' distributions by statin use, and multivariable linear regression models were used to assess the effect of initiating statin on these biomarkers. Overall, 1,031 cART-exposed individuals with HIV infection were included in this study. Statin use was reported by 31.5% of cART-exposed participants. Compared to nonstatin users on cART, statin users on cART had lower levels of IP-10, IL-10, and IL-12p70, and the effect of statin use was decreased in participants using lipophilic statins (atorvastatin, simvastatin, fluvastatin, or lovastatin); these results were statistically significant (p < .05). Among cART users not on aspirin, starting statins decreased levels of high sensitivity c-reactive protein (hsCRP), IL-12p70, and IL-6. Statin therapy is associated with reduced levels of certain biomarkers of immune activation and inflammation in cART users, which may contribute to a lower burden of disease.

Sustained delivery and molecular targeting of a therapeutic monoclonal antibody to metastases in the central nervous system of mice.

Approximately 15-40% of all cancers develop metastases in the central nervous system (CNS), yet few therapeutic options exist to treat them. Cancer therapies based on monoclonal antibodies are widely successful, yet have limited efficacy against CNS metastases, owing to the low levels of the drug reaching the tumour site. Here, we show that the encapsulation of rituximab within a crosslinked zwitterionic polymer layer leads to the sustained release of rituximab as the crosslinkers are gradually hydrolysed, enhancing the CNS levels of the antibody by approximately tenfold with respect to the administration of naked rituximab. When the nanocapsules were functionalized with CXCL13-the ligand for the chemokine receptor CXCR5, which is frequently found on B-cell lymphoma-a single dose led to improved control of CXCR5-expressing metastases in a murine xenograft model of non-Hodgkin lymphoma, and eliminated lymphoma in a xenografted humanized bone marrow-liver-thymus mouse model. Encapsulation and molecular targeting of therapeutic antibodies could become an option for the treatment of cancers with CNS metastases.

Predictive Value of Cytokines and Immune Activation Biomarkers in AIDS-Related Non-Hodgkin Lymphoma Treated with Rituximab plus Infusional EPOCH (AMC-034 trial).

PURPOSE: The aims of this study were to determine whether pretreatment plasma levels of cytokines and immune activation-associated molecules changed following treatment for AIDS-NHL with rituximab plus infusional EPOCH, and to determine whether pretreatment levels of these molecules were associated with response to treatment and/or survival. EXPERIMENTAL DESIGN: We quantified plasma levels of B-cell activation-associated molecules (sCD27, sCD30, and sCD23) and cytokines (IL6, IL10, and CXCL13) before and after the initiation of treatment in persons with AIDS-NHL (n = 69) in the AIDS Malignancies Consortium (AMC) 034 study, which evaluated treatment of AIDS-NHL with EPOCH chemotherapy and rituximab. RESULTS: Treatment resulted in decreased plasma levels of some of these molecules (CXCL13, sCD27, and sCD30), with decreased levels persisting for one year following the completion of treatment. Lower levels of CXCL13 before treatment were associated with complete responses following lymphoma therapy. Elevated levels of IL6 pretreatment were associated with decreased overall survival, whereas higher IL10 levels were associated with shorter progression-free survival (PFS), in multivariate analyses. Furthermore, patients with CXCL13 or IL6 levels higher than the median levels for the NHL group, as well as those who had detectable IL10, had lower overall survival and PFS, in Kaplan-Meier analyses. CONCLUSIONS: These results indicate that CXCL13, IL6, and IL10 have significant potential as prognostic biomarkers for AIDS-NHL.

Efficacy of an Anti-transferrin Receptor 1 Antibody Against AIDS-related Non-Hodgkin Lymphoma: A Brief Communication.

The transferrin receptor 1 (TfR1), also known as CD71, is a target for antibody-based cancer immunotherapy due to its high expression on the surface of cancer cells and its ability to internalize. We have previously developed a mouse/human chimeric IgG3 specific for human TfR1 genetically fused to avidin, as a vector to deliver biotinylated anticancer agents into malignant cells. However, we found that this fusion protein (ch128.1Av), and to a lesser extent the same antibody without avidin (ch128.1), exhibits direct cytotoxic activity in vitro against certain malignant hematopoietic cells through the induction of TfR1 degradation and lethal iron starvation. Importantly, both ch128.1 and ch128.1Av have also shown significant anticancer activity in 2 xenograft models of the B-cell malignancy multiple myeloma. It is interesting to note that ch128.1 exhibited superior anticancer activity in both models compared with ch128.1Av, even against malignant cells that show no sensitivity to ch128.1 in vitro. In the present study, we evaluated the efficacy of ch128.1 against an AIDS-related human Burkitt lymphoma cell line (2F7) to determine if ch128.1 can eliminate these cells in vitro and in an in vivo model of AIDS-related non-Hodgkin lymphoma (AIDS-NHL). Even though 2F7 cells expressed high TfR1 levels, these cells lacked sensitivity to the cytotoxicity induced by ch128.1 in vitro. However, ch128.1 showed significant anticancer activity against these AIDS-NHL cells in vivo by significantly prolonging the survival of immunodeficient mice bearing 2F7 tumors. Therefore, ch128.1 warrants further study as a candidate for the treatment of AIDS-NHL and other B-cell malignancies.

Serum levels of cytokines and biomarkers for inflammation and immune activation, and HIV-associated non-Hodgkin B-cell lymphoma risk.

BACKGROUND: HIV infection is associated with a marked increase in risk for non-Hodgkin lymphoma (AIDS-NHL). However, the mechanisms that promote the development of AIDS-NHL are not fully understood. METHODS: In this study, serum levels of several cytokines and other molecules associated with immune activation were measured in specimens collected longitudinally during 1 to 5 years preceding AIDS-NHL diagnosis, in 176 AIDS-NHL cases and 176 HIV(+) controls from the Multicenter AIDS Cohort Study (MACS). RESULTS: Multivariate analyses revealed that serum levels of immunoglobulin free light chains (FLC), interleukin (IL)-6, IL-10, IP-10/CXCL10, neopterin, and TNF-α were elevated in those HIV(+) individuals who went on to develop AIDS-NHL. In addition, the fraction of specimens with detectable IL-2 was increased and the fraction with detectable IL-4 was decreased in these subjects. CONCLUSIONS: These results suggest that long-term, chronic immune activation, possibly driven by macrophage-produced cytokines, precedes development of NHL in HIV(+) individuals. IMPACT: FLC, IL-6, IL-10, IP-10/CXCL10, neopterin, and TNF-α may serve as biomarkers for AIDS-NHL. .

Levels of murine, but not human, CXCL13 are greatly elevated in NOD-SCID mice bearing the AIDS-associated Burkitt lymphoma cell line, 2F7.

Currently, few rodent models of AIDS-associated non-Hodgkin's lymphoma (AIDS-NHL) exist. In these studies, a novel mouse/human xenograft model of AIDS-associated Burkitt lymphoma (AIDS-BL) was created by injecting cells of the human AIDS-BL cell line, 2F7, intraperitoneally into NOD-SCID mice. Mice developed tumors in the peritoneal cavity, with metastases to the spleen, thymus, and mesenteric lymph nodes. Expression of the chemokine receptor, CXCR5, was greatly elevated in vivo on BL tumor cells in this model, as shown by flow cytometry. CXCL13 is the ligand for CXCR5, and serum and ascites levels of murine, but not human, CXCL13 showed a striking elevation in tumor-bearing mice, with levels as high as 200,000 pg/ml in ascites, as measured by ELISA. As shown by immunohistochemistry, murine CXCL13 was associated with macrophage-like tumor-infiltrating cells that appeared to be histiocytes. Blocking CXCR5 on 2F7 cells with neutralizing antibodies prior to injection into the mice substantially delayed tumor formation. The marked elevations in tumor cell CXCR5 expression and in murine CXCL13 levels seen in the model may potentially identify an important link between tumor-interacting histiocytes and tumor cells in AIDS-BL. These results also identify CXCL13 as a potential biomarker for this disease, which is consistent with previous studies showing that serum levels of CXCL13 were elevated in human subjects who developed AIDS-lymphoma. This mouse model may be useful for future studies on the interactions of the innate immune system and AIDS-BL tumor cells, as well as for the assessment of potential tumor biomarkers for this disease.

Effect of highly active antiretroviral therapy on biomarkers of B-lymphocyte activation and inflammation.

OBJECTIVE: Chronic inflammation and B-cell hyperactivation are seen in HIV infection, contributing to an increased risk for the accrual of genetic errors that may result in B-cell lymphoma. The primary objective of this study was to determine the effect of highly active antiretroviral therapy (HAART) on serum levels of molecules that are associated with immune activation and/or inflammation, including several that are associated with B-cell activation, specifically IL-6, sCD30, sCD27, IgG, IgA, CXCL13 (B lymphocyte chemoattractant, BLC), a B-lymphocyte chemokine involved in B-cell trafficking, as well as C-reactive protein, an acute-phase protein. DESIGN: We used a retrospective cohort study design, measuring serum levels of these markers at each of four 1-year intervals, 2 years before and 2 years after HAART initiation, in a subgroup of 290 HIV-infected men enrolled in the Multicenter AIDS Cohort Study (MACS). METHODS: Serum levels of immune activation-associated molecules were measured by ELISA and multiplexed immunometric assays. Reference values were determined by the 5th to 95th percentiles from a sample of 109 HIV-uninfected MACS men. RESULTS: HAART use was associated with a reduction, but not normalization, of most biomarkers tested. Serum levels of IL-6 and C-reactive protein appeared to be unaffected by HAART. CONCLUSIONS: These results suggest a partial normalization of serum cytokine levels post HAART. However, a chronic state of B-cell hyperactivation continues 2-3 years after HAART initiation. These findings may explain, in part, the excess incidence of lymphoma still occurring in HIV-infected persons in the post-HAART era.

Expression and Function of the Chemokine, CXCL13, and Its Receptor, CXCR5, in Aids-Associated Non-Hodgkin's Lymphoma.

Background. The homeostatic chemokine, CXCL13 (BLC, BCA-1), helps direct the recirculation of mature, resting B cells, which express its receptor, CXCR5. CXCL13/CXCR5 are expressed, and may play a role, in some non-AIDS-associated B cell tumors. Objective. To determine if CXCL13/CXCR5 are associated with AIDS-related non-Hodgkin's lymphoma (AIDS-NHL). Methods. Serum CXCL13 levels were measured by ELISA in 46 subjects who developed AIDS-NHL in the Multicenter AIDS Cohort Study and in controls. The expression or function of CXCL13 and CXCR5 was examined on primary AIDS-NHL specimens or AIDS-NHL cell lines. Results. Serum CXCL13 levels were significantly elevated in the AIDS-NHL group compared to controls. All primary AIDS-NHL specimens showed CXCR5 expression and most also showed CXCL13 expression. AIDS-NHL cell lines expressed CXCR5 and showed chemotaxis towards CXCL13. Conclusions. CXCL13/CXCR5 are expressed in AIDS-NHL and could potentially be involved in its biology. CXCL13 may have potential as a biomarker for AIDS-NHL.

Pathogenesis of AIDS lymphoma: role of oncogenic viruses and B cell activation-associated molecular lesions.

PURPOSE OF REVIEW: We discuss recently published studies that elucidate the pathogenesis of AIDS-associated lymphoma. RECENT FINDINGS: Several recent reports have provided valuable new information on the role of gamma-herpesviruses in the pathogenesis of AIDS-associated lymphoma. In addition to this, significant new information has become available on how B cell activation-associated DNA-modifying events, involving activation-induced cytidine deaminase and DNA polymerase-eta, contribute to the molecular lesions that result in AIDS-associated lymphoma. In particular, new evidence that oncogenic viruses can directly induce activation-induced cytidine deaminase expression and oncogene mutation in human B cells is of central relevance to better understanding the pathogenesis of AIDS-associated lymphoma. SUMMARY: New information provides insights into the contributions of immune dysfunction and oncogenic virus infection to pathogenesis of AIDS-associated lymphoma, and may lead to new potential targets for therapeutic intervention in these cancers.

Serum levels of the homeostatic B cell chemokine, CXCL13, are elevated during HIV infection.

HIV infection is associated with B cell dysfunction, which includes B cell hyperactivation, hypergammaglobulinemia, impaired production of antibodies against specific antigens, and a loss of B cell memory. Because lymph node architecture is progressively destroyed during HIV infection, it is possible that normal B cell trafficking is impaired as well, which could be a cause or a result of these abnormalities. Because the homeostatic chemokine, CXCL13 (BLC, BCA-1), is a major regulator of B cell trafficking, we assessed circulating levels of this molecule in HIV infection. Serum levels of CXCL13 were seen to be progressively elevated in HIV disease. Serum levels of CXCL13 correlated strongly with those of the inflammation-associated chemokine, inducible protein-10 (IP-10), in subjects who had advanced HIV disease, and more moderately with levels of soluble CD30 (sCD30), sCD27, and sCD23. CXCL13 levels also correlated moderately with viral load and showed a significant decline after use of highly active antiretroviral treatment (HAART). Elevated levels of CXCL13 could cause impaired or altered trafficking of B cells during HIV infection and could contribute to the previously reported loss of CXCR5, the receptor for CXCL13, from the surface of circulating B cells in HIV infection.

CXCR3 and its ligands participate in the host response to Bordetella bronchiseptica infection of the mouse respiratory tract but are not required for clearance of bacteria from the lung.

Intranasal inoculation of mice with Bordetella bronchiseptica produces a transient pneumonia that is cleared over several weeks in a process known to require both neutrophils and lymphocytes. In this study, we evaluated the roles of the chemokines MIG (CXCL9), IP-10 (CXCL10), and I-TAC (CXCL11) and their common receptor, CXCR3. Following bacterial inoculation, message expression of interleukin-1 (IL-1), IL-6, and the neutrophil-attracting chemokines KC, LIX, and MIP-2 was rapidly induced, with maximal expression found at 6 h. In contrast, message expression of gamma interferon, MIG, IP-10, and I-TAC peaked at 2 days. Expression of all of these chemokines and cytokines returned to near baseline by 5 days, despite the persistence of high levels of live bacteria at this time. Induced MIG, IP-10, and I-TAC protein expression was localized in areas of inflammation at 2 to 3 days and was temporally associated with increased levels of CXCR3(+) lymphocytes in bronchoalveolar lavage fluid. There was no increase in mortality in mice lacking CXCR3. However, the clearance of bacteria from the lung and trachea was delayed, and the recruitment of lymphocytes and NK cells was slightly decreased, for CXCR3(-/-) mice relative to CXCR3(+/+) mice. We conclude that the CXCR3 receptor-ligand system contributes to pulmonary host defense in B. bronchiseptica infection by recruiting lymphocytes and NK cells into the lung.

Expression and function of CD28 on Epstein-Barr virus-positive B cell lines and AIDS-associated non-Hodgkin's lymphoma cell lines.

CD28, which is expressed on most T cells, can provide a costimulatory signal during T cell activation. Although principally considered to be a T cell-associated molecule, CD28 has been seen to be expressed on mast cells and natural killer cells, as well as on plasma and myeloma cells, but not on cells representing earlier stages of B cell development. Here were report that CD28 was expressed on Epstein-Barr virus (EBV)-positive B lymphoblastoid and AIDS-associated non-Hodgkin's lymphoma cell lines. These cells also expressed the ligands for CD28, B7-1 and B7-2, but not CTLA-4. Furthermore, peripheral blood B cells infected with EBV ex vivo expressed CD28 after infection. Cross-linking with a stimulatory anti-CD28 antibody resulted in an increased expression of CD71 (transferrin receptor) or CD25 (interleukin-2 alpha receptor subunit). The addition of a blocking CTLA-4-Ig fusion protein, or antisense oligonucleotides for CD28, resulted in a decreased expression of these molecules. In 1 cell line, the addition of an anti-CD28 stimulatory antibody reduced Fas-induced apoptosis, and antisense oligonucleotide-induced inhibition of CD28 expression enhanced Fas-mediated apoptosis. Overall, these results suggest a role for CD28 and its ligands, B7-1 and B7-2, in homotypic interactions in EBV+ B cell lines, which may mediate cellular activation and/or viability.

Murine GBP-5, a new member of the murine guanylate-binding protein family, is coordinately regulated with other GBPs in vivo and in vitro.

A new murine member of the interferon (IFN)-inducible guanylate-binding protein (GBP) family was cloned in a search for glucocorticoid-attenuated response genes induced in the lung during endotoxemia. The full-length MuGBP-5 cDNA encodes a 590 amino acid residue protein with GTP binding motifs identical to those in human GBP-1 (HuGBP-1) and a similar isoprenylation sequence at the C-terminus. An alternatively spliced form of MuGBP-5 that lacks the second GTP binding motif and differs at the C-terminus was also identified. The MuGBP-5 gene is located on chromosome 3, near MuGBP-3 and MuGBP-2, and has a genomic organization similar to other GBP genes. To facilitate the evaluation of GBP family message expression, we constructed RNase protection assay probes for MuGBP-1, MuGBP-2, MuGBP-3, MuGBP-4/Mag-2 (macrophage activation gene-2), and MuGBP-5 and validated their use in Swiss Webster, BALB/c, and C57BL/6 mice. In BALB/c mice, all five MuGBPs were induced in multiple organs during endotoxemia, and all had a similar pattern of expression in different tissues. With minor quantitative differences, the MuGBPs also had similar patterns of response to IFN-gamma, lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) in RAW 264.7 and Swiss 3T3 cells. The coordinate expression of the MuGBPs suggests that they share common mechanisms of regulation.

Glucocorticoid-attenuated response genes induced in the lung during endotoxemia.

Cytokines and other mediators whose induction in inflammatory lung disease is attenuated by glucocorticoids are potential targets for development of selective anti-inflammatory treatments. We refer to genes with these regulatory characteristics as glucocorticoid-attenuated response genes, or GARGs. Systematic identification of GARGs has not been attempted previously in vivo. Using an endotoxemia model in adrenalectomized mice, we constructed a subtracted lung library enriched in endotoxemia-induced genes and identified candidate GARGs by differential hybridization screening. Northern analysis confirmed induction in the lung during endotoxemia and attenuation by glucocorticoids of 36 genes of diverse types. The majority were genes of unknown function not previously implicated in the pulmonary response to inflammation, including a new member of a 2'-5'-oligoadenylate synthetase-like family and a novel lung inducible Neuralized-related C3HC4 RING protein. Our results suggest that a full understanding of glucocorticoid effects on lung inflammation will require elucidation of the roles of an extensive network of glucocorticoid-modulated genes.

Immune dysfunction and the pathogenesis of AIDS-associated non-Hodgkin's lymphoma

Much has been learned about how HIV-induced immune dysfunction contributes to B cell hyperactivation, and potentially, to the pathogenesis of AIDS-lymphoma. However, further studies are needed to fully understand how HIV infection and immune dysfunction promote B cell hyperactivation and the development/growth of AIDS-lymphoma. In particular, studies are needed to define the role of HHV8 vIL6, IL6 receptor-expression, and lymphocyte surface stimulatory molecules, in promoting B cell hyperactivation or lymphoma cell growth.