Expression of the Chemokine Receptor CCR1 in Burkitt Lymphoma Cell Lines Is Linked to the CD10-Negative Cell Phenotype and Co-Expression of the EBV Latent Genes EBNA2, LMP1, and LMP2.

Chemokines and their receptors regulate the migration of immune cells and the dissemination of cancer cells. CCR1, CCR2, CCR3, and CCR5 all belong to a single protein homology cluster and respond to the same inflammatory chemokines. We previously reported that CCR1 and CCR2B are induced upon Epstein-Barr virus (EBV) infection of B cells in vitro. EBV is present in almost all cases of endemic Burkitt lymphoma (BL); however, the contribution of EBV in the pathogenesis of the disease is not fully understood. Here, we analyzed the relation of the expression of CCR1, CCR2, CCR3, and CCR5, the EBV DNA load and expression of EBV latent genes in nine EBV-carrying and four EBV-negative BL cell lines. We revealed that CCR1 is expressed at high mRNA and protein levels in two CD10-negative BL cell lines with co-expression of the EBV latent genes EBNA2, LMP1, and LMP2. Low levels of CCR2 transcripts were found in three BL cell lines. CCR3 and CCR5 transcripts were hardly detectable. Our data suggest that in vivo, CCR1 may be involved in the dissemination of BL cells and in the selection of BL cells with restricted EBV gene expression programs.

Use of exploratory factor analysis to ascertain the correlation between the activities of rheumatoid arthritis and infection by human parvovirus B19.

BACKGROUND AND OBJECTIVE: We evaluated a possible correlation between the clinical activities of rheumatoid arthritis (RA) and human parvovirus B19 (B19) infection using exploratory factor analysis (EFA). MATERIALS AND METHODS: RA patients were organized into two groups: 100 patients in the main group and 97 in the RA(DAS28) group. Four subgroups were defined from the main group according to the presence or absence of certain infection-specific markers: group I comprised 43 patients who had IgG antibodies against B19; group II, 25 patients with active B19 infection (B19-specific IgM antibodies and/or plasma viremia); group III, 19 patients with latent/persistent B19 infection (virus-specific sequences in peripheral blood leukocytes' DNA with or without B19-specific IgG antibodies), and group IV, 13 patients without infection markers. The RA(DAS28) group was divided into four subgroups similarly to the main group: group I, 35; group II, 31; group III, 19; and group IV, 12 patients. Disease-specific clinical values in both groups were analyzed employing EFA, and the RA(DAS28) group was additionally assessed using Disease Activity Score (DAS)28. RESULTS: RA activity was higher in patients who had markers of B19 infection. The highest activity of RA in both study groups was in patients with latent/persistent infection. In the RA(DAS28) group, according to DAS28, the highest activity of RA was in patients with active B19 infection. CONCLUSIONS: Using EFA and DAS28, a correlation between the clinical activity of RA and B19 infection was confirmed. These data suggest that EFA is applicable for medico-biological studies.

A novel approach for nucleic acid delivery into cancer cells.

BACKGROUND: Liposomal magnetofection is based on the use of superparamagnetic particles and cationic lipids and shows better transfection efficiency than other common nonviral gene delivery methods; however, the distribution of aggregate complexes over the cell surface may be ununiform. The use of a dynamic gradient magnetic field could overcome this limitation. A newly developed device for magnetofection under a dynamic magnetic field was used to compare the transfection efficiency of prostate carcinoma cell line PC3 with that obtained by lipofection and magnetofection. MATERIAL AND METHODS: Reporter plasmid pcDNA3.1LacZ DNA was used in combination with Lipofectamine2000 reagent and superparamagnetic nanoparticles CombiMag. The effects of incubation time under a dynamic magnetic field and a rotation frequency of magnets on transfection efficiency for PC3 cell line were determined. Alternatively, lipofection and liposomal magnetofection were carried out. Transfection efficiency of delivery methods was estimated by ß-galactosidase staining; cell viability, by acridine orange/ethidium bromide staining. RESULTS: Liposomal magnetofection under a dynamic gradient magnetic field demonstrated the highest transfection efficiency: it was greater by almost 21% and 42% in comparison with liposomal magnetofection and lipofection, respectively. The optimal incubation time under dynamic magnetic field and the optimal magnet rotation frequency were 5 minutes and 5 rpm, respectively. Liposomal magnetofection under a dynamic gradient magnetic field was less cytotoxic (7%) than that under a permanent magnetic field (17%) and lipofection (11%). CONCLUSIONS: Our new approach, based on the use of a dynamic gradient magnetic field, enhanced the transfection efficiency and had a less cytotoxic effect on prostate cancer cells in comparison with the standard magnetofection and lipofection.

Anemia as a complication of parvovirus b19 infection in renal transplant recipients.

BACKGROUND: The frequency of B19 infection in renal transplant donors and recipients was studied to determine the significance of active viral infection in the development of anemia. MATERIAL AND METHODS: Serum, plasma, and peripheral blood leukocyte samples of 47 renal transplant donors, 38 recipients with anemia (Group 1), and 25 without anemia (Group 2) after renal transplantation were evaluated for the presence of anti-B19 specific antibodies (ELISA) and B19 DNA (nPCR). RESULTS: Active persistent B19 infection after renal transplantation was detected in 12 of the 38 in the Group 1 (10 had reactivation and 2 primary infection), and none of the recipients in the Group 2 had it. Of the 12 recipients in the Group 1, 10 were seropositive and 2 seronegative before renal transplantation; 10 received the transplants from the seropositive and 2 from seronegative donors. rHuEPO therapy-resistant severe anemia was detected only in the recipients with active B19 infection after renal transplantation in the Group 1 (7/12). The logistic regression analysis revealed a significant relationship between active B19 infection and severe anemia (OR, 0.039; 95% CI, 0.006-0.257; P=0.001). CONCLUSIONS: Active B19 infection was documented only in the anemic recipients and could be associated with the development of severe anemia after renal transplantation. This allows us to recommend concurrent screening for viral DNA in plasma and detection of anti-B19 IgM class antibodies. To find the association between B19 infection and the development of anemia, further investigations are necessary.

Chemokine Receptors CCR1 and CCR2 on Peripheral Blood Mononuclear Cells of Newly Diagnosed Patients with the CD38-Positive Chronic Lymphocytic Leukemia.

Chemokines and their receptors direct migration and infiltration of immune cells. CCR1 and CCR2 maintain sequence similarity and respond to a number of the same chemokines secreted in lymphoid organs. Expression of CD38 on leukemic cells has been associated with poor clinical outcomes in patients with chronic lymphocytic leukemia (CLL) and is considered as the negative predictor of progression. In our study of newly diagnosed CLL patients, which included 39 CD38-positive and 22 CD38-negative patients, CCR1 and/or CCR2 were always detected, using flow cytometry, on the peripheral blood (PB) CD19+CD5+ lymphocytes in patients with >30% of the CD38+ CD19+CD5+ lymphocytes (n = 16). Spearman's rank correlation analysis determined correlations between the frequency of the CCR1- and CCR2-expressing PB CD19+CD5+ lymphocytes and the frequency of the CD38-positive CD19+CD5+ lymphocytes (rs = 0.50 and rs = 0.38, respectively). No significant correlations were observed between ZAP70 mRNA expression levels in PB mononuclear cells and the frequency of the circulating CCR1+ or CCR2+ CD19+CD5+ lymphocytes. Further association studies are needed to verify prognostic relevance of the CCR1/CCR2 expression on leukemic cells in CLL patients at diagnosis. We suggest that CCR1/CCR2 signaling pathways could represent attractive targets for development of CLL anti-progression therapeutics.

Upregulation of the Chemokine Receptor CCR2B in Epstein‒Barr Virus-Positive Burkitt Lymphoma Cell Lines with the Latency III Program.

CCR2 is the cognate receptor to the chemokine CCL2. CCR2⁻CCL2 signaling mediates cancer progression and metastasis dissemination. However, the role of CCR2⁻CCL2 signaling in pathogenesis of B-cell malignancies is not clear. Previously, we showed that CCR2B was upregulated in ex vivo peripheral blood B cells upon Epstein‒Barr virus (EBV) infection and in established lymphoblastoid cell lines with the EBV latency III program. EBV latency III is associated with B-cell lymphomas in immunosuppressed patients. The majority of EBV-positive Burkitt lymphoma (BL) tumors are characterized by latency I, but the BL cell lines drift towards latency III during in vitro culture. In this study, the CCR2A and CCR2B expression was assessed in the isogenic EBV-positive BL cell lines with latency I and III using RT-PCR, immunoblotting, and immunostaining analyses. We found that CCR2B is upregulated in the EBV-positive BL cells with latency III. Consequently, we detected the migration of latency III cells toward CCL2. Notably, the G190A mutation, corresponding to SNP CCR2-V64I, was found in one latency III cell line with a reduced migratory response to CCL2. The upregulation of CCR2B may contribute to the enhanced migration of malignant B cells into CCL2-rich compartments.

Single-tube nested quantitative PCR: a rational and sensitive technique for detection of retroviral DNA. Application to RERV-H/HRV-5 and confirmation of its rabbit origin.

It was reported earlier that a few patients suffering from non-Hodgkin's lymphoma had low amounts of DNA from the so-called fifth human exogenous retrovirus, HRV-5. A sensitive and rational method for large-scale screening for HRV-5 DNA was therefore developed. It is a single-tube nested quantitative PCR (stnQPCR), which uses two functionally isolated primer pairs and one probe target distinct from related endogenous retroviral sequences, yet encompassing known HRV-5 variation, allowing optimal use of sequence conservation. DNA from lymphoma, myeloma, and follicular dendritic cell lines was tested for HRV-5 positivity, as was DNA from whole blood of blood donors, non-Hodgkin's lymphoma and systemic lupus erythematosus patients, as well as DNA from lymph node biopsies of rheumatoid arthritis patients with lymphoma. One blood donor, one systemic lupus erythematosus patient, two previously known positive non-Hodgkin's lymphoma patients, and one rheumatoid arthritis lymphoma patient, came out positive. They had 24, 2, 148, 480 and 30 proviral copies per microg of DNA from PBMC or lymphoma tissue, respectively. During the completion of this work it was reported that HRV-5 is a rabbit endogenous retrovirus (RERV-H), and that HRV-5 positivity was due to presence of rabbit DNA. DNA from six RERV-H/HRV-5 positive samples was therefore retested. Three also contained rabbit mitochondrial DNA. A search for HRV-5 antibodies using synthetic peptides was negative in sera from three RERV-H/HRV-5 positive individuals, as well as in 144 other sera, according with a noninfectious origin of the RERV-H/HRV-5 DNA in human samples. A search for possible sources of rabbit DNA contamination was negative. Methods for prevention of PCR contamination were strictly adhered to. Three samples from RERV-H/HRV-5 positive individuals positive at the Uppsala laboratory were retested at one or two other laboratories, and all three were positive. Two other samples, which were positive in the Riga laboratory, were tested also in London and also found positive. One non-Hodgkin's lymphoma patient was RERV-H/HRV-5 positive in four consecutive samples, showing that positivity was a property of that patient. It is concluded that the stnQPCR developed to detect and quantify minute amounts of RERV-H/HRV-5 DNA is a principle which can be applied widely and HRV-5 is a RERV-H. Its presence in a few human blood samples could not be explained.

Incidence and clinical significance of parvovirus B19 infection in patients with rheumatoid arthritis.

OBJECTIVE: To determine the prevalence and clinical significance of human parvovirus B19 (B19) infection in patients with rheumatoid arthritis (RA). METHODS: One hundred patients with RA and 94 apparently healthy blood donor controls were enrolled for study. Plasma samples of patients and controls were examined for the presence of anti-B19-specific antibodies by ELISA. B19 DNA was detected in plasma and peripheral blood leukocyte (PBL) samples of all patients and controls as well as in synovial fluid cells of 38 RA patients by nested polymerase chain reaction. Disease activity and clinical manifestations were determined in RA patients with and without markers of B19 infection. RESULTS: IgM anti-B19-specific antibodies were detected in 24.0% of RA patients; B19 DNA was found in plasma and/or PBL, synovial fluid cells in 34.0% (34 patients); in 14.0% of the cases (14 patients) both markers were found. In blood donor controls, anti-B19 IgM antibodies were observed in 16.0% (15 donors) and B19 DNA in 6.4% (6 donors); all donors with detectable B19 genomic DNA were IgM-positive. The disease activity in patients with and without B19 infection was similar, while the frequency of clinical complications was significantly higher in the patients with anti-B19 IgM antibodies. Moreover, liver failure and sicca syndrome were observed in the viremic patients only. CONCLUSION: Our study confirms observations regarding a high prevalence of B19 DNA in patients with RA, and a possible role of this viral infection in the pathogenesis of RA.

Down regulation of 3p genes, LTF, SLC38A3 and DRR1, upon growth of human chromosome 3-mouse fibrosarcoma hybrids in severe combined immunodeficiency mice.

We have applied a functional test for tumour antagonizing genes based on human chromosome 3 (chr3)-mouse fibrosarcoma A9 MCHs that were studied in vitro and after growth as tumours in severe combined immunodeficiency (SCID) mice. Previously, we reported that 9 out of the 36 SCID-tumours maintained the transferred chr3 ("chr3+" tumours), but lost the expression of the known human TSG fragile histidine triad gene (FHIT) in contrast to 14 other 3p-genes examined. Here we report the results of the duplex RT-PCR analysis of 9 "chr3+" tumours and 3 parental MCHs. We have examined the expression of 34 human 3p-genes from known cancer-related regions of instability, including 13 genes from CER1 defined by us previously at 3p21.33-p21.31 and 10 genes from the LUCA region at 3p21.31. We have found that in addition to FHIT, expression of the LTF gene from CER1 at 3p21.33-p21.31 was lost in all 9 tumours analyzed. The transcript of the solute carrier family 38 member 3 gene (SLC38A3) gene from LUCA region at 3p21.31 was not found in 8 and was greatly reduced in 1 out of these 9 tumours. Expression of the down-regulated in renal cell carcinoma gene (DRR1) gene at 3p14.2 was lost in 7 and down regulated in 2 "chr3+" tumours. In the SCID-tumour derived cell lines treatment with 5-aza-2'-deoxycytidine restored the mRNA expression of LTF, indicating the integrity of DNA sequences. Notably that transcription of the LTF and 2 flanking genes, LRRC2 and TMEM7, as well as transcription of the SLC38A3 gene, were also impaired in all 5 RCC cell lines analyzed. Our data indicate these genes as putative tumour suppressor genes.