Histological and morphometrical evaluation of the urethral wall after bioresorbable stent implantation in male New Zealand White Rabbits: A preliminary study

The aim of the study was the histological and morphometrical evaluation of the urethral wall at three time points after bioresorbable stent implantation in male New Zealand White Rabbits. The research was performed on 26 male New Zealand White rabbits aged 3-4 months and weighing 2.1-3.0 kg. Two models of bioresorbable sodium alginate-based stents were developed and implanted into the urethral lumen for one (T1), three (T3), and six weeks (T6). Sections of 5 µm thickness were cut from the urethra at intervals of 2 mm. The sliced sections were stained with hematoxylin-eosin (H&E), Van Gieson's (VG), Von Kossa, and Movat-Russell modified pentachrome (MOVAT) staining methods. The study provided valuable information for future models of urethral stents. The first model of the stent failed to fit the requirements due to inadequate mechanical properties. It curled up on itself losing the ability to adhere to the animals' urethra and was bioresorbed three weeks after implantation. The more rigid no. 2 stent was effective in widening the urethral lumen but did not biodegrade during the experiment. A comprehensive assessment of the second model's properties of biosorption and biointegration requires an extended observation of at least 12 months for an in depth morphological analysis. Stent migration is not likely to be caused solely by the mechanical properties of the urethra or urinary flow but mainly by muscle contraction of the organ wall.

Evaluation of Selected Properties of Sodium Alginate-Based Hydrogel Material—Mechanical Strength, μDIC Analysis and Degradation

The search for ideal solutions for the treatment of urethral stenosis continues. This includes developing the material, design, while maintaining its optimal and desired properties. This paper presents the results of the research conducted on sodium alginate-based hydrogel material (AHM), which may be used as a material for stents dedicated to the treatment of pathologies occurring in the genitourinary system. In order to determine the selected parameters of the AHM samples, strength and degradation tests, as well as analysis of the micro changes occurring on the surface of the material using a digital image correlation (µDIC) system, were performed. This study shows that the material possessed good mechanical strength parameters, the knowledge of which is particularly important from the point of view of the stent-tissue interaction. The degradation analysis performed showed that the AHM samples degrade in an artificial urine environment, and that the degradation time mainly depends on the chemical composition of the material. The novel µDIC method performed allowed us to characterize the homogeneity of the material structure depending on the cross-linking agent used.

Intact Human Immunodeficiency Virus (HIV) Reservoir Estimated by the Intact Proviral DNA Assay Correlates With Levels of Total and Integrated DNA in the Blood During Suppressive Antiretroviral Therapy

Accurate characterization of the human immunodeficiency virus (HIV) reservoir is imperative to develop an effective cure. HIV was measured in antiretroviral therapy-suppressed individuals using the intact proviral DNA assay (IPDA), along with assays for total or integrated HIV DNA, and inducible HIV RNA or p24. Intact provirus correlated with total and integrated HIV.

Prognostic impact of baseline tumour immune infiltrate on disease-free survival in patients with completely resected, BRAFv600 mutation-positive melanoma receiving adjuvant vemurafenib

BACKGROUND

We conducted a retrospective exploratory analysis to evaluate the effects of baseline tumour immune infiltrate on disease-free survival (DFS) outcomes in patients with fully resected stage IIC-IIIC melanoma receiving adjuvant vemurafenib monotherapy or placebo in the BRIM8 study.

PATIENTS AND METHODS

BRIM8 was a phase III, international, double-blind, randomised, placebo-controlled study. Eligible patients with BRAF^V600 mutation-positive, completely resected melanoma were randomly assigned to oral vemurafenib (960 mg twice daily) or matching placebo for 52 weeks. The primary end point was DFS. The association of CD8+ T-cell infiltration and programmed death ligand 1 (PD-L1) expression with DFS, as measured by immunohistochemistry, was explored retrospectively.

RESULTS

Four hundred ninety-eight patients were randomly assigned to receive adjuvant vemurafenib (n = 250) or placebo (n = 248); tumour samples were available for biomarker analysis for approximately 60% of patients. In the pooled biomarker population, placebo-treated patients with <1% CD8+ T cells in the tumour centre had shorter median DFS than those with ≥1% CD8+ T cells (7.7 versus 47.8 months). DFS benefit from vemurafenib versus placebo was greater in patients with <1% CD8+ T cells [hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.34-0.92) than in patients with ≥1% CD8+ T cells (HR 0.77; 95% CI 0.48-1.22). Likewise, median DFS was shorter among placebo-treated patients with <5% versus ≥5% PD-L1+ immune cells (IC) in the tumour (7.2 versus 47.8 months). A greater DFS benefit with vemurafenib versus placebo was observed in patients with <5% PD-L1+IC (HR 0.36; 95% CI 0.24-0.56) than in patients with ≥5% PD-L1+IC (HR 0.99; 95% CI 0.58-1.69).

CONCLUSIONS

The presence of CD8+ T cells and PD-L1+IC are favourable prognostic factors for DFS. Treatment with adjuvant vemurafenib may overcome the poor DFS prognosis associated with low CD8+ T-cell count or PD-L1 expression. CLINICALTRIALS.

GOV IDENTIFIER

NCT01667419.

Gene expression profiling informs HPV cervical histopathology but not recurrence/relapse after LEEP in ART-suppressed HIV+HPV+ women

Identification of factors associated with human papillomavirus (HPV) cervical histopathology or recurrence/relapse following loop electrosurgical excision procedure (LEEP) would allow for better management of the disease. We investigated whether gene signatures could (i) associate with HPV cervical histopathology and (ii) identify women with post-LEEP disease recurrence/relapse. Gene array analysis was performed on paraffin-embedded cervical tissue-isolated RNA from two cross-sectional cohorts of antiretroviral therapy (ART)-suppressed HIV+HPV+ coinfected women: (i) 55 women in South Africa recruited into three groups: high risk (HR) (-) (n = 16) and HR (+) (n = 15) HPV without cervical histopathology and HR (+) HPV with cervical intraepithelial neoplasia (CIN) grade 1/2/3 (n = 24), (ii) 28 women in Botswana with CIN2/3 treated with LEEP 12-month prior to recruitment and presenting with (n = 13) and without (n = 15) lesion recurrence/relapse (tissue was analyzed at first LEEP). Three distinct gene expression signatures identified were able to segregate: (i) HR+ HPV and CIN1/2/3, (ii) HR HPV-free and cervical histopathology-free and (iii) HR+ HPV and cervical histopathology-free. Immune activation and neoplasia-associated genes (n = 272 genes; e.g. IL-1A, IL-8, TCAM1, POU4F1, MCM2, SMC1B, CXCL6, MMP12) were a feature of cancer precursor dysplasia within HR HPV infection. No difference in LEEP tissue gene expression was detected between women with or without recurrence/relapse. In conclusion, distinctive gene signatures were associated with presence of cervical histopathology in tissues from ART-suppressed HIV+/HPV+ coinfected women. Lack of detection of LEEP tissue gene signature able to segregate subsequent post-LEEP disease recurrence/relapse indicates additional factors independent of local gene expression as determinants of recurrence/relapse.

NK Response Correlates with HIV Decrease in Pegylated IFN-α2a-Treated Antiretroviral Therapy-Suppressed Subjects

We previously reported that pegylated IFN-α2a (Peg-IFN-α2a) added to antiretroviral therapy (ART)-suppressed, HIV-infected subjects resulted in plasma HIV control and integrated HIV DNA decrease. We now evaluated whether innate NK cell activity or PBMC transcriptional profiles were associated with decreases in HIV measures. Human peripheral blood was analyzed prior to Peg-IFN-α2a administration (ART, baseline), after 5 wk of ART+Peg-IFN-α2a, and after 12 wk of Peg-IFN-α2a monotherapy (primary endpoint). After 5 wk of ART+Peg-IFN-α2a, immune subset frequencies were preserved, and induction of IFN-stimulated genes was noted in all subjects except for a subset in which the lack of IFN-stimulated gene induction was associated with increased expression of microRNAs. Viral control during Peg-IFN-α2a monotherapy was associated with 1) higher levels of NK cell activity and IFN-γ-induced protein 10 (IP-10) on ART (preimmunotherapy) and 2) downmodulation of NK cell KIR2DL1 and KIR2DL2/DL3 expression, transcriptional enrichment of expression of genes associated with NK cells in HIV controller subjects, and higher ex vivo IFN-α-induced NK cytotoxicity after 5 wk of ART+Peg-IFN-α2a. Integrated HIV DNA decline after immunotherapy was also associated with gene expression patterns indicative of cell-mediated activation and NK cytotoxicity. Overall, an increase in innate activity and NK cell cytotoxicity were identified as correlates of Peg-IFN-α2a-mediated HIV control.

HCV viraemia associates with NK cell activation and dysfunction in antiretroviral therapy-treated HIV/HCV-co-infected subjects

The impact of hepatitis C virus (HCV) RNA levels on immune status in chronically HCV mono-infected when compared to HIV/HCV co-infected on antiretroviral therapy (ART) remains poorly understood. A total of 78 African American subjects HCV viraemic/naïve to HCV treatment (33 HCV genotype 1 mono-infected, 45 ART-treated HIV/HCV genotype 1 co-infected) were studied. Clinical and liver enzyme measurements were performed. Whole blood was analysed for immune subset changes by flow cytometry. Peripheral blood mononuclear cells (PBMC) were used for same-day constitutive and in vitro Interferon (IFN)-α-induced signal transducer and activator of transcription (STAT) phosphorylation, K562 target cell lysis and K562 target cell recognition-mediated IFN-γ production. Statistical analysis was performed using R (2.5.1) or JMP Pro 11. While both groups did not differ in the level of liver enzymes, HIV/HCV had higher T-cell activation/exhaustion, and constitutive STAT-1 phosphorylation compared to HCV. In contrast, CD4⁺ FoxP3⁺ CD25⁺ frequency, IFN-αR expression on NK cells, as well as constitutive and IFN-α-induced direct cytotoxicity were lower in HIV/HCV. Linear regression models further supported these results. Finally, increase in HCV viral load and CD4⁺ T-cell count had an opposite effect between the two groups on NK cell activity and T-cell activation, respectively. HCV viral load in ART-treated HIV/HCV co-infection was associated with greater immune activation/exhaustion and NK dysfunction than HCV viral load alone in HCV mono-infection. The more pronounced immune modulation noted in ART-treated HIV-co-infected/untreated HCV viraemic subjects may impact HCV disease progression and/or response to immunotherapy.

Comparative studies of cervical spine anterior stabilization systems--Finite element analysis

BACKGROUND

The object of the study was to assess the impact of one-level stabilization of the cervical spine for both anterior static and dynamic plates. Segments C2-C6 of the cervical spine, were investigated, from which was determined the stress and strain fields in the region of implantation and adjacent motion segments. The purpose was the comparison of changes that affect the individual stabilizers.

METHODS

For testing we used finite element analysis. The cervical spine model takes into account local spondylodesis. The study includes both an intact anatomical model and a model with implant stabilization.

FINDINGS

The analysis covered the model loaded with a moment of force for 1 Nm in the sagittal plane during movement. We compared both the modeled response of the whole fragment C2-C6 and the response of individual motion segments. The largest limitation of range of motion occurred after implantation with static plates. The study also showed that the introduction of the one-level stabilization resulted in an increase in stress in intervertebral disc endplates of adjacent segments.

INTERPRETATION

The results indicate that the increase in stress caused by stiffening may result in disorders in remodeling of bone structures. The use of dynamic plates showed improved continuity strains in the tested spine, thereby causing remodeling most similar to the physiological state and reducing the stresses in adjacent segments.

Diagnostic evaluation of cancer antigens RAK .1. Cervical and ovarian cancer

Cancer antigens RAK-p120, p42, and p25, which exhibit biological, immunological and molecular similarity to the proteins expressed by Human Immunodeficiency Virus 1 (HIV-1), were found in 47 of 47 tested cases of serous adenocarcinoma of the ovary, and 45 of 45 tested cases of squamous carcinoma of the cervix. Normal ovary and cervix did not express antigens RAK. High molecular weight protein (RAK-p160) was detected in the blood of over 61% of ovarian and 72% of cervical cancer patients, and in 14.3% of healthy women with family history of breast and/or gynecological cancer. Antigens RAK might represent new diagnostic markers.

The importance of ceruloplasmin oxidase activity in patients with chronic lower limb atherosclerotic ischemia

AIM

Inflammatory reactions accompanying ischemia increase the cytokine synthesis what leads to the increase in serum ceruloplasmin (Cp) concentration and activity. The aim of the study was to evaluate the association between serum Cp oxidase concentration and activity and the grade of lower extremity ischemia. Moreover, the correlation of Cp concentration and activity with the levels of interleukin 6 (IL-6), C-reacting protein (CRP), and a-1-acid glycoprotein (AGP) in serum was studied.

METHODS

Two groups of patients were examined: 15 patients with moderate (MI) and 32 patients with critical ischemia (CI) of the lower extremities. Cp oxidase activity was measured spectrophotometrically, after incubation with o-dianisidine. The concentration of IL-6 was measured with the ELISA method, and Cp, CRP and AGP concentration by rocket immunoelectrophoresis.

RESULTS

Significant increase in Cp oxidase concentration and activity was observed in patients with critical limb ischemia (median: 164.8 U/L), especially in patients with necrotic changes (median: 216.6 U/L). Cp oxidase activity was dependent on its concentration in patients with critical limb ischemia with necrotic changes (r=0.56; P<0.01). In patients with critical limb ischemia, the increase in Cp concentration and activity correlated significantly with CRP concentration (r=0.46; P=0.0007) (r=0.62; P=0.0001), respectively.

CONCLUSION

Concentration and the oxidase activity of Cp depend of the degree of lower extremity ischemia and correlates with the major markers of inflammation, such as CRP. Critical limb ischemia induces the inflammatory reaction triggering the increase in IL-6 and of acute phase protein production. These processes lead to the increase in Cp oxidase activity dependent of Cp and CRP concentration.

A large first-line, randomized, dose-finding, phase II study on thymosin-alpha 1 (T-alpha 1) plus dacarbazine (DTIC) with or without interferon-alpha (IFN-alpha) compared to DTIC plus IFN-alpha in stage IV melanoma. Tumor response and survival results

8535

Background: Thymosin alpha 1 is an immunomodulatory compound that promotes T cell maturation and upregulates T cell response. Ta1 showed clinical potential benefit in a previous pilot study in melanoma patients. Methods: Phase II, randomized, stratified, open-study testing different doses of Ta1 in association with DTIC and IFNa, as first-line therapy in stage IV melanoma patients (AJCC 2001) without brain metastases. The primary endpoint is tumor response and secondary overall survival. Four arms were initially planned: DTIC + IFNa + 1.6 or 3.2 mg Ta1, DTIC + 3.2 mg Ta1, and DTIC + IFNa (control group). A dose-response effect in a preliminary analysis on 142 patients led to the addition of a fifth arm with DTIC + IFNa + 6.4 mg Ta1. Ninety-five patients were allocated to each arm to test the hypothesis that P0 = 0.05 vs the alternative hypothesis that P1 = 0.15 (alpha = 5%, within-group statistical analysis, power = 95%). The five groups were analyzed independently one from the other, nine responses representing the minimal threshold for rejecting the null hypothesis Patients received DTIC (800 mg/m2) iv on day 1, Ta1 (1.6, 3.2 or 6.4 mg) sc on days 8–11 and 15–18, and IFNa (3 MIU) sc on days 11 and 18 during 28d cycles. Tumor response was evaluated every two cycles according to RECIST criteria, utilizing a central review. Results: Data of 483 pts (62% M1c; 25% M1b; 13% M1a) from 64 European sites are given in the table . Thirteen and 10 confirmed responses were observed for the DTIC+ 3.2 mg Ta1 and DTIC+ IFNa + 3.2 mg Ta1 arms (vs 5 in the control group) thus rejecting the null hypothesis that P0 = 0.05. No additional toxicity with the addition of Ta1 was observed. Conclusions: These results suggest a potential survival advantage with the addition of Ta1 to ‘standard‘ treatment of stage IV melanoma patients. The role of Interferon alpha in this therapeutic association is debatable.

[Table: see text] [Table: see text]

Recent developments in renal cell cancer immunotherapy

Various immunotherapeutic approaches for the treatment of renal cell carcinoma (RCC) have been developed for > 90 years. Existing immunotherapeutic strategies against RCC include: systemic administration of cytokines; therapeutic vaccines based on tumor cells or dendritic cells; monoclonal antibodies; and adoptive immunotherapy (T cell transfer or allogeneic hematopoietic cell transplantation). However, the overall efficacy of immunotherapy for advanced RCC remains moderate. With the advent of molecularly targeted biological therapies that turned out to be significantly effective in the treatment of metastatic RCC, to many oncologists immunotherapy may seem to be moving into the periphery of RCC treatment strategies. However, for the last 2 years there has been significant progress made in immunotherapeutic approaches for the treatment of RCC. Immunotherapy still remains the only systemic therapeutic strategy that is believed to potentially cure RCC patients. The development of active and passive specific immunotherapeutic approaches, along with the possibility to 'switch off' particular immunosuppressive mechanisms (e.g., elimination of regulatory T cells, blockage of cytotoxic T lymphocyte antigen-4 signaling), have paved the way for future trials of new immunotherapies of RCC. However, the new studies will have to enroll optimally selected patients (nephrectomized, with non-massive metastases and good performance status) and will use tumor response criteria that are specifically optimized for clinical trials of immunotherapy.

HIV-1-specific CD4+ T cell responses in chronically HIV-1 infected blippers on antiretroviral therapy in relation to viral replication following treatment interruption

The impact of transient viral load blips on anti-HIV-1 immune responses and on HIV-1 rebound following treatment interruption (TI) is not known. Clinical and immunological parameters were measured during 40 weeks of antiretroviral therapy (ART) and following TI in an observational cohort of 16 chronically HIV-1-infected subjects with or without observed viral load blips during ART. During therapy, blips in seven subjects were associated with higher anti-HIV-1 (p24) CD4+ T cell lymphoproliferative responses (p = 0.04), without a significant difference in T cell activation or total anti-HIV-1 CD8+ T cell interferon-gamma (IFN-gamma) responses when compared to nine matched non-blippers. Therapy interruption resulted in a significantly higher viral rebound in blippers by 8 week despite retention of higher lymphoproliferative p24 responses (p = 0.01) and a rise in CD3+ T cell activation (p = 0.04) and anti-HIV-1 CD8+ T cell responses in blippers by week 4 when compared to non-blippers. Past week 4 of interruption, therapy re-initiation criteria were also met by a higher frequency in blippers by week 14 (p < 0.04) with no difference between groups by week 24. These data support that blippers have higher anti-HIV lymphoproliferative responses while on ART but experience equal to higher viral rebound as compared to matched non-blippers upon TI.

BRCA1-positive breast cancers in young women from Poland

We identified 4316 unselected incident cases of early-onset breast cancers (<51 ears of age at diagnosis) in 18 Polish hospitals between 1996 and 2003. We were able to obtain a blood sample for DNA analysis from 3472 of these (80.4%). All cases were tested for the presence of three founder mutations in BRCA1. The proportion of cases with a BRCA1 mutation was 5.7%. The hereditary proportions were higher than this for women with breast cancer diagnosed before age 40 (9%), for women with cancer of medullary or atypical medullary histology (28%), for those with bilateral cancer (29%) or with a family history of breast or ovarian cancer (13%). It is reasonable to offer genetic testing to women with early-onset breast cancer in Poland.

A common variant of CDKN2A (p16) predisposes to breast cancer

BACKGROUND

A common missense variant of the CDKN2A gene (A148T) predisposes to malignant melanoma in Poland. An association between malignant melanoma and breast cancer has been reported in several families with CDKN2A mutations,

OBJECTIVE

To determine whether this variant also predisposes to breast cancer.

METHODS

Genotyping was undertaken in 4209 cases of breast cancer, unselected for family history, from 18 hospitals throughout Poland and in 3000 controls.

RESULTS

The odds ratio (OR) associated with the CDKN2A allele for women diagnosed with breast cancer before the age of 50 was 1.5 (p = 0.002) and after age 50 it was 1.3 (p = 0.2). The effect was particularly strong for patients diagnosed at or before the age of 30 (OR = 3.8; p = 0.0002).

CONCLUSIONS

CDKN2A appears to be a low penetrance breast cancer susceptibility gene in Poland. The association should be confirmed in other populations.

Human cancer gene therapy with cytokine gene-modified cells

Cytokines can impede tumour growth and activate innate and adaptive immune responses, leading to elimination of cancer cells. For many years, it was believed that systemic administration of recombinant cytokines might become a standard treatment of different cancer types. However, due to a high toxicity of therapeutic doses and a low efficacy, even in combination with chemotherapy, this strategy is generally not accepted. On the other hand, cancer gene therapy approaches utilising cells modified with cytokine genes seem to represent a novel promising approach. For the last decade, numerous Phase I and II clinical trials evaluating different therapies based on cytokine gene-modified cells have been carried out. In the early studies, several strategies have been shown to improve clinical outcomes and induce strong antitumour immune responses. Recently, a few prospective, randomised, Phase III clinical trials have been initiated in order to finally determine the efficacy of particular cancer immunogene therapy strategies. This article reviews the present status and perspectives of clinical trials of cancer immunotherapies utilising cytokine gene-modified cells.

Randomized, controlled trial of therapy interruption in chronic HIV-1 infection

BACKGROUND

Approaches to limiting exposure to antiretroviral therapy (ART) drugs are an active area of HIV therapy research. Here we present longitudinal follow-up of a randomized, open-label, single-center study of the immune, viral, and safety outcomes of structured therapy interruptions (TIs) in patients with chronically suppressed HIV-1 infection as compared to equal follow-up of patients on continuous therapy and including a final therapy interruption in both arms.

METHODS AND FINDINGS

Forty-two chronically HIV-infected patients on suppressive ART with CD4 counts higher than 400 were randomized 1:1 to either (1) three successive fixed TIs of 2, 4, and 6 wk, with intervening resumption of therapy with resuppression for 4 wk before subsequent interruption, or (2) 40 wk of continuous therapy, with a final open-ended TI in both treatment groups. Main outcome was analysis of the time to viral rebound (>5,000 copies/ml) during the open-ended TI. Secondary outcomes included study-defined safety criteria, viral resistance, therapy failure, and retention of immune reconstitution. There was no difference between the groups in time to viral rebound during the open-ended TI (continuous therapy/single TI, median [interquartile range] = 4 [1-8] wk, n = 21; repeated TI, median [interquartile range] = 5 [4-8] wk, n = 21; p = 0.36). No differences in study-related adverse events, viral set point at 12 or 20 wk of open-ended interruption, viral resistance or therapy failure, retention of CD4 T cell numbers on ART, or retention of lymphoproliferative recall antigen responses were noted between groups. Importantly, resistance detected shortly after initial viremia following the open-ended TI did not result in a lack of resuppression to less than 50 copies/ml after reinitiation of the same drug regimen.

CONCLUSION

Cycles of 2- to 6-wk time-fixed TIs in patients with suppressed HIV infection failed to confer a clinically significant benefit with regard to viral suppression off ART. Also, secondary analysis showed no difference between the two strategies in terms of safety, retention of immune reconstitution, and clinical therapy failure. Based on these findings, we suggest that further clinical research on the long-term consequences of TI strategies to decrease drug exposure is warranted.

The 34th Annual Meeting of the German Society of Immunology with participation of the Polish Society of Experimental and Clinical Immunology

The 34th Annual Meeting of the German Society of Immunology was held in Berlin on 24 - 27 September 2003. This meeting, organised for the first time in cooperation with the Polish Society for Experimental and Clinical Immunology, gathered 1200 participants, mostly from central Europe. The programme comprised > 30 symposium lectures and > 750 oral and poster presentations. The main concept of this meeting was based on the rule of ABC--Applied, Basic and Clinical immunology. The state-of-the-art lectures devoted to immuno-based therapies provided by experts in the particular fields discussed some well-known therapeutic approaches. However, several workshop presentations demonstrated novel approaches employing biological therapies. These lectures are the focus of these meeting highlights.

Loss of tumorigenicity of murine colon carcinoma MC38/0 cell line after transduction with a retroviral vector carrying murine IL-12 genes

Cells of transplantable MC38 colon carcinoma of C57BL/6 mice were adapted to growth in vitro as the MC38/0 cell line. Along the establishing process, MC38/0 cells preserved their tumorigenicity. After transduction with a retroviral vector carrying murine interleukin 12 (mIL-12) genes and further selection, stable MC38/IL-12 transductant cells were obtained. These cells produced IL-12 (approx. 2500 ng/ml/5x10(5) cells/48 h) as evaluated in the optimized bioassay. After subcutaneous inoculation into syngeneic mice, the IL-12-modified cells demonstrated reduced tumorigenicity as compared to parental MC38/0 cells. Mice that rejected the MC38/IL-12 tumour became protected against subsequent challenge with MC38/0 cells. The obtained data indicate that the IL-12-transduced murine colon carcinoma cells could be used both as a model tumour for the study of mechanisms of anticancer immunity and/or as an adjuvant to cancer vaccines.

Presence of human immunodeficiency virus-1-specific CD4 and CD8 cellular immune responses in children with full or partial virus suppression

The present study assessed antiviral T cell immune responses in 48 human immunodeficiency virus (HIV)-infected children with a stable or decreasing CD4(+) T cell counts and different levels of viral control, in the presence or absence of antiretroviral therapy. Children with full (<40 copies/mL) or partial (<50,000 copies/mL) virus suppression and with a history of stable CD4(+) T cell counts had significantly increased levels of anti-HIV CD4(+) T cell lymphoproliferative responses, lower levels of CD38(+), and higher CD8(+)/CD28(+) T cell percentage, compared with those in treated children with a lack of virus suppression (>50,000 copies/mL). Levels of anti-HIV CD8(+) T cell activity, although higher in treated children with a lack of virus suppression, were not significantly different between the groups. Although levels of anti-HIV CD4(+) and CD8(+) T cell responses were not associated, these levels of responses were associated with the percentage of specific T cell subsets. Overall, a history of stable CD4(+) T cell counts, as a result of therapy that imparted full or partial virus suppression, was associated with increased levels of anti-HIV CD4(+) T helper responses and decreased T cell activation.

Genetically modified dendritic cells--a new, promising cancer treatment strategy?

Dendritic cells (DCs), the most potent antigen-presenting cells (APCs), were discovered almost 30 years ago. Due to the priming of antigen-specific immune responses mediated by CD4+ and CD8+ lymphocytes, DCs are crucial for the induction of adaptive immunity against cancer. Therefore, vaccination of cancer patients with DCs presenting tumour-associated antigens (TAAs) have been believed to be a promising anticancer strategy. Multiple clinical trials have been carried out in order to evaluate the safety and efficacy of cancer vaccines based on antigen-pulsed DCs. However, pulsing of DCs with particular peptides has several disadvantages: i) short-time duration of antigen-major histocompatability complex (MHC) complexes, ii) a requirement for matching defined peptides with MHC complexes and iii) exclusive presentation of single antigen epitopes. Application of gene transfer technologies in the field of DC-based vaccines made possible the development of novel, anticancer immunisation strategies. In several animal models, DCs modified with genes encoding TAA or immunostimulatory proteins have been shown to be effective in the induction of antitumour immune responses. Based on these encouraging results, a first clinical trial of prostate cancer patients vaccinated with gene modified DCs has recently been initiated. In this article, methods used for genetic modification of DCs and anticancer vaccination strategies based on genetically modified DCs are reviewed.

Recent developments in retroviral gene delivery systems

Since the first gene therapy clinical trial carried out by Rosenberg et al. in 1990 [1], recombinant retroviral vectors are still the most popular gene delivery tools for gene therapy purposes. According to the databases of the Journal of Gene Medicine [101] 35% of gene therapy protocols employ retroviruses, other vectors such as adenoviral vectors are used in 27%, pox viral vectors in 6%, adeno-associated viral vectors in 2% and herpes simplex based vectors in 0.5% of clinical trials. It has become clear that the early retroviral vectors based on simple retroviruses (e.g., murine leukaemia viruses (MLV) are characterised by relatively low viral titre, low transduction efficiency and difficulties in in vivo administration. On the other hand, lentiviral vectors (complex retroviruses) can be grown to a high titre, can stably transduce non-dividing cells and can effectively deliver genes to human progenitor cells (CD34+). This article aims to summarise the first year of the 21st century's developments in the retroviral gene delivery system.