SARS-CoV-2-associated T-cell infiltration in the central nervous system

Objectives

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). Although an acute SARS-CoV-2 infection mainly presents with respiratory illness, neurologic symptoms and sequelae are increasingly recognised in the long-term treatment of COVID-19 patients. The pathophysiology and the neuropathogenesis behind neurologic complications of COVID-19 remain poorly understood, but mounting evidence points to endothelial dysfunction either directly caused by viral infection or indirectly by inflammatory cytokines, followed by a local immune response that may include virus-specific T cells. However, the type and role of central nervous system-infiltrating T cells in COVID-19 are complex and not fully understood.

Methods

We analysed distinct anatomical brain regions of patients who had deceased as a result of COVID-19-associated pneumonia or complications thereof and performed T cell receptor Vβ repertoire sequencing. Clonotypes were analysed for SARS-CoV-2 association using public TCR repertoire data.

Results

Our descriptive study demonstrates that SARS-CoV-2-associated T cells are found in almost all brain areas of patients with fatal COVID-19 courses. The olfactory bulb, medulla and cerebellum were brain regions showing the most SARS-CoV-2 specific sequence patterns. Neuropathological workup demonstrated primary CD8+ T-cell infiltration with a perivascular infiltration pattern.

Conclusion

Future research is needed to better define the relationship between T-cell infiltration and neurological symptoms and its long-term impact on patients' cognitive and mental health.

First-line treatment of unresectable or metastatic HER2 positive esophagogastric adenocarcinoma: liquid biomarker analysis of the phase 2 INTEGA trial

BACKGROUND

The addition of nivolumab to trastuzumab and chemotherapy in first-line unresectable or metastatic HER2 positive esophagogastric adenocarcinoma (HER2+ EGA) results in long progression-free and overall survival as shown by the INTEGA (ipilimumab or FOLFOX in combination with nivolumab and trastuzumab in HER2 positive esophagogastric adenocarcinoma) trial. This trial suggested that the chemotherapy backbone is needed in an unselected HER2+ patient population. Yet, it remains an open question if there are specific patient subsets that may benefit from an enhanced immunotherapeutic but chemotherapy-free approach.

METHODS

We analyzed blood T cell repertoire metrics determined by next-generation sequencing, circulating tumor cell (CTC) counts detected by CellSearch and their expression of HER2 and PD-L1 as potential liquid biomarkers predicting outcomes on ipilimumab versus FOLFOX (folinic acid, FOL, fluorouracil, F, oxaliplatin, OX) chemotherapy added to a backbone of trastuzumab and nivolumab in patients with HER2+ EGA in the INTEGA trial population.

RESULTS

Patients with two out of three baseline-determined liquid biomarkers-high T cell repertoire richness, absence of CTCs or HER2-expression on CTCs-made up approximately 44% of HER2+ EGA cases and did not show compromise in efficacy if treated with a chemotherapy-free regimen. Long-term responders showing a progression-free survival of >12 months were enriched in this biomarker triad, especially if treated on the chemotherapy-free arm.

CONCLUSION

Prospective validation of this liquid biomarker triad is needed to molecularly define HER2+ EGA patient subsets with different needs in the first-line systemic treatment setting.

Circulating Tumor DNA in Head and Neck Squamous Cell Carcinoma

Tumors shed cell-free DNA (cfDNA) into the plasma. “Liquid biopsies” are a diagnostic test to analyze cfDNA in order to detect minimal residual cancer, profile the genomic tumor landscape, and monitor cancers non-invasively over time. This technique may be useful in patients with head and neck squamous cell carcinoma (HNSCC) due to genetic tumor heterogeneity and limitations in imaging sensitivity. However, there are technical challenges that need to be overcome for the widespread use of liquid biopsy in the clinical management of these patients. In this review, we discuss our current understanding of HNSCC genetics and the role of cfDNA genomic analyses as an emerging precision diagnostic tool.

Outcome of a Real-World Patient Cohort with Secondary CNS Lymphoma Treated with High-Intensity Chemoimmunotherapy and Autologous Stem Cell Transplantation

BACKGROUND

Aggressive non-Hodgkin lymphomas with secondary central nervous system (CNS) involvement bear a dismal prognosis. Optimal treatment remains so far unclear, and effective treatment options remain an unmet clinical need. Remission rates are in general low, resulting in rapid relapses and palliative care in the majority of patients. High-intensity treatment combining effective CNS-directed chemoimmunotherapy with autologous stem cell transplantation was shown in a recent phase 2 trial to induce durable remissions. Here, we report the outcome of the first real-world patient cohort treated according to the published protocol.

METHODS

We retrospectively identified 17 HIV-negative lymphoma patients with secondary CNS involvement, either at first diagnosis or at relapse of lymphoma, treated according to the study protocol published by Ferreri et al. [J Clin Oncol. 2015] at two university medical centers in Germany. Treatment consisted of four cycles of chemoimmunotherapy with a consolidating autologous stem cell transplantation. Adverse events and overall outcome were assessed.

RESULTS

Five patients had CNS involvement at first diagnosis and 12 patients at relapse of lymphoma. A complete response was achieved in 9 patients. Median survival was 11 months. Five patients died of septic complications and 4 patients succumbed to progression or relapse of disease.

CONCLUSIONS

The outcome of our real-world cohort emphasizes the possible toxic character of the treatment protocol by Ferreri et al. [J Clin Oncol. 2015]. Further improvement in treatment regimens is still an unmet need.

Evolutionary clonal trajectories in nodular lymphocyte predominant Hodgkin lymphoma with high transformation risk

The B cell architecture of nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is complex since it is composed of malignant lymphocyte-predominant (LP) cells along with a B cell rich bystander environment. To gain insight into molecular determinants of transformation, we studied B cell evolutionary trajectories in lymphoma tissue from diagnosis to relapse or transformation to non-Hodgkin lymphoma by immunoglobulin heavy chain next-generation sequencing. NLPHL cases that later transformed showed higher age, IgD negativity, absence of the characteristic IGHV3/IGHD3/IGHJ6 LP rearrangement and high repertoire clonality. We constructed phylogenetic trees within the compartment of the malignant clone to investigate clonal evolution. In all relapsing cases, the LP rearrangement was identical at diagnosis and relapse. NLPHL cases with transformation showed more complex trajectories with strong intraclonal diversification. The dominant founder clone in transformations showed clonal evolution, if derived from the same cell of origin, or originated from a different cell of origin. Together, our data point to a significant role of antigenic drive in NLHPL transformations and identify high B cell repertoire clonality with dominant intraclonal LP cell diversification as a hallmark of transformation. Sequencing of the initial paraffin-embedded tissue may therefore be diagnostically applied to identify NLPHL cases with high transformation risk.

Prevalence of definite antiphospholipid syndrome in carriers of the JAK2V617F mutation

INTRODUCTION

Patients with Philadelphia-negative myeloproliferative neoplasms (MPNs), particularly those carrying the JAK2^V617F mutation, are at increased risk of thrombosis. While an association of MPNs with autoimmune disorders has been established, the prevalence of inherited or acquired thrombophilias in JAK2^V617F-positive patients remains obscure. We therefore investigated the coincidence of the JAK2^V617F mutation with additional thrombogenic risk factors.

METHODS

In a retrospective study, we analyzed all patients referred for thrombophilia work-up between 01/2011 and 08/2019, in whom additional JAK2^V617F mutation analysis was performed because of thromboembolic events that were recurrent, atypically located and/or associated with abnormal blood counts.

RESULTS

Of 472 tested patients, 49 (10.4%) were JAK2^V617F-positive. While the frequency of inherited thrombophilias (factor V Leiden and prothrombin G20210A mutation, deficiency of antithrombin, protein C, protein S) was not different between the two groups, the prevalence of definite antiphospholipid syndrome (APS), mostly associated with a moderate- or high-risk antibody profile, was significantly higher in patients with (22.4%) than in those without (8.4%) JAK2^V617F mutation (p < 0.01). All evaluable JAK2^V617F-positive patients with APS were subsequently diagnosed with MPN. In patients with JAK2^V617F mutation, presence of concomitant APS was associated with a significantly younger age (49 ± 14 vs. 60 ± 15 years) at the time of thrombophilia work-up (p < 0.05).

CONCLUSION

We found a significant association between JAK2^V617F-positive MPN and definite APS. The presence of concomitant APS in patients carrying the JAK2^V617F mutation may lead to earlier manifestation of thromboembolic events and may warrant more aggressive antithrombotic treatment strategies to prevent recurrence.

High-Throughput Immunogenetics Reveals a Lack of Physiological T Cell Clusters in Patients With Autoimmune Cytopenias

Autoimmune cytopenias (AIC) such as immune thrombocytopenia or autoimmune hemolytic anemia are claimed to be essentially driven by a dysregulated immune system. Using next-generation immunosequencing we profiled 59 T and B cell repertoires (TRB and IGH) of 25 newly diagnosed patients with primary or secondary (lymphoma-associated) AIC to test the hypothesis if these patients present a disease-specific immunological signature that could reveal pathophysiological clues and eventually be exploited as blood-based biomarker. Global TRB and IGH repertoire metrics as well as VJ gene usage distribution showed uniform characteristics for all lymphoma patients (high clonality and preferential usage of specific TRBV- and TRBJ genes), but no AIC-specific signature. Since T cell immune reactions toward antigens are unique and polyclonal, we clustered TCRβ clones in-silico based on target recognition using the GLIPH (grouping of lymphocyte interactions by paratope hotspots) algorithm. This analysis revealed a considerable lack of physiological T cell clusters in patients with primary AIC. Interestingly, this signature did not discriminate between the different subentities of AIC and was also found in an independent cohort of 23 patients with active autoimmune hepatitis. Taken together, our data suggests that the identified T cell cluster signature could represent a blood biomarker of autoimmune conditions in general and should be functionally validated in future studies.

T-cell repertoire profiling by next-generation sequencing reveals tissue migration dynamics of TRBV13-family clonotypes in a common experimental autoimmune encephalomyelitis mouse model

The experimental autoimmune encephalomyelitis (EAE) model is indispensable for autoimmunity research, but model-specific T cell dynamics are sparsely studied. We used next-generation immunosequencing across lymphoid organs, blood and spinal cord in response to immunization with myelin basic protein (MBP) to study T cell repertoires and migration patterns. Surprisingly, most spinal cord T cells were unique to the individual animal despite the existence of shared MBP-specific clones, suggesting a previously underestimated T cell diversity. Almost complete emigration of pathogenic clones from blood to spinal cord indicates that blood is not a suitable compartment to study EAE-mediating T cells.

Dynamic changes of the normal B lymphocyte repertoire in CLL in response to ibrutinib or FCR chemo-immunotherapy

Using next-generation immunoglobulin (IGH) sequencing and flow cytometry, we characterized the composition, diversity and dynamics of non-malignant B cells in patients undergoing treatment with the Bruton tyrosine kinase (BTK) inhibitor ibrutinib or chemo-immunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR). During ibrutinib therapy, non-malignant B cell numbers declined, but patients maintained stable IGH diversity and constant fractions of IGH-mutated B cells. This indicates partial preservation of antigen-experienced B cells during ibrutinib therapy, but impaired replenishment of the normal B cell pool with naïve B cells. In contrast, after FCR we noted a recovery of normal B cells with a marked predominance of B cells with unmutated IGH. This pattern is compatible with a deletion of pre-existing antigen-experienced B cells followed by repertoire renewal with antigen-naïve B cells. These opposite patterns in B cell dynamics may result in different responses towards neoantigens versus recall antigens, which need to be further defined.

T-cell diversification reflects antigen selection in the blood of patients on immune checkpoint inhibition and may be exploited as liquid biopsy biomarker

Cancer immunotherapy with antibodies targeting immune checkpoints, such as programmed cell death protein 1 (PD-1), shows encouraging results, but reliable biomarkers predicting response to this costly and potentially toxic treatment approach are still lacking. To explore an immune signature predictive for response, we performed liquid biopsy immunoprofiling in 18 cancer patients undergoing PD-1 inhibition before and shortly after initiation of treatment by multicolor flow cytometry and next-generation T- and B-cell immunosequencing (TCRß/IGH). Findings were correlated with clinical outcomes. We found almost complete saturation of surface PD-1 on all T-cell subsets after the first dose of the antibody. Both T- and B-cell compartments quantitatively expanded during treatment. These expansions were mainly driven by an increase in the activated T-cell compartments, as well as of naïve B- and plasma cells. Deep immunosequencing revealed a clear diversification pattern of the clonal T-cell space indicative of antigenic selection in 47% of patients, while the remaining patients showed stable repertoires. 43% of the patients with a diversification pattern showed disease control in response to the PD-1 inhibitor. No disease stabilizations were observed without clonal T-cell space diversification. Our data show for the first time a clear impact of PD-1 targeting not only on circulating T-cells, but also on B-lineage cells, shedding light on the complexity of the anti-tumor immune response. Liquid biopsy T-cell next-generation immunosequencing should be prospectively evaluated as part of a composite response prediction biomarker panel in the context of clinical studies.

Monitoring multiple myeloma by next-generation sequencing of V(D)J rearrangements from circulating myeloma cells and cell-free myeloma DNA

Recent studies suggest that circulating tumor cells and cell-free DNA may represent powerful non-invasive tools for monitoring disease in patients with solid and hematologic malignancies. Here, we conducted a pilot study in 27 myeloma patients to explore the clonotypic V(D)J rearrangement for monitoring circulating myeloma cells and cell-free myeloma DNA. Next-generation sequencing was used to define the myeloma V(D)J rearrangement and for subsequent peripheral blood tracking after treatment initiation. Positivity for circulating myeloma cells/cell-free myeloma was associated with conventional remission status (P<0.001) and 91% of non-responders/progressors versus 41% of responders had evidence of persistent circulating myeloma cells/cell-free myeloma DNA (P<0.001). About half of the partial responders showed complete clearance of circulating myeloma cells/cell-free myeloma DNA despite persistent M-protein, suggesting that these markers are less inert than the M-protein, rely more on cell turnover and, therefore, decline more rapidly after initiation of effective treatment. Positivity for circulating myeloma cells and for cell-free myeloma DNA were associated with each other (P=0.042), but discordant in 30% of cases. This indicates that cell-free myeloma DNA may not be generated entirely by circulating myeloma cells and may reflect overall tumor burden. Prospective studies need to define the predictive potential of high-sensitivity determination of circulating myeloma cells and DNA in the monitoring of multiple myeloma.

Multidimensional scaling analysis identifies pathological and prognostically relevant profiles of circulating T-cells in chronic lymphocytic leukemia

Antitumor immunity in chronic lymphocytic leukemia (CLL) is hampered by highly dysfunctional T-cells. Although certain T-cell subsets have been reported to be of prognostic significance in this disease, their interplay is complex and it remains incompletely understood which of these subsets significantly drive CLL progression. Here, we determined immunological profiles of 24 circulating T-cell subsets from 79 untreated individuals by multiparametric flow cytometry. This screening cohort included healthy donors, patients with monoclonal B-cell lymphocytosis (MBL), Rai 0 CLL and advanced CLL. We applied multidimensional scaling analysis as rigorous and unbiased statistical tool to globally assess the composition of the circulating T-cell environment and to generate T-cell scores reflecting its integrity. These scores allowed clear distinction between advanced CLL and healthy controls, whereas both MBL and Rai 0 CLL showed intermediate scores mirroring the biological continuum of CLL and its precursor stages. T-cell stimulation and suppression assays as well as longitudinal T-cell profiling showed an increasingly suppressive regulatory function initiating at the MBL stage. Effector function was impaired only after transition to CLL and partially recovered after chemoimmunotherapy. In an independent validation cohort of 52 untreated CLL cases, aberrant T-cell profiles were significantly associated with shorter time to treatment independently of other prognostic parameters. Random forest modeling predicted regulatory T-cell, gamma/delta and NKT-cells, as well as exhaustion of the CD8+ subset as potential drivers of progression. Our data illustrate a pathological T-cell environment in MBL that evolves toward a more and more suppressive and prognostically relevant profile across the disease stages.

Non-invasive genetic approaches for estimation of ungulate population size: a study on roe deer (Capreolus capreolus) based on faeces

Estimating population size is particularly difficult for animal species living in concealing habitats with dense vegetation. This is the case for roe deer as for many other ungulates. Our objective was to develop a non–invasive genetic capture–mark–recapture approach based on roe deer faeces collected along transects. In a pilot study, we collected 1,790 roe deer faeces during five sampling days in a forested study area in south western Germany. We extracted DNA from 410 of these samples and carried out microsatellite analysis using seven dinucleotide markers. The analyses resulted in 328 useable consensus genotypes which were assigned to 174 individuals. The population size estimated using a Bayesian approach was 94 (82–111) male and 136 (121–156) female roe deer. Our study shows that non–invasive genetic methods are a valuable management tool for roe deer.

A multi-site study using high-resolution HLA genotyping by next generation sequencing

The high degree of polymorphism at human leukocyte antigen (HLA) class I and class II loci makes high-resolution HLA typing challenging. Current typing methods, including Sanger sequencing, yield ambiguous typing results because of incomplete genomic coverage and inability to set phase for HLA allele determination. The 454 Life Sciences Genome Sequencer (GS FLX) next generation sequencing system coupled with conexio atf software can provide very high-resolution HLA genotyping. High-throughput genotyping can be achieved by use of primers with multiplex identifier (MID) tags to allow pooling of the amplicons generated from different individuals prior to sequencing. We have conducted a double-blind study in which eight laboratory sites performed amplicon sequencing using GS FLX standard chemistry and genotyped the same 20 samples for HLA-A, -B, -C, DPB1, DQA1, DQB1, DRB1, DRB3, DRB4, and DRB5 (DRB3/4/5) in a single sequencing run. The average sequence read length was 250 base pairs and the average number of sequence reads per amplicon was 672, providing confidence in the allele assignments. Of the 1280 genotypes considered, assignment was possible in 95% of the cases. Failure to assign genotypes was the result of researcher procedural error or the presence of a novel allele rather than a failure of sequencing technology. Concordance with known genotypes, in cases where assignment was possible, ranged from 95.3% to 99.4% for the eight sites, with overall concordance of 97.2%. We conclude that clonal pyrosequencing using the GS FLX platform and CONEXIO ATF software allows reliable identification of HLA genotypes at high resolution.

Complete remission after induction therapy of donor cell derived secondary AML in a CML transplant patient

16523

Background: Malignant diseases arising from donor derived cells are an exceptionally rare condition with approximately 20 cases only reported in the literature. We report on diagnosis and salvage chemotherapy of a CML transplant patient relapsing with donor cell derived secondary MDS resp. AML. Methods: Chimerism analysis were performed by quantitative short tandem repeat (STR) DNA detection in bone marrow as well as in peripheral blood, detection limit 0.5%. Standard procedures were used for all other methods. Results: In a female patient transplanted with a HLA-DRB1 mismatched female unrelated donor in July 1998 for Ph+ CML, secondary MDS was diagnosed in March 2005 transforming into secondary AML in June 2005. The results from chimerism analysis after diagnosis of sMDS resp. sAML in this transplant patient, i.e. no detection of the STR pattern of the recipient, clearly confirmed a donor cell derived sMDS resp. sAML almost 7 years after allogeneic BMT. Cytogenetics showed a normal female karyotype, and no molecular aberrations were detected by FISH resp. PCR. After diagnosis of sAML the patient received 2 induction courses consisting of FLAG-Ida and MTC regimen, respectively. Bone marrow analysis after the first and second course revealed no evidence of blasts whereas the MDS continued to be detectable. Cytogenetics during and after reinduction therapy were normal. Repeated chimerism analysis showed complete donor chimerism (> 99.5%). Thus, a complete remission of donor cell derived sAML using conventional induction chemotherapy was achieved. This remission is now lasting 6 months without intensification. Medical evaluation of the donor did not reveal any disturbed or malignant hematological disorder. Conclusions: This is an interesting case of rare donor cell derived leukemia and its successful treatment. The question arises with regard to altered stromal factors in the bone marrow of the patient as potential cause of the disease.

No significant financial relationships to disclose.

Second German consensus on immunogenetic donor search for allotransplantation of hematopoietic stem cells

The present paper summarizes the results of the second German consensus meeting on immunogenetic donor search for allotransplantation of hematopoietic stem cells held in Essen in November 1999 under the auspices of the German Society for Immunogenetics (DGI) and the German Working Party for Blood and Marrow Transplantation (DAG-KBT). Immunogeneticists and transplant physicians from all over the country agreed to update the national standards for: (1) search strategy including the role of unrelated and extended family donor search after unsuccessful core family donor search, (2) histocompatibility loci to be typed, (3) histocompatibility typing techniques to be used (HLA serology vs DNA-based HLA typing, cellular tests, serum cross-match), and (4) acceptable HLA mismatches in the context of a defined underlying disease, donor type, and conditioning regimen.

Endocrine-disrupting nonylphenols--ultra-trace analysis and time-dependent trend in mussels from the German bight

A very sensitive and efficient analytical procedure is presented for the determination of 4-nonylphenols (NP) in blue mussels by use of off-line coupling of high-performance liquid chromatography (HPLC) and gas chromatography with mass spectrometric detection (GC-MS). Combined steam distillation and solvent extraction were used to extract the analytes from the mussel samples. Before quantification by GC-MS the raw extracts were purified by normal-phase HPLC. 4-n-Nonylphenol was used as internal standard. The detection limit was 15 ng NP absolute, calculated from the blank value. The method was applied to the determination of NP in blue mussel samples from the German North Sea sampled over a period of 10 years. Collection, homogenization, and storage of the mussels were performed according to the Standard Operating Procedures of the German Environmental Specimen Bank since 1985. The total NP concentrations in the mussels decreased significantly from 1985 (4 microgram kg (-1)) to 1995 (1.1 microgram kg (-1)).

Cyclosporine A sensitivity in vitro and P-glycoprotein expression in patients on dialysis and after kidney transplantation

BACKGROUND

In allogeneic kidney transplantation the response to cyclosporine A (CsA) is important for graft outcome. Although CsA therapy is controlled by drug monitoring to ensure therapeutic CsA levels, the sensitivity to the effects of CsA varies among individuals. Since CsA is an antagonist of cytostatic drugs in P-glycoprotein (Pgp)-mediated transport, increased Pgp expression might contribute to an increased resistance to CsA.

METHODS

The sensitivity of lymphocytes at three different concentrations of CsA was tested in a non-radioactive lymphocyte-transformation test and related to Pgp expression as determined by flow cytometry on mononuclear cells. Five groups, including healthy donors (CON; n = 25), patients on dialysis (DIAL; n = 25), patients before transplantation (PTX; n = 5) and after transplantation [short-term (ATX; n = 5) and long-term (LTX; n = 25)] were investigated.

RESULTS

In LTX, the sensitivity to CsA at 400 and 1000 ng/ml was significantly different from CON and DIAL. Overall a higher sensitivity to CsA was seen in patients after transplantation. In ATX, sensitivity to CsA was significantly higher than in PTX at a concentration of 1000 ng/ml CsA. However, comparing all groups no significant changes in Pgp expression were noted. Analysing the relationship between CsA sensitivity and Pgp expression, no significant heterogeneity could be observed between the different groups.

CONCLUSION

In conclusion, our data suggest that in vitro testing of CsA sensitivity prior transplantation and Pgp expression monitoring yield independent results and cannot substitute for each other as predictors of graft outcome. The differential role of each test for the evaluation of CsA sensitivity or resistance remains to be determined.

Monocytes from systemic lupus erythematous patients are severely altered in phenotype and lineage flexibility

OBJECTIVE

Cells of the myeloid lineage comprise a very heterogeneous population with many phenotypes and functional activities including macrophages and dendritic cells. To investigate the status, differentiative potential and lineage commitment of monocytic cells in systemic lupus erythematosus (SLE) patients, this study isolated and cultured peripheral blood monocytes from patients and healthy donors.

METHODS

Monocytes were isolated by gradient centrifugation and adherence to plastic dishes. The cells were then cultured for three days, partially supplemented with GM-CSF and interleukin 4 (IL4) to obtain dendritic cells. The differentiation status was monitored by the expression of surface markers using flow cytometry and cytokine secretion.

RESULTS

Monocytes from SLE patients expressed significantly lower numbers of the monocytic marker CD14 and HLA-DR while secreting significantly more tumour necrosis factor alpha (TNFalpha) than monocytes from healthy donors. The addition of GM-CSF and IL4 resulted in an inhibition of TNFalpha secretion, but was not sufficient to generate monocytederived dendritic cells.

CONCLUSION

Monocytes from SLE patients are severely altered in phenotype and function and have a limited differentiation flexibility towards the accessory type of monocytic cells.

Effects of anti-CD4 antibodies on the release of IL-6 and TNF-alpha in whole blood samples from patients with systemic lupus erythematosus

Anti-CD4 antibodies have been recently introduced into the therapy of various autoimmune diseases, among them systemic lupus erythematosus (SLE). Their modes of action are not yet fully understood. Interference with cytokine release may be one possible mechanism. Therefore, the effects of anti-CD4 antibodies on the cytokine release of IL-6 (interleukin-6) and TNF-alpha (tumor necrosis factor alpha) were investigated in a whole blood culture system. Basal and phytohemagglutin/lipopolysaccharide (PHA/LPS)-stimulated cytokine patterns were compared to cytokine release after the addition of anti-CD4 antibodies (MAX.16H5) or methylprednisolone in short time whole blood cell culture systems from 12 patients with active SLE, 23 patients with inactive SLE and 12 healthy volunteers. TNF-alpha and IL-6 concentrations were determined in the supernatants by ELISA. High disease activity correlated with an increased production of proinflammatory cytokines. Cell cultures of patients with inactive SLE showed a diminished capacity to respond to mitogenic stimulation. Anti-CD4 antibodies added in vitro suppressed significantly the unstimulated production of IL-6 (P<0.02) in the cell cultures of patients with active SLE and in the PHA/LPS-stimulated cell cultures from both groups of SLE patients (both P<0.001) and healthy volunteers (P<0.01). However, MAX.16H5 did not affect the release of TNF-alpha. In control samples methylprednisolone considerably reduced stimulated and unstimulated IL-6 and TNF-alpha production in all SLE patients, irrespective of the disease state, and in all healthy controls. These data indicate that the proinflammatory cytokines are involved in the pathogenesis of SLE. It is assumed that anti-CD4 antibodies, which can be effective in the treatment of highly active lupus patients, may act via their influence on cytokine release. The decrease of the proinflammatory cytokines IL-6 under therapy with MAX.16H5 could explain the observations of clinical trials and animal studies which showed a reduction of inflammatory parameters and diminished production of autoantibodies following treatment with anti-CD4 antibodies.

Complete androgen insensitivity caused by a new frameshift deletion of two base pairs in exon 1 of the human androgen receptor gene

We describe a novel mutation in exon 1 of the androgen receptor gene in a patient with complete androgen insensitivity (CAIS). Endocrine findings were typical for androgen insensitivity (testosterone serum levels in the upper limit of normal males and increased LH serum concentrations). Biochemical investigations in cultured genital skin fibroblasts of the patient showed a normal 5alpha-reductase activity but a complete absence of androgen binding. Western blot analysis revealed no detectable protein product. Sequence analysis of the entire coding region of the androgen receptor gene resulted in the identification of a 2-bp deletion in codon 472, causing frameshift and introduction of a premature stop codon 27 codons downstream of the mutation.

Anti-endothelial cell antibodies in Takayasu arteritis

BACKGROUND

Although a specific etiology for Takayasu arteritis has not been found, the bulk of evidence favors an autoimmune mechanism. We examined the sera of 19 patients with Takayasu arteritis for antineutrophil cytoplasmic antibodies (ANCA), antinuclear antibodies (ANA), anti-DNA antibodies, antibodies to extractable nuclear antigens (ENA), anti-Ro anti-bodies, anticardiolipin antibodies, circulating immune complexes, and anti-endothelial cell antibodies (AECA).

METHODS AND RESULTS

We used enzyme-linked immunoassays, immunofluorescence, counterimmunoelectrophoresis, fluorescent-activated cell sorter (FACS) analysis, and confocal microscopy. We found that although no patient had positive ANCA, ANA, anti-DNA antibodies, ENA antibodies, anti-Ro antibodies, or anticardiolipin antibodies, 18 of the 19 patients had AECA. The AECA titers of the patients were 2561 +/- 1458 compared with 126 +/- 15 arbitrary units in a normal group of control subjects (P < .001). To verify the specificity of AECA, we performed cytofluorimetry on human endothelial cells with the sera from patients and control subjects. Two entirely separate patterns of fluorescence intensity were identified. We next performed immunocytochemistry and confocal microscopy with human endothelial cells subjected to patients' sera and to sera from normal subjects. The cells subjected to sera from patients with Takayasu arteritis demonstrated specific immunofluorescent staining of their plasma membrane and cytosol.

CONCLUSIONS

AECA are frequently present in patients with Takayasu arteritis. They may play a role in the pathogenesis. Furthermore, they may be useful as an additional diagnostic tool.

Effects of methylprednisolone and 21-aminosteroids on mitogen-induced interleukin-6 and tumor necrosis factor-alpha production in human peripheral blood mononuclear cells

The compounds U-74389G (16-desmethyl tirilazad) and U-74500A are two of the novel series of nonglucocorticoid 21-aminosteroids (or lazaroids) which mimic the high-dose neuroprotective pharmacology of the glucocorticoid methylprednisolone (MP) in the injured CNS. Despite structural analogies to MP, it has been shown previously for a variety of endpoints that lazaroids are devoid of classical glucocorticoid effects. Our objective here was to measure the immunosuppressive effects of these lazaroids directly. Specifically, we have compared the in vitro effects of MP, U-74389G, and U-74500A on the mitogen-induced cytokine production in human peripheral blood mononuclear cells, which is known to be very sensitive and perhaps the most clinically relevant parameter reflecting immunomodulation. We show that, in contrast to the glucocorticoid MP, both lazaroids at therapeutically relevant concentrations have no significant inhibitory effects on stimulated interleukin-6 and tumor necrosis factor-alpha production, neither via residual glucocorticoid receptor-mediated activities nor via direct physicochemical effects on cellular membranes. These results strongly support the view that lazaroids lack glucocorticoid activities, but rather exert their tissue protective effects via mechanisms that are independent of glucocorticoid-receptor binding.

[Photodynamic therapy of eyelid basalioma after topical administration of delta-aminolevulinic acid]

Delta-aminolevulinic acid (ALA) induced Protoporphyring IX photodynamic therapy (PDT) is a new method in the therapy of cutaneous malignancies. Topical application prevents photosensibilization of normal skin. Promising results in the treatment of superficial basal cell carcinomas have been reported. To evaluate the efficiency of this method in the therapy of basal cell carcinomas of the lid, 10 patients were treated by PDT 5 h after application of ALA. The lesions were irradiated by an argon-ion-laser-pumped dye laser at a wavelength of 630 or 635 nm and at cumulative radiant exposures of 50 and 100 J/cm2. After 5-8 weeks follow-up, the basal cell carcinomas were excised to assess histologic changes. In the first few days after PDT the lesions seemed clinically to regress, due to erythematous swelling, but after a few weeks all tumours showed the same configuration they had before irradiation. Histological examination revealed small areas of necrotic cells in all irradiated basal cell carcinomas, surrounded by residual tumour formations. The reason for the poor results may be limited penetration of ALA or light. Although ALA-induced Protoporphyrin-IX PDT is a promising approach in the therapy of dermal lesions, it is not yet an acceptable alternative method in the treatment of basal cell carcinomas of the lid.

The influence of methylprednisolone on the energy metabolism of Ehrlich ascites tumour cells

Using Ehrlich ascites tumour cells, the short-term effects of the therapeutic glucocorticoid Methylprednisolone (MP) on the cellular energy metabolism were studied. ATP-consuming processes involved in the rapid MP effects were identified indirectly from the effects of MP on cellular oxygen consumption related to the inhibition of respiration by selective inhibitors of Ca(2+)-ATPase and protein synthesis. The effects of MP on plasma membrane permeability for Ca2+ ions and phospholipid turnover were studied directly by using confocal laser scanning microscopy and tracerkinetic measurements, respectively. MP inhibited cellular oxygen consumption, suppressed the inhibitory effect of lanthanum but not that of cycloheximide on oxygen consumption, blocked the [Ca2+]i rise in response to calcium ionophore A 23187, and decreased phospholipid turnover. MP acted instantly in a dose-dependent manner. The observed effects of MP are discussed in relation to the hypothesis that the drug has direct membrane effect affecting plasma membrane permeability and function.

Modulation of cytokine expression by hypericum extract

The effect of hypericum extract LI 160 on the stimulated cytokine expression was investigated in vitro in a whole blood culture system. Blood samples were taken from five healthy volunteers and four depressive patients. The release of interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) was measured quantitatively after an incubation time of 24 hours on microtiter plates. A massive suppression of the interleukin-6 release was found for PHA-stimulated hypericum extract. Possible relations to the antidepressive effects of hypericum extract are discussed.

Phenotypic investigation of mononuclear phagocytes by flow cytometry

A simple and rapid method for the phenotypic analysis of mononuclear phagocytes is described. Using flow cytometry, surface markers, as well as intracellular antigens and DNA content of peripheral blood monocytes, or differentiated monocytic cells could be analysed. Furthermore, the method has been of use in several species and is therefore not restricted to applications in humans. Different modes of data acquisition and analysis were compared and are discussed.

Dextran sulphate induces a PKC and actin independent internalisation of CD4

Internalisation of CD4 is a well-known phenomenon. It occurs in the presence of phorbol myristate acetate (PMA), TPA or gangliosides and is usually completed within 30 min. Here, we describe an internalisation of CD4 molecules induced by low concentrations of high molecular weight dextran sulfate (M(r) 500 kDa) which differs from the classical mode in several ways. Internalisation is demonstrated by flow cytometry after simultaneous and consecutive staining of extracellular and internalised CD4 molecules and by visualisation by electron micrographs. A simple blockage of antibody binding sites on the CD4 molecule (epitope masking) by DS500, as widely believed, is definitely not responsible for the observed effects. DS500-mediated internalisation is a slow and energy-dependent process, where CD4 but not CD 2, 3, 8, 16, 56 and HLA-DR molecules are involved. The reaction reveals a characteristic time and concentration dependency. It does not require activation of protein kinase C (PKC) and cannot be inhibited by cytochalasin D. These results provide some more insight in the behavior of CD4 on lymphoid cell surfaces in response to high molecular weight polyanions such as dextran sulfate.

The recognition of UV-irradiation melanocyte with HMB-45 monoclonal antibody

Monoclonal antibody HMB-45 was previously thought to be melanoma specific antibody and was taken recently as a marker for melanocyte proliferation or activation. A single UV-irradiation system which may induce a functional activity change in melanocytes was used to test the irradiated epidermal melanocyte for expression of HMB-45. Melanocytes, in the epidermis of the biopsies taken 7 days after a single UV exposure, showed markedly stained HMB-45, accompanied by morphological changes such as enlarged size, rich cytoplasma and elongated dendrites. We conclude that since morphological changes in irradiated melanocytes may be interpreted as signs of functional activity changes, melanocytes are exposed to stimulatory factors induced by UV light and get into a functional activating state to produce melanosome and HMB-45 antigen. Besides, the presence of HMB-45 in a single UV exposed epidermal melanocyte may support the hypothesis that its expression is inducible and is closely related to the functional activity of melanocyte.

Influence of phospholipid liposomes (PLL) on UVB-induced erythema formation

Application of liposomal phospholipids (Natipide II) caused a significant decrease in erythema induced by UVB (280-312 mm) in patients with skin types II and III (n = 31). In accordance with findings in other organs, e.g. liver, the present findings suggest that phospholipids are capable of reducing H2O2 formation and/or increasing glutathione synthesis in human skin, thus reducing erythema formation by preventing oxidative stress.

[Scabies norvegica sive crustosa in a patient with AIDS]

We report the case of a 20-year-old homosexual man with HIV-1 infection presenting with AIDS. An erythemato-squamous, papulo-crustous, non-itching dermatosis of 4 months duration was finally diagnosed as Norwegian scabies in the immunosuppressed. For clinical and epidemiological reasons the high contagiosity of this rare entity requires an appropriate therapy without delay.

Development of a Langerhans cell phenotype from peripheral blood monocytes

Epidermal Langerhans cells (ELC) are definitively primed to differentiate into dendritic cells (DC). It is unknown at what stage of monocyte development this priming occurs. In a culture system characterized by low paracrine stimulation, i.e. Iscove's modified Dulbecco medium (IMDM) with 2% FCS, we tested the ability of peripheral blood monocytes to turn to the route of the LC-DC lineage. In this system monocytes did not develop significant yeast cell phagocytosis, although mannose receptors were available. However, they became strong stimulators of mannan specific T cell proliferation. Phenotype development was analysed by flow cytometry using the monoclonal antibodies OKT6 (CD1a), IOT2 (HLA-DR), IOM2 (CD14) and the ligand Man-BSA-FITC. CD1a was the first marker which distinguished cultured monocytes from developing macrophages, obtained by addition of 8% human serum. Like cord blood Langerhans cells (CBLC) they internalized OKT6 in deep coated pits. They maintained a phenotype of monocyte derived Langerhans cells (MoLC) during eight days of in vitro culture, expressing CD1a, mannose receptors and HLA-DR and decreasing CD14, if left in their own conditioned medium. MoLC could be converted into macrophages by addition of human serum only within the first four days in vitro. Our data suggest that monocytes acquire an LC phenotype by autocrine stimulation.

Lipoxygenases from soybeans and rabbit reticulocytes: inactivation and iron release

Various inactivation methods were applied to lipoxygenases from soybean (isoenzyme 1) and rabbit reticulocytes to compare the inactivation behaviour of both enzymes and to elucidate the state of the iron which is known to be involved in the catalytic reaction of lipoxygenases: 1. Titration of the enzyme with mercury compounds shows that there are one or two SH groups responsible for the loss of activity in the presence of mercury. The SH groups seem not to be involved in the tight iron binding. 2. Inactivation by chelating agents such as o-phenanthroline or batho-phenanthroline sulfonic acid occurs only in the presence of reducing agents (mercaptoethanol and ascorbic acid). Our data support a co-oxidation mechanism. The complexation of iron by chelators is not the rate-limiting step. Both lipoxygenases show a very similar behaviour in this respect despite the fact that the reticulocyte enzyme requires the addition of trace amounts of copper ions for efficient inactivation. 3. Release of iron from the enzyme is also achieved by denaturation with guanidinium hydrochloride (Gu-HCl). In all cases, inactivation and release of iron were irreversible processes. 4. A sequence comparison for both animal and plant lipoxygenases shows strongly conserved amino acids, especially histidines and hydrophobic residues, which possibly may be involved in iron complexation and substrate binding.