Targeting intracellular oncoproteins with dimeric IgA promotes expulsion from the cytoplasm and immune-mediated control of epithelial cancers

Dimeric IgA (dIgA) can move through cells via the IgA/IgM polymeric immunoglobulin receptor (PIGR), which is expressed mainly on mucosal epithelia. Here, we studied the ability of dIgA to target commonly mutated cytoplasmic oncodrivers. Mutation-specific dIgA, but not IgG, neutralized KRASG12D within ovarian carcinoma cells and expelled this oncodriver from tumor cells. dIgA binding changed endosomal trafficking of KRASG12D from accumulation in recycling endosomes to aggregation in the early/late endosomes through which dIgA transcytoses. dIgA targeting of KRASG12D abrogated tumor cell proliferation in cell culture assays. In vivo, KRASG12D-specific dIgA1 limited the growth of KRASG12D-mutated ovarian and lung carcinomas in a manner dependent on CD8+ T cells. dIgA specific for IDH1R132H reduced colon cancer growth, demonstrating effective targeting of a cytoplasmic oncodriver not associated with surface receptors. dIgA targeting of KRASG12D restricted tumor growth more effectively than small-molecule KRASG12D inhibitors, supporting the potential of this approach for the treatment of human cancers.

Sézary syndrome originates from heavily mutated hematopoietic progenitors

The pathogenesis of cutaneous T-cell lymphoma (CTCL) remains unclear. Using single-cell RNA or T-cell receptor (TCR) sequencing of 32 619 CD3+CD4+ and CD26+/CD7+ and 29 932 CD3+CD4+ and CD26-/CD7- lymphocytes from the peripheral blood of 7 patients with CTCL, coupled to single-cell ATAC-sequencing of 26,411 CD3+CD4+ and CD26+/CD7+ and 33 841 CD3+CD4+ and CD26-/CD7- lymphocytes, we show that tumor cells in Sézary syndrome and mycosis fungoides (MF) exhibit different phenotypes and trajectories of differentiation. When compared to MF, Sézary cells exhibit narrower repertoires of TCRs and exhibit clonal enrichment. Surprisingly, we identified ≥200 mutations in hematopoietic stem cells from multiple patients with Sézary syndrome. Mutations in key oncogenes were also present in peripheral Sézary cells, which also showed the hallmarks of recent thymic egression. Together our data suggest that CTCL arises from mutated lymphocyte progenitors that acquire TCRs in the thymus, which complete their malignant transformation in the periphery.

Olfactory Receptor OR2H1 Is an Effective Target for CAR T Cells in Human Epithelial Tumors

Although chimeric antigen receptor (CAR)-expressing T cells have proven success in hematologic malignancies, their effectiveness in solid tumors has been largely unsuccessful thus far. We found that some olfactory receptors are expressed in a variety of solid tumors of different histologic subtypes, with a limited pattern of expression in normal tissues. Quantification of OR2H1 expression by qRT-PCR and Western blot analysis of 17 normal tissues, 82 ovarian cancers of various histologies, eight non-small cell lung cancers (NSCLCs), and 17 breast cancers demonstrated widespread OR2H1 expression in solid epithelial tumors with expression in normal human tissues limited to the testis. CAR T cells recognizing the extracellular domain of the olfactory receptor OR2H1 were generated with a targeting motif identified through the screening of a phage display library and demonstrated OR2H1-specific cytotoxic killing in vitro and in vivo, using tumor cells with spontaneous expression of variable OR2H1 levels. Importantly, recombinant OR2H1 IgG generated with the VH/VL sequences of the CAR construct specifically detected OR2H1 protein signal in 60 human lung cancers, 40 ovarian carcinomas, and 73 cholangiocarcinomas, at positivity rates comparable with mRNA expression and without OR2H1 staining in 58 normal tissues. CRISPR/Cas9-mediated ablation of OR2H1 confirmed targeting specificity of the CAR and the tumor-promoting role of OR2H1 in glucose metabolism. Therefore, T cells redirected against OR2H1-expressing tumor cells represent a promising therapy against a broad range of epithelial cancers, likely with an admissible toxicity profile.

Ovarian cancer immunogenicity is governed by a narrow subset of progenitor tissue-resident memory T cells

Despite repeated associations between T cell infiltration and outcome, human ovarian cancer remains poorly responsive to immunotherapy. We report that the hallmarks of tumor recognition in ovarian cancer-infiltrating T cells are primarily restricted to tissue-resident memory (TRM) cells. Single-cell RNA/TCR/ATAC sequencing of 83,454 CD3+CD8+CD103+CD69+ TRM cells and immunohistochemistry of 122 high-grade serous ovarian cancers shows that only progenitor (TCF1low) tissue-resident T cells (TRMstem cells), but not recirculating TCF1+ T cells, predict ovarian cancer outcome. TRMstem cells arise from transitional recirculating T cells, which depends on antigen affinity/persistence, resulting in oligoclonal, trogocytic, effector lymphocytes that eventually become exhausted. Therefore, ovarian cancer is indeed an immunogenic disease, but that depends on ∼13% of CD8+ tumor-infiltrating T cells (∼3% of CD8+ clonotypes), which are primed against high-affinity antigens and maintain waves of effector TRM-like cells. Our results define the signature of relevant tumor-reactive T cells in human ovarian cancer, which could be applicable to other tumors with unideal mutational burden.

Spontaneous class-switched antibody responses at endometrial cancer tumor bed drives superior patients’ outcome

The role of humoral responses in endometrial cancer remains insufficiently investigated. Using a cohort of 107 patients with different histological subtypes of endometrial carcinoma, we report that concomitant accumulation of T, B and plasma cells at tumor beds predicts better survival. However, only B cell markers predict survival specifically in high-grade endometrioid type and serous tumors. Accordingly, immune protection is associated with class-switched IgA and, to a lesser extent, IgG. Notably, expression of polymeric immunoglobulin receptor (pIgR) by tumor cells and its occupancy by IgA are superior predictors of outcome, and correlate with defects in methyl mismatch repair. Mechanistically, pIgR-dependent, antigen-independent IgA occupancy drives inflammatory pathways associated with IFN and TNF signaling in tumor cells, along with apoptotic and ER stress pathways, while thwarting DNA repair mechanisms. Therefore, coordinated humoral and cellular immune responses, characterized by IgA:pIgR interactions in tumor cells, determine the progression of human endometrial cancer, and therefore the potential for effective immunotherapies.

Supported by grants from NIH (R01CA157664, R01CA124515, R01CA178687 and R01CA211913), and from Cancer Center Support Grant (CCSG) CA076292

TGF-β-mediated silencing of genomic organizer SATB1 promotes Tfh cell differentiation and formation of intra-tumoral tertiary lymphoid structures

The immune checkpoint receptor PD-1 on T follicular helper (Tfh) cells promotes Tfh:B cell interactions and appropriate positioning within tissues. Here, we examined the impact of regulation of PD-1 expression by the genomic organizer SATB1 on Tfh cell differentiation. Vaccination of CD4^CreSatb1^f/f mice enriched for antigen-specific Tfh cells, and TGF-β-mediated repression of SATB1 enhanced Tfh differentiation of human T cells. Mechanistically, high Icos expression in Satb1^-/- CD4⁺ T cells promoted Tfh cell differentiation by preventing T follicular regulatory cell skewing and resulted in increased isotype-switched B cell responses in vivo. Ovarian tumors in CD4^CreSatb1^f/f mice accumulated tumor antigen-specific, LIGHT⁺CXCL13⁺IL-21⁺ Tfh cells and tertiary lymphoid structures (TLS). TLS formation decreased tumor growth in a CD4⁺ T cell and CXCL13-dependent manner. The transfer of Tfh cells, but not naive CD4⁺ T cells, induced TLS at tumor beds and decreased tumor growth. Thus, TGF-β-mediated silencing of Satb1 licenses Tfh cell differentiation, providing insight into the genesis of TLS within tumors.

Methyltransferase inhibitors restore SATB1 protective activity against cutaneous T cell lymphoma in mice

Cutaneous T cell lymphoma (CTCL) has a poorly understood etiology and no known cure. Using conditional knockout mice, we found that ablation of the genomic organizer special AT-rich sequence-binding protein 1 (Satb1) caused malignant transformation of mature, skin-homing, Notch-activated CD4+ and CD8+ T cells into progressively fatal lymphoma. Mechanistically, Satb1 restrained Stat5 phosphorylation and the expression of skin-homing chemokine receptors in mature T cells. Notably, methyltransferase-dependent epigenetic repression of SATB1 was universally found in human Sézary syndrome, but not in other peripheral T cell malignancies. H3K27 and H3K9 trimethylation occluded the SATB1 promoter in Sézary cells, while inhibition of SUV39H1/2 methyltransferases (unlike EZH2 inhibition) restored protective SATB1 expression and selectively abrogated the growth of primary Sézary cells more effectively than romidepsin. Therefore, inhibition of methyltransferases that silence SATB1 could address an unmet need for patients with mycosis fungoides/Sézary syndrome, a set of incurable diseases.

Examination of the biological safety of a drug derived from mammalian organs

In order to assess the safety of a biological drug, a variety of factors have to be examined and then brought into an overall context considering the specific aspects of each individual product. Quoting Trasylol, the aprotinin (CAS 9087-70-1) drug extracted from bovine lungs as an example for such an approach, the complete procedure is discussed. The rationale of a safety concept, its implementation including safety related validation studies, and the combinatorial evaluation of results from these validations with underlying specificities for manufacture allow for an overall safety assessment. Validation of the removal/inactivation capacity of the manufacturing process for bovine spongiform encephalopathy (BSE) and various viruses showed high reduction potentials. These results constitute the cornerstone for the conclusion that Trasylol is safe with regard to BSE and viruses.

Treatment of chronic relapsing inflammatory demyelinating polyneuropathy by cyclosporin A and plasma exchange. A case report

A patient with chronic relapsing inflammatory demyelinating polyneuropathy was successfully treated with plasma exchanges and cyclosporin A (CsA). Dynamometric measurements of hand force during the time of CsA treatment showed a highly significant correlation between hand force and CsA blood levels. The largest influence of CsA on hand force occurred 11-13 days after CsA uptake.

Model for individual substitution of immunoglobulins after membrane plasma separation

Patients who undergo extensive plasma exchanges using albumin replacement may be more susceptible to infection because they develop significant hypogammaglobulinemia. Substitution of IgG in these patients could be beneficial. A model to calculate the individual amount of IgG required is described. The course of IgG during chronic intermittent membrane plasma separation (MPS) therapy was simulated using an one-pool model. Three modes of substitution were considered for their efficacy: infusion after MPS infusion after discarding an equivalent plasma quantity after termination of MPS, and plasma exchange at the end of MPS against an IgG solution. Mode B was shown to be most economical and was subsequently used to check the validity of the substitution model in a prospective test. The difference between predicted and measured IgG levels was 5% both for simulations from one MPS to the next and for the long-term prediction. The data prove that replacement of IgG after plasma separation is practicable. The substitution model allows to fix in advance any plasma limit value for indication and target of the substitution therapy. Thus it permits to give therapeutic recommendations for individual IgG substitution therapy of secondary antibody deficiency after MPS.

Aluminum load in chronic intermittent plasma exchange

Aluminum (Al) loading due to administration of human albumin (HA) solutions was studied in 2 patients with stable renal function who underwent plasma exchange once (patient A) and twice (patient B) per week for treatment of hyperviscosity syndrome. Al was determined by Zeeman-AAS in plasma before, during and after treatment, also in bone of one patient and in various preparations of HA from different manufacturers. In addition, the net Al uptake (difference between total Al influx and efflux) and the 24th urinary excretion between 2 exchanges were determined. The electrolyte solution used for dilution had no detectable Al, while HA contained between 15 and 1900 micrograms Al/l. Increase of Al in plasma after treatment was clearly related to Al content of the HA used. When the patients received substitution solutions based on inadvertently highly Al contaminated 20% HA (1419 micrograms/l), the average net uptake was 2265 in patient A and 2049 micrograms in patient B and plasma Al rose from 8.4 respectively 18.0 before to 69.2 and 86.5 micrograms/l after treatment. By using medium Al contaminated HA (574 micrograms/l), the net uptake was 742 (pat. A) and 819 micrograms (pat.B), and there was an elevation of plasma Al from 5.1 respectively 18.2 to 34.2 and 39.8 micrograms/l. Following a net uptake of 870 micrograms patient A excreted 668 micrograms Al until the next treatment (23% positive balance). Treating patient A with a low Al HA (47 micrograms/l), there was a slight increase of plasma Al from 10.8 to 16.2 micrograms/l, the net Al uptake was negligible (less than 10 micrograms), and the weekly Al balance was negative. After 10 months of plasma exchange therapy (patient A) there was no increase of Al in bone (6.4 micrograms/g). We conclude, that the use of HA with a low Al contamination is recommended for all patients receiving this therapy during chronic intermittent plasma exchange or for other indications, especially in cases with impaired renal function.

Nomograms for the prediction of patient's plasma volume in plasma exchange therapy from height, weight, and hematocrit

The knowledge of plasma volume (PV) is a basic requirement for the standardization of plasma exchange therapy. PV has to be determined by calculation, as the measurement of PV before every plasma exchange is too cost- and time consuming. A known correlation with measured values results from calculation of plasma volume by means of patient's height and weight. But the present equations are only reliable at normal hematocrit. For this reason we modified the Retzlaff-equations and compared the validity of plasma volume predictions, calculated by these and own equations, with plasma volume measured by the 51Cr-method in 59 patients with pathological hematocrit. The correlation coefficient was 0.82 for men and 0.81 for women (2 0.001) with the modified Retzlaff-equations. On the average the relative error was -1.5% for all and 2.8% for fat and thin men. No significant improvement of accuracy was achieved with other equations. Thus, plasma volume can accurately be calculated from height, weight, and hematocrit with our modified Retzlaff-equations in patients with pathological hematocrit, even if they are very fat or thin. Nomograms for men and women were constructed in order to facilitate the calculation.

[Successful treatment of kappa light chain nephropathy using membrane plasma separation]

Often the diagnosis "light chain nephropathy" is not made before renal failure has developed. In the past these patients had a poor prognosis. Special features of this disease and improvement of renal function by plasma exchange therapy are shown in a case report. A 51-year-old man admitted to hospital with renal failure, proteinuria and hypercalcaemia was treated by Ca-free dialysis and membrane plasma separation (MPS). Renal biopsy studied by light and electron microscopy showed mainly tubular protein casts. It is assumed that this nephropathy is caused by a direct toxic effect of the kappa light chains on function and structure of tubuli. Proteinuria was markedly lowered and renal failure was made partly reversible by prompt and effective MPS. Thus, MPS may improve the prognosis of this stage of disease.

Membrane plasma separation: complications and monitoring

During the last 3 years, 306 membrane plasma separations (MPS) were performed on 40 patients. Activated partial thromboplastin time (APTT), oncotic pressure (OP), blood count, free hemoglobin, prothrombin time, fibrinogen, and factors II, V, VII, VIII, IX, X, XI, and XIII were determined. The complication rate was evaluated. Mild complications were observed in 4.2% of the cases (extracorporeal coagulation 1.5%, hypotensive episodes 2%, allergic reactions 0.7%). Severe complications were not observed. A flexible heparinization schedule dependent on the APTT values is necessary. In general, 4,500-7,000 IU/MPS is required. The serum OP is maintained within the normal range using a 3-6% human albumin solution to prevent circulatory complications. A marked loss of fibrinogen occurs with short intervals between successive treatments. The remaining coagulation factors are reduced by an average of 32% and the prothrombin time by 28%. Control of the heparinization and OP is essential for monitoring plasma exchange therapy.

Improvement of uremic neuropathy and hypogeusia by dialysate zinc supplementation: a double-blind study

A reduction in the plasma zinc concentration is a well-recognized complication of hemodialysis. A positive clinical response to zinc therapy under controlled conditions is the most reliable criterion of zinc deficiency. Zinc therapy using a nonproprietary zinc dialysate was evaluated in 12 dialysis patients with proven hypogeusia and polyneuropathy, in a randomized double-blind crossover comparison (preliminary phase, 4 weeks; placebo phase, 12 weeks; initial phase, 12 weeks; final phase, 6 weeks; post phase, 4 weeks). The dosage was related to the zinc plasma and erythrocyte levels, measured weekly. Nerve conduction velocity (NCV) and taste-testing were used to evaluate the effect of treatment at the end of the placebo and therapy phases. There was significant reduction in the recognition and determination threshold level for each of the four qualities of taste. The NCV improved significantly. The plasma zinc level could be elevated in all patients to the desired concentration, using individualized supplementation of dialysate with zinc. The erythrocyte zinc level remained constant, at double the normal value. The plasma zinc concentration fell back to the initial level 6 weeks after conclusion of therapy. We conclude that (1) zinc substitution may provide a specific therapy for uremic polyneuropathy, (2) the observed hypogeusia results from zinc deficiency, (3) long-term therapy is necessary to obtain a constant normal plasma zinc concentration, (4) zinc substitution by dialysate is a suitable and nonstressful method of administration.

Viscosity adaption for an automated micromethod of flame atomic absorption spectrometry, and intracellular trace-element analysis after pressure decomposition: zinc determination in plasma and erythrocytes

We measured zinc in the plasma of 50 normal persons, and in erythrocytes of six, by an automated micromethod of atomic absorption spectrometry. Using a rotation viscometer, we measured the viscosity and flow behavior of plasma, undiluted and equi-volume diluted (with water), from 12 patients, and, for comparison, of two- to 20-fold dilutions of an 870 mL/L glycerol solution. Erythrocytes were washed three times, lyophilized, and wet-ashed in a pressure decomposition device. The mean viscosity of equi-volume diluted plasma is about the same as that of the glycerol solution diluted 7.5-fold. The observed concentration of zinc in normal plasma was 13.8 (SD 1.9) mumol/L, with intra-assay CV (n = 30) of 2%, day-to-day CV (n = 22) 3.8%, and accuracy (measurement of an aqueous std.) 2.5%. The mean normal value for erythrocyte zinc was 34.7 micrograms/g, with intra-assay CV (n = 8) 5%, day-to-day CV (n = 6) 5.9%, and accuracy 4.6%. Our results compare well with those by neutron activation analysis, the differences in values being 3% for plasma, 1% for erythrocytes.

Viscosity adaption for an automated micromethod of flame atomic absorption spectrometry, and intracellular trace-element analysis after pressure decomposition: zinc determination in plasma and erythrocytes

We measured zinc in the plasma of 50 normal persons, and in erythrocytes of six, by an automated micromethod of atomic absorption spectrometry. Using a rotation viscometer, we measured the viscosity and flow behavior of plasma, undiluted and equi-volume diluted (with water), from 12 patients, and, for comparison, of two- to 20-fold dilutions of an 870 mL/L glycerol solution. Erythrocytes were washed three times, lyophilized, and wet-ashed in a pressure decomposition device. The mean viscosity of equi-volume diluted plasma is about the same as that of the glycerol solution diluted 7.5-fold. The observed concentration of zinc in normal plasma was 13.8 (SD 1.9) mumol/L, with intra-assay CV (n = 30) of 2%, day-to-day CV (n = 22) 3.8%, and accuracy (measurement of an aqueous std.) 2.5%. The mean normal value for erythrocyte zinc was 34.7 micrograms/g, with intra-assay CV (n = 8) 5%, day-to-day CV (n = 6) 5.9%, and accuracy 4.6%. Our results compare well with those by neutron activation analysis, the differences in values being 3% for plasma, 1% for erythrocytes.

Haemodiafiltration

Using haemodiafiltration--a combination of haemodialysis and haemofiltration--an increased clearance rate for middle and small molecules can be obtained compared to the single technique alone. Low molecular weight substances are removed mainly by diffusion, and middle molecules predominantly by convection. Using currently available equipment the duration of therapy can thus be reduced by at least one-third, compared with haemodialysis, without deterioration in the patient's general condition. The withdrawal of large volumes of fluid is markedly better tolerated by the patient than with other short-time blood purification procedures. With the aid of haemodiafiltration both molecular groups can be diminished independently of each other according to individual demand, thereby leading to optimization of dialysis therapy.