A neoepitope derived from a novel human germline APC gene mutation in familial adenomatous polyposis shows selective immunogenicity.

Familial adenomatous polyposis (FAP) is an inherited condition arising from genetic defects in the Adenomatous polyposis coli (APC) gene. Carriers with mutations in the APC gene develop polyps in the colon and rectum which if not managed, transition into colon cancer. In this study, we identified a novel germline mutation in the APC gene in members of an FAP-affected (Familial adenomatous polyposis) family. This unique heterozygous variant (c.735_736insT; p.Ser246PhefsTer6) was identified in ten out of twenty six family members, ranging in age from 6 to 60 years. Polyps were detected in six of the ten individuals (35-60 years) carrying this mutation. The remaining four members (6-23 years) remain polyp free. A significant fraction of FAP affected individuals eventually develop colon cancer and therapeutic interventions to prevent cancer progression remain elusive. To address this issue, we sought to determine if peptides derived from the novel APC mutation could induce a cytotoxic T cell response, thereby qualifying them as vaccine candidates. Peptides harboring the variant amino acids were first interrogated in silico for their immunogenicity using a proprietary neoepitope prioritization pipeline, OncoPeptVAC. A single 9-mer peptide was predicted to be immunogenic. Remarkably, CD8+ T cells isolated from either an FAP+/ APCmut individual, or from a FAP-/ APCmut individual, failed to respond to the peptide, whereas those from either an unaffected family member (FAP-/ APCwt) or from healthy unrelated donors, showed a robust response, suggesting that CD8+ T cells from individuals carrying this germline APC mutation have been tolerized to the mutation. Furthermore, experimental testing of six additional reported APC gene mutation-derived peptides revealed one of the six to be immunogenic. While not all APC mutant peptides are inmmunogenic, a few qualify as vaccine candidates offering novel treatment opportunities to patients with somatic APC gene mutations to delay/treat colorectal cancer.

A cancer vaccine approach for personalized treatment of Lynch Syndrome.

Lynch syndrome (LS) is a cancer predisposition disorder wherein patients have a 70-80% lifetime risk of developing colorectal cancers (CRC). Finding germline mutations in predisposing genes allows for risk assessment of CRC development. Here we report a germline heterozygous frame-shift mutation in the mismatch repair MLH1 gene which was identified in members of two unrelated LS families. Since defects in DNA mismatch repair genes generate frame-shift mutations giving rise to highly immunogenic neoepitopes, we postulated that vaccination with these mutant peptide antigens could offer promising treatment options to LS patients. To this end we performed whole-exome and RNA seq analysis on the blood and tumour samples from an LS-CRC patient, and used our proprietary neoepitope prioritization pipeline OncoPeptVAC to select peptides, and confirm their immunogenicity in an ex vivo CD8+ T cell activation assay. Three neoepitopes derived from the tumour of this patient elicited a potent CD8+ T cell response. Furthermore, analysis of the tumour-associated immune infiltrate revealed CD8+ T cells expressing low levels of activation markers, suggesting mechanisms of immune suppression at play in this relapsed tumour. Taken together, our study paves the way towards development of a cancer vaccine to treat or delay the onset/relapse of LS-CRC.

Infusion of pharmaceutical-grade natural human C-reactive protein is not proinflammatory in healthy adult human volunteers.

RATIONALE: Baseline circulating concentrations of C-reactive protein (CRP) are significantly associated with cardiovascular disease risk in general populations. This modest association has been inappropriately conflated with causality, and it has been claimed that CRP is proatherogenic. Most of the known causative factors for atherosclerosis stimulate increased CRP production, but comprehensive genetic epidemiology studies provide no support for a pathogenic role of CRP. The reported proinflammatory effects of human CRP preparations on healthy cells in vitro and in healthy animals in vivo have all been produced by poorly characterized CRP preparations, demonstrably caused by impurities, or elicited by CRP made in recombinant Escherichia coli not by humans. None of the in vitro or animal findings have been reproduced with pure natural human CRP. Nevertheless, the strong proinflammatory effects of infusing recombinant bacterial CRP into humans have still been inappropriately ascribed to CRP. OBJECTIVE: To investigate the effects of infusion into healthy adult human volunteers of pure natural human CRP. METHODS AND RESULTS: Comprehensively characterized, pharmaceutical-grade, endotoxin-free, purified CRP, prepared to GMP standard from pooled normal human donor plasma was infused as an intravenous bolus in 7 healthy adult human volunteers at ≤2 mg/kg to provide circulating CRP concentrations ≤44 mg/L. No recipient showed any significant clinical, hematologic, coagulation, or biochemical changes, or any increase in proinflammatory cytokines or acute phase proteins. CONCLUSIONS: The human CRP molecule itself is not proinflammatory in healthy human adults.

Isolation and characterization of pharmaceutical grade human pentraxins, serum amyloid P component and C-reactive protein, for clinical use.

The human pentraxin proteins, serum amyloid P component (SAP) and C-reactive protein (CRP) are important in routine clinical diagnosis, SAP for systemic amyloidosis and CRP for monitoring the non-specific acute phase response. They are also targets for novel therapies currently in development but their roles in health and disease are controversial. Thus, both for clinical use and to rigorously elucidate their functions, structurally and functionally intact, pharmaceutical grade preparations of the natural, authentic proteins are required. We report here the production from normal human donor plasma and the characterization of the first such preparations. Importantly, we demonstrate that, contrary to reports using recombinant proteins and less well characterized preparations, neither CRP nor SAP stimulate the release by human peripheral blood mononuclear cells in vitro of any TNFα, IL-6 or IL-8, nor does SAP cause release of IL-1ß or IL-10. Furthermore neither of our preparations was pro-inflammatory in mice in vivo.

Usefulness of whole body FDG18 PET-CT imaging in comprehensive oncologic management--initial experience.

AIMS: Retrospective analysis of outcome with PET-CT imaging used for various clinical situations. MATERIALS AND METHODS: Whole body PET-CT scan of 29 patients was evaluated. In first group, PET-CT was used for response evaluation after curative radio-chemotherapy. In second group, PET-CT was used as an additional diagnostic tool. In third group, PET-CT was used for delineating target volume. For first and second group, uptake was recorded with respect to primary, regional and distant site of involvement and confirmed through PET-CT guided biopsies whenever required. For third group, hypermetabolic volume delineated on PET image was compared with gross target volume delineated on CT image. RESULTS: In first group, 50 % (6/12) of the patients had distant systemic disease, 33% (4/12) had residual regional disease and 58% (7/12) had residual/recurrent local disease. In second group, 30% (3/10) patients had distant systemic disease on PET-CT where CT was inconclusive. 25% (4/10) had variable extent of disease involvement on PET-CT that changed the technique of radiotherapy treatment. In 20% (2/10) patients, PET-CT changed the sequence of treatment. In third group (n = 7), PET delineated volume was significantly higher (10-50%) than CT delineated volume for local site but for regional targets the difference was <10%. CONCLUSIONS: With the initial use of FDG18 PET-CT imaging, we realized that rate of distant metastasis is much higher which usually remain unnoticed because of conventional approach of investigation. PET-CT imaging has potential to improve the method of conventional IMRT planning.

Improved in vitro methods to predict the in vivo toxicity in man of therapeutic monoclonal antibodies including TGN1412.

TGN1412 is a "superagonistic" CD28 monoclonal antibody (IgG4) that caused serious adverse events at its first time in human clinical trial. In the present study, different in vitro methods for detecting and quantifying unwanted pro-inflammatory activity of therapeutic monoclonal antibodies (mAbs) such as TGN1412 are described. The antibody of interest is immobilised by wet-coating or air-drying onto polypropylene or polystyrene 96-well plates prior to the addition of human peripheral blood mononuclear cells (PBMCs). The cells are incubated for 16-24h with the immobilised antibody which allows the accumulation of pro-inflammatory cytokines, quantified by enzyme-linked immunoabsorbent assay (ELISA), in response to the antibody. Cytokine responses stimulated by TGN1412 immobilised by air-drying onto polypropylene and polystyrene plates were much larger than responses to TGN1412 wet-coated onto polypropylene and polystyrene plates, respectively. In additional experiments with other mAbs associated with clinical reactions, air-dried mAbs stimulated larger tumour necrosis factor-alpha (TNF) responses than antibodies added in aqueous phase. Also, TGN1412 air-dried onto plastic plates stimulated large proliferative responses of 3-day cultures of lymphocytes. It was concluded that immobilising mAbs by air-drying offers a useful in vitro method for detecting and quantifying pro-inflammatory activities of therapeutic mAbs.

Calcifying fibrous tumour: an unusual omental lesion.

Calcifying fibrous tumour (CFT) is a recently described distinct clinicopathological entity characterized by calcifying lesions usually occurring in soft tissue of the extremities, trunk, axilla, pleura, mediastinum and peritoneum of children and adults. Most reported cases involving the peritoneum have been in adults. We present the imaging, surgical and pathology findings of CFT in a 7-year-old child who presented with an incidental finding of a large omental mass.

"Cytokine storm" in the phase I trial of monoclonal antibody TGN1412: better understanding the causes to improve preclinical testing of immunotherapeutics.

The CD28-specific mAb TGN1412 rapidly caused a life-threatening "cytokine storm" in all six healthy volunteers in the Phase I clinical trial of this superagonist, signaling a failure of preclinical safety testing. We report novel in vitro procedures in which TGN1412, immobilized in various ways, is presented to human white blood cells in a manner that stimulates the striking release of cytokines and profound lymphocyte proliferation that occurred in vivo in humans. The novel procedures would have predicted the toxicity of this superagonist and are now being applied to emerging immunotherapeutics and to other therapeutics that have the potential to act upon the immune system. Data from these novel procedures, along with data from in vitro and in vivo studies in nonhuman primates, suggest that the dose of TGN1412 given to human volunteers was close to the maximum immunostimulatory dose and that TGN1412 is not a superagonist in nonhuman primates.

Attenuated fever in rats during late pregnancy is linked to suppressed interleukin-6 production after localized inflammation with turpentine.

An attenuated fever response to pathogens during late pregnancy is a phenomenon that has been described in several mammalian species, and although mechanisms are not completely understood, decreased prostaglandin E2 (PGE2) synthesis has been implicated. Upstream of PGE2, there is evidence to suggest that anti-inflammatory cytokines such as interleukin-1 receptor antagonist (IL-1ra) could play a significant role. In the present study we addressed the role of pro-inflammatory cytokines during late pregnancy, specifically interleukin-6 (IL-6), an important circulating mediator in fever. Turpentine oil (TURP), a very potent pyrogen and activator of IL-6, was injected into the hind-limb muscle of rats at the 18th day of pregnancy (GD 18) or in non-pregnant (NP) age-matched female controls. As expected, TURP injection induced a highly significant fever in the NP animals, which peaked 11 h post-injection and lasted for over 24 h. This was accompanied by a significant rise in circulating IL-6 levels, which correlated with changes in PGE2 synthesizing enzymes expression in the hypothalamus. In complete contrast, TURP-induced fever was totally absent in GD 18 animals whose body temperature did not deviate from basal values. The lack of response was additionally reflected by the absence of change in IL-6 concentration and by the significant attenuation of PGE2 synthesizing enzymes expression, which correlated with the suppressed expression of SOCS3, a hypothalamic marker of IL-6 activity. Contrary to the changes in circulating IL-6 levels at GD 18, IL-1ra was induced to levels comparable to those of NP females, suggesting that the influence of this anti-inflammatory cytokine on the fever response to TURP is at best minimal. These data further confirm the importance of IL-6 in fever generation and provide evidence that it may be a key component of the attenuated fever response in late pregnancy.

International validation of novel pyrogen tests based on human monocytoid cells.

It is a requirement that parenteral medicines be tested for pyrogens (fever causing agents) using one of two animal-based tests: the rabbit pyrogen test and the bacterial endotoxin test. Understanding the human fever reaction has led to novel non-animal alternative tests based on in vitro activation of human monocytoid cells in response to pyrogens. Using 13 prototypic drugs, clean or contaminated with pyrogens, we have validated blindly six novel pyrogen tests in ten laboratories. Compared with the rabbit test, the new tests have a lower limit of detection and are more accurate as well as cost and time efficient. In contrast to the bacterial endotoxin test, all tests are able to detect Gram-positive pyrogens. The validation process showed that at least four of the tests meet quality criteria for pyrogen detection. These validated in vitro pyrogen tests overcome several shortcomings of animal-based pyrogen tests. Our data suggest that animal testing could be completely replaced by these evidence-based pyrogen tests and highlight their potential to further improve drug safety.

Monocyte activation test for pro-inflammatory and pyrogenic contaminants of parenteral drugs: test design and data analysis.

An optimised test designed for an in vitro monocyte activation test for pro-inflammatory and pyrogenic contaminants of parenteral drugs is described, together with ways to address the inherent variability of such assays in which cells are cultured using 96-well plates. The test preparation is cultured with peripheral blood mononuclear cells (PBMNC) and the contaminants in the test article stimulate the release from the cells of the endogenous pyrogenic cytokine interleukin-6 (IL-6). The test system is in use within the pharmaceutical industry and at a national control authority for detecting pro-inflammatory and pyrogenic contaminants, including 'rabbit-negative' and 'LAL-negative' non-endotoxin pyrogens. Products tested include small molecules, biologicals and vaccines. The PBMNC/IL-6 monocyte activation test has been approved by the US FDA as an 'end-product release test' and also is being used for in-process testing.

A rapid 'one-plate' in vitro test for pyrogens.

A rapid, 'one-plate' monocyte-activation test is described for detecting endotoxin and non-endotoxin pyrogens in parenteral medicinal products. The one-plate test offers useful gains over conventional 'two-plate' (cell culture plate+ELISA plate) tests in terms of its limit of detection, robustness, speed and cost. The 'one-plate' test is likely to be applicable to a wide range of products because it allows less time for product interference in the test. The 'one-plate' test utilises pyrogen-free anti-cytokine (interleukin (IL)-6 or tumour necrosis factor alpha (TNFalpha)) antibodies (Ab), coated and stabilised onto (pyrogen-free) 96-well plates. Monocytes/monocytic cells, endotoxin (lipopolysaccharides, LPS) standard or sample and (pyrogen-free) second (labelled) Ab are cultured together (usually for 2-4 h) on the Ab-coated plate and then the plate is washed and the ELISA completed. There is no transfer from one plate to another and no (further) incubations of (released) cytokine with, first, coating Ab and, then, developing Ab since these steps have already taken place during the initial cell culture. The rapid, 'one-plate' test is readily automated. The preferred readout is IL-6, which gives a limit of detection of 0.015 endotoxin units (EU)/ml with peripheral blood mononuclear cell (PBMNC), 0.03 EU/ml with diluted whole blood and 0.05 EU/ml with a monocytic cell line (MONO MAC 6).