Neoantigens - the next frontier in precision immunotherapy for B-cell lymphoproliferative disorders.

Broad activation of host T-cell immunity by immune checkpoint blockade, has revolutionized the treatment of some but not all B-cell lymphoproliferative disorders (LPDs). The challenge for next generation immunotherapeutics, is to successfully induce anti-tumor specific T-cell immunity across a range of B-LPDs, without provoking immune-related adverse events. An emerging strategy is to target neoantigens. Neoantigens are immunogenic peptides, unique to malignant cells, that are presented to T-cells via human leukocyte antigens. Neoantigens most commonly arise from non-synonymous mutations but can also be derived from tumor specific alterations along the protein biosynthesis pathway. B-cell LPDs uniquely express a clonal B-cell receptor (BCR) idiotype, consisting of immunoglobulin genes that undergo recombination and somatic hypermutation. Notably, the BCR idiotype can also give rise to 'immunoglobulin neoantigens'. Here, we provide an overview of current strategies to identify and validate immunoglobulin and non-immunoglobulin neoantigens as well as summarizing studies investigating neoantigens within B-cell LPDs.

Intratumoral T cells have a differential impact on FDG-PET parameters in follicular lymphoma.

Data on the prognostic impact of pretherapy 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in follicular lymphoma (FL) is conflicting. The predictive utility of pretherapy total metabolic tumor volume (TMTV) and maximum standardized uptake value (SUVmax) on outcome appears to vary between regimens. Chemoimmunotherapies vary in the extent of T-cell depletion they induce. The role of intratumoral T cells on pretherapy FDG-PET parameters is undefined. We assessed pretherapy FDG-PET parameters and quantified intratumoral T cells by multiple methodologies. Low intratumoral T cells associated with approximately sixfold higher TMTV, and FL nodes from patients with high TMTV showed increased malignant B-cell infiltration and fewer clonally expanded intratumoral CD8+ and CD4+ T-follicular helper cells than those with low TMTV. However, fluorescently labeled glucose uptake was higher in CD4+ and CD8+ T cells than intratumoral B cells. In patients with FDG-PET performed prior to excisional biopsy, SUVmax within the subsequently excised node associated with T cells but not B cells. In summary, TMTV best reflects the malignant B-cell burden in FL, whereas intratumoral T cells influence SUVmax. This may contribute to the contradictory results between the prognostic role of different FDG-PET parameters, particularly between short- and long-term T-cell-depleting chemoimmunotherapeutic regimens. The impact of glucose uptake in intratumoral T cells should be considered when interpreting pretherapy FDG-PET in FL.

Isothermal Point Mutation Detection: Toward a First-Pass Screening Strategy for Multidrug-Resistant Tuberculosis.

Point mutations in DNA are useful biomarkers that can provide critical classification of disease for accurate diagnosis and to inform clinical decisions. Conventional approaches to detect point mutations are usually based on technologies such as real-time polymerase chain reaction (PCR) or DNA sequencing, which are typically slow and require expensive lab-based equipment. While rapid isothermal strategies such as recombinase polymerase amplification (RPA) have been proposed, they tend to suffer from poor specificity in discriminating point mutations. Herein, we describe a novel strategy that enabled exquisite point mutation discrimination with isothermal DNA amplification, using mismatched primers in conjunction with a two-round enrichment process. As a proof of concept, the method was applied to the rapid and specific identification of drug-resistant Mycobacterium tuberculosis using RPA under specific conditions. The assay requires just picogram levels of genomic DNA input, is sensitive and specific enough to detect 10% point mutation loading, and can discriminate between closely related mutant variants within 30 min. The assay was subsequently adapted onto a low-cost 3D-printed isothermal device with real-time analysis capabilities to demonstrate a potential point-of-care application. Finally, the generic applicability of the strategy was shown by detecting three other clinically important cancer-associated point mutations. We believe that our assay shows potential in a broad range of healthcare screening processes for detecting and categorizing disease phenotypes at the point of care, thus reducing unnecessary therapy and cost in these contexts.