Engaging the Innate and Adaptive Antitumor Immune Response in Lymphoma

Immunotherapy has emerged as a powerful therapeutic strategy for many malignancies, including lymphoma. As in solid tumors, early clinical trials have revealed that immunotherapy is not equally efficacious across all lymphoma subtypes. For example, immune checkpoint inhibition has a higher overall response rate and leads to more durable outcomes in Hodgkin lymphomas compared to non-Hodgkin lymphomas. These observations, combined with a growing understanding of tumor biology, have implicated the tumor microenvironment as a major determinant of treatment response and prognosis. Interactions between lymphoma cells and their microenvironment facilitate several mechanisms that impair the antitumor immune response, including loss of major histocompatibility complexes, expression of immunosuppressive ligands, secretion of immunosuppressive cytokines, and the recruitment, expansion, and skewing of suppressive cell populations. Accordingly, treatments to overcome these barriers are being rapidly developed and translated into clinical trials. This review will discuss the mechanisms of immune evasion, current avenues for optimizing the antitumor immune response, clinical successes and failures of lymphoma immunotherapy, and outstanding hurdles that remain to be addressed.     

Binary Targeting of siRNA to Hematologic Cancer Cells In Vivo Using Layer‐by‐Layer Nanoparticles

Using siRNA therapeutics to treat hematologic malignancies has been unsuccessful because blood cancer cells exhibit remarkable resistance to standard transfection methods. Herein, the successful delivery of siRNA therapeutics with a dual‐targeted, layer‐by‐layer nanoparticle (LbL‐NP) is reported. The LbL‐NP protects siRNA from nucleases in the bloodstream by embedding it within polyelectrolyte layers that coat a polymeric core. The outermost layer consists of hyaluronic acid (a CD44‐ligand) covalently conjugated to CD20 antibodies. The CD20/CD44 dual‐targeting outer layer provides precise binding to blood cancer cells, followed by receptor‐mediated endocytosis of the LbL‐NP. This siRNA delivery platform is used to silence B‐cell lymphoma 2 (BCL‐2), a pro‐survival protein, in vitro and in vivo. The dual‐targeting approach significantly enhances internalization of BCL‐2 siRNA in lymphoma and leukemia cells, which leads to significant downregulation of BCL‐2 expression. Systemic administration of the dual‐targeted, siRNA‐loaded nanoparticle induces apoptosis and hampers proliferation of blood cancer cells, both in cell culture and in orthotopic non‐Hodgkin's lymphoma animal models. These results provide the basis for approaches to targeting blood‐borne cancers and other diseases and suggest that LbL nanoassemblies are a promising approach for delivering therapeutic siRNA to hematopoetic cell types that are known to evade transfection by other means.     

Functional humanization of an anti-CD30 Fab fragment for the immunotherapy of Hodgkin's lymphoma using an in vitro evolution approach

CD30, the so-called Reed-Sternberg antigen, constitutes a promising cell-specific target for the treatment of Hodgkin's lymphoma. Starting from the previously characterized cognate HRS3 mouse monoclonal antibody, the bacterially produced functional Fab fragment was humanized by grafting the CDRs from the mouse antibody framework on to human immunoglobulin consensus sequences. This procedure led to a 10-fold decreased antigen affinity, which surprisingly was found to be mainly due to the VH domain. To improve the antigen-binding activity, an in vitro evolution strategy was employed, wherein random mutations were introduced into the humanized VH domain by means of error-prone PCR, followed by a filter sandwich Escherichia coli colony screening assay for functional Fab fragments using a recombinant extracellular domain of the CD30 antigen. After three cycles of in vitro affinity maturation, the optimized Fab fragment huHRS3-VH-EP3/1 was identified, which carried four exchanged residues within or close to the VH CDRs and had an affinity that was almost identical with that of the murine HRS3 Fab fragment. The resulting humanized Fab fragment was fully functional with respect to CD30 binding both in ELISA with the recombinant antigen and in FACS experiments with CD30-positive L540CY cells. In the light of the previously successful clinical application of an alphaCD30 x alphaCD16 bispecific mouse quadroma antibody derived from HRS3, the humanized Fab fragment comprises an important step towards the construction of a fully recombinant therapeutic agent. The combination of random mutagenesis and colony filter screening assay that was successfully applied here should be generally useful as a method for the rapid functional optimization of humanized antibody fragments.     

淋巴瘤图像分类技术研究综述

淋巴瘤是源于淋巴造血系统的一类恶性肿瘤,基于医学影像及病理图像的精准诊断对临床治疗淋巴瘤具有重要价值。随着机器学习和深度学习技术的发展,利用人工智能技术对淋巴瘤图像分类已成为医学领域的研究热点之一。对淋巴瘤影像及病理图像分类技术的研究进展进行了系统总结与分析,并重点阐述了基于机器学习等新技术的图像分类方法与研究概况,对淋巴瘤图像分类的相关技术做了总结与展望。     

Molecular Characterization of a Rare Case of Bilateral Vitreoretinal T Cell Lymphoma through Vitreous Liquid Biopsy

Vitreoretinal lymphoma (VRL) is an uncommon eye malignancy, and VRLs of T cell origin are rare. They are difficult to treat, and their molecular underpinnings, including actionable genomic alterations, remain to be elucidated. At present, vitreous fluid liquid biopsies represent a valuable VRL sample for molecular analysis to study VRLs. In this study, we report the molecular diagnostic workup of a rare case of bilateral T cell VRL and characterize its genomic landscape, including identification of potentially targetable alterations. Using next-generation sequencing of vitreous-derived DNA with a pan-cancer 126-gene panel, we found a copy number gain of BRAF and copy number loss of tumor suppressor DNMT3A. To the best of our knowledge, this represents the first exploration of the T cell VRL cancer genome and supports vitreous liquid biopsy as a suitable approach for precision oncology treatments.     

Structure–Activity Relationship of Tumor‐Selective 5‐Substituted 2‐Amino‐3‐carboxymethylthiophene Derivatives

Methyl‐2‐amino‐5‐[2‐(4‐methoxyphenethyl)]thiophene‐3‐carboxylate ( 8 c ) is the prototype of a well‐defined class of tumor‐selective agents. Compound 8 c preferentially inhibited the proliferation of a number of tumor cell lines including many human T‐lymphoma/leukemia cells, but also several prostate, renal, central nervous system and liver tumor cell types. Instead, a broad variety of other tumor cell lines including B‐lymphomas and HeLa cells were not affected. The tumor selectivity (TS; selectivity index or preferential suppression of CEM lymphoma (IC₅₀=0.90 μM ) versus HeLa tumor cell carcinoma (IC₅₀=39 μM )) amounted up to ～43 for 8 c . At higher concentrations, the compound proved cytotoxic rather than cytostatic. The antiproliferative potency and selectivity of 8 c could be preserved by replacing the ethyl linker between the 2‐amino‐3‐carboxymethylthiophene and the substituted aryl by a thioalkyl but not by an oxyalkyl nor an aminoalkyl. Among >50 novel 8 c derivatives, the 5‐(4‐ethyl‐ and 4‐isopropylarylmethylthio)thiophene analogues, methyl‐2‐amino‐5‐((4‐ethylphenylthio)methyl)thiophene‐3‐carboxylate ( 13 m ) and methyl‐2‐amino‐5‐((4‐isopropylphenylthio)methyl)thiophene‐3‐carboxylate ( 13 n ), were more potent (IC₅₀: 0.3–0.4 μM ) and selective (TS: 100–144) anti‐T‐lymphoma/leukemia agents than the prototype compound.     

低剂量辐射抑制辐射诱发小鼠胸腺淋巴瘤的免疫学机制

为探讨低剂量辐射对高剂量辐射诱发小鼠胸腺淋巴瘤抑制作用的免疫学机制,采用４次１．７５ＧｙＸ射线全身照射Ｃ５７ＢＬ／６Ｊ小鼠诱发胸腺淋巴瘤模型,检测不同辐射剂量照后１个月小鼠脾脏ＮＫ细胞毒活性及其ＩＬ－２和γ－ＩＦＮ分泌活性,腹腔巨噬细胞吞噬功能及其ＴＮＦ－α分泌活性。结果显示每次１．７５Ｇｙ照射前１２ｈ接受７５ｍＧｙ照射小鼠,上述免疫功能均比单纯１．７５Ｇｙ照射组增强,且接近假照射组小鼠。提示低剂     

Antiproliferative Effects of St. John’s Wort,Its Derivatives,and Other Hypericum Species in Hematologic Malignancies

Hypericum is a widely present plant, and extracts of its leaves, flowers, and aerial elements have been employed for many years as therapeutic cures for depression, skin wounds, and respiratory and inflammatory disorders. Hypericum also displays an ample variety of other biological actions, such as hypotensive, analgesic, anti-infective, anti-oxidant, and spasmolytic abilities. However, recent investigations highlighted that this species could be advantageous for the cure of other pathological situations, such as trigeminal neuralgia, as well as in the treatment of cancer. This review focuses on the in vitro and in vivo antitumor effects of St. John’s Wort (Hypericum perforatum), its derivatives, and other Hypericum species in hematologic malignancies. Hypericum induces apoptosis in both myeloid and lymphoid cells. Other Hypericum targets include matrix metalloproteinase-2, vascular endothelial growth factor, and matrix metalloproteinase-9, which are mediators of cell migration and angiogenesis. Hypericum also downregulates the expression of proteins that are involved in the resistance of leukemia cells to chemotherapeutic agents. Finally, Hypericum and its derivatives appear to have photodynamic effects and are candidates for applications in tumor photodynamic therapy. Although the in vitro studies appear promising, controlled in vivo studies are necessary before we can hypothesize the introduction of Hypericum and its derivatives into clinical practice for the treatment of hematologic malignancies.