Cetuximab and panitumumab bind the human epidermal growth factor receptor (EGFR). Although the chimeric cetuximab (IgG1) triggers antibody‐dependent‐cellular‐cytotoxicity (ADCC) of EGFR positive target cells, panitumumab (a human IgG2) does not. The inability of panitumumab to trigger ADCC reflects the poor binding affinity of human IgG2 Fc for the FcγRIII (CD16) on natural killer (NK) cells. However, both human IgG1 and IgG2 bind the FcγRII (CD32A) to a similar extent. Our study compares the ability of T cells, engineered with a novel low‐affinity CD32A131R‐chimeric receptor (CR), and those engineered with the low‐affinity CD16158F‐CR T cells, in eliminating EGFR positive epithelial cancer cells (ECCs) in combination with cetuximab or panitumumab. After T‐cell transduction, the percentage of CD32A131R‐CR T cells was 74 ± 10%, whereas the percentage of CD16158F‐CR T cells was 46 ± 15%. Only CD32A131R‐CR T cells bound panitumumab. CD32A131R‐CR T cells combined with the mAb 8.26 (anti‐CD32) and CD16158F‐CR T cells combined with the mAb 3g8 (anti‐CD16) eliminated colorectal carcinoma (CRC), HCT116FcγR+ cells, in a reverse ADCC assay in vitro. Crosslinking of CD32A131R‐CR on T cells by cetuximab or panitumumab and CD16158F‐CR T cells by cetuximab induced elimination of triple negative breast cancer (TNBC) MDA‐MB‐468 cells, and the secretion of interferon gamma and tumor necrosis factor alpha. Neither cetuximab nor panitumumab induced Fcγ‐CR T antitumor activity against Kirsten rat sarcoma (KRAS)‐mutated HCT116, nonsmall‐cell‐lung‐cancer, A549 and TNBC, MDA‐MB‐231 cells. The ADCC of Fcγ‐CR T cells was associated with the overexpression of EGFR on ECCs. In conclusion, CD32A131R‐CR T cells are efficiently redirected by cetuximab or panitumumab against breast cancer cells overexpressing EGFR.

For many years, disappointing results have been generated by many investigations, which have utilized a variety of immunologic strategies to enhance the ability of a patient’s immune system to recognize and eliminate malignant cells. However, in recent years, immunotherapy has been used successfully for the treatment of hematologic and solid malignancies. The impressive clinical responses observed in many types of cancer have convinced even the most skeptical clinical oncologists that a patient’s immune system can recognize and reject his tumor if appropriate strategies are implemented. The success immunotherapy is due to the development of at least three therapeutic strategies. They include tumor-associated antigen (TAA)-specific monoclonal antibodies (mAbs), T cell checkpoint blockade, and TAA-specific chimeric antigen receptors (CARs) T cell-based immunotherapy. However, the full realization of the therapeutic potential of these approaches requires the development of strategies to counteract and overcome some limitations. They include off-target toxicity and mechanisms of cancer immune evasion, which obstacle the successful clinical application of mAbs and CAR T cell-based immunotherapies. Thus, we and others have developed the Fc gamma chimeric receptors (Fcγ-CRs)-based strategy. Like CARs, Fcγ-CRs are composed of an intracellular tail resulting from the fusion of a co-stimulatory molecule with the T cell receptor ζ chain. In contrast, the extracellular CAR single-chain variable fragment (scFv), which recognizes the targeted TAA, has been replaced with the extracellular portion of the FcγRIIIA (CD16). Fcγ-CR T cells have a few intriguing features. First, given in combination with mAbs, Fcγ-CR T cells mediate anticancer activity in vitro and in vivo by an antibody-mediated cellular cytotoxicity mechanism. Second, CD16-CR T cells can target multiple cancer types provided that TAA-specific mAbs with the appropriate specificity are available. Third, the off-target effect of CD16-CR T cells may be controlled by withdrawing the mAb administration. The goal of this manuscript was threefold. First, we review the current state-of-the-art of preclinical CD16-CR T cell technology. Second, we describe its in vitro and in vivo antitumor activity. Finally, we compare the advantages and limitations of the CD16-CR T cell technology with those of CAR T cell methodology.

Background: Epidermal hyperplasia represents a morphologic hallmark of psoriatic skin lesions. Langerhans cells (LCs) in the psoriatic epidermis engage with keratinocytes (KCs) in tight physical interactions; moreover, they induce T-cell-mediated immune responses critical to psoriasis. Objective: This study sought to improve the understanding of epidermal factors in psoriasis pathogenesis.Methods: BMP7-LCs versus TGF-b1-LCs were phenotypically characterized and their functional properties were analyzed using flow cytometry, cell kinetic studies, co-culture with CD4 T cells, and cytokine measurements. Furthermore, immunohistology of healthy and psoriatic skin was performed. Additionally, in vivo experiments with Jun f/f JunB f/f K5cre-ER T mice were carried out to assess the From a the

KRAS mutations hinder therapeutic efficacy of epidermal growth factor receptor (EGFR)‐specific monoclonal antibodies cetuximab and panitumumab‐based immunotherapy of EGFR+ cancers. Although cetuximab inhibits KRAS‐mutated cancer cell growth in vitro by natural killer (NK) cell‐mediated antibody‐dependent cellular cytotoxicity (ADCC), KRAS‐mutated colorectal carcinoma (CRC) cells escape NK cell immunosurveillance in vivo. To overcome this limitation, we used cetuximab and panitumumab to redirect Fcγ chimeric receptor (CR) T cells against KRAS‐mutated HCT116 colorectal cancer (CRC) cells. We compared four polymorphic Fcγ‐CR constructs including CD16158F‐CR, CD16158V‐CR, CD32131H‐CR, and CD32131R‐CR transduced into T cells by retroviral vectors. Percentages of transduced T cells expressing CD32131H‐CR (83.5 ± 9.5) and CD32131R‐CR (77.7 ± 13.2) were significantly higher than those expressing with CD16158F‐CR (30.3 ± 10.2) and CD16158V‐CR (51.7 ± 13.7) (p < 0.003). CD32131R‐CR T cells specifically bound soluble cetuximab and panitumumab. However, only CD16158V‐CR T cells released high levels of interferon gamma (IFNγ = 1,145.5 pg/ml ±16.5 pg/ml, p < 0.001) and tumor necrosis factor alpha (TNFα = 614 pg/ml ± 21 pg/ml, p < 0.001) upon incubation with cetuximab‐opsonized HCT116 cells. Moreover, only CD16158V‐CR T cells combined with cetuximab killed HCT116 cells and A549 KRAS‐mutated cells in vitro. CD16158V‐CR T cells also effectively controlled subcutaneous growth of HCT116 cells in CB17‐SCID mice in vivo. Thus, CD16158V‐CR T cells combined with cetuximab represent useful reagents to develop innovative EGFR+KRAS‐mutated CRC immunotherapies.

Background: Bone morphogenetic proteins (BMPs) are members of the TGF-b family that signal via the BMP receptor (BMPR) signaling cascade, distinct from canonical TGF-b signaling. BMP downstream signaling is strongly induced within epidermal keratinocytes in cutaneous psoriatic lesions, and BMP7 instructs monocytic cells to acquire characteristics of psoriasis-associated Langerhans dendritic cells (DCs). Regulatory T (Treg)-cell numbers strongly increase during psoriatic skin inflammation and were recently shown to limit psoriatic skin inflammation. However, the factors mediating Treg-cell accumulation in psoriatic skin currently remain unknown. Objective: We sought to investigate the role of BMP signaling in Treg-cell accumulation in psoriasis. Methods: The following methods were used: immunohistology of patients and healthy controls; ex vivo models of Treg-cell generation in the presence or absence of Langerhans cells; analysis of BMP versus canonical TGF-b signaling in DCs and Treg cells; and modeling of psoriatic skin inflammation in mice lacking the BMPR type 1a in CD11c 1 cells. Results: We here demonstrated a positive correlation between Treg-cell numbers and epidermal BMP7 expression in cutaneous psoriatic lesions and show that unlike Treg cells from healthy skin, a portion of inflammation-associated Treg cells exhibit constitutive-active BMP signaling. We further found