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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 CD16 158F -CR, CD16 158V -CR, CD32 131H -CR, and CD32 131R -CR transduced into T cells by retroviral vectors. Percentages of transduced T cells expressing CD32 131H -CR (83.5 ± 9.5) and CD32 131R -CR (77.7 ± 13.2) were significantly higher than those expressing with CD16 158F -CR (30.3 ± 10.2) and CD16 158V -CR (51.7 ± 13.7) (p < 0.003). CD32 131R -CR T cells specifically bound soluble cetuximab and panitumumab. However, only CD16 158V -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 CD16 158V -CR T cells combined with cetuximab killed HCT116 cells and A549 KRAS-mutated cells in vitro. CD16 158V -CR T cells also effectively controlled subcutaneous growth of HCT116 cells in CB17-SCID mice in vivo. Thus, CD16 158V -CR T cells combined with cetuximab represent useful reagents to develop innovative EGFR+KRAS-mutated CRC immunotherapies., (© 2019 UICC.)

Increasing evidence suggests that HLA-DRB1 alleles reduce or increase the risk of developing ulcerative colitis-associated colorectal carcinoma (CRC) tumors. However, the role of HLA-DRB1 locus on the susceptibility to develop CRC tumor, in the absence of a history of inflammatory bowel diseases (IBDs), is unclear. The aim of our study was to determine whether HLA-DRB1 alleles are associated with IBD-independent CRC tumor. HLA-DRB1 allele polymorphisms were identified by sequence-based typing method in 53 CRC patients and 57 sex- and age-matched healthy Caucasian controls. Pearson's chi-squared analysis with Yate's correction or Fisher's exact test with Bonferroni's correction, as appropriate, were used to compare the allele frequency (AF) differences of HLA-DRB1 in patients and controls. A total of 29 HLA-DRB1 alleles were recognized. A detailed study of these alleles allowed to identify DRB1*13:01 and DRB1*11:01 alleles that were significantly associated with an increased and reduced risk to develop CRC tumor, respectively. AF of DRB1*13:01, in CRC patients, was significantly higher than that of healthy controls, even following Bonferroni's correction (p = 0.029). In contrast, the presence of the DRB1*11:01 allele was negatively associated with CRC tumor as evidenced by the significantly lower AF in CRC patients than that of healthy controls (p = 0.005). However, following Bonferroni's correction, the AF of DRB*11:01 lost its statistical significance. These results suggest that HLA-DRB1*13:01 allele could be a potential marker for predicting genetic susceptibility to CRC tumor. In contrast, the protective role of DRB1*11:01 remains unclear., (© 2014 UICC.)

The goal of this study was to determine the frequency of HLA class II antigen expression in colorectal carcinoma (CRC) tumors, its association with the clinical course of the disease, and the underlying mechanism(s). Two tissue microarrays constructed with 220 and 778 CRC tumors were stained with HLA-DR, DQ, and DP antigen-specific monoclonal antibody LGII-612.14, using the immunoperoxidase staining technique. The immunohistochemical staining results were correlated with the clinical course of the disease. The functional role of HLA class II antigens expressed on CRC cells was analyzed by investigating their in vitro interactions with immune cells. HLA class II antigens were expressed in about 25% of the 220 and 21% of the 778 tumors analyzed with an overall frequency of 23%. HLA class II antigens were detected in 19% of colorectal adenomas. Importantly, the percentage of stained cells and the staining intensity were significantly lower than those detected in CRC tumors. However, HLA class II antigen staining was weakly detected only in 5.4% of 37 normal mucosa tissues. HLA class II antigen expression was associated with a favorable clinical course of the disease. In vitro stimulation with interferon gamma (IFNγ) induced HLA class II antigen expression on two of the four CRC cell lines tested. HLA class II antigen expression on CRC cells triggered interleukin-1β (IL-1β) production by resting monocytes. HLA class II antigen expression in CRC tumors is a favorable prognostic marker. This association may reflect stimulation of IL-1β production by monocytes.