Functional T Cell Responses to Tumor Antigens in Breast Cancer Patients Have a Distinct Phenotype and Cytokine Signature

Abstract

The overall prevalence with which endogenous tumor Ags induce host T cell responses is unclear. Even when such responses are detected, they do not usually result in spontaneous remission of the cancer. We hypothesized that this might be associated with a predominant phenotype and/or cytokine profile of tumor-specific responses that is different from protective T cell responses to other chronic Ags, such as CMV. We detected significant T cell responses to CEA, HER-2/neu, and/or MAGE-A3 in 17 of 21 breast cancer patients naive to immunotherapy. The pattern of T cell cytokines produced in response to tumor-associated Ags (TAAs) in breast cancer patients was significantly different from that produced in response to CMV or influenza in the same patients. Specifically, there was a higher proportion of IL-2-producing CD8+ T cells, and a lower proportion of IFN-γ-producing CD4+ and/or CD8+ T cells responding to TAAs compared with CMV or influenza Ags. Finally, the phenotype of TAA-responsive CD8+ T cells in breast cancer patients was almost completely CD28+CD45RA− (memory phenotype). CMV-responsive CD8+ T cells in the same patients were broadly distributed among phenotypes, and contained a high proportion of terminal effector cells (CD27−CD28−CD45RA+) that were absent in the TAA responses. Taken together, these results suggest that TAA-responsive T cells are induced in breast cancer patients, but those T cells are phenotypically and functionally different from CMV- or influenza-responsive T cells. Immunotherapies directed against TAAs may need to alter these T cell signatures to be effective.

1086 IGHV1-69 as a Promising Candidate for the Development of a Shared Immunotherapy to B-cell Lymphomas

“…Figure 11 displays the adopted scheme of flow cytometric analysis, which was performed in the presence of α-CD4, α-CD19 and α-CD8 to define the specific binding of these new reagents. As shown in Table 4, the background signal in the HLA mismatched donors was generally very low, with the exception of pentamers SSN [105][106][107][108][109][110][111][112][113] (HLA-A*2402) and DSS [104][105][106][107][108][109][110][111][112] (HLA-B*3501) derived from the patient's IGHV1-69, where the observed positivity was mainly due to an unspecific binding to B cells. Interestingly, the specific positive signals were usually higher in samples obtained from patients (n=5) carrying IGHV1-69 + lymphoproliferation, than in HLA-matched healthy donors (n=6).…”

“…Drawbacks are mainly linked to the necessity to know exactly which peptide to use and which HLA background characterized each patient [5]. The lack of information about the functional state of T cells identified with this technique could instead be bypassed by the combination of tetramer staining with surface markers of T cell memory status or activation [105][106][107][108], or with the measurement of T cell proliferation in response to antigen re-exposure in vitro [5].…”

“…Interestingly, the specific positive signals were usually higher in samples obtained from patients (n=5) carrying IGHV1-69 + lymphoproliferation, than in HLA-matched healthy donors (n=6). In view of the noticeable un-specific binding of pentamers obtained from the CDR3 epitopes (SSN [105][106][107][108][109][110][111][112][113] , DSS [104][105][106][107][108][109][110][111][112] ) identified in the patient's IGHV1-69 sequence, we decided to focus further analyses only on the candidates identified in the IGHV1-69 optimized sequence.…”

“…Because of the different contribution of memory T cells subsets in mediating anti-tumor immune responses [105][106][107], the differentiation stage of pentamer + CD8 + T cells was investigated through the combined analysis of the chemokine receptor CCR7 and the CD45RA isoform, to distinguish CCR7…”

“…Drawbacks are mainly linked to the necessity to know exactly which peptide to use and which HLA background characterized each patient [5]. The lack of information about the functional state of T cells identified with this technique could instead be bypassed by the combination of tetramer staining with surface markers of T cell memory status or activation [105][106][107][108], or with the measurement of T cell proliferation in response to antigen re-exposure in vitro [5].In addition, combined with this approach, intracellular staining can simultaneously assess cell subtype and cytokine production and allow measurement of multiple cytokines within a single cell [5,109,110]. New evidence suggest that the quality of T cell responses, and especially the presence of multifunctional T cells, correlates with the disease outcome to various infections and with the induction of an effective anti-viral immune response after vaccination [111].…”