An HLA-Presented Fragment of Macrophage Migration Inhibitory Factor Is a Therapeutic Target for Invasive Breast Cancer

Abstract

This report describes a novel HLA/peptide complex with potential prognostic and therapeutic roles for invasive breast cancer. Macrophage migration inhibitory factor (MIF) mediates inflammation and immunity, and MIF overexpression is observed in breast cancer. We hypothesized that the HLA class I of cancerous breast epithelial cells would present MIF-derived peptides. Consistent with this hypothesis, the peptide FLSELTQQL (MIF19–27) was eluted from the HLA-A*0201 (HLA-A2) of breast cancer cell lines. We posited that if this MIF19–27/HLA-A2 complex was exclusively found in invasive breast cancer, it could be a useful prognostic indicator. To assess the presentation of MIF peptides by the HLA of various cells and tissues, mice were immunized with the MIF19–27/HLA-A2 complex. The resulting mAb (RL21A) stained invasive ductal carcinoma (IDC) but not ductal carcinoma in situ, fibroadenoma, or normal breast tissues. RL21A did not stain WBCs (total WBCs) or normal tissues from deceased HLA-A2 donors, substantiating the tumor-specific nature of this MIF/HLA complex. As this MIF/HLA complex appeared specific to the surface of IDC, RL21A was tested as an immunotherapeutic for breast cancer in vitro and in vivo. In vitro, RL21A killed the MDA-MB-231 cell line via complement and induction of apoptosis. In an in vivo orthotopic mouse model, administration of RL21A reduced MDA-MB-231 and BT-20 tumor burden by 5-fold and by >2-fold, respectively. In summary, HLA-presented MIF peptides show promise as prognostic cell surface indicators for IDC and as targets for immunotherapeutic intervention.

Novel Anti-inflammatory Activity of Epoxyazadiradione against Macrophage Migration Inhibitory Factor

“…The ethnopharmacological exploration and bioactivity testing of various neem compounds and extracts revealed its efficacy to prevent a wide variety of inflammatory disorders in infectious and non-infectious diseases (34, [37][38][39][40][41][42][43][44][45]. It is interesting to note that neem compounds show a beneficial effect in pathological conditions in which MIF-mediated pathologies are prevalent (6,10,11,14,16,17,21).…”

Detection of Human Leukocyte Antigen Biomarkers in Breast Cancer Utilizing Label-free Biosensor Technology

“…RL21A is specific for the FLSL/HLA monomer with little cross reactivity with other peptide/HLA complexes 3 . This specificity is recapitulated using the label-free bioassay system (Figure 4).…”

“…A representative set of experiments was performed using the well-characterized TCRm, RL21A, a murine IgG2a monoclonal antibody which specifically recognizes a peptide (MIF 19-27 or FLSL) within the context of the HLA-A*02:01 molecule 3 . The cognate peptide/HLA monomer, as well as irrelevant HLA monomer 15 , was used to demonstrate the described procedure.…”

“…However, the immune system exerts pressure which often promotes selection for viruses or tumor capable of evading an effective CTL response. T-cell receptor mimicking (TCRm) monoclonal antibodies (mAbs) which recognize specific peptide/HLA-A*02:01 complexes such as those derived from breast cancer associated proteins, macrophage migration inhibitory factor (MIF [19][20][21][22][23][24][25][26][27] ) 3 and NY-ESO-1 157-165 , enable detection and destruction of breast cancer cells in the absence of an effective anti-tumor CTL response 4,5 . This representative work is focused on the HLA-A*0201 molecule, which is expressed by up to 30% of the population.…”

TCR-like antibody drug conjugates mediate killing of tumor cells with low peptide/HLA targets

“…20,21 Interestingly, TCR-like antibodies engage their specific target and become internalized over a short period of time, 16,22 but we have not previously focused on the killing potential of TCR-like antibodies conjugated to toxins or small molecule drugs. To initially assess cytotoxicity, the TCR-like antibodies YLL-Ab and FLS-Ab (Supplementary Table 1) were indirectly labeled with the ribosomal inhibiting protein saporin (see Materials and Methods) and incubated alongside breast (MDA-MB-231 (Fig.…”