Panel Of Human Antibodies Research Articles

The identification of endometrial immune cell densities and clustering analysis in the mid-luteal phase as predictor for pregnancy outcomes after IVF-ET treatment

Changes in endometrial immune cell density has been reported to be associated with reproductive failure. The prognostic value of endometrial immune cell density measurement remains uncertain. We aimed to investigate the prognostic value of endometrial immune cells measurement on pregnancy outcome after IVF in women. In this prospective study, one hundred twenty-eight women underwent endometrial sampling in a natural cycle preceding single frozen-thawed embryo transfer (ET). Endometrial biopsy was obtained precisely 7 days after luteinizing hormone surge (LH + 7). Multiplex immunohistochemical method was employed to simultaneously stain the endometrium samples with a panel of human antibodies against CD56 for uterine natural killer (uNK) cells, CD3 and CD8 for T cell, CD3 for pan T cells and CD68 for macrophages. The density of the various immune cells and the clustering levels between them were measured. ET was performed at the blastocyst stage. Women who did not conceive had a significantly higher density of uNK cells and higher clustering level between uNK cells-and-macrophages than women who did conceive. In accordance, the prognostic value of uNK measurement on pregnancy outcome was significantly improved when combined with uNK-to-macrophage clustering analysis simultaneously. Taken together, our results suggested that uNK cells density and clustering level between uNK cells-and macrophages may be a promising predictor for successful implantation after IVF-ET.

Effects of transportation, relocation, and acclimation on phenotypes and functional characteristics of peripheral blood lymphocytes in rhesus monkeys (Macaca mulatta).

Nonhuman primates from domestic sources constitute a small, but critical, proportion of animals studied in research laboratories. Many of these nonhuman primates are raised at one facility and subsequently transported/relocated to another facility for research purposes. We examined the effects of transport, relocation, and acclimation on the phenotype and function of peripheral blood mononuclear cells (PBMCs) in a group of rhesus monkeys that were transported by road for approximately 21 hours from one facility to another. Using a panel of human antibodies and a set of standardized human immune assays, we evaluated the phenotype of lymphocyte subsets by flow, mitogen-specific immune responses of PBMCs in vitro, and levels of circulating cytokines and cortisol in plasma at various time points including immediately before transport, immediately upon arrival, and after approximately 30 days of acclimation. Analyses of blood samples revealed that CD3+ T-cell and CD20+ B-cell populations had decreased significantly immediately after relocation but had recovered within 30 days after arrival at the new facility. Similarly, circulating cortisol and cytokine levels in plasma were significantly higher immediately after relocation; and by the 30-day time point, these differences were no longer significant. However, immune assays of PBMCs indicated that mitogen-specific responses for proliferation, interferon γ (IFN-γ), and perforin were significantly higher after relocation and 30 days of acclimation. These findings have implications on the research participation of transported and relocated nonhuman primates in immunologic research studies, suggesting that 30 days is not sufficient to ensure return to baseline immune homeostasis. These data should be considered when planning research studies in order to minimize potential confounding factors associated with relocation and to maximize study validity.

Abstract 646: Structurally guided development of meditope-based antibody-drug conjugates

Abstract Meditopes are cyclic peptides that bind the Fab fragment noncovalently, in a novel and unique site, outside the paratope. This property can be utilized to harness cytotoxic payloads to an antibody in a site-specific and consistent manner. One of the originally described peptides, named cQFD, presents a moderate affinity for the humanized antibody cetuximab (KD = 0.43 uM). The binding site involves residues from the heavy as well as the light chain of the antibody, and from both sides of the variable-to-constant hinge of the Fab domain, with a predominance for residues of the variable region. A similar affinity of cQFD to trastuzumab was achieved by mutating thirteen specific residues of the antibody, all located in the variable (Fv) region of the Fab domain; Nine of which are located in the light chain (LC: V9, I10, R39, T40, N41, G42, S43, R45, I83, D85, A100), two in the heavy chain (HC: S40 and I89). We refer to those mutations as to the “meditope enabling”. Via a combined approach, we (i) looked into peptide modifications to increase meditope's affinity for the antibody, and (ii) evaluated the transferability of this approach onto a panel of human antibodies of therapeutic relevance. Based on X-ray crystallography analysis, antibody modeling—in the case of antibodies for which no structure is available—and guided docking, we suggested a number of modifications (point mutations and/or peptide extension) that were subsequently tested via surface plasmon resonance. The top meditope leads were conjugated to MMAE and DM1 and their binding was reassessed to a number of humanized/IgG1 antibodies-confirming that payload conjugation does not interfere with meditope binding and also that meditope enabling and binding does not interfere with antigen binding. Finally, the complexes between antibodies and meditope-drug conjugates were tested in vitro in a panel of tumor cell lines, to measure and rank the efficacy of those leads in our ADC pipeline for further development as novel oncology therapeutics. Citation Format: Michael M. Matho, Elisabeth M. Gardiner, Calin D. Dumitru. Structurally guided development of meditope-based antibody-drug conjugates. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 646. doi:10.1158/1538-7445.AM2015-646

Abstract LB-154: Generation of antagonistic anti-DDR1 monoclonal antibodies as a potential novel cancer therapeutic

Abstract Discoidin domain receptor 1 (DDR1) is a nonintegrin tyrosine kinase receptor for collagen implicated in diverse cellular roles, including cell adhesion, proliferation, and extracellular matrix remodeling. Multiple tumor types have been shown to overexpress DDR1, including lung, esophageal, breast, ovarian, and pediatric brain cancers, suggesting a potential role for DDR1 in tumor progression. Inhibition of DDR1 signaling may therefore represent a novel therapeutic approach for treating these cancers. Potential therapeutic molecules that modulate human DDR1 activity were identified by screening the AnaptysBio Evolvable Library (ABEL) of fully human germline antibodies. The initial ABEL screen used the soluble DDR-1 extra cellular domain, followed by secondary screening on cell-surface DDR-1. The resulting panel of human antibodies was affinity matured using SHM-XELTM which uses mammalian cell display of human IgG followed by in vitro somatic hypermutation (SHM) as described for a number of other antibodies (Bowers et al., 2014, Methods 65, 44-56). The matured antibodies bound specifically to DDR1 with high affinity (KD<1nM as measured by Biacore), and were able to functionally inhibit collagen triggered DDR1 signaling in multiple cell-based assays. The antibody panel shows selectivity for DDR1 over closely related molecules such as DDR2 and has other properties suitable for preclinical development, including cross-reactivity with the cynomolgus monkey DDR-1 ortholog and good biophysical properties. These antibodies are being further explored for their therapeutic efficacy in tumor types where DDR1 signaling plays a role in disease progression. Citation Format: H. Toni Jun, Brandon Hynes, John L. Macomber, Andrew Lassen, Larry Altobell, Josh MacLaren, David King, Robert A. Horlick. Generation of antagonistic anti-DDR1 monoclonal antibodies as a potential novel cancer therapeutic. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-154. doi:10.1158/1538-7445.AM2014-LB-154

Abstract LB-266: Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations

Abstract Among the most promising approaches in the treatment of cancer is the activation of antitumor immunity by blockade of immune checkpoints. These inhibitory immune checkpoints are crucial for maintaining self-tolerance in the normal immune system but can be co-opted in cancer to allow tumor escape from immune surveillance. Therapeutic validation has been provided using antibodies that inhibit the CTLA-4 and PD-1 signaling pathways, which have shown significant clinical activity. Interestingly, blockade of other T-cell inhibitory signaling molecules TIM-3 and LAG-3 has also been shown to be effective in mouse models of cancer. Potential therapeutic molecules that inhibit the negative signaling of TIM-3 or LAG-3 were identified by screening the AnaptysBio Evolvable Library (ABEL) of fully human germline antibodies. The initial ABEL screens used the soluble extra cellular domains (ECD) of either TIM-3 or LAG-3, followed by screening on cell-surface expressed antigens. The resulting panels of human antibodies were matured to high affinity and potency using SHM-XEL™ which uses mammalian cell display of human IgG followed by in vitro somatic hypermutation (SHM). We have explored the activity of these antibodies both as single agents as well as simultaneous blockade of multiple pathways in in vitro cell-based assays. Inhibition of each pathway in isolation demonstrated immune stimulatory activity as evidenced by increased secretion of IL-2 in a mixed lymphocyte reaction or an activated T-cell assay. Combination of an anti LAG-3 or an anti TIM-3 antibody with an anti-PD-1 inhibitory antibody could increase IL-2 secretion over that seen with blockade of a single checkpoint alone. The magnitude of this effect was donor cell dependent. These data are suggestive that combination immunotherapy towards these targets is worthy of clinical evaluation and may lead to increased efficacy. Citation Format: H. Toni Jun, Patricia A. McNeeley, Andrew Lassen, Brandon Hynes, Larry Altobell, Mark Chhoa, Jesus Olvera, Josh MacLaren, Minjee Do, Michael Brown, Jean da Silva Correia, David King. Generation of antagonistic anti-TIM-3 and anti-LAG-3 monoclonal antibodies for potential novel immunotherapy combinations. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-266. doi:10.1158/1538-7445.AM2014-LB-266