custom-conjugates

Knuplez E, Krier-Burris R, Cao Y, Marsche G, O’Sullivan J, Bochner BS (2020) Superior mouse eosinophil depletion in vivo targeting transgenic Siglec-8 instead of endogenous Siglec-F: Mechanisms and pitfalls. J Leukoc Biol 108:43-58. doi: 10.1002/jlb.3hi0120-381r

Objective: To determine if targeting Siglec-8 with mouse IgG1 antibodies, rather than targeting Siglec-F with rat IgG antibodies, in mice transgenic for Siglec-8, will prove to be a more effective strategy for eliminating mouse eosinophils in vivo.

Summary: This study is the first to describe a novel mouse strain of Siglec-8+F− eosinophils—a useful tool for studying human Siglec biology in preclinical models.

Usage: Siglec-8+F− mouse eosinophils were pretreated with 10 μg/mL saporin-conjugated isotype controls (mouse IgG1 or rat IgG2), anti-Siglec-8 (2C4) or anti-Siglec-F (9C7) antibodies for 24 h.

Related Products: Custom Conjugates

Qian L, Kasas L, Milne MR, Rawashdeh O, Marks N, Sharma A, Bellingham MC, Coulson EJ (2020) Cholinergic basal forebrain degeneration due to obstructive sleep apnoea increases Alzheimer’s pathology in mice. bioRxiv 2020.03.12.989848. doi: 10.1101/2020.03.12.989848

Usage: bilateral injections of urotensin II-saporin (UII-SAP; 0.07 μg/μL per site – unless stated otherwise; generous gift from Advanced Targeting Systems)

Related Products: Custom Conjugates, Blank-SAP (Cat. #IT-21)

Porter D, Moore A, Goodman R, Hileman S, Coolen L, Lehman M (2019) Cell-specific ablation of GnRH neurons using kisspeptin-saporin in the preoptic area of sheep, but not mice. J Endocrine Society 3(1):SAT–421. ENDO 2019 – 101st Annual Meeting of the Endocrine Society, New Orleans, Louisiana doi: 10.1210/js.2019-SAT-421

Objective: To invesigate the potential of integrin α10β1 as a therapeutic target in glioblastomas (GBMs).

Summary: Integrin α10β1 has a crucial role in the migration, proliferation, and survival of GBM cells and that an integrin α10β1 antibody–drug conjugate induced cell death of GBM cells both in vitro and in vivo.

Usage: Infusions of anti-10-SAP or Anti-ctrl-SAP were made icv (1 µg/2 L per infusion).

Related Products: Custom Conjugates

Thorén MM, Chmielarska Masoumi K, Krona C, Huang X, Kundu S, Schmidt L, Forsberg-Nilsson K, Floyd Keep M, Englund E, Nelander S, Holmqvist B, Lundgren-Åkerlund E (2019) Integrin α10, a novel therapeutic target in glioblastoma, regulates cell migration, proliferation, and survival. Cancers (Basel) 11(4):587. doi: 10.3390/cancers11040587 PMID: 31027305

Objective: To investigate the potential of integrin alpha10beta1 as a therapeutic target in glioblastomas (GBMs).

Summary: Integrin alpha10beta1 has a crucial role in the migration, proliferation, and survival of GBM cells and that an integrin alpha10beta1 antibody–drug conjugate induced cell death of GBM cells both in vitro and in vivo.

Usage: Infusions of anti- 10-SAP or Anti-ctrl-SAP were made icv (1 mcg/2 L per infusion).

Related Products: Custom Conjugates

Pang HW, Linares A, Couling L, Santollo J, Ancheta L, Daniels D, Speth RC (2019) Novel high molecular weight albumin-conjugated angiotensin II activates β-arrestin and G-protein pathways. Endocrine 66(2):349-359. doi: 10.1007/s12020-019-01930-z

Objective: To study the ability of a novel bovine serum albumin-angiotensin II (BSA-Ang II) conjugate to effect responses of the AT1 angiotensin II receptor subtype mediated by the G-protein-coupled and the beta-arrestin pathways.

Summary: BSA-Ang II and Ang II stimulated water appetite equivalently but BSA-Ang II stimulated saline appetite more than Ang II. Both BSA-Ang II and Ang II were considerably more potent at causing calcium mobilization than β-arrestin binding.

Usage: Angiotensin II (Ang II) was conjugated with bovine serum albumin and compared with Ang II for competition binding to AT1 receptors, to stimulate aldosterone release from adrenocortical cells, to promote beta-arrestin binding to AT1 receptors, to promote calcium mobilization, and stimulate drinking of water and saline by rats.

Related Products: Custom Conjugates

Goodman RL, Lopez JA, Bedenbaugh MN, Connors JM, Hardy SL, Hileman SM, Coolen LM, Lehman MN (2018) Evidence that the LH surge in ewes involves both neurokinin B-dependent and -independent actions of kisspeptin. Neuroscience 2018 Abstracts 773.20 / YY14. Society for Neuroscience, San Diego, CA.

Summary: It is generally recognized that kisspeptin plays a key role in induction of the LH surge in sheep and we have reported evidence that neurokinin B (NKB) does so as well. Specifically, disrupting NKB signaling in the retrochiasmatic area (RCh) using either an antagonist to its receptor, NK3R, or lesions of NK3R-containing neurons in the RCh with a saporin conjugate (NK3-SAP) reduced the amplitude of the estrogen-induced LH surge by 50%. Because a KISS1R antagonist (p271) also produced a 50% decrease in surge amplitude, we hypothesized that these two systems are organized in series with NKB actions in the RCh stimulating kisspeptin release. If this is the case, then the combination of NK3R lesions and a KISS1R antagonist should produce the same inhibition as either treatment alone. This experiment tested this prediction using a 2 x 2 design. Breeding season ewes were ovariectomized and immediately given an estradiol (E) implant sc and two progesterone implants (CIDRs) intravaginally that produced luteal phase levels of these steroids. Ewes then received bilateral injections of either NK3-SAP (n=6) or Blank-SAP (n=5) into the RCh. Three weeks later, an artificial follicular phase was produced by inserting four 3 cm long E implants 24 hrs after CIDR removal and either saline or p271 was infused into the lateral ventricle for 16-24 hrs after E implantation; LH was monitored every 2-4 hrs for two days. CIDRs were then reinserted and the protocol repeated in a cross-over design so that all ewes received saline and p271 treatment. In Blank-SAP ewes, p271 decreased the peak of the LH surge from 61.2 ± 7.6 to 27.4 ± 4.6 ng/mL and delayed it 8 hrs (from 26.5 ± 0.5 to 34.1 ± 1.2 hrs post E implantation). The NK3-SAP injections alone decreased the peak of the LH surge to 29.7 ± 10.7 ng/mL compared to Blank-SAP, but the peak was not further inhibited by p271 in these NK3-SAP-treated ewes (24.4 ± 1.4 ng/mL). However, p271 delayed the peak of the LH surge (from 28.8 ± 1.2 to 34.8 ± 2.1 hrs post E implantation) in the ewes injected with NK3-SAP. Based on these results, we propose that kisspeptin has two roles in the LH surge in ewes: it initiates the surge independent of NKB signaling in the RCh, and maintains LH secretion during the surge by a NKB-dependent system.

Related Products: NKB-SAP (Cat. #IT-63), Blank-SAP (Cat. #IT-21)

Cua S, Tan HL, Fong WJ, Chin A, Lau A, Ding V, Song Z, Yang Y, Choo A (2018) Targeting of embryonic annexin A2 expressed on ovarian and breast cancer by the novel monoclonal antibody 2448. Oncotarget 9:13206-13221. doi: 10.18632/oncotarget.24152

Objective: To develop mAbs to potentially target oncofetal antigens and be repurposed for antibody or antibody drug conjugate (ADC) therapy.

Summary: The novel IgG1, 2448, was shown to target a unique glycosylated surface epitope on ANXA2. As a possible therapeutic candidate for ovarian and breast cancer, 2448 demonstrated anti-tumor activity via two independent mechanisms of action.

Usage: Cells were seeded in 96-well plates at 1000 or 2000 cells/well. Primary antibody, 2448 or ch2448 (10 μg/mL) was pre-mixed with appropriate secondary saporin conjugate, Mab-ZAP or Hum-ZAP.  The most significant decreases in cell viability (20% to 60%) were observed against the epithelial IGROV1 and MCF7 cell lines.  ATS created a Custom ADC by direct conjugation of saporin to ch2448 (ch2448-SAP).  As a control, an isotype chimeric IgG was also conjugated to saporin (IgG-SAP). Compared to using secondary saporin conjugates, ch2448-SAP induced and increase of  20–30% cytotoxicity.)

Related Products: Mab-ZAP (Cat. #IT-04), Hum-ZAP (Cat. #IT-22), Custom Conjugates

Schiroli G, Ferrari S, Conway A, Jacob A, Capo V, Albano L, Plati T, Castiello M, Sanvito F, Gennery A, Bovolenta C, Palchaudhuri R, Scadden D, Holmes M, Villa A, Sitia G, Lombardo A, Genovese P, Naldini L (2017) Preclinical modeling highlights the therapeutic potential of hematopoietic stem cell gene editing for correction of SCID-X1. Sci Transl Med 9(411):eaan0820. doi: 10.1126/scitranslmed.aan0820

Objective: To study potential approaches to gene therapy in mouse models of severe combined immunodeficiency.

Summary: The threshold of IL2RG gene editing can be reached for safe and efficient correction of SCID-X1 established in a preclinical model in human long-term repopulating HSPCs.

Usage: Biotinylated Anti-CD45 was mixed equimolar to Streptavidin-ZAP and administered as a single dose which caused substantial depletion (~70%) of the HSPC compartments and milder depletion of the more mature cell populations.

Related Products: Streptavidin-ZAP (Cat. #IT-27), Anti-CD45.2-SAP (Cat. #IT-91)

Therapeutic Potential of Hematopoietic Stem Cell Gene Editing

O’Sullivan J, Carroll D, Cao Y, Salicru A, Bochner B (2018) Leveraging Siglec-8 endocytic mechanisms to kill human eosinophils and malignant mast cells. J Allergy Clin Immunol 141:1774-1785.e1777. doi: 10.1016/j.jaci.2017.06.028

Summary: Therapeutic payloads can be targeted selectively to eosinophils and malignant mast cells by exploiting this Siglec-8 endocytic pathway.

Usage: Eosinophil cell death was assessed with 2C4 mAb or isotype control (both at 2.5 μg/mL).

Related Products: Custom Conjugates

Sedlik C, Heitzmann A, Viel S, Ait Sarkouh R, Batisse C, Schmidt F, De La Rochere P, Amzallag N, Osinaga E, Oppezzo P, Pritsch O, Sastre-Garau X, Hubert P, Amigorena S, Piaggio E (2016) Effective antitumor therapy based on a novel antibody-drug conjugate targeting the Tn carbohydrate antigen. Oncoimmunology 5:e1171434. doi: 10.1080/2162402X.2016.1171434

Summary: Scientists wanted to study the potential of Chi-Tn, a monoclonal antibody against a glycol-peptidic tumor-associated antigen, as an anticancer antibody-drug conjugate. They demonstrated that Chi-Tn specifically targeted tumor cells in vivo, using flow cytometry and deconvolution microscopy to show that Chi-Tn is rapidly internalized. Chi-Tn-SAP (ATS Custom Services) effectively killed Tn-positive cells, but had no effect on Tn-negative cells. Saporin (Cat. #PR-01) was used as control. The cytotoxicity of the Chi-Tn-SAP correlated with the level of tumoral Tn expression.

Related Products: Saporin (Cat. #PR-01), Custom Conjugates