Anti-Mouse Thy1.1 (CD90.1) [Clone 19E12] — Purified in vivo GOLD™ Functional Grade

The 19E12 clone is primarily used in in vivo mouse studies as a depletion antibody to eliminate specific cell populations expressing the Thy1.1 (CD90.1) surface marker.

Primary Applications

Cell Depletion StudiesThe 19E12 antibody is designed for in vivo T cell depletion experiments where researchers need to remove Thy1.1-expressing cells from living mice. This depletion capability works on both naturally occurring Thy1.1+ T cells and cells that have been genetically modified to express Thy1.1 through transgenic approaches.

Antitumor ResearchBeyond basic cell depletion, 19E12 has demonstrated antitumor activity in multiple mouse strain studies. It showed effectiveness in (B6 x AKR)F1 hybrid mice, AKR parental mice, and AKR/J mice that were inoculated with AKR SL2 tumor cells. The antitumor effects were enhanced when 19E12 was administered in combination with other monoclonal antibodies like rat antibody R17 208.

Depletion Mechanisms

The antibody achieves cell depletion through several biological pathways, including antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-dependent cellular phagocytosis (ADCP). These mechanisms work together to effectively eliminate target cells from the mouse system.

Research Applications

Adoptive Transfer StudiesIn complex immunological experiments, 19E12 is used to create specific cell populations for transfer studies. For example, researchers use it to separate CD4+ T cells into CD90.1-enriched and CD90.1-depleted populations, which can then be transferred into naïve mice to study different immune responses.

Bispecific Antibody DevelopmentThe clone has been utilized to create hybrid antibodies that can redirect T cell activity against Thy1.1-expressing tumor cells, enabling targeted tumor cell lysis in laboratory settings.

The 19E12 clone is particularly valuable because it targets the Thy1.1 allelic variant, which is found in specific mouse strains like AKR/J and PL, making it useful for strain-specific studies and experiments requiring precise cellular targeting.

Commonly used antibodies or proteins with 19E12 (anti-mouse Thy1.1/CD90.1) in the literature include several that target related mouse cell surface markers or are used for cell depletion, tracking, or hybrid applications.

Key co-used antibodies or proteins (as reported in the literature) include:

• Rat monoclonal antibody R17 208: 19E12 and R17 208 have been administered together to enhance antitumor activity in mouse models, specifically in the context of AKR SL2 cell tumor therapy.
• Other anti-mouse lineage markers: While not always listed by clone, studies using 19E12 frequently also use antibodies targeting CD90.2 (Thy1.2) to distinguish Thy1.1+ from Thy1.2+ mouse strains or cells, as well as general T-cell (e.g., anti-CD3, anti-CD4, anti-CD8) and B-cell (e.g., anti-B220) markers for flow cytometry or immunophenotyping.
• Bispecific hybrid antibodies: 19E12 has been engineered into bispecific molecules that redirect T cell cytotoxicity against Thy1.1-expressing targets. These constructs inherently pair 19E12 with antibodies (or fragments) targeting other specific cell surface or tumor antigens.
• Biotinylated 19E12 with streptavidin-tagged effectors: A biotinylated version of 19E12 has been used for tumor pretargeting strategies, where it enables the localization of proteins such as human tumor necrosis factor alpha (TNF-?) to mouse tumor sites.

Additionally, in multiparametric flow cytometry and depletion studies, 19E12 is often used in tandem with antibodies against:

• CD45 (pan-leukocyte marker)
• CD3 (T cell marker)
• CD4/CD8 (helper/cytotoxic T cell markers)
• CD90.2 (to distinguish mouse strain alleles)

These combinations allow for more precise immunological phenotyping or functional studies in murine models.

Summary table:

These antibodies and proteins are frequently used together in mouse immunology, cancer immunotherapy, and cell depletion studies, reflecting 19E12's central role in tracking or manipulating Thy1.1+ cells.

Key findings from scientific literature citing clone 19E12 focus on its specificity for mouse Thy1.1 (CD90.1) and its utility in immunological research, especially regarding cell targeting, depletion, and cancer studies.

• Specificity and Background: Clone 19E12 is a monoclonal antibody targeting mouse Thy1.1 (CD90.1), a GPI-linked surface protein involved in the immune and nervous systems. Thy1 has context-dependent effects, particularly in T cell activation and cell-cell interactions.

• Antitumor Activity: 19E12 has demonstrated efficacy in mediating cytotoxic responses against Thy1.1-expressing tumor cells in vitro and in mouse models. Its antitumor effects are enhanced when used in combination with other monoclonal antibodies (e.g., rat mAb R17 208) and have been observed in hybrid and parental AKR mice inoculated with leukemia cells.

• Bispecific and Pretargeting Applications: 19E12 has been employed to generate bispecific hybrid antibodies, which concentrate T cell activity against Thy1.1-positive tumor cells, increasing their lysis in vitro. It has also been biotinylated for use as a pretargeting agent, enhancing the local concentration and retention of therapeutic agents such as human tumor necrosis factor alpha at tumor sites in mice.

• Selective Depletion: This antibody is frequently used in vivo to deplete Thy1.1-expressing cells, both among natural T cell populations and in genetically engineered mice that express Thy1.1 as part of experimental protocols.

• Cloning Origin and Utility: Clone 19E12 was derived from immunized mice (129 strain) with allogeneic AKR SL3 leukemia cells and has high specificity in cytotoxicity assays, making it a standard tool for distinguishing between mouse strains carrying the Thy1.1 or Thy1.2 alleles.

In summary, core citations for clone 19E12 highlight its high specificity for Thy1.1, utility in cell depletion and targeting in vivo, and pivotal role in designing antibody-based research tools for tumor immunology and cell lineage tracking in murine models.

Dosing regimens for clone 19E12 (anti-mouse Thy1.1/CD90.1) can vary significantly depending on the mouse model, experimental objectives, and target cell populations. However, publicly available data on precise dosing schedules across different mouse strains is limited, with most published uses describing qualitative rather than quantitative regimen details.

Essential context:

• 19E12 has been employed in various mouse models, including (B6 x AKR)F1 hybrid mice, AKR parental mice, and AKR/J mice, often in experiments targeting Thy1.1-expressing tumors or depleting Thy1.1+ cells.
• The dosing regimen is typically tailored based on:
  • The purpose (e.g., cytotoxicity assays, antitumor activity, cell depletion).
  • The presence of Thy1.1-expressing cells (either endogenous or transgenically introduced).
  • Whether the antibody is administered alone or in combination (notably, antitumor effect is enhanced with co-administration of other antibodies, such as rat monoclonal R17 208).
• Route: Intravenous and intraperitoneal routes have both been described for in vivo antibody administration in related studies, but specific regimens for 19E12 are not detailed in the available sources.

Additional relevant information:

• 19E12 can be used for in vivo cell depletion of naturally occurring Thy1.1+ T cells or transgenically expressed Thy1.1+ cells; depletion protocols in mouse models commonly span several days to weeks, with multiple antibody doses, but 19E12-specific schedules are not stated.
• Specialized application protocols (e.g., use in tumor pretargeting or bispecific hybrid antibody generation) may require adjusted concentrations and dosing intervals tailored to maximize activity or targeting efficiency.
• General in vivo monoclonal antibody dosing guides for mice (including antibodies with similar purposes) recommend doses in the range of 100–250 ?g per mouse, administered intraperitoneally every 3–4 days for depletion or therapeutic effects. This may serve as a reference when designing 19E12 studies in the absence of explicit published dosing schedules.

In summary, while clone 19E12 dosing regimens are adapted to individual experimental settings and mouse strains, specific, standardized schedules are not well-documented in the current literature. Researchers typically base their regimens on standard in vivo antibody dosing practices for mice, purpose of use, and the requirement for cell depletion or tumor targeting.