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

Clone 19E12 is most commonly used in vivo in mice to deplete cells expressing the Thy1.1 (CD90.1) surface antigen, particularly for targeting and eliminating specific T cell populations in experimental models.

These are the primary in vivo applications:

• Selective depletion of Thy1.1+ cells: Researchers administer clone 19E12 intraperitoneally or intravenously to mice to eliminate Thy1.1-positive cells, such as certain T lymphocyte subsets, for immune cell population studies or to study the effects of specific T cell populations on disease outcomes.
• Experimental transplantation and immune response studies: 19E12 is used to remove Thy1.1+ donor or recipient T cells in models of cell transfer, transplantation, or graft-versus-host studies, enabling selective tracking or ablation of transferred cell populations distinguished by the Thy1.1 marker.
• Tumor immunology and antitumor activity: In cancer models, 19E12 has been used both to deplete Thy1.1+ T cells and, in some studies, as a component of bispecific or pretargeted therapies to enhance antitumor activity by focusing immune responses or delivering effector molecules to Thy1.1+ tumor cells.
• Functional and fate-mapping studies: By permitting the conditional removal or labeling of Thy1.1-expressing cells (either naturally expressing or engineered via transgenic approaches), clone 19E12 supports functional dissection of immune and stem cell populations in development, inflammation, and disease.

In summary, the most common in vivo application of clone 19E12 in mice is antibody-mediated depletion of Thy1.1+ cell populations, particularly for manipulating or studying T cells in immunological, transplantation, and tumor models.

Commonly used antibodies or proteins paired with 19E12 (anti-mouse Thy1.1/CD90.1) in the literature include those targeting CD45 (pan-leukocyte marker), CD3 (T cell marker), and CD4/CD8 (helper/cytotoxic T cell markers). These are used in multiparametric flow cytometry and depletion studies to identify and characterize lymphocyte subsets and other immune cell populations in mouse models.

Additional context and usage details include:

• 19E12 is most often used in flow cytometry and functional depletion experiments to distinguish Thy1.1-positive cells (usually AKR/J or PL mouse strains) from Thy1.2 populations.
• It is frequently combined with other lineage-specific antibodies such as anti-CD45 (to identify all leukocytes), anti-CD3 (for T cells), and anti-CD4/anti-CD8 (for T cell subset analysis and functional studies).
• In studies of adoptive cell transfer or lineage tracing, 19E12 can be used in conjunction with antibodies against congenic markers like CD45.1/CD45.2, or Thy1.2 to track transferred cell populations against the host background.
• For broader immunophenotyping panels, antibodies against markers such as B220 (B cells), Gr-1 (granulocytes), NK1.1 (NK cells), and others may be included, depending on the experimental context.

Summary table of common pairings:

Secondary antibodies (e.g., anti-rat IgG, anti-mouse IgG) conjugated to various fluorochromes are also routinely used for multicolor detection in flow cytometry and immunohistochemistry setups.

In summary, CD45, CD3, CD4, and CD8 antibodies are most commonly used together with 19E12 for immunophenotyping and functional studies of mouse immune cells. Additional markers may be added depending on the specific design and objectives of the experiment.

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

• Specificity and Function: Clone 19E12 is a monoclonal antibody that binds specifically to the mouse Thy1.1 alloantigen (also known as CD90.1), distinguishing it sharply from Thy1.2. This specificity is pivotal in studies requiring selective targeting and depletion of Thy1.1-expressing cells, either natively (as in certain mouse strains) or in engineered/experimental cell populations.
• Generation and Background: 19E12 was developed by immunizing mice with allogeneic AKR SL3 leukemia cells, followed by standard hybridoma technology, and it demonstrated strong cytotoxic activity against Thy1.1+ targets in vitro and in vivo.
• Applications in Research:
  • Cancer and Cell Depletion Studies: 19E12 exhibits antitumor activity in mouse models bearing Thy1.1+ tumors, especially when combined with other monoclonal antibodies. It has also been used experimentally to deplete Thy1.1+ T cells and other cell populations, aiding in immune cell subset characterization and in the study of graft-versus-host reactions or adoptive cell transfer experiments.
  • Bispecific Antibody Engineering: 19E12 has served as a component in engineered bispecific antibodies capable of directing T cells to lyse Thy1.1-expressing tumor cells, an approach relevant to immunotherapy research.
  • Tumor Pretargeting: Biotinylated 19E12 has been used to pretarget tumor sites, facilitating the concentration of therapeutic agents like tumor necrosis factor alpha (TNF-α) at the tumor site in experimental mouse models.
• Other Notable Findings:
  • Glycosylation and Isoform Biology: Thy1 is highly N-glycosylated, with variable glycan composition between tissues and during differentiation stages, adding complexity to cell surface marker studies using clone 19E12.
  • Immunological Context: While Thy1 deficiency does not critically impair immunity, its modulation can influence cancer progression, fibrotic disease phenotypes, and neuronal injury responses in mice.

No substantial findings link "clone 19E12" to resistance genes or systemic reviews outside of immunology and tumor biology, suggesting its principal relevance is as an experimental reagent in mouse model research and antibody engineering.

Dosing regimens for clone 19E12 (anti-mouse Thy1.1/CD90.1) are tailored to experimental objectives and can vary across mouse models according to strain, target cell population, and intended outcome such as T cell depletion, tumor targeting, or immunomodulation.

In published usage, clone 19E12 was originally generated for specificity to the Thy1.1 antigen in mouse strains like 129 and AKR—models where Thy1.1 is naturally expressed. In these models, 19E12 has been deployed to:

• Deplete Thy1.1+ T cells (naturally or transgenically expressed).
• Serve as an antitumor agent or as part of tumor pretargeting strategies.
• Enhance antitumor activity, sometimes in combination with other monoclonal antibodies such as rat mAb R17.

Key factors affecting dose and schedule:

• The background strain of mouse determines whether Thy1.1 is a native or introduced antigen, affecting both dosing and immunogenicity response.
• For T cell depletion or tumor cell targeting, the antibody is typically administered intraperitoneally at single or repeated doses, with regimens often ranging from 100–250 μg per mouse per dose (analogous to dosing for other monoclonal antibodies targeting T cell antigens), given every 3–4 days over 1–3 weeks.
• The number of doses and frequency may be increased if total cell depletion or sustained effect is desired, keeping in mind immune activation and tolerability, especially in immune-competent vs transgenic/tolerant strains.

Examples from literature:

• Antitumor activity studies in (B6 × AKR)F1, parental AKR, and AKR/J mice have used 19E12 with dosing adjusted based on tumor burden and experimental endpoint.
• Depletion protocols in both wild-type and transgenic mouse models may involve single high doses or repetitive dosing over days to weeks, depending on the degree and persistence of depletion needed.
• Bispecific and biotinylated forms of 19E12 used for pretargeting or delivery of effector molecules may require additional regimen optimization for pharmacokinetic compatibility.

General principles echoed for in vivo antibody dosing in murine models:

• Aggregate dose and dosing frequency influence immunogenicity (risk of anti-antibody responses), and should be optimized depending on study goals and mouse model background.
• Dosing regimens in mouse models typically do not directly translate to human therapeutic protocols due to differences in immune tolerance, genetic variability, and antibody clearance rates.

In sum, clone 19E12 dosing is adjusted for the mouse strain’s Thy1.1 expression, the immunological goal (depletion vs targeting), and the specific experimental design; regimens may range from single to multiple intraperitoneal injections, often at 100–250 μg per dose, generally given every few days, but are best optimized based on population, immune status, and intended outcome.