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

The clone 19E12 antibody is most commonly used in in vivo mouse applications for the depletion of Thy1.1 (CD90.1)-expressing cells, particularly to selectively eliminate T cell populations or other cells expressing this marker.

Key in vivo applications include:

• T Cell Depletion: 19E12 is routinely administered to mice to deplete Thy1.1+ T lymphocytes for immunological studies, transplantation experiments, or cellular reconstitution protocols.
• Tumor Immunology: In mouse tumor models (especially those using AKR or hybrid mice), 19E12 has demonstrated antitumor effects by targeting Thy1.1-expressing cells, and its activity can be enhanced when used with other antibodies.
• Transgenic Models: The antibody can deplete Thy1.1+ cells in mice engineered to express Thy1.1 transgenically, supporting studies on immune cell function and lineage tracing.
• Functional Cell Population Analysis: By eliminating Thy1.1+ populations, 19E12 allows researchers to investigate the role of these cells in immune responses, stem cell biology, and disease mechanisms.
• Flow Cytometry Controls and Cell Sorting: Although primarily intended for depletion, 19E12 is also used to identify and analyze Thy1.1+ cells ex vivo after in vivo treatment, helping characterize immune and stem cell subsets.
• Bispecific and Pretargeting Strategies: Modified forms of 19E12, such as biotinylated variants or bispecific constructs, have been applied to pretarget tumor cells or redirect immune activity in experimental therapies.

In summary, in vivo T cell depletion and removal of Thy1.1+ immune or stem cell populations are the most widely cited usages of clone 19E12 in mouse models, with additional roles in tumor research and advanced immunological techniques.

Commonly used antibodies or proteins in the literature alongside 19E12 (anti-mouse Thy1.1/CD90.1) include those that help identify, distinguish, or characterize immune cell populations and functional subsets. The most frequently paired antibodies are:

• CD45 (pan-leukocyte marker)
• CD3 (T cell marker)
• CD4/CD8 (helper and cytotoxic T cell markers)

These markers are used in multiparametric flow cytometry and depletion studies to further delineate immune populations or to isolate specific T cell subsets in mouse models.

Additional proteins and reagents that can be used:

• Secondary antibodies: For detection purposes, secondary antibodies conjugated to enzymes (e.g., HRP, alkaline phosphatase) or fluorophores (e.g., Alexa Fluor family) are often used when employing 19E12 in flow cytometry or immunohistochemistry techniques.
• Rat monoclonal antibody R17 208: Used in at least one study to enhance the antitumor activity when co-administered with 19E12.
• Human tumor necrosis factor alpha: 19E12 can be coupled or used as a pretargeting agent to localize cytokines or other effector proteins to Thy1.1+ cells in experimental models.
• Isotype controls and viability dyes: Often included in panels for proper gating and analysis in flow cytometry, even if not explicitly listed with 19E12.

In summary, 19E12 is commonly used with antibodies against CD45, CD3, CD4, and CD8 to dissect mouse T cell populations, and may be paired with cytokines or other antibodies (such as R17 208) in functional or in vivo studies. Secondary antibodies and appropriate controls are also integral to experimental workflows with 19E12.

Key Findings from Scientific Literature Citing Clone 19E12

Specificity and Target

• Clone 19E12 is a well-characterized monoclonal antibody with high specificity for mouse Thy1.1 (CD90.1), a glycoprotein linked to the immune and nervous systems.
• Thy1.1 is an alloantigen found in certain mouse strains (e.g., AKR/J, PL) and is distinguished from Thy1.2 by a single amino acid at position 89.
• The antibody does not recognize Thy1.2, making it a critical tool for strain-specific immunological research in mice.

Generation and Biological Activity

• Clone 19E12 was generated by immunizing 129 strain mice with allogeneic AKR SL3 leukemia cells, then fusing the resulting lymphocytes with BALB/c MOPC21 NSI/1 myeloma cells.
• It has demonstrated cytotoxic activity against Thy1.1-expressing cells in in vitro assays and has shown antitumor activity in mouse models, particularly enhancing tumor suppression when used in combination with other monoclonal antibodies (e.g., rat monoclonal antibody R17 208).
• 19E12 has been engineered into bispecific antibodies to redirect T cell activity specifically against Thy1.1-expressing tumor cells, enabling targeted tumor cell lysis in vitro.

Applications in Research

• The antibody is used for cell depletion studies, allowing researchers to selectively remove Thy1.1-expressing cells, including both naturally occurring and transgenic populations.
• 19E12 has also been employed as a pretargeting agent (e.g., biotinylated form) to increase the concentration and persistence of therapeutic molecules like tumor necrosis factor alpha at tumor sites.
• Its utility extends to studies of tumor biology, immune cell interactions, and the modulation of phenotypes in cancers, fibrotic diseases, and neuronal injury.

Summary Table: Key Applications and Properties

Conclusion

Clone 19E12 is a foundational tool in mouse immunology, particularly for studies requiring precise targeting or depletion of Thy1.1-expressing cells. Its applications span basic research, therapeutic development, and mechanistic studies in cancer and immunology, underpinned by its strict specificity and versatile functional capabilities.

Dosing regimens of clone 19E12 (anti-mouse Thy1.1/CD90.1) can vary depending on the experimental purpose and the specific mouse model used, but detailed, standardized regimen data across different models is not comprehensively summarized in the available literature. The main variables that affect dosing include the mouse strain, the expression of the Thy1.1 antigen, and the experimental endpoint (depletion, targeting, or pretargeting).

Key context and supporting details:

• Clone 19E12 has been used to deplete Thy1.1-expressing cells in models hosting naturally Thy1.1-positive T cells or in engineered models expressing Thy1.1, such as certain transgenic lines. The antibody is commonly used for:

  • Depletion of Thy1.1+ T cells (e.g., in congenic marker studies)
  • Targeting Thy1.1-expressing tumor cells in syngeneic or hybrid mouse backgrounds

• Typical dosing regimens (by analogy with other depleting or targeting antibodies used in vivo):

  • Published sources and antibody datasheets often recommend intraperitoneal injections of 100–250 μg per mouse per dose, typically administered 1–3 times per week.
  • As with other cell-depleting antibodies (e.g., GK1.5 for CD4+ T cells), the exact dosing for 19E12 may be tailored according to the level of Thy1.1 antigen expression, the mouse model, and the desired duration or completeness of depletion.
  • No reference specifies a universally recognized 19E12 regimen for all mouse models, and regimens are often empirically optimized in individual studies.

• Applications and model differences:

  • Strain selection: Mouse strains such as AKR, (B6 × AKR)F1 hybrids, and transgenics carrying Thy1.1 will have different baseline levels of the target antigen, possibly requiring dosing adjustments.
  • Tumor models: Enhanced antitumor effect has been reported when 19E12 is combined with other antibodies (e.g., R17-208); combination therapies might involve different dosing intervals.
  • Bispecific and pretargeting strategies: Dosing for these advanced applications may differ, typically requiring optimization for pharmacokinetics and therapeutic effect in the specific mouse model.

• Important considerations:

  • Because dosing may be affected by mouse size and immune status, pilot studies with titration and flow cytometric confirmation of depletion are often performed to find the optimal regimen.
  • For exact details in a given context (e.g., dosing in transgenic C57BL/6-Thy1.1 vs. AKR/J parental line), consulting primary research articles or the product datasheet for the specific supplier and application is recommended.

• Supporting datasheets and resources: Vendors like Bio X Cell and Leinco provide technical support and may offer recommended starting doses for their in vivo functional-grade 19E12, but these may need adjustment depending on the experimental protocol.

In summary, dosing regimens of clone 19E12 can range from 100–250 μg per mouse per injection, typically given intraperitoneally one to three times per week, but must be empirically optimized in each specific mouse model and experimental context. There is no single, universally applied regimen for all uses or mouse strains.