Anti-Mouse CD90 (Thy-1) (Clone M5/49.4.1) – Purified in vivo PLATINUM™ Functional Grade

The M5/49.4.1 clone, an anti-mouse CD90 (Thy-1) monoclonal antibody, is most commonly used in vivo in mice for depletion or blocking of CD90-positive cells, particularly T cells, to study immune, fibrotic, and neurodegenerative processes.

Key in vivo applications include:

• T cell depletion: M5/49.4.1 is a standard tool for effectively eliminating T cells in mice, as CD90 is a pan-T cell marker in this species. This allows researchers to assess the roles of T cells in various physiological and pathological contexts, such as immunity, tolerance, and tissue regeneration.
• Functional blockade of CD90: The antibody is used to block the function of CD90, enabling studies into cell signaling and cell-cell interactions that rely on this surface marker.
• Neurodegeneration and fibrosis studies: Because CD90 is also expressed on neurons and fibroblasts, the antibody can be used to examine these cell types in models of brain injury, neurodegenerative disease, or fibrotic tissue remodeling.
• Depletion of other CD90+ cells: In addition to T cells, CD90 depletion can target other populations, such as certain natural killer (NK) cells and progenitor cells, allowing researchers to dissect their contributions in vivo.

Supporting examples:

• NK cell depletion: In published experiments, M5/49.4.1 has been used to deplete NKR+ cells (a subset including some NK cells) to study their function in immune responses.
• General immunology research: Broadly, the clone is referenced by vendors and research consortia as a go-to reagent for the selective removal or study of CD90+ cells in mouse models of immune function and disease.

In summary, the primary in vivo applications of M5/49.4.1 in mice are for selective T cell depletion and functional studies targeting CD90+ cell populations, which are pivotal in immunology, fibrosis, and neurobiology research.

The M5/49.4.1 antibody, which targets CD90 (Thy-1), is commonly used in studies involving various cell types, including T cells and antigen-presenting cells. When used in combination with other antibodies or proteins, it can enhance the specificity and scope of research. Here are some commonly used antibodies or proteins that are often employed alongside M5/49.4.1:

1. Anti-CD3 Antibodies: Specifically, clone 145-2C11 is often used for T cell targeting, similar to M5/49.4.1, as it helps in the identification and manipulation of T cells in research settings.

2. Anti-CD4 and Anti-CD8 Antibodies: These antibodies are used to differentiate between CD4+ and CD8+ T cells, providing a more detailed understanding of T cell subsets and their functions.

3. Anti-CD45 Antibodies: CD45 is a pan-leukocyte marker that helps in identifying various immune cells, making it a useful tool when studying immune responses alongside CD90.

4. Cytokines and Chemokines: Proteins like IL-2, IL-4, and CCL2 are important for immune cell function and are often studied in conjunction with antibodies like M5/49.4.1 to understand the broader immune response.

5. Other Depletion Antibodies: In studies involving cell depletion, antibodies targeting other cell types, such as anti-CD19 for B cells, are used to manipulate specific immune cell populations.

These combinations allow researchers to explore a wide range of immunological processes and cell interactions, providing insights into immune system function and disease mechanisms.

Clone M5/49.4.1 is a rat monoclonal antibody (IgG2a, κ) that targets mouse Thy-1 (CD90), a highly conserved glycoprotein with significant roles in immune and nervous system function. The antibody was generated by immunizing (Lewis x BN) F1 rats with a secondary mixed lymphocyte culture consisting of C57BL/6 mouse anti-irradiated BN rat lymphoma, followed by fusion of spleen cells with NS-1 myeloma cells.

Target Protein Characteristics

Thy-1/CD90 is a GPI-anchored member of the immunoglobulin superfamily with a molecular weight of 25-35 kDa. The protein exhibits extensive N-glycosylation, with carbohydrate content comprising up to 40% of its molecular mass, and this glycosylation pattern varies between tissues and across different stages of cellular differentiation. Thy-1 exists in both membrane-bound and soluble forms, and in mice, it is encoded by two alleles (Thy1.1 and Thy1.2) that differ by a single amino acid at position 89.

Expression Pattern and Function

The antibody recognizes CD90 expressed on thymocytes, peripheral T cells, myoblasts, epidermal cells, and keratinocytes, making it a pan-T cell marker in mice. Thy1.1 serves as an alloantigen in AKR/J and PL mouse strains, while Thy1.2 is expressed by most other mouse strains.

Thy-1 plays context-dependent roles in cell adhesion, apoptosis, metastasis, inflammation, and fibrosis. It interacts with CD45 in signal transduction during lymphocyte proliferation. Although Thy-1 deficiency does not compromise immunity, its presence or absence modulates phenotypes in certain cancers, fibrotic diseases, and neuronal injury.

Experimental Applications

The M5/49.4.1 clone has been extensively utilized for T lymphocyte depletion in vivo. In experimental protocols, researchers have administered 250 µg of anti-Thy1 (including clone M5/49.4.1) to deplete NKR+ cells. The antibody has also been employed for cell isolation procedures, where cells are labeled with anti-CD90 (clone M5/49.4.1) for 15 minutes on ice, followed by incubation with magnetic beads for separation.

For flow cytometry applications, the recommended concentration is 2 µg/mL for 1×10⁵-5×10⁵ cells, with verified effectiveness on C57/BL6 mouse splenocytes. The antibody is also suitable for functional assays, immunoprecipitation, and flow cytometry analysis.

Dosing Regimens of Clone M5/49.4.1 in Mouse Models

Clone M5/49.4.1 is a widely used monoclonal antibody targeting mouse CD90 (Thy-1), principally employed for T-cell depletion and other immunological applications in murine models. Its dosing regimen can vary significantly depending on the experimental context, target population, mouse strain, and scientific objective.

Key Factors Influencing Dosing

• Application Type: Dosing differs between in vitro (e.g., depletion of T cells from splenocyte preparations) and in vivo (e.g., systemic T-cell depletion in live animals) use.
• Mouse Strain: Thy-1 exists as two alleles in mice (Thy1.1 and Thy1.2), with distinct strain-specific expression patterns. Most strains express Thy1.2, but AKR/J and PL strains express Thy1.1, which may influence antibody binding and efficacy.
• Target Population: The abundance and accessibility of Thy-1-positive cells (thymocytes, peripheral T cells, myoblasts, etc.) can vary, necessitating adjustments in dose and administration frequency.
• Experimental Design: The desired extent and duration of depletion, as well as the need to minimize off-target effects, guide dosing decisions.

Typical Dosing Practices

In Vitro Depletion:
A common in vitro protocol uses anti-Thy1 antibody (clone M5/49.4.1) at 50 µg/mL in combination with rabbit complement to deplete T cells from splenocyte preparations. This concentration is effective for selective removal of Thy-1+ cells in cell culture assays.

In Vivo Depletion:
For in vivo applications, there is no universally standardized dosing regimen due to the variability in experimental needs. Each investigator must optimize the dose, frequency, and route of administration (intraperitoneal, intravenous, etc.) based on preliminary titration experiments and the specific model. Published studies often withhold exact in vivo dosing details, focusing instead on methodological outcomes (e.g., effective depletion verified by flow cytometry).

• General Guidance: Most suppliers and method protocols recommend that investigators determine the optimal working dilution and administration schedule for their specific application, referring to lot-specific datasheets for updated information.
• Variability: Dosing can range widely—some protocols may use a single high dose, while others employ repeated lower doses over several days to achieve sustained depletion.

Summary Table

Conclusion

There is no one-size-fits-all dosing regimen for clone M5/49.4.1 across mouse models. In vitro, a concentration of 50 µg/mL is commonly used for T-cell depletion, whereas in vivo dosing must be tailored to the specific mouse strain, target population, and experimental objectives, with optimization guided by pilot studies and manufacturer recommendations. Always consult the most recent product datasheet and relevant literature for your model system.