Anti-Mouse CD8 [Clone YTS-169] — Purified in vivo GOLD™ Functional Grade

The YTS-169 clone is extensively used in in vivo mouse studies as a depleting antibody to eliminate CD8+ T cells, making it a valuable research tool for studying immune function and disease models.

Primary Applications in Mouse Studies

CD8+ T Cell Depletion: YTS-169 exhibits depleting activity when administered in vivo, effectively removing CD8+ T lymphocytes from the mouse immune system. This depletion capability makes it particularly useful for researchers investigating the role of CD8+ T cells in various biological processes.

Cancer Research: The antibody has been utilized in tumor studies where CD8+ T cell depletion is combined with other therapeutic agents. Research has shown that this combination approach can demonstrate greater efficacy than single agents and strongly suppress tumor growth in vivo.

Autoimmune Disease Research: YTS-169 has potential applications in the treatment and study of autoimmune diseases, where modulating CD8+ T cell populations can provide insights into disease mechanisms.

Technical Specifications for In Vivo Use

Formulation: The antibody is available in specialized low-endotoxin formulations specifically designed for in vivo applications. It is supplied in phosphate-buffered saline (PBS) at pH 7.2 with 150 mM NaCl, without carrier proteins, potassium, or preservatives.

Purity and Quality: The antibody maintains greater than 95% purity as determined by SDS-PAGE and HPLC, ensuring consistent results in experimental studies.

Strain Compatibility and Binding Characteristics

A key advantage of YTS-169 over other anti-CD8 antibodies is its universal binding capability. Unlike the 2.43 antibody clone which only binds CD8? in Lyt2.2+ mouse strains, YTS-169 binds CD8? in all mouse strains. This broad compatibility makes it the preferred choice for studies involving different mouse genetic backgrounds.

The antibody recognizes the murine CD8 cell surface antigen expressed by a subset of T lymphocytes and acts as an antigen co-receptor that mediates efficient cell-to-cell interactions within the immune system. YTS-169 is classified as a rat IgG2b monoclonal antibody that was originally generated using CBA mouse thymocytes as the immunogen.

Based on the literature, YTS-169 antibody is commonly used alongside several other antibodies and proteins in research studies, particularly in immunological and vaccine research contexts.

Companion Antibodies

The 2.43 antibody appears most frequently with YTS-169 in comparative studies. Both antibodies bind to mouse CD8? (Lyt2), but they have different specificities - YTS-169 binds both Lyt2.1 and Lyt2.2 epitopes, while 2.43 is specific only for Lyt2.2. These antibodies are often used together in flow cytometry analyses and engineered antibody fragment studies, with both showing similar binding affinities (equilibrium constants of 33 nM for YTS-169 and 34 nM for 2.43).

Anti-CD4 antibodies are routinely used in combination with YTS-169 for T cell subset identification. Studies commonly employ phycoerythrin (PE)-conjugated anti-CD4 antibodies alongside FITC-conjugated YTS-169 or other CD8 antibodies to distinguish CD4+ and CD8+ T cell populations.

Related CD8-Targeting Proteins

The YTS156 antibody represents another member of this antibody family, though it has different specificity, targeting the Lyt3 epitope rather than Lyt2. This antibody is often included in comparative binding studies to demonstrate the specificity of YTS-169 and 2.43.

Recombinant soluble CD8?? (sCD8??) heterodimer fusion proteins are frequently used as target antigens in studies involving YTS-169. These engineered proteins, created by removing transmembrane domains and fusing CD8? and CD8? with ?-helical linkers, serve as purified antigens for binding affinity measurements and validation studies.

Vaccine Research Context

In malaria vaccine research, YTS-169 appears alongside chimeric recombinant proteins such as PyLPC (P. yoelii recombinant linear peptide chimera) and PyRMC (P. yoelii recombinant modular chimera). These proteins incorporate multiple T cell epitopes and are used in multistage vaccine approaches where immune response monitoring requires CD8+ T cell identification using antibodies like YTS-169.

The literature demonstrates that YTS-169 is most commonly paired with other CD8-specific antibodies for comparative studies, anti-CD4 antibodies for T cell subset analysis, and various recombinant proteins in vaccine and immunological research applications.

Clone YTS-169 is a widely cited rat monoclonal antibody targeting murine CD8?, and it has been fundamental in immunology for detecting, imaging, and depleting CD8+ T cells in mice. Key findings from scientific literature referencing YTS-169 include:

• Broad CD8? Isoform Reactivity: YTS-169 binds both CD8? isoforms, Lyt2.1 and Lyt2.2, making it applicable across all major mouse strains, in contrast to the 2.43 clone which is Lyt2.2-specific.
• Immuno-PET Imaging Innovations: YTS-169-derived antibody fragments, such as minibodies (Mb), have enabled high-contrast, rapid immuno-PET visualization of CD8+ lymphoid organs in vivo, with effective imaging achieved within 4 hours post-injection. The rapid clearance of these fragments from the blood improves imaging specificity by minimizing background signal, although abundant CD8 expression (antigen sink) makes tumor imaging more challenging.
• Functional Depletion in Immunological Studies: YTS-169 is routinely used for in vivo depletion of CD8+ T cells, allowing researchers to study the role of CD8+ cells in immune responses and disease models. For example, depleting CD8+ cells with YTS-169 abolishes memory in acquired immunity contexts, demonstrating its efficacy and specificity.
• Antibody Fragment Engineering: Variable regions of YTS-169 have been sequenced and engineered into different formats (minibodies, diabodies) to enhance their utility in molecular imaging and therapy. These fragments retain their antigen specificity as confirmed by flow cytometry and imaging data.
• Production and Purity: YTS-169 antibody and its derivatives can be produced at reasonably high yields (e.g., 8.9 mg/L for minibodies) and are available in low-endotoxin, high-purity formulations for sensitive in vivo applications.

In summary, clone YTS-169 is valued for its broad strain applicability, reliable CD8+ T cell targeting in both imaging and depletion experiments, and its role in the development of next-generation immuno-imaging agents. These properties make YTS-169 a reference standard in mouse CD8 immunology.

Dosing regimens for clone YTS-169 in mouse models vary depending on experimental goals, mouse strain, disease model, and desired degree and duration of CD8+ T cell depletion, but standardized dosing guidance is rarely published directly by vendors or in product datasheets. In contrast, other CD8 depleting clones such as 2.43 have more widely available regimen details for comparison.

Key details on dosing of YTS-169 from available sources:

• Product Information: Bio-Rad's technical sheet for clone YTS169.4 confirms it is commonly used for in vivo CD8+ T cell depletion in mice but does not provide explicit dosing regimens.
• Experimental Reports: In published mouse studies employing YTS-169 (sometimes also referenced as YTS169.4), typical in vivo doses range from 200–400?µg per mouse, administered intraperitoneally or intravenously, generally on a weekly or every 3-4 days schedule, depending on the duration of depletion needed or the experimental context (e.g., infectious disease, tumor immunology, transplantation). These parameters are broadly similar to those used for clone 2.43, though direct manufacturer guidelines for YTS-169 are lacking, so researchers usually reference protocols from the literature or pilot experiments.

Comparative reference:

• For other widely-used CD8 depleting clones such as 2.43, a typical regimen is 100–500?µg per mouse (commonly 250?µg), administered i.p. or i.v., every 3–7 days to maintain depletion.
• Clone YTS-169 is commonly selected for its robust efficacy in depleting CD8+ T cells in C57BL/6 and BALB/c mice, and the regimen is generally adapted to match that of clone 2.43 when literature-specific details for YTS-169 are missing.

Considerations for different mouse models:

• Disease model and strain: Some protocols report adjusting the YTS-169 dose upward within the 200–400?µg range for larger or more depletion-resistant strains, or for achieving longer-term deletion.
• Route of administration: Both i.p. and i.v. routes are utilized; i.p. is more common for convenience and consistent absorption in routine studies.
• Experimental design: For single-time point depletion, a higher dose may be used acutely; for chronic depletion, repeated lower doses at defined intervals (usually weekly) are preferred.

Summary Table: YTS-169 vs. 2.43 Dosing Regimens

Summary: The dosing regimen for clone YTS-169 in mouse models is typically 200–400?µg per mouse every 3–7 days by i.p. or i.v. injection, closely mirroring standard protocols for other anti-CD8 clones like 2.43, with adjustments according to strain, experimental goals, and duration of depletion required. It is recommended to consult published studies specific to the disease or model in question for optimal dosing, as direct vendor guidance is limited.