Anti-Mouse TIM-1 (CD365) [Clone RMT1-10] — Purified in vivo GOLD™ Functional Grade

Clone RMT1-10 is a rat monoclonal antibody specific for mouse TIM-1 (CD365), and its most common in vivo applications in mice include:

• Expansion and modulation of B1a cells: RMT1-10 has been used to selectively expand TIM-1^+ B1a cells in vivo, particularly in the peritoneal cavity, and to increase populations of IgM^+ and IL-10^+ B1a cells. This therapeutic expansion has demonstrated the ability to attenuate both the development and progression of atherosclerosis in models such as ApoE knockout mice fed a high-fat diet. The atheroprotective effects depend on the presence and activity of B1a cells.

• Attenuation of autoimmune and inflammatory diseases: RMT1-10 treatment in mice has been shown to reduce disease severity and delay onset in models of experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. This is attributed to the antibody’s ability to modulate immune cell responses, including inhibition of antigen-specific T cell proliferation and preferential promotion of Th2 responses.

• Inhibition of antigen-specific T cell responses: RMT1-10 can inhibit PLP139-151-specific T cell responses in vivo, suppressing T cell proliferation and cytokine production in models of autoimmunity.

• Promotion of allograft survival: In transplantation studies, RMT1-10 is used to block TIM-1 and has been shown to extend allograft survival, likely via immunomodulatory effects on T cell and B cell function.

Mechanism:
TIM-1 is a co-stimulatory molecule highly expressed on activated CD4^+ T cells and B1a cells. RMT1-10 acts as a blocking antibody, modulating immune tolerance, cytokine production, and promoting regulatory functions, often leading to disease amelioration in immune-mediated pathology.

Other Applications:RMT1-10 is also used in flow cytometry, functional assays, and experimental models of atopic diseases due to its role in T cell co-stimulation and immune regulation, but its principal and best-characterized use is in in vivo therapeutic modulation of immune responses in mouse models.

Other commonly used antibodies or proteins in the literature alongside RMT1-10 (anti-Tim-1) include control antibodies such as isotype controls (e.g., rat IgG2a) and alternative anti–Tim-1 clones (notably 3B3 and 3D10), as well as markers for immune cell phenotyping like CD19, CD5, CD1d, IgM, and cytokines such as IL-10, IFN-γ, and IL-17.

Key details:

• Isotype controls (e.g., rat IgG2a): Frequently used as negative controls to match nonspecific binding when studying RMT1-10 effects in cell cultures or in vivo.
• Other anti–Tim-1 clones:
  • 3B3 is another anti–Tim-1 monoclonal that is often directly compared to RMT1-10 due to their opposing effects on T cell proliferation and cytokine profiles.
  • 3D10 has been used to illustrate differential regulation of atherogenesis and T cell activation.
• CD19, CD5, and CD1d: Commonly used for the identification and quantification of B1a cells, regulatory B cells, and other B cell subsets by flow cytometry in studies using RMT1-10.
• IgM: Used to assess humoral (antibody) responses and specifically as a marker for B1a cell populations and their functional status after RMT1-10 treatment.
• Cytokines—IL-10, IFN-γ, IL-17, IL-4: Measured by ELISA or flow cytometry to characterize immune modulation caused by RMT1-10, particularly Th1/Th17 versus Th2/IL-10+ regulatory responses.
• Plasmatic and tissue markers: Sometimes, additional markers for T cells (e.g., CD4, CD8), dendritic cells, and monocytes are analyzed to determine the broader immunomodulatory effects of RMT1-10.

In summary, RMT1-10 is commonly used in concert with isotype controls, alternative anti–Tim-1 mAbs (such as 3B3), and a variety of immune cell surface and cytokine markers to dissect functional consequences in immune regulatory studies.

The key findings from scientific literature using clone RMT1-10, an anti-mouse TIM-1 monoclonal antibody, are:

• RMT1-10 blocks TIM-1 and selectively expands atheroprotective B1a cells, leading to significant attenuation of atherosclerosis development and progression in mouse models. This expansion is characterized by increases in peritoneal TIM-1^+^IgM^+^ B1a cells (up to 3-fold).
• Therapeutic implications: Antibody-mediated in vivo expansion of B1a cells presents a potential therapeutic strategy for treating atherosclerosis and related vascular diseases, such as heart attack and stroke.
• Immunomodulation: Blocking TIM-1 with RMT1-10 reduces T cell proliferation, inhibits interferon-gamma (IFN-γ) and interleukin-17 (IL-17) (typically pro-inflammatory), and induces Th2 cytokines (IL-4, IL-10), fostering a more regulatory immune environment.
• Promotion of regulatory B cells (Bregs): RMT1-10 increases TIM-1^+^ Bregs, which are associated with protection against ischemia-reperfusion injuries in organs such as the liver and heart, by limiting tissue inflammation and injury.
• Allograft survival: RMT1-10 improves corneal allograft survival, suggesting a broader role in modulating immune tolerance in transplantation settings.

The cited studies indicate that RMT1-10's effects are mediated through TIM-1-dependent mechanisms, as only TIM-1^+^ B1a/Breg cell populations expand, while TIM-1^- populations remain unchanged post-treatment. This highlights clone RMT1-10 as an important experimental tool for dissecting TIM-1 biology and for development of novel immunomodulatory therapies in mice.

Dosing regimens of clone RMT1-10 (anti-mouse Tim-1) vary considerably between mouse models and experimental goals, typically ranging from acute to prolonged administration, with dosing schedules adjusted for disease model and study phase.

Supporting details from various models:

• Cardiac Transplantation / Alloimmunity Models:

  • Dose: 0.5 mg (500 μg) intraperitoneally (i.p.) on the day of transplantation
  • Follow-up doses: 0.25 mg (250 μg) i.p. on days 2, 4, 6, 8, and 10 after transplantation
  • Purpose: Prolong allograft survival in fully MHC-mismatched heart transplantation models
  • Reference mouse strains used: B6 (C57BL/6), BALB/c, and others.

• Experimental Autoimmune Encephalomyelitis (EAE) Model:

  • Dose reported in vitro: 10 μg/ml used in culture
  • In vivo effect: Administration during disease induction phase (specific dosing schedule not fully detailed, but typically acute/short-term delivery to coincide with induction phase)
  • Purpose: Inhibit disease onset and severity.

• Atherosclerosis (ApoE-/-) Model:

  • Dose: Not precisely specified in μg/mouse, but described as "every other day for 8 weeks" during high-fat diet administration in ApoE knockout mice
  • Purpose: Chronic/prolonged intervention to modulate B1a cell populations and attenuate disease progression
  • Duration: Extended (8 weeks, every other day).

Administration Route:

• Most in vivo studies administer RMT1-10 intraperitoneally (i.p.), which is standard for monoclonal antibody studies in mice.

Frequency and Duration:

• Acute immune modulation (e.g., transplantation, EAE): Multiple doses over a short window (days to 2 weeks after induction or transplantation).
• Chronic disease modulation (e.g., atherosclerosis): Regular dosing (every other day) sustained over several weeks.

Model Comparison Table:

Key insight:
The dose and schedule for RMT1-10 is tailored to the disease model, acute for transplantation/autoimmune induction phases, and chronic for long-term inflammatory or metabolic disease. Doses typically range from 250–500 μg per injection, with the frequency and duration adjusted for the specific hypothesis and disease course. For precise studies, refer to published protocols within the model of interest, as variations do occur between experimental designs.