Anti-Human CD18 (ITGB2) (Clone IB4) – Purified in vivo GOLD^TM Functional Grade

Common in vivo applications of clone IB4 (Isolectin B4, Griffonia simplicifolia agglutinin) in mice primarily involve selective labeling and manipulation of non-peptidergic nociceptive neurons and endothelial cells, especially in contexts such as pain research and vascular biology.

Key in vivo applications include:

• Labeling Non-Peptidergic Nociceptors: IB4 is commonly used to identify and selectively target non-peptidergic, C-fiber sensory neurons in dorsal root ganglia (DRG), which are critical in pain pathways. In vivo, IB4 can be conjugated to molecules (e.g., antisense oligonucleotides) to deliver them selectively to these neuron populations, allowing for manipulation of protein expression within these cells. For example, IB4-conjugated streptavidin has been used for targeted knockdown of PKCε in IB4(+) neurons to investigate mechanisms of chronic pain and hyperalgesic priming.

• Histochemical Labeling of Endothelial Cells and Microvasculature: IB4 is routinely used in vivo to label vasculature, especially to visualize and study transformation of microvascular structures in the central nervous system (CNS) following injury (e.g., spinal cord injury, stroke). Intravascular administration of IB4 enables detailed mapping of neovascular profiles, assessment of vascular permeability, and characterization of endothelial glycoconjugate expression after CNS trauma or disease.

• Marking Activated Microglia and Pathologic Extracellular Matrix/Neuropil: In CNS injury models, IB4 histochemistry is used in tissue sections post-injury to identify activated microglia, pathologic extracellular matrix, and regions of degraded neural tissue, offering insights into neuroinflammatory processes accompanying trauma or disease.

• Applications in Developmental and Tumor Studies: Beyond the CNS, IB4 is applied in vivo for studying endothelial plasticity during development, chronic inflammation, and neovascularization in tumor models in mice, due to its affinity for specific vascular glycoconjugates.

Important distinctions:

• In mice, "clone IB4" typically refers to the plant-derived isolectin itself, not a monoclonal antibody clone. It acts as a lectin—binding terminal α-D-galactosyl residues on cell surfaces.
• There are also monoclonal antibodies referred to as IB4 that may target proteins (e.g., CD18), but these are not the typical IB4 lectin used in the applications described above and may differ in function and specificity.

In summary, IB4 is widely used in vivo in mice to selectively label, trace, and manipulate specific subpopulations of neurons and endothelial cells, especially in pain and neurovascular research.

Commonly used antibodies and proteins with IB4 (Isolectin B4) in the literature include markers for neuronal subtypes, ion channels, signaling proteins, and extracellular matrix components. These allow researchers to discriminate between distinct cell populations or elucidate molecular mechanisms in tissues where IB4 is used.

Frequently co-used antibodies or proteins:

• trkA (Tropomyosin receptor kinase A): Used extensively with IB4 to distinguish between peptidergic (trkA+) and non-peptidergic (IB4+) sensory neurons.
• Nav1.8 and Nav1.9 (Voltage-gated sodium channels): These markers identify specific subtypes of nociceptors; immunostaining for Nav1.8 and Nav1.9 is often performed on sections also stained for IB4.
• CGRP (Calcitonin Gene-Related Peptide): CGRP is a marker of peptidergic neurons, providing contrast to IB4 labeling of non-peptidergic neurons.
• CaMKIV, Pan-CaMKK, Pan-CaMKI, Pan-CaMKII (Calcium/calmodulin-dependent kinases): These signaling proteins may be examined alongside IB4 to characterize molecular phenotypes of neuron populations.
• Versican: An extracellular matrix glycoprotein shown to bind IB4, used in studies probing IB4 interactions with ECM components.
• PKCε (Protein kinase C epsilon): Targeted in functional studies using IB4-conjugates to knockdown proteins selectively in IB4+ nociceptors.
• Rab7 (a marker of vesicular trafficking): Expressed in IB4-binding sensory neurons; its antibody is also used in parallel for phenotyping.
• GAPDH (housekeeping protein control): Frequently included for normalization in western blotting with other targets in IB4+ neuron studies.

Contextual usage notes:

• IB4 is typically employed either as a direct conjugate (e.g., fluorescent IB4) or followed by anti-IB4 antibodies and secondary detection for anatomical or phenotypic classification.
• In studies on dorsal root ganglion (DRG) neurons, IB4 labeling is contrasted with peptidergic markers (trkA, CGRP) to parse neuron classes based on developmental and functional attributes.
• Use of ion channel antibodies (Nav1.8, Nav1.9) with IB4 enables molecular classification of sensory neurons relevant to pain signal transduction.
• In extracellular matrix research, IB4’s binding partner versican is identified with anti-versican antibodies to highlight IB4’s target in tissue sections.
• PKCε studies employ IB4 conjugates for targeted molecular manipulation, often validated by PKCε immunostaining.

Summary table:

These markers represent the most common antibodies or proteins employed with IB4 for immunostaining, classification, and functional experiments in neuroscience and cell biology literature.

Clone IB4 in scientific literature broadly refers to two distinct entities: 1) Isolectin B4 (IB4) used for labeling specific neuronal populations, and 2) the anti-CD18 monoclonal antibody, clone IB4 used for immunological studies. Below are the key findings associated with these IB4 citations, with a focus on their scientific uses and novel discoveries.

1. Isolectin B4 (IB4): Key Findings

• Neuronal Subpopulation Labeling: IB4 binds specifically to a subset of small-diameter sensory neurons (nociceptive C-fiber afferents) in the dorsal root ganglia (DRG), which are pivotal in pain research.
• Experimental Applications: IB4, often conjugated with streptavidin or fluorochromes, is used to selectively target and study these nociceptive C-fiber neurons, enabling precise manipulation and functional analysis of distinct sensory neuron populations.
• Molecular Features: IB4-binding neurons express specific molecular markers and signaling pathways distinct from non-IB4-binding populations. For example, a novel subtype expresses high levels of cytoplasmic CaMKIV, indicating functional heterogeneity among sensory nociceptors.
• Functional Studies: Techniques using IB4 facilitate the study of protein function and signal transduction in pain pathways by enabling the delivery of biotin-conjugated or IB4-linked reagents to defined neuronal subsets.
• Cell Selection Tool: IB4, when conjugated to saporin (a toxin), selectively eliminates α-Gal-positive cells (since IB4 binds the α-Gal epitope), which has been used to efficiently isolate α-Gal-negative porcine cell clones, especially relevant in xenotransplantation research.

2. Anti-CD18 Monoclonal Antibody, Clone IB4: Key Findings

• Cell Surface Marker Detection: The IB4 clone anti-CD18 antibody is widely used in immunology for identifying and characterizing CD18, an integrin expressed on leukocytes.
• Cardiac and Immune Implications: Studies using clone IB4 have explored roles of cardiac vagal activation and leukocyte trafficking, though detailed recent findings were not provided in the accessible search results.

3. Major Advances Enabled by IB4 Tools

• Isolation and Functional Study: Both forms of IB4 enable:
  • Isolation of specific cell subpopulations based on surface carbohydrates or integrins.
  • Precise targeting for depletion or detailed study of cellular function in immunology and neurobiology.
• Pain Mechanism Research: The ability to distinguish and manipulate IB4-positive sensory neurons has led to discoveries concerning mechanical and inflammatory pain mechanisms.

Summary Table: Key Applications and Findings

Most citations regarding clone IB4 concern the use of Isolectin B4 as a neuroscientific tool and as a cell selection molecule in biotechnology. Recent studies emphasize its power to isolate and manipulate subpopulations of neurons or non-human cells for research in pain, regeneration, and transplantation.

Dosing Regimens of Clone IB4 in Mouse Models: Current Evidence

Summary:
There is no direct evidence in the provided search results for the dosing regimen of clone IB4 (anti-CD18) in mouse models. The available data primarily detail dosing for other monoclonal antibodies, such as anti-CTLA-4 (clones 9H10 and 9D9), anti-CD4 (GK1.5), anti-CD8 (2.43), and anti-Gr-1 (RB6-8C5). No information is provided for IB4 specifically, nor is there literature cited regarding its in vivo use, administration route, schedule, or dose-response in different mouse models.

What Is Known About IB4

• IB4 is an anti-CD18 monoclonal antibody, primarily used to block the binding of ICAM-1 and ICAM-3 to LFA-1 in vitro, such as in FACS analysis of human cells.
• There is no indication in the search results of its in vivo use in mice, let alone variations in dosing regimens across different mouse models.

Reference Dosing Regimens for Other Monoclonal Antibodies

While not directly relevant to IB4, it is worth noting how dosing regimens for other monoclonal antibodies are commonly described in the literature:

• Dose ranges for immune-modulating antibodies (e.g., anti-CTLA-4, anti-CD4, anti-CD8) typically fall between 100–250 μg per mouse, administered intraperitoneally.
• Dosing schedules are often every 2–3 days or every 3 days, depending on the antibody and experimental objective.
• Model-specific adjustments may be necessary due to differences in tumor biology, immune status, or genetic background of the mice.

Conclusion

There is no published information in the provided search results about the dosing regimen of clone IB4 in mouse models. Researchers interested in using IB4 in vivo should consult primary research articles, product sheets, or directly contact the supplier for guidance on in vivo use, potential toxicity, and optimal dosing. Any in vivo use of IB4 should be carefully validated empirically, with close monitoring of animal welfare and experimental outcomes, as dosing regimens for monoclonal antibodies can vary significantly depending on the target, antibody isotype, and experimental model.