Anti-Mouse IFNγ [Clone H22] — Purified in vivo GOLD™ Functional Grade

Clone H22 in mice has two distinct and common in vivo applications:

• As a murine hepatoma cell line (H22) to establish liver cancer mouse models for oncology and immunotherapy research.
• As a monoclonal antibody (H22) that neutralizes mouse interferon-gamma (IFN-γ) to study immunological pathways or block IFN-γ activity in models of infection, autoimmunity, and tumor immunity.

Essential details and context:

1. H22 Murine Hepatoma Cell Line:

• H22 cells are injected into mice (commonly BALB/c strain) either intraperitoneally or subcutaneously to induce liver tumors or malignant ascites.
• These models are widely used to:
  • Evaluate anti-tumor agents (e.g., chemotherapeutics, natural products like Brucea javanica oil, immunotherapies).
  • Study tumor-associated immune responses and microenvironment.
  • Test cancer vaccines and anti-angiogenic therapies using DNA vaccines or other experimental approaches.
• Outcome measures often include tumor growth inhibition, survival, cytokine levels, immune cell infiltration, and organ indices.

2. Clone H22 Monoclonal Antibody (Anti-IFN-γ):

• Anti-mouse IFN-γ H22 antibody is injected in vivo to neutralize or block interferon-gamma signaling.
• Common applications:
  • Mechanistic studies of IFN-γ in infection, cancer, and autoimmune diseases.
  • Modulation of immune responses, such as suppressing Th1-type inflammation or preventing IFN-γ-driven pathology.
  • Assessment of therapeutic strategies involving cytokine signaling manipulation.
• Can be administered for functional assays, neutralization, immunoprecipitation, immunofluorescence, and ELISA.
• Specificity: H22 mAb targets mouse IFN-γ and does not cross-react with human IFN-γ or mouse IFN-α/β/IL-6.

Summary Table:

Notes:

• "H22" refers to either the cell line or the antibody depending on experimental context—clarification is essential.
• Both uses are widespread, so consult primary research protocols for dosing and specific design.

If you need detail on a specific application (e.g., dosing, protocol, or disease model), please specify the context (cell line or antibody).

Commonly Used Antibodies and Proteins Used with H22 in the Literature

The term "H22" appears in several distinct scientific contexts, so it is crucial to clarify whether the user is referring to the H22 clone as a monoclonal antibody (e.g., anti-IFNγ, anti-CD64), the H22 hepatocellular carcinoma cell line, or another context. Here, we focus on the H22 antibody context, especially as related to CD64 (FcγRI) and IFNγ.

H22 as an Anti-CD64 (FcγRI) Antibody

When H22 is used as an antibody (either the original murine mAb22, its humanized version H22, or the single-chain fragment H22(scFv)), it specifically targets CD64 (FcγRI), the high-affinity IgG receptor. In research and applications involving H22, several other antibodies and proteins are commonly referenced:

• Anti-TNF monoclonal antibodies (e.g., infliximab, adalimumab): These are frequently discussed in the context of H22 because H22(scFv) blocks CD64-mediated capture of anti-TNF mAbs, thus inhibiting their uptake by immune cells and potentially their inflammatory side effects. This interaction is of particular interest in chronic inflammatory diseases.
• Detection antibodies: Such as anti-His tag antibodies or anti-TNF detection antibodies, used alongside H22 in experimental setups.
• Cell surface markers: General markers for immune cell subsets, often used to identify and isolate cells expressing CD64 for functional studies.
• Fusion constructs: Including recombinant proteins such as 9R (a cell-penetrating peptide) or toxin fusions, which can be paired with H22(scFv) to create targeted therapeutics.
• Anti-mouse CD64 (clone 10.1): Used in competition assays to demonstrate specific CD64 blocking by H22(scFv).
• Bispecific antibodies: The F(ab') fragment of H22 (anti-CD64) has been chemically crosslinked with mAb 520C9 (anti-HER2/neu) to create the bispecific antibody MDX-H210, which was tested in clinical trials for cancer immunotherapy.

H22 as an Anti-IFNγ Antibody

When H22 refers to the anti-mouse IFNγ monoclonal antibody, its typical uses are in immunoassays (e.g., ELISA), immunofluorescence, and immunoprecipitation to detect or neutralize mouse interferon-gamma. In these contexts, it is used alongside:

• Complementary detection antibodies (e.g., biotinylated or enzyme-conjugated secondary antibodies) for signal amplification in ELISA.
• Standard control proteins such as recombinant IFNγ for assay validation.
• General immunoprecipitation reagents (e.g., Protein A/G beads, secondary antibodies for western blotting).

Summary Table

Key Point:
Always clarify the context when referring to "H22." In immunology and antibody research, H22 most commonly refers to anti-CD64 or anti-IFNγ antibodies, each paired with distinct sets of proteins and detection reagents depending on the experimental goal.

If you have a specific experimental or therapeutic context, please specify, and a more targeted summary can be provided.

Key findings from clone H22 in scientific literature span multiple distinct biological contexts, each with important applications in research and potential therapeutic development.

H22 Hepatoma Cell Line

The murine H22 hepatocellular carcinoma cell line serves as a widely-used experimental model in cancer research. This ascites hepatoma model has been instrumental in studying tumor biology, particularly regarding metastatic potential. Research has demonstrated that nm23 mRNA expression levels correlate with the metastatic capacity of H22 clones, suggesting this molecular marker may be associated with tumor spread.

The H22 cell line has proven valuable for evaluating anti-cancer therapeutics and immunotherapy approaches. Studies have utilized H22 tumors to test DNA vaccines targeting VEGFR-2 (flk-1 domains 1–3), which successfully induced immune responses capable of blocking tumor growth by inhibiting angiogenesis. This demonstrates the utility of the H22 model for immunotherapy research and preclinical validation of novel treatment strategies.

H22 Anti-IFNγ Monoclonal Antibody

In immunology research, clone H22 refers to a monoclonal antibody that specifically targets mouse interferon-gamma (IFNγ). This antibody has become an essential tool for studying immune responses and inflammatory processes. IFNγ plays critical roles in antiviral activity, tumor antiproliferative effects, induction of class I and II MHC molecules, and macrophage activation.

The H22 antibody clone is frequently employed in functional studies to neutralize IFNγ activity in vivo and in vitro, enabling researchers to dissect the specific contributions of this cytokine to various immunological phenomena. Its purified format makes it suitable for demanding experimental applications requiring high specificity and minimal cross-reactivity.

H22(scFv) CD64-Blocking Fragment

A distinct application involves H22(scFv), a recombinant single-chain variable fragment derived from the original murine mAb22, later humanized to full-length mAb H22. This engineered antibody fragment selectively binds and blocks CD64 (FcγRI), preventing the receptor from capturing therapeutic antibodies like anti-TNF monoclonal antibodies.

Research has revealed several advantageous properties of H22(scFv). It binds an epitope on CD64 outside the Fcγ domain binding site, allowing it to function independently of other IgG molecules in human serum. The fragment effectively blocks CD64-mediated phagocytosis and downregulates receptor surface expression under physiological conditions. Critically, H22(scFv) binding does not trigger receptor activation or induce pro-inflammatory cytokine expression, unlike some therapeutic antibodies that can paradoxically stimulate TNF production when binding CD64. These characteristics position H22(scFv) as a promising therapeutic candidate for chronic inflammatory diseases.

HT22 Differentiated Hippocampal Cell Line

Though labeled "HT22" rather than "H22," this immortalized mouse hippocampal neuronal cell line warrants mention due to naming similarity. When differentiated, HT22 cells exhibit significant upregulation of NMDA receptors, choline acetyltransferase (ChAT), and brain-derived neurotrophic factor (BDNF), with morphological changes resembling mature neurons. This makes differentiated HT22 cells valuable for screening neuroprotective compounds and studying hippocampal neuron physiology.

The diverse applications of H22-designated clones across cancer biology, immunology, and antibody engineering underscore the importance of specifying context when referencing this nomenclature in scientific literature.

Dosing regimens involving clone H22 (including both the H22 murine tumor cell line and anti-mouse IFNγ [Clone H22] antibody) differ across mouse models depending on experimental goals, administration route, and the agent (e.g., cell line, antibody, or drug being tested). There is no universal dosing standard for clone H22 regimens.

Key variations across studies include:

• Cell injection doses and sites:
  • For tumor establishment, the most common dose is 1 × 10⁶ H22 cells in 100 μL, often injected subcutaneously into the hind leg, flank, or other anatomical sites of immunodeficient or syngeneic mice (such as NOD/SCID or athymic nude mice).
  • Some studies use higher doses, e.g., 3 × 10⁶ cells per mouse.
• Timing and frequency of dosing:
  • In many “unstaged” studies, administration of the therapeutic compound begins 4–5 days after xenografting, once tumors are established, and continues once or twice a day for up to 28 days or as specified.
  • In “staged” studies, treatment starts when tumor volume reaches a specific size (e.g., 150–200 mm³).
• Route of administration:
  • Intraperitoneal (i.p.), intravenous (i.v.), or subcutaneous (s.c.) routes are used based on the agent (antibody, chemotherapy, or experimental drug).
• Drug/compound dosing:
  • For example, studies using 5-FU in H22-bearing mice administer doses of 10, 20, or 40 mg/kg i.p. for 10 consecutive days.
  • For immunomodulatory therapies, specific antibody or drug dosing regimens are adjusted in relation to desired immune or tumoricidal effects.
• Mouse strain-dependent variations:
  • The strain’s immune background dictates protocol modifications—syngeneic (e.g., BALB/c) mice versus immunodeficient (e.g., NOD/SCID, nude) models affect engraftment, tumor growth rate, and response to therapy.

Summary Table of Common H22 Experimental Regimens

• Tumor monitoring and dose-response evaluation are consistently employed via caliper measurements, necropsy, and histological analyses in all models.

In conclusion, dosing regimens are highly tailored to the specific mouse model, cell line, intervention strategy, and research question involved, with adjustments in cell number, timing, frequency, and drug or antibody dose.