Clone 1a3 is primarily an antibody that recognizes human HLADQ (MHC Class II) and has specific applications in mouse models where human immune systems or human cells are studied. The common in vivo applications include:

Humanized Mouse Models for Immunotherapy Testing

Clone 1a3 is utilized in human immune system (HIS) mice, also known as humanized mice, which serve as preclinical in vivo models for investigating immunotherapies. These mice are generated by engrafting human hematopoietic stem cells into immunodeficient mouse hosts that lack endogenous T, B, and natural killer cells. The mice develop a robust multilineage human immune system and can support growth of human tumors, making them valuable for testing cancer immunotherapies.

HLA Expression Validation in Transgenic Models

In humanized mouse models expressing human HLA molecules, clone 1a3 is employed to verify HLADQ expression through flow cytometry and immunological assays. The antibody specifically recognizes a monomorphic epitope on human HLADQ1 without crossreacting with HLADR or HLADP, making it suitable for distinguishing human immune cells from mouse cells in these chimeric systems.

Hepatic Cell Research

Clone 1a3 has been used in the context of direct reprogramming to generate hepatic stem/progenitor cells, which are subsequently tested in mouse models of liver disease. This application leverages the antibody's ability to identify specific cell populations expressing HLADQ markers.

Quality and Preparation for In Vivo Use

For in vivo applications, clone 1a3 is manufactured as a functional grade preclinical antibody with extremely low endotoxin levels (<0.5 EU/mg) and high purity (>95% by SDS Page). The antibody is produced using animalfree, proteinfree cell culture techniques and undergoes pathogen testing to ensure it does not introduce infections into mouse colonies.

In the literature, the antiHLADQ antibody clone 1a3 is commonly used to study the major histocompatibility complex (MHC) class II molecules. Other commonly used antibodies or proteins that are often used in conjunction with or in similar contexts include:

• Signaling Pathway Markers: Antibodies such as antiERK and antiMEK, which are involved in signaling pathways, are used alongside MHC markers to understand cellular responses and interactions.
• Housekeeping Proteins: Antibodies like antiβactin are used as controls to ensure equal protein loading in experiments.
• PLA Partner Antibodies: Used when visualizing proteinprotein interactions.
• Other Rasfamily or GTPase Antibodies: Such as antiRap1B and antiRap2, which are involved in different aspects of cellular signaling and regulation.

These antibodies and proteins help in understanding various biological processes and interactions, particularly in the context of immune responses and cellular signaling.

Key findings from scientific literature citing clone 1a3 primarily relate to the following contexts:

• Clone 1a3 as AntiHuman HLADQ Antibody: "Clone 1a3" most commonly refers to a monoclonal antibody specific for HLADQ, a major histocompatibility complex (MHC) class II molecule found on antigenpresenting cells in humans. It is utilized to:

  • Detect and stain HLADQ molecules on the cell surface in flow cytometry and immunological assays, enabling identification and characterization of HLADQ expression patterns for research and clinical applications.
  • Recommended use for flow cytometry is ≤ 1.0 μg per 10^6 cells in a 100 μl volume, supporting its role in precise immunophenotyping.
  • Its application is essential in immune research, particularly relating to transplantation immunology and autoimmune disease studies, due to the importance of HLADQ in antigen presentation and immune recognition.

• Expression of UGT1A3 Enzyme (Unrelated to Antibody Clone 1a3): A distinct and unrelated use of "clone 1a3" occurs in studies about the expression of human uridine diphosphate glucuronosyltransferase 1A3 (UGT1A3):

  • Scientific findings include the heterologous expression of active UGT1A3 enzyme in Chinese hamster lung (CHL) cells, using a recombinant plasmid incorporating the UGT1A3 gene.
  • This system allowed for the production and functional analysis of the enzyme, confirmed by the glucuronidation of quercetin, implying successful expression and activity testing in a nonhuman system.

• Ambiguity of “1a3” in Literature:

  • No direct connection was found between clone 1a3 and scientific findings around ALDH1A3 or other clonelabeled T cell or myomaker studies in the provided search results; mentions in other contexts (such as ALDH1A3 in cancer or 1A3 in gene editing) are unrelated to the monoclonal antibody or UGT application.
  • The primary, specific scientific findings referring to "clone 1a3" are thus those above, concerning HLADQ antibody and UGT1A3 enzyme expression.

Summary Table: Key Findings from Clone 1a3 Citations

Important Note:
The search indicates “clone 1a3” may refer to either a specific antibody or a labeled clone in gene/protein expression experiments. The majority of scientific citations are for the antibody against HLADQ. If you require findings specific to another context, please clarify which "clone 1a3" is of interest.

There are no published, standardized in vivo dosing regimens specifically for clone 1a3 across different mouse models. Most sources indicate that dose selection for this antibody in mice is influenced by factors such as:

• Target engagement requirements
• Mouse strain or humanization status
• Experimental objectives

For similar antibodies used in immunological and in vivo studies (e.g., antiHLA or other MHCtargeting antibodies), initial doses generally range from 100–250 μg per mouse, commonly delivered via intraperitoneal injection, and are often repeated at intervals (such as every 3–4 days or 2–3 times per week). Exact regimens are typically customized based on pilot studies, strain background (e.g., wildtype vs. humanized mice like BHLAA3.1), and the nature of the immune manipulation required.

Key considerations for dosing clone 1a3:

• Humanized mouse models expressing HLA molecules (such as BHLAA3.1) may require different dosing for effective engagement compared to wildtype mice due to differences in recirculation, expression levels, or immune context.
• The experimental goal (e.g., acute depletion, chronic modulation, or tolerance induction) can alter both the dose and frequency.
• In absence of published data, recommended starting regimens mimic those of comparable in vivo antibodies: 100–250 μg per dose, adjusted based on pilot studies and assessment of target engagement or biological response.

Summary Table: Typical In Vivo Antibody Dosing in Mouse Models

*Dose for clone 1a3 is inferred from typical practices with similar antibodies due to lack of direct published data. Always confirm with smallscale pilot studies and consult manufacturer datasheets when available.

In summary:
Dosing regimens of clone 1a3 vary depending on immune target, mouse model (wildtype vs. humanized), and experimental context, with initial guidance drawing from analogous antibody dosing (100–250 μg per dose), but require empirical optimization.