Comparison of immunophenotypes between Rag2 knockout mice derived from two different sources.

Area of Science:

• Immunology
• Genetics
• Animal Models

Background:

• Recombination activating gene2 (Rag2) knockout (KO) mice are crucial research tools in immunology, vaccine development, and transplantation.
• Phenotypic variations among Rag2 KO mice from different sources are not well-documented.
• This study addresses the need for comparative analysis of Rag2 KO mouse immunophenotypes.

Purpose of the Study:

• To investigate and compare the immunophenotypes of Rag2 KO mice from distinct genetic backgrounds.
• To identify potential differences in spleen and thymus characteristics between C57BL/6-Rag2em1hwl/Korl (Rag2/Korl KO) and B6.Cg-Rag2tm1.1Cgn/J (Rag2/J KO) mice.
• To evaluate organ weight, histological structure, and immune cell subpopulations.

Main Methods:

• Comparative analysis of organ weights (spleen, thymus) between Rag2 KO and wild-type (WT) mice.
• Histological examination of spleen and thymus tissues.
• Flow cytometry to quantify immune cell subpopulations, including CD4+ T cells, CD8+ T cells, and B cells.

Main Results:

• Both Rag2/Korl KO and Rag2/J KO mice exhibited reduced spleen and thymus weights compared to WT mice.
• Histological analysis revealed decreased white pulp in the spleen and cortex in the thymus of both Rag2 KO groups.
• Significant differences were observed in CD8+ T and B cell counts between Rag2/Korl KO and Rag2/J KO mice, while CD4+ T cell counts remained similar.

Conclusions:

• Rag2/Korl KO and Rag2/J KO mice display largely similar immunophenotypes in spleen and thymus.
• Key differences lie in the specific counts of CD8+ T and B cell subpopulations between these two Rag2 KO mouse models.
• These findings highlight the importance of source-specific characterization of KO mouse models for research reproducibility.