• This gene encodes one member of a family of immunoglobulin Fc receptor genes found on the surface of many immune response cells.
• The regulatory region and exons 1-5 of mouse Fcgr3 gene that encode the full-length protein were replaced by human FCGR2A exons 1-7 and regulatory region in B-hCD32A mice.
• The human CD32A was expressed on monocytes, macrophages, and neutrophils of humanized CD32A mice.
• Humanization of CD32A does not change the overall frequency or distribution of immune cell types in spleen, blood, and lymph nodes.
• Application: For example, This product is used for pharmacodynamics and safety evaluation of cancer and autoimmune diseases.

Gene targeting strategy for B-hCD32A mice.
The regulatory region and exons 1-5 of mouse Fcgr3 gene that encode the full-length protein were replaced by human FCGR2A exons 1-7 and regulatory region in B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), respectively, and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was not detectable in T cells of wild-type C57BL/6 mice. hCD32A was not detectable in T cells of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was not detectable in B cells of wild-type C57BL/6 mice. hCD32A was not detectable in B cells of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was detectable in NK cells of wild-type C57BL/6 mice. hCD32A was not detectable in NK cells of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was detectable in DC cells of wild-type C57BL/6 mice. hCD32A was detectable in DC cells of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was detectable in monocytes of wild-type C57BL/6 mice. hCD32A was weakly detectable in monocytes of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was detectable in macrophages of wild-type C57BL/6 mice. hCD32A was detectable in macrophages of homozygous B-hCD32A mice.

Strain specific CD32A expression analysis in wild-type C57BL/6 mice and homozygous humanized B-hCD32A mice by flow cytometry. Splenocytes (A) and blood cells (B) were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCD32A mice (H/H), and analyzed by flow cytometry with species-specific anti-mCD16 antibody and anti-hCD32A antibody. mCD16 was detectable in neutrophils of wild-type C57BL/6 mice. hCD32A was detectable in neutrophils of homozygous B-hCD32A mice.

Frequency of leukocyte subpopulations in the spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6 mice and homozygous B-hCD32A mice (n=3, 7-week-old). A. Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. B. Frequency of T cell subpopulations. Percentages of T cells, B cells, NK cells, dendritic cells, granulocytes, monocytes, macrophages, CD4+ T cells, CD8+ T cells, and Tregs in B-hCD32A mice were similar to those in C57BL/6 mice, demonstrating that humanization of CD32A does not change the frequency or distribution of these cell types in the spleen. The frequency of leukocyte subpopulations in lymph nodes and blood of B-hCD32A mice was also comparable to wild-type C57BL/6 mice (Data not shown). Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test. *P < 0.05, **P < 0.01, ***p < 0.0001.

Anti-CD40L ICs (immune complexes) induce Fc-mediated anaphylaxis and thrombocytopenia in B-hCD32A mice. Blood cells were isolated from homozygous B-hCD32A mice (n=1, female, 7-week-old). Mice were injected (i.v.) with preformed CD40L mAb ICs. Body temperature was counted after 0, 10, 20, 30 min injection. Platelets were counted 30 min post injection. (A) Change in body temperature. (B) platelet counts. Preformed anti-CD40L ICs caused thrombocytopenia in B-hCD32A mice.