CD8⁺ T cells are a vital part of adaptive immunity, helping to monitor the body and destroying infected cells with granzymes, perforins, and cytokines. Encountering antigens via MHC I allows CD8⁺ T cells to proliferate and generate effector cells to help clear the infection and memory cells to respond to secondary challenge. However, when the body repeatedly encounters an antigen in chronic diseases, like cancer or long-term infection, constant stimulation can lead to T cells becoming exhausted, limiting their effectiveness in clearing the threat. The progression and development of exhausted CD8 T cells is displayed in Fig. 1 and in our CD8 T Cell Functions Poster.

 

In a recent Cell Reports publication, Hyslop et al. used a novel anti-mouse CD7 antibody developed by BioLegend (clone S23010B) to help uncover a role for CD7 in promoting the survival of exhausted CD8⁺ T cells during chronic disease. Research into CD7 in mouse models has long been limited by the historical lack of high-quality, commercially available antibodies. BioLegend's clone S23010B helps address this gap and is available in purified and fluorescently conjugated formats, with additional options coming soon.

 

Fig. 1. The phenotype and progression of exhausted CD8 T cells. Image from Hyslop, S. et al. 2025. Cell reports, (44)10:116316.¹ Creative Commons CC BY 4.0.

 

Hudson and colleagues previously reported that CD7 is upregulated on exhausted T cells.² In their latest research, they investigated the impact of CD7 deficiency on CD8⁺ T cells during acute and chronic lymphocytic choriomeningitis virus (LCMV) infection. They found that cell-intrinsic absence of CD7 did not significantly affect CD8⁺ T cell populations during acute LCMV infection. In contrast, during chronic LCMV infection, CD7 deficiency led to a marked reduction in terminally exhausted CD8⁺ T cells within the liver, highlighting a key tissue-specific role for CD7 in sustaining this population.

 

In addition, Hyslop et al. performed single-cell RNA sequencing (scRNA-seq) using TotalSeq™-C hashtag antibodies for sample multiplexing on CD8⁺ T cells isolated from the spleen and liver of infected mice. This analysis confirmed CD7-dependent, tissue-specific differences in the transcriptional profiles of terminally exhausted CD8⁺ T cells. They also identified several key genes involved in metabolic function and apoptosis, further delineating the functional role of CD7 in maintaining exhausted CD8⁺ T cells within the liver.

 

Altogether, these findings have important implications in human cancer, as they reveal a conserved pattern of CD7 upregulation in a tumor-infiltrating lymphocyte population enriched for terminally exhausted CD8⁺ T cells in the peripheral blood of patients with head and neck squamous cell carcinoma.

 

CD7 has been actively studied as a promising target for CAR-T cell therapy, particularly in the treatment of T-ALL. The parallel expression of CD7 in terminally exhausted CD8⁺ T cells in human cancer and mouse chronic viral infection models suggests that targeting CD7 may represent a common therapeutic strategy for treating chronic diseases and other malignancies.

 

Learn more by reading the full article.

 

As a scientist-driven company, BioLegend is proud to contribute to the basic research that drives future medical breakthroughs by developing novel tools, like anti-mouse CD7 (clone S23010B). Ask us how we can help support your research with promotions like Publish and Prosper, where you can earn up to $250 in products for publishing using BioLegend reagents.

 

Learn more about clone S23010B by downloading our scientific poster. Topics include:

 

• Distinct mouse and human CD7 expression patterns
• Mouse CD7 expression on T cells and myeloid cells
• CD7 expression levels after T cell activation
• Expression patterns in relation to age and gender

 

 

References

 

1. Hyslop, Sean et al. “CD7 regulates the persistence of terminally exhausted CD8⁺ T cells during chronic infection.” Cell reports, vol. 44,10 116316. 18 Sep. 2025, doi:10.1016/j.celrep.2025.116316
2. Hudson, William H et al. “Proliferating Transitory T Cells with an Effector-like Transcriptional Signature Emerge from PD-1+ Stem-like CD8+ T Cells during Chronic Infection.” Immunity vol. 51,6 (2019): 1043-1058.e4. doi:10.1016/j.immuni.2019.11.002