About this Research Topic
Since the 1970s, it has been consistently reported that human CD4+ T cells were not merely helper cells, but may also mediate cytotoxicity, particularly in cloned cell lines, and also directly ex vivo. Murine models have now confirmed that cytotoxic CD4+ T cells are an important CD4 subset.
Cytotoxic CD4+ T cells may play an important role in chronic human viral infections, including EBV and CMV infection, while CD4+ T cells from HIV-infected patients have been shown to express large quantities of cytolytic effector molecules like perforin and granzymes. HIV-specific CD4+ T cell clones and cell lines can readily mediate target cell lysis and viral inhibition in vitro. In the context of experiment viral infections in murine models, such as West Nile virus, influenza, and Friend virus, it has been demonstrated that cytotoxic CD4 T cells are readily detectable ex vivo and can contribute to viral containment even in the absence of antigen-specific CD8+ T cell or B cell responses.
Distinct phenotype, lineage commitment and function of these cytotoxic CD4+ T cells in viral infections are currently under intense investigation. Emerging research on this subset will expand our knowledge of the complex T helper response and will shed light on another effector cell type that may be important in vaccine development. We encourage original articles, reviews, perspectives, and discussions on this research topic.
Keywords: Cytotoxic CD4 T cells, Viral Infections, adaptive immunity, CMV, EBV, HIV, CD4 T cell subset
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