Unraveling Helminth-Specific T Cells: Insights from Gene Editing in Strongyloides ratti 2176

Abstract Description CD4+ helper 2 (TH2) cells are crucial for protective Type 2 immunity against parasitic helminths, but the importance of antigen-specificity in this context remains a controversial topic. This study, generated, characterized and employed a novel CRISPR-targeted Strongyloides ratti mutant to interrogate the functional role of helminth-specific CD4 T cells. Termed Atilla, this parasite line expresses two copies of the immunodominant CD4+ T cell epitope 2W1S, fused with FLAG and HA peptides from the astacin-like metalloendopeptidase gene locus. Infected C57BL/6 mice with Atilla show significant expansion of 2W1S tetramer positive CD4+ T cells in the lung, spleen, mesenteric lymph nodes, and peritoneal cavity. Peptide re-stimulation experiments show increased type 2 cytokine release compared to controls, and repeated inoculation of mice with Attila progressively expands a memory-like 2W1S+CD62L-CD44+CD4+ population that co-expresses GATA3, T1/ST2, and CXCR6. Adoptive transfer of enriched 2W1S+CD62L-CD44+CD4+ T cells into naïve C57BL/6 mice lacking alpha-beta and gamma-delta T cells was sufficient to confer protection against subsequent parasite challenge. These findings support the hypothesis that antigen-specific CD4+ T cells have a role in anti-helminth immunity, and ongoing studies seek to test whether they are functionally superior to “bystander” non-antigen specific TH2 cells. Funding Sources NIH U01AI163062 NIH R01AI164715 NIH 1R21AI171740 Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)