Raymond Johnson, MD, PhD

The primary goal of our laboratory is to understand protective immunity against chlamydia infections of the reproductive tract to facilitate vaccine development. That effort includes a focus on T cell interactions with infected epithelial cells because chlamydia replicates primarily in reproductive tract epithelium. We utilize T cell cloning as a research tool because unlike strategies based on flow cytometry-RNAseq, this approach provides representative T cell clones that can be used as experimental tools to understand mucosal T cell immunobiology, and do cause-and-effect pathogenesis rather than associative-biology. The payout has been the discovery of novel T cell subsets involved in the adaptive immune response to chlamydia genital tract infections and a wealth of data enabled by subset-representative T cell clones, including transcriptomic identification of differentiation and activation pathway biomarkers, and investigations of their contributions to host defense and immunopathology. We have found that IL-13 is a central player in chlamydia immunobiology, but not in the conventional Th1/Th2 narrative sense. We are currently focused chlamydia-specific CD4 and CD8 T cells polarized to coproduce IFN-γ and IL-13 that prevent immunopathology during primary C. muridarum genital tract infections, and a highly conserved biomarker that is likely the signaling scaffold for IL-13 production in this novel T cell phenotype. We also apply the mucosal immunology learned to other human diseases including systemic sclerosis.