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Juelg, B.

Publications and source records attributed to Juelg, B..

3 recordsLinked to original sources

Immune activation during broadly neutralizing antibody-mediated HIV suppression prior to post-intervention control

Broadly neutralizing antibodies (bNAbs) have been associated with enhancement of HIV-specific T or B cell responses and sustained partial control of HIV replication in some people with HIV (PWH). The mechanisms through which bNAbs may potentiate host immunity in this context are not known. We previously reported the outcomes of a clinical trial in which ten PWH on antiretroviral therapy (ART) received a combination of immunotherapies including two bNAbs administered immediately preceding an analytic treatment interruption (ATI). After bNAb levels waned, seven participants exhibited varying degrees of post-intervention control of HIV linked to a robust expansion of activated CD8+ T cells in response to rebounding virus. To investigate the role of the bNAbs in enhancing endogenous immune responses, we looked for evidence of HIV-specific or broader immune activation during the period after ART was paused and prior to rebound when bNAbs were controlling HIV replication. At a timepoint early post-ART interruption and at least one month before virus emerged in plasma, we detected an increase in levels of plasma inflammatory proteins as well as phenotypic and transcriptional activation of innate and adaptive immune cells. Compared to non-controllers, post-intervention controllers demonstrated unique transcriptional activation patterns as well as differential longitudinal plasma inflammatory protein trends. No enhancement of HIV-specific T cell or antibody responses was observed in this window. This study identifies activated cell types and inflammatory pathways that are recruited early during bNAb-mediated HIV suppression and that may play a role in potentiating long-lasting HIV immune control after bNAb therapy. One Sentence SummaryIn a combination immunotherapy trial with high rates of post-intervention control, bNAb-mediated HIV suppression was associated with increased immune activation compared to HIV suppression by ART.

immunology↗

Early cross-coronavirus reactive signatures of protective humoral immunity against COVID-19

The introduction of vaccines has inspired new hope in the battle against SARS-CoV-2. However, the emergence of viral variants, in the absence of potent antivirals, has left the world struggling with the uncertain nature of this disease. Antibodies currently represent the strongest correlate of immunity against COVID-19, thus we profiled the earliest humoral signatures in a large cohort of severe and asymptomatic COVID-19 individuals. While a SARS-CoV-2-specific immune response evolved rapidly in survivors of COVID-19, non-survivors exhibited blunted and delayed humoral immune evolution, particularly with respect to S2-specific antibody evolution. Given the conservation of S2 across {beta}-coronaviruses, we found the early development of SARS-CoV-2-specific immunity occurred in tandem with pre-existing common {beta}-coronavirus OC43 humoral immunity in survivors, which was selectively also expanded in individuals that develop paucisymptomatic infection. These data point to the importance of cross-coronavirus immunity as a correlate of protection against COVID-19.

immunology↗

Predicting the Immunogenicity of T cell epitopes: From HIV to SARS-CoV-2

We describe a physics-based learning model for predicting the immunogenicity of Cytotoxic T Lymphocyte (CTL) epitopes derived from diverse pathogens, given a Human Leukocyte Antigen (HLA) genotype. The model was trained and tested on experimental data on the relative immunodominance of CTL epitopes in Human Immunodeficiency Virus infection. The method is more accurate than publicly available models. Our model predicts that only a fraction of SARS-CoV-2 epitopes that have been predicted to bind to HLA molecules is immunogenic. The immunogenic CTL epitopes across all SARS-CoV-2 proteins are predicted to provide broad population coverage, but the immunogenic epitopes in the SARS-CoV-2 spike protein alone are unlikely to do so. Our model predicts that several immunogenic SARS-CoV-2 CTL epitopes are identical to those contained in low-pathogenicity coronaviruses circulating in the population. Thus, we suggest that some level of CTL immunity against COVID-19 may be present in some individuals prior to SARS-CoV-2 infection.

immunology↗