👤 Jay Rappaport

A signature of 16 serum proteins that were previously profiled using the aptamer-based Somascan technology highlighted the roles of the e2 allele of APOE in lipid regulation via apolipoprotein B (APOB) and apolipoprotein E (APOE) and in inflammation. Here, the serum protein signature of APOE is validated and expanded using a combination of mass-spectrometry, ELISA, Luminex, blood transcriptomics, and antibody-based Olink serum proteomics. Some of the findings were replicated in the UK Biobank using antibody-based Olink serum proteomics. This analysis replicated the association between APOB and the e2 allele of APOE, detected a new, robust pattern of association between APOE genotypes and the serum level of APOE, and discovered new associations between APOE genotypes and the complex of apolipoproteins APOC1, APOC2, APOC3, APOC4, APOE, APOF, and APOL1. In addition, 13 new proteins correlated with APOE genotypes. This extended signature includes granule proteins CAMP, CTSG, DEFA3, and MPO secreted from neutrophils and points to olfactomedin 4 (OLFM4) as a new target for the prevention of Alzheimer's disease. Show less

Despite effective viral suppression with antiretroviral therapy (ART), people living with HIV (PLWH) experience persistent inflammation, immune dysfunction, and premature onset of cardiovascular and aging-related comorbidities. The mechanisms driving this transition from acute immune activation to chronic inflammatory remodeling under viral suppression remain incompletely understood. Here, we leveraged a nonhuman primate model to characterize the longitudinal transcriptomic changes across key stages of SIV infection and ART. To define the underlying mechanisms, we performed longitudinal transcriptomic profiling in peripheral blood mononuclear cells (PBMCs) from a cohort of simian immunodeficiency virus (SIV)-infected rhesus macaques spanning four key stages: pre-infection, acute infection, short-term ART, and long-term ART. Bulk RNA sequencing revealed dynamic immune remodeling across infection and treatment. Acute SIV infection induced robust antiviral and inflammatory programs, with upregulation of interferon-stimulated genes (ISGs), IL-27, JAK/STAT, and NF-κB signaling, coupled with suppression of T- and B-cell activation pathways. Short-term ART effectively reversed these transcriptional perturbations, restoring adaptive immune gene expression and reducing innate antiviral responses to near-baseline levels. In contrast, chronic SIV infection on long-term ART maintained viral suppression but was characterized by reactivation of innate immune pathways, including TLR2/TLR4/MYD88, NF-κB, and inflammasome (NLRP3/NLRP12, caspase-1) signaling, along with sustained macrophage activation, platelet/coagulation signaling, and senescence-associated secretory phenotype. Protein analyses confirmed persistent CASPASE-1 and NF-κB activation in spleen tissue. Pathologic evaluation of a carotid artery from an SIV-infected, long-term ART-treated macaque revealed macrophage-rich plaques with p21⁺ senescent cells with intraluminal thrombus formation, recapitulating key features of HIV-associated atherogenesis. While ART normalizes acute infection-induced immune dysregulation, chronic SIV infection sustains a chronic, macrophage- and TLR-driven inflammatory state linked to vascular injury and aging process regardless of long-term suppression of viremia. Targeting inflammasome, NF-κB, and senescence pathways may mitigate non-AIDS comorbidities in PLWH. Show less

We previously identified a signature of 16 serum proteins that highlighted a role of the e2 allele of APOE in lipid regulation via apolipoprotein B (APOB) and apolipoprotein E (APOE), and in inflammation. The serum proteins were profiled using the aptamer-based Somalogic technology. Here, we validate and expand the serum protein signature of APOE using a combination of mass-spectrometry, ELISA, Luminex, antibody-based Olink proteomics, and blood transcriptomics. We replicate the association between APOB and the e2 allele of APOE, we correct the pattern of association between APOE genotypes and serum level of APOE, and we detect new associations between APOE genotypes and the complex of apolipoproteins APOC1, APOC4, APOC2, APOC3, APOE, APOF and APOL1. In addition, we discover 13 new proteins that correlate with APOE genotypes. This extended signature includes granule proteins CAMP, CTSG, DEFA3, and MPO secreted from neutrophils and points to olfactomedin 4 (OLFM4) as a new target for the prevention of Alzheimer's disease. Show less

Despite effective viral suppression with antiretroviral therapy (ART), people living with HIV (PLWH) experience persistent inflammation, immune dysfunction, and premature onset of cardiovascular and aging-related comorbidities. To define the underlying mechanisms, we performed longitudinal transcriptomic profiling in peripheral blood mononuclear cells (PBMCs) from a cohort of simian immunodeficiency virus (SIV)-infected rhesus macaques spanning four key stages: pre-infection, acute infection, short-term ART, and long-term ART. Bulk RNA sequencing revealed dynamic immune remodeling across infection and treatment. Acute SIV infection induced robust antiviral and inflammatory programs, with upregulation of interferon-stimulated genes (ISGs), IL-27, JAK/STAT, and NF-κB signaling, coupled with suppression of T- and B-cell activation pathways. Short-term ART effectively reversed these transcriptional perturbations, restoring adaptive immune gene expression and reducing innate antiviral responses to near-baseline levels. In contrast, chronic SIV infection on long-term ART maintained viral suppression but was characterized by reactivation of innate immune pathways, including TLR2/TLR4/MYD88, NF-κB, and inflammasome (NLRP3/or NLRP12, caspase-1) signaling, along with sustained macrophage activation, platelet/coagulation signaling, and senescence-associated secretory phenotype. Protein analyses confirmed persistent CASPASE-1 and NF-κB activation in spleen tissue. Pathologic evaluation of a carotid artery from an SIV-infected, long-term ART-treated macaque revealed macrophage-rich plaques with p21 Show less

Identifying translocations of the MLL gene at chromosome band 11q23 is important for the characterization and treatment of leukemia. However, cytogenetic analysis does not always find the translocations and the many partner genes of MLL make molecular detection difficult. We developed cDNA panhandle PCR to identify der(11) transcripts regardless of the partner gene. By reverse transcribing first-strand cDNAs with oligonucleotides containing coding sequence from the 5' MLL breakpoint cluster region at the 5' ends and random hexamers at the 3' ends, known MLL sequence was attached to the unknown partner sequence. This enabled the formation of stem-loop templates with the fusion point of the chimeric transcript in the loop and the use of MLL primers in two-sided PCR. The assay was validated by detection of the known fusion transcript and the transcript from the normal MLL allele in the cell line MV4-11. cDNA panhandle PCR then was used to identify the fusion transcripts in two cases of treatment-related acute myeloid leukemia where the karyotypes were normal and the partner genes unknown. cDNA panhandle PCR revealed a fusion of MLL with AF-10 in one case and a fusion of MLL with ELL in the other. Alternatively spliced transcripts and exon scrambling were detectable by the method. Leukemias with normal karyotypes may contain cryptic translocations of MLL with a variety of partner genes. cDNA panhandle PCR is useful for identifying MLL translocations and determining unknown partner sequences in the fusion transcripts. Show less