Biology subjects

Collins, D. R.

Publications and source records attributed to Collins, D. R..

4 recordsLinked to original sources

bioRxiv2026

Self-reactive human CD8⁺ T cells restricted by HLA-E mediate immunoregulatory and antiviral functions

HLA-E constitutively presents self VL9 peptides on healthy cells, signaling an intact HLA class I pathway and protecting cells from natural killer cell attack. Beyond this canonical role, HLA-E-restricted CD8 T cells that recognize foreign pathogen peptides have emerged as mediators of immunity in multiple human infections, with orthologous responses conferring unprecedented protection in an HIV vaccine model. However, the poor stability of most pathogen-derived HLA-E ligands raises the possibility that additional modes of HLA-E-restricted recognition remain undiscovered. Here, we establish an alternative paradigm in which HLA-E-restricted CD8+ T cells recognize disease-associated increases in self-VL9/HLA-E rather than foreign antigen. These cells, which we term E-sensors, integrate activating and inhibitory signals to discriminate physiological from pathological levels of HLA-E expression. We demonstrate that E-sensors selectively eliminate highly activated, proliferating immune cells that express high levels of HLA-E, establishing a mechanistically resolved pathway of human CD8+ T cell immunoregulation. E-sensors also recognize pathogen-induced HLA-E upregulation and directly eliminate infected cells without prior pathogen-specific priming, demonstrating immediate immunosurveillance through recognition of increased self. Consistent with this antiviral function, we establish E-sensors as a previously unrecognized component of spontaneous HIV immune control in persons who naturally control infection. Together, our findings establish a pathway of human immunosurveillance and immunoregulation in which CD8 T cells detect pathological increases in a constitutively expressed non-classical HLA class I molecule presenting a conserved self-peptide. This disease-agnostic mechanism of immune recognition has implications across infection, cancer, autoimmune disease, and other pathologies that upregulate HLA-E. Unlike classical HLA class I molecules, the near-monomorphic nature of HLA-E further positions this pathway as an untapped effector axis, warranting investigation as a potential target for immune interventions.

immunology↗

bioRxiv2026

NK-like and networked CD8+ T cell immunity mediates exceptional HIV control

Durable treatment-free remission remains a defining goal for people living with HIV (PLWH). Studies of spontaneous elite controllers have revealed that functional CD8 T cells targeting structurally networked viral epitopes can mediate durable viral suppression1,2. However, rare reservoir-defined exceptional controllers within the spectrum of elite control3-5, characterized by the absence of intact provirus or proviruses confined to transcriptionally repressed genomic regions6, provide a unique opportunity to define mechanisms of cure-like immunity. Here, we integrate functional epitope mapping, single-cell transcriptomics, and infected cell elimination assays to identify networked HIV epitope targeting and a natural killer (NK)-like killer-cell immunoglobulin-like receptor (KIR) CD8 T cell subset as key features of exceptional control. This NK-like subset was selectively enriched within HIV-specific, but not CMV-specific, CD8 T cells from controllers, and was transcriptionally similar to highly cytotoxic subsets within the broader KIR+ CD8+ T cell compartment. Flow cytometry revealed increased frequencies of KIR CD8 T cells in exceptional controllers relative to antiretroviral therapy (ART)-suppressed individuals, and unexpectedly, enrichment of dual KIR+ NKG2A+ CD8 T cells. Functional depletion of KIR CD8 T cells significantly impaired the elimination of autologous HIV-infected CD4 T cells, despite preserved recognition by proliferative networked HIV-specific CD8 T cells. These findings thereby identify an NK-like KIR CD8 T cell state as a previously unrecognized component of exceptional HIV immunity that complements networked epitope targeting, providing a novel framework for immunotherapeutic HIV cure strategies.

immunology↗

bioRxiv2026

Duration of Initial Viremia Modulates Functional Properties of HIV-specific T Cell Receptors

Virus-specific CD8+ T cells are crucial in controlling chronic human viral infections such as HIV-1, but the effect of persistent antigen exposure on T cell repertoire formation is not well understood. In this study, we examined epitope-specific CD8+ T cell repertoires in people living with HIV-1, where duration of viremia following hyperacute infection was modulated by the time of initiation of continuous suppressive antiretroviral therapy (ART). After ART-induced undetectable viremia in persons expressing the same HLA class I allele, we analyzed the impact of early (n=6) versus delayed (n=6) ART initiation on the clonotypic composition, clonotypic cross-reactivity, functional avidity and memory differentiation profile of the HIV-specific T cell repertoire restricted by HLA-B*58:01. Using a panel of barcoded tetramers, we mapped T cell receptor (TCR) clonotypes specific for three dominant epitopes and their variants. Both groups exhibited polyclonal TCR repertoires with evidence of cross-reactivity, which was significantly enriched in donors with prolonged antigen exposure. Within this cohort, broadly cross-reactive clonotypes capable of recognizing all autologous variants were identified, but these were rare (<1%). Early ART initiation preserved repertoires characterized by higher-avidity TCRs and a relative enrichment of transitional memory CD8+ T cell subsets. These functional differences were not associated with differences in TRBV gene sharing, indicating that ART timing shapes repertoire quality and memory differentiation without altering TRBV gene bias. These findings demonstrate how antigen suppression dynamics differentially shape the breadth, functional sensitivity, and memory composition of the HIV-specific TCR repertoire, with implications for T cell-directed immunotherapies and HIV cure strategies. One Sentence SummaryThe duration of viral antigen exposure during early HIV infection shapes the functional quality, breadth, and memory composition of virus-specific CD8 T cell receptor repertoires. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/702605v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@9a5a6dorg.highwire.dtl.DTLVardef@1a6bbdaorg.highwire.dtl.DTLVardef@17707e8org.highwire.dtl.DTLVardef@1a84d9e_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2019

Mannose receptor is a restriction factor of HIV in macrophages and is counteracted by the accessory protein Vpr

HIV-1 Vpr is necessary to support HIV infection and spread in macrophages. Evolutionary conservation of Vpr suggests an important yet poorly understood role for macrophages in HIV pathogenesis. Vpr counteracts a previously unknown macrophage-specific restriction factor that targets and reduces the expression of HIV Env. Here, we report that the macrophage mannose receptor (MR), is the restriction factor targeting Env in primary human monocyte-derived macrophages. Vpr acts synergistically with HIV Nef to target distinct stages of the MR biosynthetic pathway and dramatically reduce MR expression. Silencing MR or deleting mannose residues on Env rescues Env expression in HIV-1-infected macrophages lacking Vpr. However, we also show that disrupting interactions between Env and MR reduces initial infection of macrophages by cell-free virus. Together these results reveal a Vpr-Nef-Env axis that hijacks a macrophage mannose-MR response system to facilitate infection while evading MRs normal role, which is to trap and destroy mannose-expressing pathogens.

immunology↗