Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/398529

Viral Infection Skews Immunoglobulin Light Chain Repertoire Diversity

Schwartz, J. C. C.·Murtaugh, M. P.
View original source ↗Export metadata ↓

Abstract

Antibody responses are fundamentally important to effector and memory mechanisms of disease resistance. Antibody repertoire diversity and its response to natural infection is poorly understood, yet is a prerequisite for molecular and structural elucidation of functionally protective immunity to viral infections. Using a swine model of mammalian viral infection, we observed marked changes following infection with the major porcine pathogen, porcine reproductive and respiratory syndrome virus (PRRSV). Deep sequencing of >516,000 light chain VJ mRNA genes showed that, similar to humans, swine utilize both lambda and kappa loci equivalently. However, V and J gene usage were highly restricted; [≥]99% of lambda light chains were IGLV3 and IGLV8 family members joined to IGLJ2 or IGLJ3, and 100% of kappa locus transcripts were IGKV1 or IGKV2 with only IGKJ2. Complementarity-determining region (CDR) variation was limited. Nevertheless, total diversity richness estimates were 2.3 x 105 for lambda and 1.5 x 105 for kappa, due in part to extensive germline variation in framework regions and allelic variation. Infection by PRRSV reduced total richness due to expression of several highly abundant clonal populations. Antibody light chain repertoires differed substantially among individuals, thus illustrating extensive potential variation in immune response in outbred populations. These findings demonstrate that individual variation in light chain repertoires may be an important component of variable antibody responses to infection and vaccination, and that swine are a relevant model of human antibody diversification in which the immune response capacity is critical to understanding individual variation in immune protection against disease.\n\nConflict of interest statementThe authors declare no conflicts of interest.\n\nHighlightsO_LI{lambda} and {kappa} light chain diversity is equivalent to heavy chain diversity\nC_LIO_LIHigh diversity is present despite limited gene segment usage\nC_LIO_LIPRRSV infection increases abundance of dominant {lambda} and {kappa} VJ clones\nC_LIO_LIHigh levels of variation are present among animals\nC_LI

Explore related subjects

immunologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Schwartz, J. C. C., Murtaugh, M. P.. 2018-08-23. Viral Infection Skews Immunoglobulin Light Chain Repertoire Diversity. https://doi.org/10.1101/398529

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

CD19-CAR T-cell therapy resets the EBV+ autoreactive B cell repertoire in autoimmune disease

Epstein-Barr virus (EBV) reprograms autoreactive B cells into activated antigen-presenting cells that drive pathogenic T- and B-cell responses in autoimmune disease. Using EBV B-cell sequencing (EBV-seq), we profiled EBV+ B cells in patients treated with CD19 chimeric antigen receptor (CAR) T cells (systemic lupus, n=6; idiopathic inflammatory myopathies, n=3; systemic sclerosis, n=3) or rituximab (n=15). CAR T cells, but not rituximab, depleted EBV+ B cells, resetting the repertoire toward a naive state: predominantly IgM+ with minimal somatic hypermutation. Post-rituximab B-cells remained class-switched, hypermutated, and activated. Monoclonal antibodies cloned from EBV+ B cells lost autoreactivity after CAR T cells but not rituximab. Sustained drug-free remission occurred in 8/12 CAR-treated but 0/15 rituximab-treated patients. EBV+ B cells were predominantly Latency III and resisted anti-CD20 and anti-CD19 antibodies, yet were killed by CAR T cells and T-cell engagers. CD19-CAR T-cell therapy resets the autoreactive EBV+ B-cell repertoire, which may underlie sustained drug-free remission.

immunology↗
bioRxiv2026

A minimal two-residue C-terminal truncation of AID in adult-onset hyper-IgM syndrome type 2 (HIGM2)

Activation-induced cytidine deaminase (AID), encoded by AICDA, facilitates class-switch recombination (CSR) and somatic hypermutation (SHM) in activated B cells. Loss of AID function causes hyper-IgM syndrome type 2 (HIGM2). While typically autosomal recessive, three C-terminal truncation variants have been reported to act in autosomal dominant manner. We describe a novel heterozygous AICDA nonsense variant, c.589G>T (p.G197*), that truncates the final two C-terminal residues of AID and results in adult-onset HIGM2. Single-cell sequencing of primary patient B cells revealed a complete block in CSR and a [~]10-fold reduction in SHM. AICDA mRNA expression was balanced between wild-type and variant alleles, yet AID protein abundance was reduced to [~]56% with normal subcellular localization. Remarkably, inducible germinal center (iGB) cultures restored CSR in purified naive patient B cells. CRISPR-Cas9 editing of healthy donor B cells confirmed that the iGB platform can rescue B cells harboring heterozygous, but not homozygous, AICDA variants. These results demonstrate that even a two-amino-acid truncation at the AID C-terminus is sufficient to disrupt its function and cause HIGM2.

immunology↗
bioRxiv2026

Defining the Functional Consequence of the Human Ocular Microbiome

The ocular surface is one of the body's most environmentally exposed mucosal barriers, yet it is considered low biomass and harbors orders of magnitude fewer bacteria than microbe-rich sites like the gut. This has cast doubt on whether a functional core ocular microbiome exists at all. Having previously defined a protective gd T cell and IL-17 axis engaged by the murine commensal Corynebacterium mastitidis, we asked whether human-derived bacteria could do the same. Pairing sequencing and culturomics of healthy human conjunctiva from two geographically distinct cohorts, we define a stable core microbiome and identify Corynebacterium bovis as a consistent eye-resident commensal rather than a transient contaminant. In humans, C. bovis elicits a non-pathogenic response marked by IL-17 secretion by {gamma}{delta} T cells and circulating C. bovis-specific IgG, which suggests commensalism rather than pathology. Colonizing mice with human C. bovis strains from Pittsburgh or Miami reproduced this program and conferred protection against ocular infection with Staphylococcus aureus. Together, these findings identify C. bovis as a human-derived ocular commensal that can drive protective {gamma}{delta} T cell immunity, translating a mechanism previously defined only in mice into human relevance and a rational target against sight-threatening infection.

immunology↗