Longitudinal B Cell Receptor Repertoire Profiling of Heavy- and Light-Chain Features in Injured Rat Spinal Cord Tissue After Traumatic Spinal Cord Injury
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Purpose B cell receptor (BCR) repertoire features detectable in injured spinal cord tissue after traumatic spinal cord injury (SCI) remain poorly characterized. This study performed an exploratory longitudinal analysis of immunoglobulin heavy-chain (IGH) and light-chain (IGL) repertoire features in injured rat spinal cord tissue. Methods Adult male Sprague–Dawley rats underwent traumatic SCI using a modified Allen’s weight-drop model. Lesion-centered spinal cord tissues were collected at 1, 3, 7, 14, and 28 days post-injury, with four biological replicates per time point. BCR repertoire sequencing was used to assess functional sequence composition, isotype or constant-region distribution, sequencing saturation, diversity indices, germline-divergence metrics, V/J gene usage, V–J pairing, CDR3 length distribution, dominant clonotype abundance, and repertoire similarity. Uninjured baseline libraries failed construction; therefore, analyses were restricted to post-injury samples and interpreted descriptively. Results Productive BCR sequences were detected across injured spinal cord samples, and saturation curves supported repertoire coverage in most samples. IGH repertoires showed greater inter-sample heterogeneity in isotype composition, diversity indices, germline-divergence metrics, V/J gene usage, V–J pairing, CDR3 length distribution, dominant clonotype abundance, and clonotype sharing. In contrast, IGL repertoires were predominantly IgK-associated and showed a restricted CD
Abstract
Purpose B cell receptor (BCR) repertoire features detectable in injured spinal cord tissue after traumatic spinal cord injury (SCI) remain poorly characterized. This study performed an exploratory longitudinal analysis of immunoglobulin heavy-chain (IGH) and light-chain (IGL) repertoire features in injured rat spinal cord tissue. Methods Adult male Sprague–Dawley rats underwent traumatic SCI using a modified Allen’s weight-drop model. Lesion-centered spinal cord tissues were collected at 1, 3, 7, 14, and 28 days post-injury, with four biological replicates per time point. BCR repertoire sequencing was used to assess functional sequence composition, isotype or constant-region distribution, sequencing saturation, diversity indices, germline-divergence metrics, V/J gene usage, V–J pairing, CDR3 length distribution, dominant clonotype abundance, and repertoire similarity. Uninjured baseline libraries failed construction; therefore, analyses were restricted to post-injury samples and interpreted descriptively. Results Productive BCR sequences were detected across injured spinal cord samples, and saturation curves supported repertoire coverage in most samples. IGH repertoires showed greater inter-sample heterogeneity in isotype composition, diversity indices, germline-divergence metrics, V/J gene usage, V–J pairing, CDR3 length distribution, dominant clonotype abundance, and clonotype sharing. In contrast, IGL repertoires were predominantly IgK-associated and showed a restricted CDR3 length distribution centered at 11 amino acids, with higher repertoire sharing. These heavy- and light-chain contrasts are best interpreted as repertoire-architecture differences within the post-injury dataset. Conclusion Injured male rat spinal cord tissue contained detectable BCR repertoire signals with descriptive variation across post-injury time points, supporting the feasibility of longitudinal repertoire profiling in this setting. These data provide a receptor-level resource for SCI neuroimmunology and support future studies to clarify antigen specificity, functional relevance, and translational potential of post-injury B-cell responses.