On The Organization Of Human T Cell Receptor Loci

Abstract

The human T cell repertoire is complex and is generated by the rearrangement of variable (V), diversity (D) and joining (J) segments on the T cell receptor (TCR) loci. The T cell repertoire demonstrates selfsimilarity in terms clonal frequencies when defined by V, D and J gene segment usage; therefore to determine whether the structural ordering of these gene segments on the TCR loci contributes to the observed clonal frequencies, the TCR loci were examined for self-similarity and periodicity in terms of gene segment organization. Logarithmic transformation of numeric sequence order demonstrated that the V and J gene segments for both T cell receptor α (TRA) and β (TRB) loci were arranged in a selfsimilar manner when the spacing between the adjacent segments was considered as a function of the size of the neighboring gene segment, with an average fractal dimension of ͠1.5. The ratio of genomic distance between either the J (in TRA) or D (in TRB) segments and successive V segments on these loci declined logarithmically with a slope of similar magnitude. Accounting for the gene segments occurring on helical DNA molecules in a logarithmic distribution, sine and cosine functions of the log transformed angular coordinates of the start and stop nucleotides of successive TCR gene segments showed an ordered progression from the 5’ to the 3’ end of the locus, supporting a log-periodic organization. T cell clonal frequencies, based on V and J segment usage, from three normal stem cell donors were plotted against the V and J segment on TRB locus and demonstrated a periodic distribution. We hypothesize that this quasi-periodic variation in gene-segment representation in the T cell clonal repertoire may be influenced by the location of the gene segments on the periodic-logarithmically scaled TCR loci. Interactions between the two strands of DNA in the double helix may influence the probability of gene segment usage by means of either constructive or destructive interference resulting from the superposition of the two helices.

Liquid Tubule Formation and Stabilization Using Cellulose Nanocrystal Surfactants

“…[1][2][3][4] Enhancement of the interfacial activity of NPs by interactions with polymeric ligands has also been demonstrated. [6] Plateau-Rayleigh (PR) instabilities,w hich were first proposed in the mid-1800s,describe the break-up of afalling stream of fluid into droplets. [5] Upon removing the field, the system attempts to minimize the interfacial area (hence,i nterfacial energy), but the NPsurfactants are jammed at the interface,a rresting further shape change,l ocking in highly non-equilibrium shapes.T he shape of the liquid domains can be structured into aw ide range of different shapes with external fields,w hich opens an ew platform for the fabrication of all-liquid separation media and electronic devices.…”

“…[5] Upon removing the field, the system attempts to minimize the interfacial area (hence,i nterfacial energy), but the NPsurfactants are jammed at the interface,a rresting further shape change,l ocking in highly non-equilibrium shapes.T he shape of the liquid domains can be structured into aw ide range of different shapes with external fields,w hich opens an ew platform for the fabrication of all-liquid separation media and electronic devices. [6] Plateau-Rayleigh (PR) instabilities,w hich were first proposed in the mid-1800s,describe the break-up of afalling stream of fluid into droplets. [7,8] Them inimization of the surface or interfacial energy of the fluid with the surrounding medium drives the transition from an ever-thinning stream of fluid into spherical droplets.This phenomenon has been used for the fabrication of micro/nanoparticles in microfluidic devices and inkjet printing technology.…”