The genetic spectrum of a Chinese series of patients with 46, XY disorders of the sex development

PURPOSE

The etiology of 46, XY disorders of sex development (46, XY DSD) is complex, and studies have shown that different series of patients with 46, XY DSD has different genetic spectrum. In this study, we aimed to investigate the underlying genetic etiology in a Chinese series of patients with 46, XY DSD by whole exome sequencing (WES).

METHODS

Seventy patients with 46, XY DSD were enrolled from the Peking Union Medical College Hospital (Beijing, China). The detailed clinical characteristics were evaluated, and peripheral blood was collected for WES to find the patients' rare variants (RVs) of genes related to 46, XY DSD. The clinical significance of the RVs was annotated according to American College of Medical Genetics and Genomics (ACMG) guidelines.

RESULTS

A total of 57 RVs from nine genes were identified in 56 patients with 46, XY DSD, which include 21 novel RVs and 36 recurrent RVs. Based on the American ACMG guidelines, 43 variants were classified as pathogenic(P) or likely pathogenic (LP) variants and 14 variants were defined as variants of uncertain significance (VUS). P or LP variants were identified in 64.3% (45/70) patients of the series. Thirty-nine, 14, and 4 RVs were involved in the process of androgen synthesis and action, testicular determination and developmental process, and syndromic 46, XY DSD, respectively. The top three genes most frequently affected to cause 46, XY DSD were AR, SRD5A2, and NR5A1. Seven patients were found harboring RVs of the 46, XY DSD pathogenic genes identified in recent years, namely DHX37 in four patients, MYRF in two patients, and PPP2R3C in one patient.

CONCLUSION

We identified 21 novel RVs of nine genes, which extended the genetic spectrum of 46, XY DSD pathogenic variants. Our study showed that 60% of the patients were caused by AR, SRD5A2 or NR5A1 P/LP variants. Therefore, polymerase chain reaction (PCR) amplification and Sanger sequencing of these three genes could be performed first to identify the pathogeny of the patients. For those patients whose pathogenic variants had not been found, whole-exome sequencing could be helpful in determining the etiology.

Evolution of two distinct variable lymphocyte receptors in lampreys: VLRD and VLRE

Jawless vertebrates possess an alternative adaptive immune system in which antigens are recognized by variable lymphocyte receptors (VLRs) generated by combinatorial assembly of leucine-rich repeat (LRR) cassettes. Three types of receptors, VLRA, VLRB, and VLRC, have been previously identified. VLRA- and VLRC-expressing cells are T cell-like, whereas VLRB-expressing cells are B cell-like. Here, we report two types of VLRs in lampreys, VLRD and VLRE, phylogenetically related to VLRA and VLRC. The germline VLRD and VLRE genes are flanked by 39 LRR cassettes used in the assembly of mature VLRD and VLRE, with cassettes from chromosomes containing the VLRA and VLRC genes also contributing to VLRD and VLRE assemblies. VLRD and VLRE transcription is highest in the triple-negative (VLRA-/VLRB-/VLRC-) population of lymphocytes, albeit also detectable in VLRA+ and VLRC+ populations. Tissue distribution studies suggest that lamprey VLRD+ and VLRE+ lymphocytes comprise T-like sublineages of cells.

Genetic Lesions in Russian CLL Patients with the Most Common Stereotyped Antigen Receptors

Chronic lymphocytic leukemia (CLL) is one of the most common B-cell malignancies in Western countries. IGHV mutational status is the most important prognostic factor for this disease. CLL is characterized by an extreme narrowing of the IGHV genes repertoire and the existence of subgroups of quasi-identical stereotyped antigenic receptors (SAR). Some of these subgroups have already been identified as independent prognostic factors for CLL. Here, we report the frequencies of TP53, NOTCH1, and SF3B1 gene mutations and chromosomal aberrations assessed by NGS and FISH in 152 CLL patients with the most common SAR in Russia. We noted these lesions to be much more common in patients with certain SAR than average in CLL. The profile of these aberrations differs between the subgroups of SAR, despite the similarity of their structure. For most of these subgroups mutations prevailed in a single gene, except for CLL#5 with all three genes affected by mutations. It should be noted that our data concerning the mutation frequency in some SAR groups differ from that obtained previously, which could be due to the population differences between patient cohorts. The research in this area should be important for better understanding the pathogenesis of CLL and therapy optimization.

Monogenic TCRβ Assembly and Expression Are Paramount for Uniform Antigen Receptor Specificity of Individual αβ T Lymphocytes

The ability of individual T and B cells to display Ag receptors of unique uniform specificity is the molecular basis of adaptive immunity. Most αβ T cells achieve uniform specificity by assembling in-frame genes on only one allelic copy of TCRβ and TCRα loci, while others prevent incorporation of TCRα protein from both alleles into TCRs. Analysis of mice expressing TCR proteins from a restricted combination of transgenes showed that TCR protein pairing restrictions achieve uniform specificity of cells expressing two types of TCRβ protein. However, whether this mechanism operates in the physiological context where each dual-TCRβ cell expresses one set of a vast number of different TCRβ proteins remains an open question, largely because there is a low, but significant, portion of cells carrying two in-frame TCRβ genes. To resolve this issue, we inactivated one allelic copy of the TCRα locus in a new mouse strain that assembles two in-frame TCRβ genes in an elevated fraction of cells. This genetic manipulation has no effect on the frequency of cells that display multiple types of αβ TCR, yet increases the representation of cells displaying TCRβ proteins that generate more highly expressed TCRs. Our data demonstrate that some TCRβ proteins exhibit differential functional pairing with TCRα proteins, but these restrictions have negligible contribution for ensuring uniform specificity of cells that express two types of TCRβ protein. Therefore, we conclude that mechanisms governing monogenic assembly and expression of TCRβ genes in individual cells are paramount for uniform specificity of αβ T lymphocytes.

Cas9-Based Local Enrichment and Genomics Sequence Revision of Megabase-Sized Shark IgNAR Loci

The 0.8-Mb Ig new Ag receptor (IgNAR) region of the whitespotted bamboo shark (Chiloscyllium plagiosum) is incompletely assembled in Chr_44 of the reference genome. Here we used Cas9-assisted targeting of chromosome segments (CATCH) to enrich the 2 Mb region of the Chr_44 IgNAR loci and sequenced it by PacBio and next-generation sequencing. A fragment >3.13 Mb was isolated intact from the RBCs of sharks. The target was enriched 245.531-fold, and sequences had up to 94% coverage with a 255× mean depth. Compared with the previously published sequences, 20 holes were filled, with a total length of 3508 bp. In addition, we report five potential germline V alleles of IgNAR1 from six sharks that may belong to two clusters of the IgNAR. Our results provide a new method to research the germline of large Ig gene segments, as well as provide the enhanced bamboo shark IgNAR gene loci with fewer gaps.

Generation of Redirected Engineered Human Chimeric Antigen Receptor (CAR) T Cells

Chimeric antigen receptor (CAR) T cell therapy that involves genetic engineering a patient's own immune cells with antigen-specific receptors has shown remarkable efficacy in blood cancer treatment. Numerous clinical studies with CAR T cells targeting the blood cell surface protein CD19 led to the FDA 's first approval of a genetically engineered cell therapy. The process of generating potent CAR T cells involves several carefully performed manufacturing steps. Here, we describe the generation of redirected engineered human CAR T cells for preclinical studies starting with the CAR design, retroviral gene transfer, detection of CAR expression, and expansion of transduced T cells.

Lost structural and functional inter-relationships between Ig and TCR loci in mammals revealed in sharks

Immunoglobulins and T cell receptors (TCR) have obvious structural similarities as well as similar immunogenetic diversification and selection mechanisms. Nevertheless, the two receptor systems and the loci that encode them are distinct in humans and classical murine models, and the gene segments comprising each repertoire are mutually exclusive. Additionally, while both B and T cells employ recombination-activating genes (RAG) for primary diversification, immunoglobulins are afforded a supplementary set of activation-induced cytidine deaminase (AID)-mediated diversification tools. As the oldest-emerging vertebrates sharing the same adaptive B and T cell receptor systems as humans, extant cartilaginous fishes allow a potential view of the ancestral immune system. In this review, we discuss breakthroughs we have made in studies of nurse shark (Ginglymostoma cirratum) T cell receptors demonstrating substantial integration of loci and diversification mechanisms in primordial B and T cell repertoires. We survey these findings in this shark model where they were first described, while noting corroborating examples in other vertebrate groups. We also consider other examples where the gnathostome common ancestry of the B and T cell receptor systems have allowed dovetailing of genomic elements and AID-based diversification approaches for the TCR. The cartilaginous fish seem to have retained this T/B cell plasticity to a greater extent than more derived vertebrate groups, but representatives in all vertebrate taxa except bony fish and placental mammals show such plasticity.

Changes of Taste, Smell and Eating Behavior in Patients Undergoing Bariatric Surgery: Associations with PROP Phenotypes and Polymorphisms in the Odorant-Binding Protein OBPIIa and CD36 Receptor Genes

Bariatric surgery is the most effective long-term treatment for severe obesity and related comorbidities. Although patients who underwent bariatric surgery report changes of taste and smell perception, results from sensory studies are discrepant and limited. Here, we assessed taste and smell functions in 51 patients before, one month, and six months after undergoing bariatric surgery. We used taste strip tests to assess gustatory function (including sweetness, saltiness, sourness, umaminess, bitterness and oleic acid, a fatty stimulus), the “Sniffin’ Sticks” test to assess olfactory identification and the 3-Factor Eating Questionnaire to assess eating behavior. We also explored associations between these phenotypes and flavor-related genes. Results showed an overall improvement in taste function (including increased sensitivity to oleic acid and the bitterness of 6-n-propylthiouracil (PROP)) and in olfactory function (which could be related to the increase in PROP and oleic acid sensitivity), an increase in cognitive restraint, and a decrease in disinhibition and hunger after bariatric surgery. These findings indicate that bariatric surgery can have a positive impact on olfactory and gustatory functions and eating behavior (with an important role of genetic factors, such PROP tasting), which in turn might contribute to the success of the intervention.

Reconsidering phosphorylation in the control of inducible CARD11 scaffold activity during antigen receptor signaling

Protein phosphorylation is a commonly used regulatory step that controls signal transduction pathways in a wide array of biological contexts. The finding that a residue is phosphorylated, coupled with the observation that mutation of that residue impacts signaling, often forms the basis for concluding that the phosphorylation of that residue is a key signaling step. However, in certain cases, the situation is more complicated and warrants further study to obtain a clear mechanistic understanding of whether and how the kinase-mediated modification in question is important. CARD11 is a multi-domain signaling scaffold that functions as a hub in lymphocytes to transmit the engagement of antigen receptors into the activation of NF-κB, JNK and mTOR. The phosphorylation of the CARD11 autoinhibitory Inhibitory Domain in response to antigen receptor triggering has been proposed to control the signal-induced conversion of CARD11 from an inactive to an active scaffold in a step required for lymphocyte activation. In this review, I discuss recent data that suggests that this model should be reconsidered for certain phosphorylation events in CARD11 and propose possible experimental avenues for resolution of raised issues.

Complement component C1q plays a critical role in VLRA/VLRC-mediated immune response

In jawless vertebrates, the lamprey complement component C1q (LC1q) acts as a lectin and activates lamprey complement component C3 (LC3) in association with mannose-binding lectin (MBL)-associated serine protease (MASP) via the lectin pathway. Furthermore, LC1q may interact with variable lymphocyte receptor B (VLRB) in a complex with antigens and mediate the activation of LC3, leading to cytolysis. In the present study, we found, for the first time, that LC1q plays a critical role in VLRA/VLRC-mediated immune response. Escherichia coli, Shigella flexneri, Aeromonas hydrophila, Pseudomonas plecoglossicida, Aeromonas allosaccharophila, P. luteola, Brevundimonas diminuta, and Bacillus cereus were isolated from infected Lampetra morii in our laboratory and identified using the 16s rRNA method. A. hydrophila was confirmed as a rapidly spreading lethal pathogen in the larvae of L. morii and was used in subsequent immune stimulation experiments. The results of real-time quantitative polymerase chain reaction (Q-PCR) and immunofluorescence analyses indicated that the RNA and protein expression levels of LC1q were upregulated following exposure to 10⁷ cfu/mL of A. hydrophila, compared to the levels of the naïve group. We obtained LC1q morphants (LC1q MO) of lamprey larvae by morpholino-mediated knockdowns. We found that LC1q played key roles in the embryonic development of lamprey. The median lethal time (LT50) of LC1q MO larvae was 2 d after being exposed to the pathogens, whereas the LT50 of control MO was 5 d. The drastic decrease in LT50 values after LC1q knockdown implies that LC1q plays a critical role in lamprey immune response. Gene expression profiles of LC1q-deficient A. hydrophila, control MO A. hydrophila, wild type A. hydrophila, and naive 1-month-old ammocoetes larvae were compared by examining the expression levels of a selected panel of orthologous genes. It is worth mentioning that LC1q MO affected the VLRA+/VLRC + population genes but did not affect the VLRB + populations. Immunohistochemical data indicated that LC1q deficiency also affected VLRA and VLRC but not VLRB. Thus, LC1q plays a critical role in VLRA/VLRC-mediated immune response in lamprey.

Biological characterisation, expression and functional analysis of non-specific cytotoxic cell receptor protein 1 in Nile tilapia (Oreochromis niloticus)

Non-specific cytotoxic cell receptor protein 1 (NCCRP-1) plays a role in recognition of target cell and activation of non-specific cytotoxic cell (NCC). In this study, the full length of Nile tilapia NCCRP-1 (On-NCCRP-1) was cloned. cDNA is composed of 1045 bp with a 90 bp of 5'-Untranslated Regions (UTR), 702 bp open reading frame (ORF) and 253 bp 3'-UTR, encoding 233 amino acids (GenBank accession no: MF162296). The On-NCCRP-1 genomic sequence is 4471 bp in length and contains six exons and five introns. On-NCCRP-1 possesses some inherent conservative domains, such as proline-rich motifs, antigen recognition site, and F-box-related domain. Subcellular localisation and Western blot analysis indicated that On-NCCRP-1 is located in the cell membrane. The transcript of On-NCCRP-1 was detected in all the examined tissues of healthy Nile tilapia by using qRT-PCR, with the highest expression levels in the liver. Following Streptococcus agalactiae challenged in vivo, the On-NCCRP-1 expression was up-regulated significantly in brain, intestines, head kidney and spleen. In the in vitro analysis, the On-NCCRP-1 expression in NCCs was up-regulated significantly from 8 h to 12 h after LPS challenge, and up-regulated significantly at 12 h after challenged with polyI:C. After NCCs were challenged with inactivated S. agalactiae, the On-NCCRP-1 expression was down-regulated significantly after 24 h. NF-кB pathway was strongly activated by the over-expression of On-NCCRP-1 in HEK-293T cells. These results indicate that On-NCCRP-1, as a membrane surface receptor of NCCs, may play an important role in immune response to pathogenic infection in Nile tilapia.

Sequence-dependent dynamics of synthetic and endogenous RSSs in V(D)J recombination

Developing lymphocytes of jawed vertebrates cleave and combine distinct gene segments to assemble antigen-receptor genes. This process called V(D)J recombination that involves the RAG recombinase binding and cutting recombination signal sequences (RSSs) composed of conserved heptamer and nonamer sequences flanking less well-conserved 12- or 23-bp spacers. Little quantitative information is known about the contributions of individual RSS positions over the course of the RAG-RSS interaction. We employ a single-molecule method known as tethered particle motion to track the formation, lifetime and cleavage of individual RAG-12RSS-23RSS paired complexes (PCs) for numerous synthetic and endogenous 12RSSs. We reveal that single-bp changes, including in the 12RSS spacer, can significantly and selectively alter PC formation or the probability of RAG-mediated cleavage in the PC. We find that some rarely used endogenous gene segments can be mapped directly to poor RAG binding on their adjacent 12RSSs. Finally, we find that while abrogating RSS nicking with Ca2+ leads to substantially shorter PC lifetimes, analysis of the complete lifetime distributions of any 12RSS even on this reduced system reveals that the process of exiting the PC involves unidentified molecular details whose involvement in RAG-RSS dynamics are crucial to quantitatively capture kinetics in V(D)J recombination.

Sequence structure character of IgNAR Sec in whitespotted bamboo shark (Chiloscyllium plagiosum)

Whitespotted bamboo shark (Chiloscyllium plagiosum) is a demersal cartilaginous fish with an adaptive immune system founded upon immunoglobulins. In this manuscript, we characterize the IgNAR of the whitespotted bamboo shark. A newly discovered alternative splicing form of IgNAR Sec (IgNAR_short (ΔC2-C3) Sec) was identified, in which the C1 domain was spliced directly to the C4 domain, the process resulted in a molecule containing three constant domains. However, a single unpaired cysteine remains in the highly flexible hinge region, contributing in the formation of an interchain disulfide bond. Two types of C1 domain were found, and the one lacking a short α-helix showed lower proportion. This finding suggests that short α-helices might be important to the stability of IgNAR. High-throughput sequencing revealed that the percentage of V_NAR types significantly vary between the diverse species of sharks. The variable region of IgNAR (the V_NAR) with small size and stabilization is a potential candidate for immunotherapeutic agents. The structure and stability analysis in this manuscript may be useful in future biomedical applications.

Genome Topology Control of Antigen Receptor Gene Assembly

The past decade has increased our understanding of how genome topology controls RAG endonuclease-mediated assembly of lymphocyte AgR genes. New technologies have illuminated how the large IgH, Igκ, TCRα/δ, and TCRβ loci fold into compact structures that place their numerous V gene segments in similar three-dimensional proximity to their distal recombination center composed of RAG-bound (D)J gene segments. Many studies have shown that CTCF and cohesin protein-mediated chromosome looping have fundamental roles in lymphocyte lineage- and developmental stage-specific locus compaction as well as broad usage of V segments. CTCF/cohesin-dependent loops have also been shown to direct and restrict RAG activity within chromosome domains. We summarize recent work in elucidating molecular mechanisms that govern three-dimensional chromosome organization and in investigating how these dynamic mechanisms control V(D)J recombination. We also introduce remaining questions for how CTCF/cohesin-dependent and -independent genome architectural mechanisms might regulate compaction and recombination of AgR loci.

Alterations in chromatin at antigen receptor loci define lineage progression during B lymphopoiesis

Developing lymphocytes diversify their antigen receptor (AgR) loci by variable (diversity) joining (V[D]J) recombination. Here, using the micrococcal nuclease (MNase)-based chromatin accessibility (MACC) assay with low-cell count input, we profile both small-scale (kilobase) and large-scale (megabase) changes in chromatin accessibility and nucleosome occupancy in primary cells during lymphoid development, tracking the changes as different AgR loci become primed for recombination. The three distinct chromatin structures identified in this work define unique features of immunoglobulin H (IgH), Igκ, and T cell receptor-α (TCRα) loci during B lymphopoiesis. In particular, we find locus-specific temporal changes in accessibility both across megabase-long AgR loci and locally at the recombination signal sequences (RSSs). These changes seem to be regulated independently and can occur prior to lineage commitment. Large-scale changes in chromatin accessibility occur without significant change in nucleosome density and represent key features of AgR loci not previously described. We further identify local dynamic repositioning of individual RSS-associated nucleosomes at IgH and Igκ loci while they become primed for recombination during B cell commitment. These changes in chromatin at AgR loci are regulated in a locus-, lineage-, and stage-specific manner during B lymphopoiesis, serving either to facilitate or to impose a barrier to V(D)J recombination. We suggest that local and global changes in chromatin openness in concert with nucleosome occupancy and placement of histone modifications facilitate the temporal order of AgR recombination. Our data have implications for the organizing principles that govern assembly of these large loci as well as for mechanisms that might contribute to aberrant V(D)J recombination and the development of lymphoid tumors.

Identification, functional characterization and the potential role of variable lymphocyte receptor EsVLRA from Eriocheir sinensis in response to secondary challenge after Vibrio parahaemolyticus vaccine

Variable lymphocyte receptors (VLRs) play an important role via their antigen-special reorganization in jawless vertebrates (agnathans) adaptive immune response. In the present study, the open reading frame (ORF) of Eriocheir sinensis VLRA (designated as EsVLRA) was identified. EsVLRA comprised a 799-amino-acid polypeptide with one LRR_NT domain, thirteen LRR domains and one LRR_CT domain, which showed a high domain consistency of the VLR genes in lamprey (Petromyzon marinus). The transcript of EsVLRA was detected in all examined tissues with the highest level detected in hepatopancreas. Notably, the expression of EsVLRA in hepatopancreas, gonads, gill and intestine of male crabs was significantly higher than that in females. The recombinant EsVLRA exhibited strong bacteria-binding activity rather than antibacterial activity, suggesting its crucial role in immune recognition. Furthermore, 6 h earlier response and a significantly higher peak of EsVLRA mRNA expression was observed after challenge with live Vibrio parahaemolyticus (240.6-fold, P < 0.01, crabs receive secondary challenge after V. parahaemolyticus vaccine to the carbs only receive twice PBS injection, N = 6), compared with those only received first injection with formalin-inactivated V. parahaemolyticus (39.7-fold, P < 0.01, challenge 6 h to vaccination 12 h). The findings of this study together demonstrated that EsVLRA plays an important role in the immune system of E. sinensis, serving as a pattern recognition receptor and involving in the immune priming.

In Vitro Maturation of a Humanized Shark VNAR Domain to Improve Its Biophysical Properties

VNAR domains are the binding regions of new antigen receptor proteins (IgNAR) which are unique to sharks, skates, and rays (Elasmobranchii). Individual VNAR domains can bind antigens independently and are the smallest reported adaptive immune recognition entities in the vertebrate kingdom. Sharing limited sequence homology with human immunoglobulin domains, their development and use as biotherapeutic agents require that they be humanized to minimize their potential immunogenicity. Efforts to humanize a human serum albumin (HSA)-specific VNAR, E06, resulted in protein molecules that initially had undesirable biophysical properties or reduced affinity for cognate antigen. Two lead humanized anti-HSA clones, v1.10 and v2.4, were subjected to a process of random mutagenesis using error-prone PCR. The mutated sequences for each humanized VNAR variant were screened for improvements in affinity for HSA and biophysical properties, achieved without a predicted increase in overall immunogenicity.

Coordinated regulation of scaffold opening and enzymatic activity during CARD11 signaling

The activation of key signaling pathways downstream of antigen receptor engagement is critically required for normal lymphocyte activation during the adaptive immune response. CARD11 is a multidomain signaling scaffold protein required for antigen receptor signaling to NF-κB, c-Jun N-terminal kinase, and mTOR. Germline mutations in the CARD11 gene result in at least four types of primary immunodeficiency, and somatic CARD11 gain-of-function mutations drive constitutive NF-κB activity in diffuse large B cell lymphoma and other lymphoid cancers. In response to antigen receptor triggering, CARD11 transitions from a closed, inactive state to an open, active scaffold that recruits multiple signaling partners into a complex to relay downstream signaling. However, how this signal-induced CARD11 conversion occurs remains poorly understood. Here we investigate the role of Inducible Element 1 (IE1), a short regulatory element in the CARD11 Inhibitory Domain, in the CARD11 signaling cycle. We find that IE1 controls the signal-dependent Opening Step that makes CARD11 accessible to the binding of cofactors, including Bcl10, MALT1, and the HOIP catalytic subunit of the linear ubiquitin chain assembly complex. Surprisingly, we find that IE1 is also required at an independent step for the maximal activation of HOIP and MALT1 enzymatic activity after cofactor recruitment to CARD11. This role of IE1 reveals that there is an Enzymatic Activation Step in the CARD11 signaling cycle that is distinct from the Cofactor Association Step. Our results indicate that CARD11 has evolved to actively coordinate scaffold opening and the induction of enzymatic activity among recruited cofactors during antigen receptor signaling.

Antigen Receptor Sequence Reconstruction and Clonality Inference from scRNA-Seq Data

In this chapter, we describe TraCeR and BraCeR, our computational tools for reconstruction of paired full-length antigen receptor sequences and clonality inference from single-cell RNA-seq (scRNA-seq) data. In brief, TraCeR reconstructs T-cell receptor (TCR) sequences from scRNA-seq data by extracting sequencing reads derived from TCRs by aligning the reads from each cell against synthetic TCR sequences. TCR-derived reads are then assembled into full-length recombined TCR sequences. BraCeR builds on the TraCeR pipeline and accounts for somatic hypermutations (SHM) and isotype switching. Here we discuss experimental design, use of the tools, and interpretation of the results.

Transcriptomic analysis of immunoglobulin novel antigen receptor (IgNAR) heavy chain constant domains of brownbanded bamboo shark (Chiloscyllium punctatum)

Cartilaginous fish are the evolutionarily oldest group of animals which possess antibodies, T cell receptors and major histocompatibility complex (MHC). The immunoglobulin novel antigen receptor (IgNAR) found in cartilaginous fish is a heavy chain homodimer which lacks light chain. The presence of non-canonical cysteine molecules and lack of CDR2 region make it more significant. To synthesize active binding domains based on variable region of IgNAR (VNAR), knowledge on the constant region dynamics play a significant role. The IgNAR exhibit species variations in its primary sequence features; hence, this study was conducted to determine the IgNAR heavy chain constant domain of the brownbanded bamboo shark (Chiloscyllium punctatum). Peripheral blood leukocytes (PBL) isolated from adult bamboo sharks were used to synthesize a cDNA library. A total of four billion residues of two million sequences (average length 218.41 bp) were obtained. Assembled sequences were aligned with published cartilaginous fish IgNAR constant region sequences. Transcriptome analysis revealed two distinct types of IgNAR in the brownbanded bamboo shark. Also, constant-1 domain sequences displayed 13 unique sequences which may reflect the least number of IgNAR gene clusters. The phylogenetic analysis revealed the closest relationship with the nurse shark (Ginglymostoma cirratum) followed by the wobbegong shark (Orectolobus maculatus) which belong to the same order Orectolobiformes. Analysis of the constant domains of the brownbanded bamboo shark IgNAR revealed an evolutionarily conserved nature and this knowledge can be used to design primers for VNAR cloning. Furthermore, knowledge on the structural features in IgNAR constant domains that increase the stability could be useful in the process of stabilizing human immunoglobulins.

Exploiting antigen receptor information to quantify index switching in single-cell transcriptome sequencing experiments

By offering high sequencing speed and ultra-high-throughput at a low price, Illumina next-generation sequencing platforms have been widely adopted in recent years. However, an experiment with multiplexed library could be at risk of molecular recombination, known as "index switching", which causes a proportion of the reads to be assigned to an incorrect sample. It is reported that a new advance, exclusion amplification (ExAmp) in conjunction with the patterned flow cell technology introduced on HiSeq 3000/HiSeq 4000/HiSeq X sequencing systems, potentially suffers from a higher rate of index switching than conventional bridge amplification. We took advantage of the diverse but highly cell-specific expression of antigen receptors on immune cells to quantify index switching on single cell RNA-seq data that were sequenced on HiSeq 3000 and HiSeq 4000. By utilizing the unique antigen receptor expression, we could quantify the spread-of-signal from many different wells (n = 55 from total of three batches) due to index switching. Based on full-length T cell receptor (TCR) sequences from all samples reconstructed by TraCeR and TCR gene expression quantified by Kallisto, we found index switching in all three batches of experiments investigated. The median percentage of incorrectly detected markers was estimated to be 3.9% (interquartile range (IQR): 1.7%-7.3%). We did not detect any consistent patterns of certain indices to be more prone to switching than others, suggesting that index switching is a stochastic process. Our results confirm that index switching is a problem that affects samples run in multiplexed libraries on Illumina HiSeq 3000 and HiSeq 4000 platforms.

A novel CD81 homolog identified in lamprey, Lampetra japonica, with roles in the immune response of lamprey VLRB+ lymphocytes

The cluster of differentiation 81 (CD81), a member of the transmembrane 4 superfamily, is primarily found to be expressed in a wide variety of cells including T and B cells of vertebrates as a critical modulator. In the present study, the open reading frame of a CD81 gene homolog (Lja-CD81) was cloned in lamprey, Lampetra japonica, which is 702 bp long and encodes a protein of 233-amino acids. Although Lja-CD81 seems to be close to CD9 molecules in their full-length sequences, Lja-CD81 possesses higher identity to vertebrates' CD81 than to CD9 (including a lamprey CD9) molecules in their large extracellular loops. In addition, it also possesses a myristoylation site (Met-Gly-Val-Glu-Gly-Cys-Leu-Lys) in its N-terminal region which is identical to the N-terminal regions of CD81 molecules. These data suggest that CD9 and CD81 molecules diverged no later than the emergence of jawless vertebrates. The mRNA levels of Lja-CD81 in lymphocytes and supraneural myeloid bodies were up-regulated significantly after stimulation with mixed antigens, and a similar expressional pattern of Lja-CD81 at protein level was also confirmed. Furthermore, Lja-CD81 was found to be co-localized with variable lymphocyte receptor B (VLRB) evenly on the cell membrane of peripheral blood lymphocytes isolated from control group, but they were found to aggregate on one side of the membrane of peripheral blood VLRB+ lymphocytes after stimulation with mixed antigens. All these results indicate that the Lja-CD81 identified in lamprey may play an important role in the immune response of lamprey VLRB+ lymphocytes.

The chimeric TAC receptor co-opts the T cell receptor yielding robust anti-tumor activity without toxicity

Engineering T cells with chimeric antigen receptors (CARs) is an effective method for directing T cells to attack tumors, but may cause adverse side effects such as the potentially lethal cytokine release syndrome. Here the authors show that the T cell antigen coupler (TAC), a chimeric receptor that co-opts the endogenous TCR, induces more efficient anti-tumor responses and reduced toxicity when compared with past-generation CARs. TAC-engineered T cells induce robust and antigen-specific cytokine production and cytotoxicity in vitro, and strong anti-tumor activity in a variety of xenograft models including solid and liquid tumors. In a solid tumor model, TAC-T cells outperform CD28-based CAR-T cells with increased anti-tumor efficacy, reduced toxicity, and faster tumor infiltration. Intratumoral TAC-T cells are enriched for Ki-67+ CD8+ T cells, demonstrating local expansion. These results indicate that TAC-T cells may have a superior therapeutic index relative to CAR-T cells.

A cold-blooded view of adaptive immunity

The adaptive immune system arose 500 million years ago in ectothermic (cold-blooded) vertebrates. Classically, the adaptive immune system has been defined by the presence of lymphocytes expressing recombination-activating gene (RAG)-dependent antigen receptors and the MHC. These features are found in all jawed vertebrates, including cartilaginous and bony fish, amphibians and reptiles and are most likely also found in the oldest class of jawed vertebrates, the extinct placoderms. However, with the discovery of an adaptive immune system in jawless fish based on an entirely different set of antigen receptors - the variable lymphocyte receptors - the divergence of T and B cells, and perhaps innate-like lymphocytes, goes back to the origin of all vertebrates. This Review explores how recent developments in comparative immunology have furthered our understanding of the origins and function of the adaptive immune system.

Genetic restriction of antigen-presentation dictates allergic sensitization and disease in humanized mice

BACKGROUND

Immunoglobulin(Ig)E-associated allergies result from misguided immune responses against innocuous antigens. CD4+ T lymphocytes are critical for initiating and perpetuating that process, yet the crucial factors determining whether an individual becomes sensitized towards a given allergen remain largely unknown.

OBJECTIVE

To determine the key factors for sensitization and allergy towards a given allergen.

METHODS

We here created a novel human T cell receptor(TCR) and human leucocyte antigen (HLA)-DR1 (TCR-DR1) transgenic mouse model of asthma, based on the human-relevant major mugwort (Artemisia vulgaris) pollen allergen Art v 1 to examine the critical factors for sensitization and allergy upon natural allergen exposure via the airways in the absence of systemic priming and adjuvants.

RESULTS

Acute allergen exposure led to IgE-independent airway hyperreactivity (AHR) and T helper(Th)2-prone lung inflammation in TCR-DR1, but not DR1, TCR or wildtype (WT) control mice, that was alleviated by prophylactic interleukin(IL)-2-αIL-2 mAb complex-induced expansion of Tregs. Chronic allergen exposure sensitized one third of single DR1 transgenic mice, however, without impacting on lung function. Similar treatment led to AHR and Th2-driven lung pathology in >90% of TCR-DR1 mice. Prophylactic and therapeutic expansion of Tregs with IL-2-αIL-2 mAb complexes blocked the generation and boosting of allergen-specific IgE associated with chronic allergen exposure.

CONCLUSIONS

We identify genetic restriction of allergen presentation as primary factor dictating allergic sensitization and disease against the major pollen allergen from the weed mugwort, which frequently causes sensitization and disease in humans. Furthermore, we demonstrate the importance of the balance between allergen-specific T effector and Treg cells for modulating allergic immune responses.

Crystal structure of an anti-idiotype variable lymphocyte receptor

Variable lymphocyte receptors (VLRs), the leucine-rich repeat (LRR)-based antigen receptors of jawless fish, have great utility in a wide variety of biochemical and biological applications, similar to classical Ig-based antibodies. VLR-based reagents may be particularly useful when traditional antibodies are not available. An anti-idiotype lamprey VLR, VLR39, has previously been identified that recognizes the heavy-chain CDR3 of the B-cell receptor (BCR) of a leukemic clone from a patient with chronic lymphocytic leukemia (CLL). VLR39 was used successfully to track the re-emergence of this clone in the patient following chemotherapy. Here, the crystal structure of VLR39 is presented at 1.5 Å resolution and compared with those of other protein-specific VLRs. VLR39 adopts a curved solenoid fold and exhibits substantial structural similarity to other protein-binding VLRs. VLR39 has a short LRRCT loop that protrudes outwards away from the concave face and is similar to those of its protein-specific VLR counterparts. Analysis of the VLR39-BCR interaction by size-exclusion chromatography and biolayer interferometry using the scFv version of the BCR confirms that VLR39 recognizes the BCR Fv region. Such VLR-based reagents may be useful for identifying and monitoring leukemia in CLL patients and in other clinical diagnostic assays.

Omics in fish mucosal immunity

The mucosal immune system of fish is a complex network of immune cells and molecules that are constantly surveilling the environment and protecting the host from infection. A number of "omics" tools are now available and utilized to understand the complexity of mucosal immune systems in non-traditional animal models. This review summarizes recent advances in the implementation of "omics" tools pertaining to the four mucosa-associated lymphoid tissues in teleosts. Genomics, transcriptomics, proteomics, and "omics" in microbiome research require interdisciplinary collaboration and careful experimental design. The data-rich datasets generated are proving really useful at discovering new innate immune players in fish mucosal secretions, identifying novel markers of specific mucosal immune responses, unraveling the diversity of the B and T cell repertoires and characterizing the diversity of the microbial communities present in teleost mucosal surfaces. Bioinformatics, data analysis and storage platforms should be developed to facilitate rapid processing of large datasets, especially when mammalian tools such as bioinformatics analysis software are not available in fishes.

Anti-CD 19 and anti-CD 20 CAR-modified T cells for B-cell malignancies: a systematic review and meta-analysis

Chimeric antigen receptor modified T cells targeting CD19 and CD20 have shown activity in Phase I, II trials of patients with hematological malignancies. We conducted a systematic review and meta-analysis of all published clinical trials studying the role of efficacy as well as safety of CD-19 and CD-20 chimeric antigen receptor-T therapy for B-cell hematologic malignancies. A total of 16 studies with 195 patients were identified. The pooled analysis showed an overall response rate of 61% (118/195) with complete response of 42% (81/195) and partial response of 19% (37/195). Major adverse events were cytokine release syndrome 33%, neurotoxicity 33% and B-cell aplasia 54%. Collectively, the results indicate encouraging response in relapsed/refractory B lymphoma and leukemia, especially in acute lymphoblastic leukemia (ALL) patients.

False-positive HIV nucleic acid amplification testing during CAR T-cell therapy

Advancements in immunotherapy have opened a new era in oncology, to include genetic modification of human T-cells to express a chimeric antigen receptor (CAR) that enables targeted tumor recognition (Kochenderfer et al., 2015; Lee et al., 2015; Maus and Levine 2016; Rosenberg et al., 2008). Herein, we report a false-positive HIV testing in a patient who had undergone CAR T-cell therapy created with a lentiviral vector.

Harnessing the Immunotherapy Revolution for the Treatment of Childhood Cancers

Cancer immunotherapies can be classified into agents that amplify natural immune responses (e.g., checkpoint inhibitors) versus synthetic immunotherapies designed to initiate new responses (e.g., monoclonal antibodies [mAbs], chimeric antigen receptors [CARs]). Checkpoint inhibitors mediate unprecedented benefit in some adult cancers, but have not demonstrated significant activity in pediatric cancers, likely due their paucity of neoantigens. In contrast, synthetic immunotherapies such as mAbs and CAR T cells demonstrate impressive effects against childhood cancers. Intense efforts are underway to enhance the effectiveness of pediatric cancer immunotherapies through improved engineering of synthetic immunotherapies and by combining these with agents designed to amplify immune responses.

T Cell-Associated Immunotherapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases worldwide with limited therapeutic options. Accumulating evidences suggest that immunotherapy could be a promising option for treating HCC. T cell-associated immunotherapy lights up the hope for the improvement of complementary approach to conventional HCC treatments, which needs further research to consummate the clinical consequences. The present work reviewed several T cells associated cellular immunotherapies for HCC, including immune checkpoint blockade, gene-engineered T cells, bispecific T cell engagers, and so on. We also analyzed how these immunotherapies can mediate tumor cell eradication and evaluated their superiority or insufficiency.

Checkpoint inhibition and cellular immunotherapy in lymphoma

Hodgkin and non-Hodgkin lymphoma are both good targets for immunotherapy, as they are accessible to antibodies and cell-based immunotherapy, express costimulatory molecules, and express lineage-restricted, viral, and unique tumor antigens. Blockade of the programmed-death 1 (PD-1) immune checkpoint has produced very encouraging response rates in patients with Hodgkin lymphoma, whereas adoptive transfer of Epstein-Barr Virus (EBV)-specific T cells has shown clinical activity in patients with posttransplant lymphoma and other EBV-associated lymphomas. T cells can also be genetically modified with chimeric antigen receptors (CARs) to confer specificity for surface antigens, and studies of CD19 CARs in lymphoma also have had encouraging response rates. Future directions include combination of checkpoint blockade and adoptive T-cell studies.

Progress in the use of swine in developmental immunology of B and T lymphocytes

The adaptive immune system of higher vertebrates is believed to have evolved to counter the ability of pathogens to avoid expulsion because their high rate of germline mutations. Vertebrates developed this adaptive immune response through the evolution of lymphocytes capable of somatic generation of a diverse repertoire of their antigenic receptors without the need to increase the frequency of germline mutation. The focus of our research and this article is on the ontogenetic development of the lymphocytes, and the repertoires they generate in swine. Several features are discussed including (a) the "closed" porcine placenta means that de novo fetal development can be studied for 114 days without passive influence from the mother, (b) newborn piglets are precocial permitting them to be reared without their mothers in germ-free isolators, (c) swine are members of the γδ-high group of mammals and thus provides a greater opportunity to characterize the role of γδ T cells and (d) because swine have a simplified variable heavy and light chain genome they offer a convenient system to study antibody repertoire development.

Investigation of variable lymphocyte receptors in the alternative adaptive immune response of hagfish

Jawless vertebrates have an alternative adaptive immune system mediated by variable lymphocyte receptors (VLRs), VLRA, VLRC and VLRB. In investigation on the adaptive immunity of hagfish, avian influenza virus hemagglutinin (H9N2-HA1) was used as a model antigen, with mRNA expression levels of VLRA, VLRC and Ikaros were up-regulated in the first week post-immunization. CD45 was up-regulated after the first week; and expression of VLRB progressively increased over the course of the trial. The transcriptional/translational activation of VLRB in blood was verified. The VLRBs cloned from these transcripts showed diversity in their leucine-rich repeats (LRRs). The production of specific VLRB increased in a time- and dose-dependent manner, detected by an anti-VLRB antibody (11G5). The plasma VLRB could distinguish H9N2-HA1 from unrelated proteins, but not from other HA1 subtypes. Together, our findings show that VLRs play a major role in the alternative adaptive immune system of hagfish by responding to specific foreign substances, such as H9N2-HA1.

Biochemical Characterization of Nonamer Binding Domain of RAG1 Reveals its Thymine Preference with Respect to Length and Position

RAG complex consisting of RAG1 and RAG2 is a site-specific endonuclease responsible for the generation of antigen receptor diversity. It cleaves recombination signal sequence (RSS), comprising of conserved heptamer and nonamer. Nonamer binding domain (NBD) of RAG1 plays a central role in the recognition of RSS. To investigate the DNA binding properties of the domain, NBD of murine RAG1 was cloned, expressed and purified. Electrophoretic mobility shift assays showed that NBD binds with high affinity to nonamer in the context of 12/23 RSS or heteroduplex DNA. NBD binding was specific to thymines when single stranded DNA containing poly A, C, G or T were used. Biolayer interferometry studies showed that poly T binding to NBD was robust and comparable to that of 12RSS. More than 23 nt was essential for NBD binding at homothymidine stretches. On a double-stranded DNA, NBD could bind to A:T stretches, but not G:C or random sequences. Although NBD is indispensable for sequence specific activity of RAGs, external supplementation of purified nonamer binding domain to NBD deleted cRAG1/cRAG2 did not restore its activity, suggesting that the overall domain architecture of RAG1 is important. Therefore, we define the sequence requirements of NBD binding to DNA.

Efficient generation of gene-modified human natural killer cells via alpharetroviral vectors

Natural killer (NK) cells play an important role in tumor immunotherapy with their unique capability of killing transformed cells without the need for prior sensitization and without major histocompatibility complex (MHC)/peptide restriction. However, tumor cells can escape NK cell cytotoxicity by various tumor immune escape mechanisms. To overcome these escape mechanisms, NK cells can be modified to express chimeric antigen receptors (CARs), enhancing their tumor-specific cytotoxicity. To determine the most efficacious method to modify human NK cells, we compared different retroviral vector systems, retroviral pseudotypes, and transduction protocols. Using optimized transduction conditions, the highest transduction levels (up to 60%) were achieved with alpharetroviral vectors. Alpharetroviral-modified primary human NK cells exhibited no alteration in receptor expression and had similar degranulation activity as untransduced NK cells, thus demonstrating that alpharetroviral modification did not negatively affect NK cell cytotoxicity. Transduction of NK cells with an alpharetroviral vector containing a CD19 CAR expression cassette selectively enhanced NK cell cytotoxicity towards CD19-expressing leukemia cells, achieving nearly complete elimination of leukemia cells after 48 h. Taken together, alpharetroviral vectors are promising tools for NK cell-mediated cancer immunotherapy applications.

KEY MESSAGES

Efficient modification of human NK cells using alpharetroviral vectors. Anti-CD19-CAR-NK cells exhibited improved cytotoxicity towards CD19(+) leukemia cells. Alpharetroviral vectors are promising tools for immunotherapy applications using NK cells.

In Vitro Generation of Human NK Cells Expressing Chimeric Antigen Receptor Through Differentiation of Gene-Modified Hematopoietic Stem Cells

NK cells represent a very promising source for adoptive cellular approaches for cancer immunotherapy, and extensive research has been conducted, including clinical trials. Gene modification of NK cells can direct their specificity and enhance their function, but the efficiency of gene transfer techniques is very limited. Here we describe two protocols designed to generate mature human NK cells from gene-modified hematopoietic stem cells. These protocols use chimeric antigen receptor as the transgene, but could potentially be modified for the expression any particular transgene in human NK cells.

Modification of cytokine-induced killer cells with chimeric antigen receptors (CARs) enhances antitumor immunity to epidermal growth factor receptor (EGFR)-positive malignancies

Epidermal growth factor receptor (EGFR, ErbB1, Her-1) is a cell surface molecule overexpressing in a variety of human malignancies and, thus, is an excellent target for immunotherapy. Immunotherapy targeting EGFR-overexpressing malignancies using genetically modified immune effector cells is a novel and promising approach. In the present study, we have developed an adoptive cellular immunotherapy strategy based on the chimeric antigen receptor (CAR)-modified cytokine-induced killer (CAR-CIK) cells specific for the tumor cells expressing EGFR. To generate CAR-CIK cells, a lentiviral vector coding the EGFR-specific CAR was constructed and transduced into the CIK cells. The CAR-CIK cells showed significantly enhanced cytotoxicity and increased production of cytokines IFN-γ and IL-2 when co-cultured with EGFR-positive cancer cells. In tumor xenografts, adoptive immunotherapy of CAR-CIK cells could inhibit tumor growth and prolong the survival of EGFR-overexpressing human tumor xenografts. Moreover, tumor growth inhibition and prolonged survival in mice with EGFR(+) human cancer were associated with the increased persistence of CAR-CIK cells in vivo. Our study indicates that modification with EGFR-specific CAR strongly enhances the antitumor activity of the CIK cells against EGFR-positive malignancies.

Structural Design of Engineered Costimulation Determines Tumor Rejection Kinetics and Persistence of CAR T Cells

T cell engineering is a powerful means to rapidly generate anti-tumor T cells. The costimulatory properties of second-generation chimeric antigen receptors (CARs) determine the overall potency of adoptively transferred T cells. Using an in vivo "stress test" to challenge CD19-targeted T cells, we studied the functionality and persistence imparted by seven different CAR structures providing CD28 and/or 4-1BB costimulation. One configuration, which uses two signaling domains (CD28 and CD3ζ) and the 4-1BB ligand, provided the highest therapeutic efficacy, showing balanced tumoricidal function and increased T cell persistence accompanied by an elevated CD8/CD4 ratio and decreased exhaustion. Remarkably, induction of the IRF7/IFNβ pathway was required for optimal anti-tumor activity. Thus, 1928z-41BBL T cells possess strikingly potent intrinsic and immunomodulatory qualities.

[Clonality lymphoid study through rearrangement analysis of antigen receptor]

As a rule, malignant lymphoid proliferations are clonal. While most of the time the biological potential can be established through routine pathologic examination and auxiliary techniques, some cases are difficult to classify. Moreover, there are situations in which there are dominant clones whose analysis are important, such as occur in autoimmune diseases and immunodeficiency. This paper presents in an understandable way the main techniques for the study of clonality in lymphoid lesions, i.e. the analysis of rearrangements of antigen receptor genes by multiplex polymerase chain reaction (PCR) based tests.

Variable Lymphocyte Receptors: A Current Overview

Jawless vertebrates represented by lampreys and hagfish mount antigen-specific immune responses using variable lymphocyte receptors. These receptors generate diversity comparable to that of T-cell and B-cell receptors by assembling multiple leucine-rich repeat modules with highly variable sequences. Although it is true that jawed and jawless vertebrates have structurally unrelated antigen receptors, their adaptive immune systems have much in common. Most notable is the conservation of lymphocyte lineages. It appears that specialized lymphocyte lineages emerged in a common vertebrate ancestor and that jawed and jawless vertebrates co-opted different antigen receptors within the context of such lymphocyte lineages.

Enhanced cytotoxicity of natural killer cells following the acquisition of chimeric antigen receptors through trogocytosis

Natural killer (NK) cells have the capacity to target tumors and are ideal candidates for immunotherapy. Viral vectors have been used to genetically modify in vitro expanded NK cells to express chimeric antigen receptors (CARs), which confer cytotoxicity against tumors. However, use of viral transduction methods raises the safety concern of viral integration into the NK cell genome. In this study, we used trogocytosis as a non-viral method to modify NK cells for immunotherapy. A K562 cell line expressing high levels of anti-CD19 CARs was generated as a donor cell to transfer the anti-CD19 CARs onto NK cells via trogocytosis. Anti-CD19 CAR expression was observed in expanded NK cells after these cells were co-cultured for one hour with freeze/thaw-treated donor cells expressing anti-CD19 CARs. Immunofluorescence analysis confirmed the localization of the anti-CD19 CARs on the NK cell surface. Acquisition of anti-CD19 CARs via trogocytosis enhanced NK cell-mediated cytotoxicity against the B-cell acute lymphoblastic leukemia (B-ALL) cell lines and primary B-ALL cells derived from patients. To our knowledge, this is the first report that describes the increased cytotoxicity of NK cells following the acquisition of CARs via trogocytosis. This novel strategy could be a potential valuable therapeutic approach for the treatment of B-cell tumors.

Molecular cloning of NCCRP-1 gene from orange-spotted grouper (Epinephelus coioides) and characterization of NCCRP-1(+) cells post Cryptocaryon irritans infection

Nonspecific cytotoxic cells (NCCs) are an important cytotoxic cell population in the innate teleost immune system. The receptor designated "NCC receptor protein 1" (NCCRP-1) has been reported to be involved in the recognition and activation of NCCs. In this study, the full-length cDNA of Epinephelus coioides NCCRP-1 (ecnccrp-1) was cloned. The open reading frame (ORF) of ecnccrp-1 is 699 bp, encoding a 232 amino acid protein that includes proline-rich motifs at the N-terminus and is related to the F-box associated family. Although a bioinformatics analysis showed that EcNCCRP-1 had no signal peptide or transmembrane helices, a polyclonal antibody directed against recombinant EcNCCRP-1 efficiently labeled a membrane protein in the head kidney, detected with Western blot analysis, which indicated that the protein localized to the cell surface. RT-PCR showed that the constitutive expression of ecnccrp-1 was higher in the lymphoid organs, such as the trunk kidney, spleen, head kidney, and thymus, and lower in brain, heart, fat, liver, muscle, and skin. After infection with Cryptocaryon irritans, the transcription of ecnccrp-1 was analyzed at the infected sites (skin and gills) and in the systemic immune organs (head kidney and spleen). At the infected sites, especially the skin, ecnccrp-1 expression was upregulated at 6h post infection, reaching peak expression on day 3 post the primary infection. However, the expression patterns differed in the systemic immune organs. In the spleen, ecnccrp-1 was gradually increased in the early infection period and decreased sharply on day 3 post the primary infection, whereas in the head kidney, the transcription of ecnccrp-1 was depressed during almost the whole course of infection. An immunohistochemical analysis showed that EcNCCRP-1(+) cells accumulated at the sites of infection with C. irritans. These results suggested that NCCs were involved in the process of C. irritans infection in E. coioides.

A novel ex vivo isolation and expansion procedure for chimeric antigen receptor engrafted human T cells

Genetically engineered T lymphocytes are a promising option for cancer therapy. Prior to adoptive transfer they have to be expanded in vitro to reach therapeutically sufficient numbers. So far, no universal method exists for selective in vitro expansion of engineered T lymphocytes. In order to overcome this problem and for proof of concept we incorporated a novel unique peptide sequence of ten amino acids as epitope (E-Tag) into the binding domains of two novel chimeric antigen receptors (ECARs) directed against either prostate stem cell antigen (PSCA) for the treatment of prostate cancer (PCa) or CD33 for the treatment of acute myeloide leukemia (AML). The epitope tag then was utilized for expanding ECAR engrafted T cells by triggering the modified T cells via a monoclonal antibody directed against the E-Tag (Emab). Moreover, the E-Tag served as an efficient selection epitope for immunomagnetic isolation of modified T cells to high purity. ECAR engrafted T cells were fully functional and mediated profound anti-tumor effects in the respective models of PCa or AML both in vitro and in vivo. The method can be integrated straightforward into clinical protocols to improve therapeutic efficiency of tumor treatment with CAR modified T lymphocytes.

Advanced generation anti-prostate specific membrane antigen designer T cells for prostate cancer immunotherapy

BACKGROUND

Adoptive immunotherapy by infusion of designer T cells (dTc) engineered with chimeric antigen receptors (CARs) for tumoricidal activity represents a potentially highly specific modality for the treatment of cancer. In this study, 2nd generation (gen) anti-prostate specific membrane antigen (PSMA) dTc were developed for improving the efficacy of previously developed 1st gen dTc for prostate cancer immunotherapy. The 1st gen dTc are modified with chimeric immunoglobulin-T cell receptor (IgTCR) while the 2nd gen dTc are engineered with an immunoglobulin-CD28-T cell receptor (IgCD28TCR), which incorporates a CD28 costimulatory signal for optimal T cell activation.

METHODS

A 2nd gen anti-PSMA IgCD28TCR CAR was constructed by inserting the CD28 signal domain into the 1st gen CAR. 1st and 2nd gen anti-PSMA dTc were created by transducing human T cells with anti-PSMA CARs and their antitumor efficacy was compared for specific activation on PSMA-expressing tumor contact, cytotoxicity against PSMA-expressing tumor cells in vitro, and suppression of tumor growth in an animal model.

RESULTS

The 2nd gen dTc can be optimally activated to secrete larger amounts of cytokines such as IL2 and IFNγ than 1st gen and to proliferate more vigorously on PSMA-expressing tumor contact. More importantly, the 2nd gen dTc preserve the PSMA-specific cytotoxicity in vitro and suppress tumor growth in animal models with significant higher potency.

CONCLUSIONS

Our results demonstrate that 2nd gen anti-PSMA designer T cells exhibit superior antitumor functions versus 1st gen, providing a rationale for advancing this improved agent toward clinical application in prostate cancer immunotherapy.

Genetic modification of mouse effector and helper T lymphocytes expressing a chimeric antigen receptor

Genetic modification of primary mouse T cells with chimeric antigen receptors (CAR) has emerged as an important tool for optimizing adoptive T cell immunotherapy strategies. However, limitations in current protocols for generating highly pure and sufficient numbers of enriched effector and helper CAR(+) T cell subsets remain problematic. Here, we describe a new retroviral transduction protocol for successfully generating transduced CD8(+) and CD4(+) T lymphocytes for in vitro and in vivo characterization.

Functional aspects of fish lymphocytes

After almost 40 years of studies in comparative immunology, some light has been shed on the evolutive immunobiology of vertebrates, and experimental evidences have shown that acquired immunity, defined by somatic recombination of antigen-binding molecules and memory, is an achievement as ancient as jawless vertebrates. However, the molecular processes generating antigen receptors evolved independently between jawless and jawed fishes, and produced lymphocytic cells with similar functions but employing different sets of genes. In recent years, data have been provided describing some in vitro and in vivo functional responses of fish lymphocytes. After a long gap, the number of specific markers for fish lymphocytes is increasing, thus allowing a first characterisation of lymphocyte subsets. Overall, in the near future it will be possible to open a new chapter in fish immunology and investigate functional immunity of lymphocyte responses by combining the extensive knowledge on immune gene products with markers for molecules and cells. The present review summarizes current knowledge on functional features of fish lymphocytes.

Stochastic gene expression in mammals: lessons from olfaction

One of the remarkable characteristics of higher organisms is the enormous assortment of cell types that emerge from a common genome. The immune system, with the daunting duty of detecting an astounding number of pathogens, and the nervous system with the equally bewildering task of perceiving and interpreting the external world, are the quintessence of cellular diversity. As we began to appreciate decades ago, achieving distinct expression programs among similar cell types cannot be accomplished solely by deterministic regulatory systems, but by the involvement of some type of stochasticity. In the last few years our understanding of these non-deterministic mechanisms is advancing, and this review will provide a brief summary of the current view of stochastic gene expression with focus on olfactory receptor (OR) gene choice, the epigenetic underpinnings of which recently began to emerge.