OBJECTIVE

A semi-mechanistic multiple-analyte population pharmacokinetics (PK) model was developed to describe the complex relationship between the different analytes of monomethyl auristatin E (MMAE) containing antibody-drug conjugates (ADCs) and to provide insight regarding the major pathways of conjugate elimination and unconjugated MMAE release in vivo.

METHODS

For an anti-CD79b-MMAE ADC the PK of total antibody (Tab), conjugate (evaluated as antibody conjugated MMAE or acMMAE), and unconjugated MMAE were quantified in cynomolgus monkeys for single (0.3, 1, or 3 mg/kg), and multiple doses (3 or 5 mg/kg, every-three-weeks for 4 doses). The PK data of MMAE in cynomolgus monkeys, after intravenous administration of MMAE at single doses (0.03 or 0.063 mg/kg), was included in the analysis. A semi-mechanistic model was developed and parameter estimates were obtained by simultaneously fitting the model to all PK data using a hybrid ITS-MCPEM method.

RESULTS

The final model well described the observed Tab, acMMAE and unconjugated MMAE concentration-time profiles. Analysis suggested that conjugate is lost via both proteolytic degradation and deconjugation, while unconjugated MMAE in systemic circulation appears to be mainly released via proteolytic degradation of the conjugate.

CONCLUSIONS

Our model improves the understanding of ADC catabolism, which may provide useful insights when designing future ADCs.

The 2016 WHO classification defines diffuse large B-cell lymphoma subtypes based on EBV infection and oncogenic rearrangements of MYC/BCL2/BCL6 as drivers of lymphomagenesis. A subset of diffuse large B-cell lymphoma, however, is characterized by activating mutations in MYD88/CD79B. We investigated whether MYD88/CD79B mutations could improve the classification and prognostication of diffuse large B-cell lymphomas. In 250 primary diffuse large B-cell lymphomas, MYD88/CD79B mutations were identified by allele-specific PCR or next-generation-sequencing, MYC/BCL2/BCL6 rearrangements were analyzed by FISH, and EBV was studied by EBER-ISH. Associations of molecular features with clinicopathologic characteristics, outcome, and prognosis according to International Prognostic Index were investigated. MYD88 and CD79B mutations were identified in 29.6% and 12.3%, , MYC, BCL2, and BCL6 rearrangements in 10.6%, 13.6%, and 20.3%, and EBV in 11.7% of diffuse large B-cell lymphomas, respectively. Prominent mutual exclusivity between EBV positivity, rearrangements, and MYD88/CD79B mutations established the value of molecular markers for recognition of biologically distinct diffuse large B-cell lymphoma subtypes. MYD88-mutated diffuse large B-cell lymphoma had a significantly inferior 5-year overall survival than wild-type MYD88 diffuse large B-cell lymphoma (log-rank;P=0.019). Diffuse large B-cell lymphoma without any of the studied aberrations had superior overall survival compared to cases carrying ≥1 aberrancy (log-rank;P=0.010). MYD88 mutations retained their adverse prognostic impact upon adjustment for other genetic and clinical variables by multivariable analysis and improved the prognostic performance of the International Prognostic Index. This study demonstrates the clinical utility of defining MYD88-mutated diffuse large B-cell lymphoma as a distinct molecular subtype with adverse prognosis. Our data call for sequence analysis of MYD88 in routine diagnostics of diffuse large B-cell lymphoma to optimize classification and prognostication, and to guide the development of improved treatment strategies.

Exome-sequencing for somatic mutation detection and copy number variation analysis are effective and valid methods for evaluating human cancers in current molecular medicine. We conducted target amplicon exome-sequencing analyses using PCR target enrichment and next-generation sequencing on Ion Proton semiconductor sequencers. Twenty-seven primary central nervous system lymphoma (PCNSL) specimens and their corresponding noncancerous tissues were used for multiplex PCR amplification to obtain targeted coverages of the entire coding regions of 409 cancer-related genes. The average of the total numbers of somatic mutations including single-nucleotide variations and insertion/deletion mutations in each specimen was 13.3. Of these, the average of the ratios of nonsynonymous substitutions in each specimen was 74.8%. The most frequent mutations in 27 specimens were in PIM1, MYD88, CD79B, DST, IRF4, ERBB3, MYH11, DCC, and KMT2D. Furthermore, somatic mutations of MYH11 were related to poor prognoses in PCNSL patients. Copy number variations were also duplicated and/or deleted from deep-sequencing in segmental genomic islands. In addition to these prognostic marker candidates, analysis of RTK-RAS-MAPK signaling and the PTEN-PI3K-AKT proapoptotic pathway showed that somatic activations and aberrations, respectively, may be involved in a promising central oncopathway harboring mTOR, c-Myc, FOXO1, and p53. This study provides a foundation for molecular targeted therapies based on genome diagnostics and prognosis in PCNSL.

Approximately 30% of patients with follicular lymphoma (FL) transform to a more aggressive malignancy, most commonly diffuse large B cell lymphoma. Rarely, FL transformation results in clinical findings, histology, and immunophenotype reminiscent of B-lymphoblastic leukemia/lymphoma. We report the largest series to date with detailed analysis of 7 such patients. Lymphoblastic transformation occurred on average 2 years after initial diagnosis of FL. Five patients had prior intensive chemotherapy. Two patients developed mature high-grade lymphoma, followed by the lymphoblastic transformation. FL had BCL2 gene rearrangement in 4 of 5 cases. High-grade transformation was accompanied by MYC gene rearrangement (5 of 5). Transformation was characterized by expression of TdT, loss of Bcl6, variable loss of immunoglobulin light chain, and persistence of Pax-5, Bcl2, and CD10. Whole-exome sequencing in 1 case revealed presence of several actionable mutations (CD79B, CCND3, CDK12). FL, aggressive mature B cell lymphoma, and lymphoblastic transformation were clonally related in 6 evaluable cases. After transformation, survival ranged from 1 to 14 months. Four patients died of disease, 2 were in remission after stem cell transplant, and 1 was alive with disease.

The human B cell-specific protein, CD79b (also known as Igβ and B29) constitutes an essential signal transduction component of the B cell receptor. Although its function is central to the triggering of B cell terminal differentiation in response to antigen stimulation, the transcriptional determinants that control CD79b gene expression remain poorly defined. In the present study, we explored these determinants using a series of hCD79b transgenic mouse models. Remarkably, we observed that the previously described hCD79b promoter along with its associated enhancer elements and first exon could be deleted without appreciable loss of hCD79b transcriptional activity or tissue specificity. In this deletion setting, a secondary promoter located within exon 2 maintained full levels and specificity of hCD79b transcription. Of note, this secondary promoter was also active, albeit at lower levels, in the wild-type hCD79b locus. The activity of the secondary promoter was dependent on the action(s) of a conserved sequence element mapping to a chromatin DNase I hypersensitive site located within intron 1. mRNA generated from this secondary promoter is predicted to encode an Igβ protein lacking a signal sequence and thus unable to serve normal B cell receptor function. Although the physiologic role of the hCD79b secondary promoter and its encoded protein remain unclear, the current data suggest that it has the capacity to play a role in normal as well as pathologic states in B cell proliferation and function.

The aim of this study was to evaluate the prognostic significance of international prognostic index (IPI), mantle cell lymphoma IPI (MIPI), simplified MIPI (sMIPI), and MIPI biological (MIPIb), as well as their correlation with immunophenotype, clinical characteristics, and overall survival (OS), in a selected group of 54 patients with advanced-stage mantle cell lymphoma (MCL), treated uniformly with CHOP. Seventeen patients had IV clinical stage (CS), while other 37 had leukemic phase at presentation. Diffuse type of marrow infiltration was verified in 68.5% and nodular in remainder patients. Extranodal localization (25.9%) included bowel (20.4%), pleural effusion, sinus, and palpebral infiltration. All of analyzed patients expressed typical MCL immunophenotypic profile: CD19(+)CD20(+)CD22(+)CD5(+)Cyclin-D1(+)FMC7(+)CD79b(+)smIg(+)CD38(+/-)CD23(-)CD10(-). Median OS of the whole group was 23 months, without significant differences between IV CS and leukemic phase patients. Thirty-two patients (59.3%) responded to initial treatment, 9 (16.7%) with complete and 23 (42.6%) with partial remission. Negative prognostic influence on OS had high IPI (P < 0.01), high sMIPI (P < 0.001), MIPI (P < 0.01), MIPIb (P < 0.01), extranodal localization (P < 0.01), and diffuse marrow infiltration (P < 0.01). Testing between randomly selected groups showed that patients with lower proportion of CD5(+) cells (<80%) correlated with cytological blastoid variant and had shorter survival comparing with the group with higher proportion of CD5(+) cells (>80%) (P < 0.01). Using univariate Cox regression, we proved that IPI, sMIPI, MIPI, and MIPIb had an independent predictive importance (P < 0.01) for OS in uniformly treated advanced MCL patients, although sMIPI prognostic significance was the highest (P < 0.001).

As for IgM, human IgA occurs either as soluble molecules in plasma and various other body fluids, or as membrane-bound molecules on differentiated B cells, where they are part of the B-cell receptor for antigen (BCR). We studied the structure of transcripts encoding the membrane-anchored alpha-chain of the human BCR alpha, which may be present in two different forms resulting from alternate splicing of the alpha-chain mRNA (type I or type II). The ratio of type I versus type II did not vary upon stimulation of a B-cell line with various cytokines. Rather, it differed strikingly in cells expressing either the IgA1 or IgA2 isotype of the BCR alpha, with virtually no type II alpha-chain in the latter. Co-modulation experiments also yielded different results for both isotypes, since they demonstrated a physical association of both membrane (m)IgA1 and mIgA2 with CD79b, the beta component of the BCR Ig alpha/Ig beta heterodimer, but only of mIgA1 with CD19. Whatever the isotype, the BCR of the IgA class was able to carry out signal transduction upon cross-linking by specific monoclonal antibodies but, in contrast to mIgM, it relied mainly on the entry of extracellular Ca2+ rather than on the release of intracellular stocks.

The lymphoid and immunohaematopoietic tissues of the embryonic and full-term brushtail possums was investigated histologically and immunohistochemically using antibodies to the T- and B-cell markers, CD3, CD5, CD79a and CD79b. No clearly defined thymus, bone marrow, spleen, lymph nodes, gut-associated lymphoid tissues or bronchus-associated lymphoid tissues were observed histologically. The liver was haematopoietic and contained erythrocytic and granulocytic precursors. No mature lymphocytes were observed histologically or detected using antibodies to T- and B-cell markers in any of the tissues. These results are consistent with other studies of the early postnatal tissues of other marsupials and support the proposition that neonatal marsupials are substantially reliant on maternal immunological protection at the time of birth and for a significant period of pouch life.

The B-cell antigen receptor (BCR) comprises membrane Igs (mIgs) and a heterodimer of Igalpha (CD79a) and Igbeta (CD79b) transmembrane proteins, encoded by the mb-1 and B29 genes, respectively. These accessory proteins are required for surface expression of mIg and BCR signaling. B cells from chronic lymphocytic leukemia (B-CLL) frequently express low to undetectable surface Ig, as well as CD79b protein. Recent work described genetic aberrations affecting B29 expression and/or function in B-CLL. Because the prevalence of CLL is increased among first degree relatives, we analyzed the B29 gene in 10 families including 2 affected members each. A few silent or replacement mutations were observed at the genomic level, which never lead to truncated CD79b protein. Both members of the same family did not harbor the same mutations. However, a single silent base change in the B29 extracellular domain, corresponding to a polymorphism, was detected on 1 allele of most patients. These results indicate that the few mutations observed in the B29 gene in these patients do not induce structural abnormalities of the CD79b protein and thus do not account for its low surface expression in B-CLL. Furthermore, genetic factors were not implicated, because identical mutations were not observed among 2 members of the same family.

We studied the expression of the immunoglobulin-associated membrane protein B29 in 499 cases of chronic B cell diseases using the monoclonal antibody SN8 (CD79b). SN8 was positive in 5% (17/330) of chronic lymphocytic leukemia (CLL) and 100% (15/15) of B prolymphocytic leukemia. The expression of B29 in other B cell disorders was, as a rule, significantly higher than in CLL. Two thirds of non-Hodgkin's lymphomas in leukemic phase were SN8 positive, including lymphoplasmacytic (45%), follicular (83%), mantle cell (92%) and splenic lymphoma with villous lymphocytes (74%) while only 25% of hairy cell leukemias were SN8 positive. Within CLL, 2.3% of typical cases were SN8+ while 16% of cases with atypical morphology and an increased number of prolymphocytes were SN8+. Our results suggest a useful role for SN8 in the immunophenotypic differentiation of B cell disorders as a marker for non-CLL diseases. The analysis of B29 expression may throw light into the structure of the B cell antigen receptor in B cell malignancies while the distinctive reactivity profile of SN8 has direct applications to diagnosis.

Panels of immunological markers are useful in refining diagnosis in view of certain variability between B-cell leukaemias. A statistical multivariate approach was used on 100 B leukaemias (preliminary sample) to explore the potential value of the combination of CD43, and the classical markers CD5, CD23, CD79b, FMC7, CD22 and surface immunoglobulin to differentiate chronic lymphoid leukaemia (CLL) from lymphoma (non-CLL). CD43 was highly effective (P < 0.00001) and its inclusion in the panels improved the accuracy of discrimination in a 'control' sample of 74 B leukaemias to 98.6%. Inclusion of CD43 facilitates the diagnosis of B-lymphoproliferative disorders and improves their classification.

This article describes the main defining criteria for chronic lymphocytic leukemia (CLL) and its differential diagnosis from closely related B-cell disorders. In addition to the morphology of circulating lymphocytes, the key diagnostic aid is the "CLL score" based on the typical immunophenotype of CLL as ascertained with five reagents: CD5, CD23, CD79b (or CD22), FMC7, and intensity of SmIg staining. The concepts of polyclonal and monoclonal B-cell lymphocytosis are defined with focus on the latter and its incidence in elderly individuals and its significant increase in healthy relatives from CLL families. The value of flow cytometry in the analysis of minimal residual disease after therapy also is discussed with a comparison with findings in bone marrow trephine biopsies. No candidate gene has been linked to the high incidence of CLL (10%) seen in families of patients with this disease.

B-cell chronic lymphocytic leukaemia (B-CLL) characteristically displays low amounts of B-cell receptor (BCR), which mainly consists of the heterodimer CD79a/CD79b bound non-covalently with the surface immunoglobulin (SIg). This heterodimer is required for SIg expression and BCR signalling. To better define the mechanisms related to low BCR expression, we have investigated transcription, protein synthesis, assembly and transport of the BCR in B-CLL cells. Our results demonstrated that: (1) there was no major defect in transcriptional expression of the B29 (CD79b) gene; (2) the BCR components were intracellularly detected, thus adequately synthesized, in almost all patients; (3) neither a genetic defect in the transmembrane region of SIg, which associated with CD79a/CD79b, nor a genetic abnormality in the chaperone protein calnexin that is involved in folding and assembly of the BCR were found; (4) a constant defect in the assembly of IgM and CD79b chains occurred leading to abnormal accumulation of both chains in different intracellular compartments; (5) in a majority of CLL patients all of the nascent IgM failed to be processed into mature chains and remained unsuitable for transport. These findings demonstrated that a post-transcriptional defect located at the BCR intracellular assembly and/or trafficking levels could be involved in its low surface expression in B-CLL.

We investigated the immunomodulatory activity of polysaccharide isolated from the root of Acanthopanax koreanum (AK) at the cellular level. AK directly increased B cell proliferation and antibody production, but did not affect the expression of IL-2, IFN-gamma or IL-4 by T cells, or T cell proliferation in vitro. Since AK cannot penetrate cells due to its large molecular mass, B cell activation may be caused by the surface binding of AK to B cell-specific receptors. The role of TLR4 as an AK receptor was shown by the fact that AK activity in B cells from C3H/HeJ mice, which are known to have a defective Toll-like receptor (TLR)-4, was found to be reduced compared with that in control cells from C3H/HeN mice. AK activity was also reduced by antibodies blocking TLR2, TLR4, CD19 or CD79b, but not by an antibody blocking CD38, which suggests AK receptor profiling in B cells. Two main differences between AK and lipopolysaccharide (LPS) were observed. First, LPS activity was inhibited by antibodies to either TLR2 or TLR4, but not by antibodies to CD19, CD79b or CD38. Another was that LPS-induced B cell proliferation was inhibited by polymyxin B (PMB), a specific inhibitor of LPS, whereas AK activity was not affected. Taken together, our results demonstrate that AK directly activates B cells, but not T cells, and suggest that AK has a broader receptor profile than LPS in B cells.

Marek's disease (MD) is a T cell lymphoma disease of domestic chickens induced by the Marek's disease virus (MDV), a highly infectious and naturally oncogenic alphaherpesvirus. Enhancing genetic resistance to MD in poultry is an attractive method to augment MD vaccines, which protect against MD but do not prevent MDV replication and horizontal spread. Previous work integrating QTL scans, transcript profiling, and MDV-chicken protein-protein interaction screens revealed 3 MD resistance genes; however, a major challenge continues to be the identification of the other contributing genes. To aid in this search, we screened for allele-specific expression (ASE) in response to MDV infection, a simple and novel method for identifying polymorphic cis-acting regulatory elements, which may contain strong candidate genes with specific alleles that confer MD genetic resistance. In this initial study, we focused on immunoglobulin β (CD79B) because it plays a critical role in the immune response and, more important, is transcriptionally coupled with growth hormone (GH1), one of the previously identified MD resistance genes. Using a coding SNP in CD79B and pyrosequencing to track the relative expression of each allele, we monitored ASE in uninfected and MDV-infected F(1) progeny from reciprocal intermatings of highly inbred chicken lines 6(3) (MD resistant) and 7(2) (MD susceptible). Upon screening 3 tissues (bursa, thymus, and spleen) at 5 time points (1, 4, 7, 11, and 15 d postinfection), we observed that MDV infection alters the CD79B allelic ratios in bursa and thymus tissues at 4 and 15 d postinfection in both mating directions. Our results suggest that CD79B has a cis-acting regulatory element that responds to MDV infection and probably cooperates with GH1 in conferring genetic resistance to MD. This result helps validates the use of ASE screens to identify specific candidate genes for complex traits such as genetic resistance to MD.

Understanding how alternative splicing affects gene function is an important challenge facing modern-day molecular biology. Using homology-based, protein sequence analysis methods, it should be possible to investigate how transcript diversity impacts protein function. To test this, high-quality exon-intron structures were deduced for over 8000 human genes, including over 1300 (17 percent) that produce multiple transcript variants. A data mining technique (DiffMotif) was developed to identify genes in which transcript variation coincides with changes in conserved motifs between variants. Applying this method, we found that 30 percent of the multi-variant genes in our test set exhibited a differential profile of conserved InterPro and/or BLOCKS motifs across different mRNA variants. To investigate these, a visualization tool (ProtAnnot) that displays amino acid motifs in the context of genomic sequence was developed. Using this tool, genes revealed by the DiffMotif method were analyzed, and when possible, hypotheses regarding the potential role of alternative transcript structure in modulating gene function were developed. Examples of these, including: MEOX1, a homeobox-containing protein; AIRE, involved in auto-immune disease; PLAT, tissue type plasminogen activator; and CD79b, a component of the B-cell receptor complex, are presented. These results demonstrate that amino acid motif databases like BLOCKS and InterPro are useful tools for investigating how alternative transcript structure affects gene function.

OBJECTIVE

Distinction between B-cell chronic leukemias can be difficult due to overlap in cell morphology and immunologic features. We investigated, by quantitative flow cytometry, the expression of CD79b, CD5 and CD19 in cells from a variety of B-cell disorders to see whether this analysis adds further information useful to the diagnosis and characterization of these diseases.

METHODS

Peripheral blood cells from 6 normal individuals were used as reference controls. The diseases of the 63 patients investigated comprised: 29 chronic lymphocytic leukemia (CLL), six of them with atypical morphology, 6 B-cell prolymphocytic leukemia (PLL), 12 splenic lymphoma with villous lymphocytes (SLVL) and 16 mantle-cell (Mc) lymphoma in leukemic phase. The study was carried out by triple immunostaining with directly conjugated monoclonal antibodies (MoAb) against CD79b, CD5 and CD19 and quantitative estimation of the antigens per cell assessed with standard microbeads (Quantum Simply Cellular).

RESULTS

Compared to normal B-cells, the number of CD19 molecules was significantly lower in cells from all of the B-cell disorders except PLL. The intensity of CD5 in leukemic B-cells was significantly higher in CLL cells, including atypical cases, and Mc lymphoma than in normal B-cells, whilst PLL and SLVL had values similar to those of normal B-lymphocytes. CD79b was expressed at lower levels in all types of leukemic cells compared to normal B-lymphocytes but differences were statistically significant in CLL, Mc lymphoma and SLVL. The number of CD79b molecules per cell was significantly lower in typical CLL than in the remaining B-cell diseases whilst the comparison of CD5 and CD19 intensity between CLL and non-CLL samples failed to show any statistically significant difference.

CONCLUSIONS

Distinct antigen density patterns for the various conditions emerged from this analysis: Typical CLL was characterized by moderate CD5 and weak or negative CD79b expression. Mc lymphoma showed an homogeneous pattern, characterized by similar expression of CD5 than CLL but significantly stronger expression of CD79b whilst PLL and SLVL had weak CD5 and moderate CD79b expression. Atypical CLL had an intermediate pattern of CD79b antigen expression ranging from weak to moderate with bright CD5. Unlike CD5 and CD79b, CD19 did not discriminate the various B-cell disorders but only between normal and leukemic cells.

CD22 and CD79b are cell-surface receptors expressed on B-cell-derived malignancies such as non-Hodgkin's lymphoma (NHL). An anti-mitotic agent, monomethyl auristatin E, was conjugated to anti-CD22 and anti-CD79b antibodies to develop target-specific therapies for NHL. The mechanism of action (MOA) and pharmacological and pharmacokinetic (PK) profiles of these antibody-drug conjugates (ADCs) were investigated in cynomolgus monkeys.

Animals were administered anti-CD22 or anti-CD79b ADCs, respective unconjugated antibodies or vehicle. Pharmacodynamic effects on total and proliferating B cells and serum PK were then assessed. Antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) of the ADCs were evaluated in vitro.

Depletion of B cells was observed after administration of either ADC or the respective unconjugated antibodies. An extended duration of depletion was observed in animals administered ADCs. Similarly, preferential depletion of proliferating B cells in blood and germinal centre B cells in spleen were only observed in animals administered ADCs. Serum PK profiles of ADCs and respective unconjugated antibodies were comparable. In vitro, anti-human CD22 and anti-human CD79b antibodies showed no or only moderate ADCC activity, respectively; neither antibody had CDC activity.

The findings support the proposed MOA: initial depletion of total B cells by antibody-mediated opsonization, followed by preferential, sustained depletion of proliferating B cells by the auristatin conjugate due to its anti-mitotic action. Delivering potent anti-mitotic agents to B cells via the specificity of monoclonal antibodies provides a means to eliminate pathogenic B cells in NHL with improved risk-benefit profiles over traditional chemotherapeutics.

The CD79a (Ig-alpha/mb-1) and CD79b (Ig-beta/B29) molecules form a membrane heterodimer that is non-covalently associated with surface membrane immunoglobulin and is the major signaling component of the B cell antigen receptor complex. We have defined variant RNA transcripts for both CD79a (Ig-alpha/mb-1) and CD79b (Ig-beta/B29) which appear to arise by alternative splicing. These splice variants are predicted to encode truncated forms of these molecules that result in the deletion of the entire extracellular Ig-like domain of CD79b and of a major portion of the extracellular domain of CD79a. The presence of these short transcripts in a variety of human B cells and B cell lines was established by an RNAse protection assay. The definition of these variant transcripts provides a basis for a continuing effort to define variant protein products of CD79a and CD79b and examine their role in B cell physiology.

OBJECTIVE

Genetic variants regulating the host immune system may contribute to the susceptibility for the development of gastric cancer. Little is known about the role of the innate immunity- and non-Hodgkin's lymphoma (NHL)-related genes for gastric cancer risk. This nested case-control study was conducted to identify candidate genes for gastric cancer risk for future studies.

METHODS

In the Discovery phase, 3,072 SNPs in 203 innate immunity- and 264 NHL-related genes using the Illumine GoldenGateTM OPA Panel were analyzed in 42 matched case-control sets selected from the Korean Multi-center Cancer Cohort (KMCC). Six significant SNPs in four innate immunity (DEFA6, DEFB1, JAK3, and ACAA1) and 11 SNPs in nine NHL-related genes (INSL3, CHMP7, BCL2L11, TNFRSF8, RAD50, CASP7, CHUK, CD79B, and CLDN9) with a permutated p-value <0.01 were re-genotyped in the Replication phase among 386 cases and 348 controls. Odds ratios (ORs) for gastric cancer risk were estimated adjusting for age, smoking status, and H. pylori and CagA sero-positivity. Summarized ORs in the total study population (428 cases and 390 controls) are presented using pooled- and meta-analyses.

RESULTS

Four SNPS had no heterogeneity across the phases: in the meta-analysis, DEFA6 rs13275170 and DEFB1 rs2738169 had both a 1.3-fold increased odds ratio (OR) for gastric cancer (95% CIs = 1.1-1.6; and 1.1-1.5, respectively). INSL3 rs10421916 and rs11088680 had both a 0.8-fold decreased OR for gastric cancer (95% CIs = 0.7-0.97; and 0.7-0.9, respectively).

CONCLUSIONS

Our findings suggest that certain variants in the innate immunity and NHL-related genes affect the gastric cancer risk, perhaps by modulating infection-inflammation-immunity mechanisms that remain to be defined.

OBJECTIVE

Primary central nervous system lymphoma (PCNSL) is a rare cancer with a somber prognosis in older patients, which it affects predominantly. Only in recent years have molecular alterations characterizing PCNSL been thoroughly described. This opens possibilities for the use of targeted therapies. Developments in imaging and biomarkers have also great potential to help clinicians faced with diagnostic and prognostic uncertainties.

RESULTS

Several biomarkers for PCNSL, such as different microRNAs, which could be tested in cerebrospinal fluid and vitreous fluid, and IL-10, which has been shown to have excellent sensitivity and specificity in the cerebrospinal fluid, have emerged in the last years. Methotrexate-based regimens remain the gold standard first-line treatment, with recent studies looking at the best adjunctive molecules to methotrexate, including rituximab, and at the role of autologous stem cell transplantation. As mutations leading to the activation of nuclear factor-kappa-B signaling are found in most PCNSLs, with mutations of MYD88 and CD79B particularly, ibrutinib is studied as molecule of great interest and encouraging results have been found in pilot studies. There is also great interest in the immunomodulatory drugs (lenalidomide) and immunotherapy (anti-programmed cell death 1/programmed cell death 1 ligand 1).

CONCLUSIONS

Identification of molecular genetic and cytokine changes in tumor and liquid biopsies will have an increasing role in the diagnostic and follow-up of PCNSL but also in the treatment and management of the disease.

The B cell receptor (BCR) is a multiprotein complex that is pivotal to antigen recognition and signal transduction in B cells. It consists of an antigen binding component, membrane Ig (mIg), non-covalently associated with the signaling component, a disulphide-linked heterodimer of CD79a and CD79b. In this study, the gene and corresponding cDNA for CD79a and CD79b in the gray short-tailed opossum, as well as the cDNA sequences for CD79a and CD79b in the tammar wallaby, are described. Many of the structural and functional features of CD79a and CD79b were conserved in both marsupials, including the ITAM regulatory motif in the cytoplasmic tails of both subunits. The marsupial CD79 sequences shared a high degree of amino acid identities of 76% (CD79a) and 72% (CD79b) to each other, as well as 60-61% (CD79a) and 58-59% (CD79b) with their eutherian counterparts. RT-PCR analysis of CD79a and CD79b transcripts in the immune tissues of tammar pouch young revealed CD79a transcripts in the bone marrow, cervical thymus and spleen at day 10 postpartum. CD79b transcripts were detected in the bone marrow and cervical thymus at day 10 but were not detected in the spleen until day 21 postpartum. These results suggest that a functional BCR may not be assembled until day 21 postpartum and the tammar neonate may not be capable of mounting an effective adaptive immune response until this time. The molecular information presented here will allow further investigation of the role of the CD79 subunits in marsupial B cell signaling, especially during ontogeny and disease.

The origin of Reed-Sternberg (RS) cells, the neoplastic cells of Hodgkin's disease, has long remained controversial. Dendritic cells (DCs) are highly specialized antigen-presenting cells that have the unique capacity to prime naive T cells, and they may be progenitors of RS cells in a population of Hodgkin's disease cells. In this study, the KM-H2 cell line, previously established from a patient with Hodgkin's disease of mixed cellularity, was reevaluated for its cellular derivation, particularly in terms of DCs. KM-H2 cells were demonstrated to carry the newly proposed DC-associated molecules fascin, CD83, and DEC-205, as well as costimulatory molecules such as CD40, CD80, and CD86. In addition, KM-H2 cells were shown to be able to potently stimulate peripheral blood T cells and to have the strong endocytotic activity of fluorescein isothiocyanate-dextran. On the other hand, KM-H2 cells were shown to have variable-diversity-joining recombination of the immunoglobulin H gene, although they did not express any subclasses of immunoglobulin and they were negative for CD79a and CD79b. In addition, KM-H2 cells produced the messenger RNA of the Pax-5 gene. These findings lead to a hypothesis that KM-H2 cells originated from the cells that had differentiated through the possible common DC-B-cell progenitors along the newly proposed pathway.