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Human natural killer (NK) cells are essential for controlling infection, cancer, and fetal development. NK cell functions are modulated by interactions between polymorphic inhibitory killer cell immunoglobulin-like receptors (KIR) and polymorphic HLA-A, -B, and -C ligands expressed on tissue cells. All HLA-C alleles encode a KIR ligand and contribute to reproduction and immunity. In contrast, only some HLA-A and -B alleles encode KIR ligands and they focus on immunity. By high-resolution analysis of KIR and HLA-A , -B , and -C genes, we show that the Chinese Southern Han (CHS) are significantly enriched for interactions between inhibitory KIR and HLA-A and -B. This enrichment has had substantial input through population admixture with neighboring populations, who contributed HLA class I haplotypes expressing the KIR ligands B*46:01 and B*58:01, which subsequently rose to high frequency by natural selection. Consequently, over 80% of Southern Han HLA haplotypes encode more than one KIR ligand. Complementing the high number of KIR ligands, the CHS KIR locus combines a high frequency of genes expressing potent inhibitory KIR, with a low frequency of those expressing activating KIR. The Southern Han centromeric KIR region encodes strong, conserved, inhibitory HLA-C-specific receptors, and the telomeric region provides a high number and diversity of inhibitory HLA-A and -B-specific receptors. In all these characteristics, the CHS represent other East Asians, whose NK cell repertoires are thus enhanced in quantity, diversity, and effector strength, likely augmenting resistance to endemic viral infections. [ABSTRACT FROM AUTHOR]

Objectives: The 3′ regulatory region of the immunoglobulin heavy chain gene (IGH) includes the HS1.2 enhancer displaying length polymorphism with four known variants. The goal of the research was to provide an overview of this variability and of its evolutionary significance across human populations. Materials and Methods: We compiled published and original data on HS1.2 polymorphism in 3,100 subjects from 26 human populations. Moreover, we imputed the haplotypic arrangement of the HS1.2 region in the 1000 Genomes Project (1KGP). In this dataset, imputation could also be obtained for the G1m‐G3m allotype by virtue of the precise correspondence between serological types and amino acid (and DNA) substitutions in IGHG1 and IGHG3. Results: HS1.2 variant frequencies displayed similar patterns of continental partitioning as those reported in the literature for the physically neighboring IGHG1‐IGHG3 system. The 1KGP data revealed that linkage disequilibrium (LD) can explain the spread of joint HS1.2‐IGHG1‐IGHG3 associations across continents and within continental populations, with stronger LD out of Africa and the features of an evolutionarily stable genomic block with differential expression in lymphoblastoid cell lines. Discussion Strong population structuring involves at least the entire 70 kb genomic region here considered, due to the tight LD which maintained HS1.2, IGHG1, and IGHG3 in nonrandom arrangements. This might be key to better understand the evolutionary path of the entire genomic region driven by immune response capabilities, during the formation of continental gene pools. [ABSTRACT FROM AUTHOR]

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a fibro-inflammatory immune condition characterized by IgG4 positive plasma cells, fibrosis, and frequently elevated serum IgG4 level. Akin to sarcoidosis, IgG4-RSD is a systemic disease with diverse organ manifestations linked by common histopathologic features. IgG4-RSD typically presents sub acutely without significant constitutional symptoms or fever. Hepatic Inflammatory pseudotumor (HIP) is a rare manifestation of IgG4-RSD composed of dense lymphoplasmacytic infiltrate and extensive fibrosis. We present an older Asian male who presented with acute onset of fever and weight loss found to have IgG4-RSD complicated by a HIP and concomitant MSSA abscess. [ABSTRACT FROM AUTHOR]

Human immunoglobulin (Ig)A exists in blood as two isotypes, IgA1 and IgA2, with IgA2 present as three allotypes: IgA2m(1), IgA2m(2), and IgA2m(n). We now demonstrate that recombinant, chimeric IgA1 and IgA2 differ in their pharmacokinetic properties. The major pathway for the clearance of all IgA2 allotypes is the liver. Liver-mediated uptake is through the asialoglycoprotein receptor (ASGR), since clearance can be blocked by injection of excess galactose-Ficoll ligand and suppressed in ASGR-deficient mice. In contrast, only a small percentage of IgA1 is cleared through this pathway. The clearance of IgA1 lacking the hinge region with its associated O-linked carbohydrate was more rapid than that of wild-type IgA1. IgA1 and IgA2 that are not rapidly eliminated by the ASGR are both removed through an undefined ASGR-independent pathway with half-lives of 14 and 10 h, respectively. The rapid clearance of IgA2 but not IgA1 through the liver may in part explain why the serum levels of IgA1 are greater than those of IgA2. In addition, dysfunction of the ASGR or altered N-linked glycosylation, but not O-glycans, that affects recognition by this receptor may account for the elevated serum IgA seen in liver disease and IgA nephropathy.

Killer-cell Ig-like receptor (KIR) genes are inherited as haplotypes. They are expressed by NK cells and linked to outcomes of infectious diseases and pregnancy in humans. Understanding how genotype relates to phenotype is difficult because of the extensive diversity of the KIR family. Indeed, high-resolution KIR genotyping and phenotyping in single NK cells in the context of disease association is lacking. In this article, we describe a new method to separate NK cells expressing allotypes of the KIR2DL1 gene carried by the KIR A haplotype (KIR2DL1A) from those expressing KIR2DL1 alleles carried by the KIR B haplotype (KIR2DL1B). We find that in KIR AB heterozygous individuals, different KIR2DL1 allotypes can be detected in both peripheral blood and uterine NK cells. Using this new method, we demonstrate that both blood and uterine NK cells codominantly express KIR2DL1A and KIR2DL1B allotypes but with a predominance of KIR2DL1A variants, which associate with enhanced NK cell function. In a case-control study of pre-eclampsia, we show that KIR2DL1A, not KIR2DL1B, associates with increased disease risk. This method will facilitate our understanding of how individual KIR2DL1 allelic variants affect NK cell function and contribute to disease risk. [ABSTRACT FROM AUTHOR]

The immunological factors that could explain the near absence of malaria parasites in bonobos are not yet understood. The MHC class I system, however, may play an important role, as particular bonobo allotypes show functional similarities to HLA-B*53/B*78, which are considered to confer protection against malaria in humans. [ABSTRACT FROM AUTHOR]

We have previously shown that plasmablasts of the G1m1 allotype of IgG1 are selectively enriched in the cerebrospinal fluid of G1m1/G1m3 heterozygous patients with multiple sclerosis, whereas both allotypes are equally used in neuroborreliosis. Here, we demonstrate a strong preference for the G1m1 allotype in the intrathecal humoral immune responses against measles, rubella, and varicella zoster virus in G1m1/G1m3 heterozygous multiple sclerosis patients. Conversely, intrathecally synthesized varicella zoster virus‐specific IgG1 in varicella zoster virus meningoencephalitis comprised both allotypes. This implies that G1m1 B cells are selected to the central nervous system of multiple sclerosis patients regardless of specificity and suggests that an antigen‐independent mechanism could drive the intrathecal humoral immune response. [ABSTRACT FROM AUTHOR]

Exposure to neurotropic viruses, such as herpes simplex virus type 1 and human cytomegalovirus, has been reported to be associated with cognitive impairment in schizophrenia. These viruses have evolved highly sophisticated strategies for decreasing the efficacy of the host immune response and interfering with viral clearance. Particular immunoglobulin GM (γ marker) genotypes modulate these viral immunoevasion strategies, influence antibody responsiveness to viral proteins, and are also associated with susceptibility to schizophrenia, providing an excellent rationale for determining their possible involvement in the cognitive functions in this highly heritable neurodevelopmental disorder. In this investigation, we assessed the cognitive functions (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, and executive function) in 145 patients with schizophrenia and characterized their DNA for several GM and KM (κ marker) alleles. Particular KM and GM genotypes were significantly associated with verbal memory and attention and processing speed scores, respectively ( P = 0.01 and 0.001). Epistatic effects of GM and KM genotypes on attention and processing speed, verbal fluency, and motor speed were also noted ( P = 0.031, 0.047, 0.003). These results, for the first time, show that hitherto understudied immunoglobulin GM and KM genotypes-individually and epistatically-contribute to the magnitude of interindividual variability in the cognitive functions in patients with schizophrenia. Additional studies involving these highly polymorphic genes of the immune system are needed. [ABSTRACT FROM AUTHOR]

Identifying genetic polymorphisms that explain variations in humoral immunity to live measles virus vaccine is of great interest. Immunoglobulin GM (heavy chain) and KM (light chain) allotypes are genetic markers known to be associated with susceptibility to several infectious diseases. We assessed associations between GM and KM genotypes and measles vaccine humoral immunity (neutralizing antibody titers) in a combined cohort (n = 1796) of racially diverse healthy individuals (age 18–41 years). We did not discover any significant associations between GM and/or KM genotypes and measles vaccine-induced neutralizing antibody titers. African-American subjects had higher neutralizing antibody titers than Caucasians (1260 mIU/mL vs. 740 mIU/mL, p = 7.10 × 10 −13 ), and those titers remained statistically significant (p = 1.68 × 10 −09 ) after adjusting for age at enrollment and time since last vaccination. There were no statistically significant sex-specific differences in measles-induced neutralizing antibody titers in our study (p = 0.375). Our data indicate a surprising lack of evidence for an association between GM and KM genotypes and measles-specific neutralizing antibody titers, despite the importance of these immune response genes. [ABSTRACT FROM AUTHOR]

X-linked severe combined immunodeficiency (X-SCID), caused by defects in the common gamma chain, is typically characterized by T and NK cell defects with the presence of B cells. T cell dysfunction and impaired class-switch recombination of B cells mean that patients typically have defects in class-switched immunoglobulins (IgG, IgA, and IgE) with detectable IgM. Here, we describe two patients with X-SCID with IgG1 gammopathy, in whom we identified maternal T and B cell engraftment. Exclusively, maternal B cells were found among the IgD − CD27 + class-switched memory B cells, whereas the patients' B cells remained naïve. In vitro stimulation with CD40L + IL-21 revealed that peripheral blood cells from both patients produced only IgG1. Class-switched maternal B cells had restricted receptor repertoires with various constant regions and few somatic hypermutations. In conclusion, engrafted maternal B cells underwent class-switch recombination and produced immunoglobulin, causing hypergammaglobulinemia in patients with X-SCID. [ABSTRACT FROM AUTHOR]

Immunoglobulin gamma (IgG) heavy chain genes are associated with susceptibility to multiple sclerosis ( MS) and IgG levels in the cerebrospinal fluid ( CSF). However, how these variants are implicated in disease mechanisms remains unknown. Here, we show that proliferating plasmablasts expressing the G1m1 allotype of IgG1 are selectively enriched in CSF of G1m1/G1m3 heterozygous MS patients, whereas plasmablasts expressing either G1m1 or G1m3 are evenly distributed in blood. Moreover, there was a preferential intrathecal synthesis of oligoclonal IgG1 of the G1m1 allotype in heterozygous patients, whereas controls with Lyme neuroborreliosis displayed oligoclonal IgG1 of both allotypes. This points to a disease-specific mechanism involved in B-cell establishment within the central nervous system in MS. [ABSTRACT FROM AUTHOR]

For targets that are homogenously expressed, such as CD19 on cells of the B lymphocyte lineage, immunotherapies can be highly effective. Targeting CD19 with blinatumomab, a CD19/CD3 bispecific antibody construct (BiTE®), or with chimeric antigen receptor T cells (CAR-T) has shown great promise for treating certain CD19-positive hematological malignancies. In contrast, solid tumors with heterogeneous expression of the tumor-associated antigen (TAA) may present a challenge for targeted therapies. To prevent escape of TAA-negative cancer cells, immunotherapies with a local bystander effect would be beneficial. As a model to investigate BiTE®-mediated bystander killing in the solid tumor setting, we used epidermal growth factor receptor (EGFR) as a target. We measured lysis of EGFR-negative populations in vitro and in vivo when co-cultured with EGFR-positive cells, human T cells and an EGFR/CD3 BiTE® antibody construct. Bystander EGFR-negative cells were efficiently lysed by BiTE®-activated T cells only when proximal to EGFR-positive cells. Our mechanistic analysis suggests that cytokines released by BiTE®-activated T-cells induced upregulation of ICAM-1 and FAS on EGFR-negative bystander cells, contributing to T cell-induced bystander cell lysis. [ABSTRACT FROM AUTHOR]

The ancestral progenitor of common chimpanzees and bonobos experienced a selective sweep that ravaged its major histocompatibility complex (MHC) class I repertoire. The causative agent was probably an ancestral retrovirus, highly related to the contemporary HIV-1 strain, which initiated the acquired immunodeficiency syndrome pandemic in the human population. As a direct result, MHC class I allotypes with the capability of targeting conserved retroviral elements were enriched in the ancestral progenitor. Even today, the impact can be traced back by studying the functional capacities of the contemporary MHC class I allotypes of common chimpanzees. Viruses, however, have developed several strategies to manipulate the cell-surface expression of MHC class I genes. Monitoring the presence and absence of the MHC class I allotypes on the cell surface is conducted, for instance, by the hosts' gene products of the killer cell immunoglobulin-like receptor (KIR) complex. Hence, one may wonder whether-in the future-any clues with regard to the signature of the MHC class I selective sweep might be unearthed for the KIR genes as well. [ABSTRACT FROM AUTHOR]

Immunological adjustments are needed to accommodate the close contact between two genetically different individuals, the mother and her baby, during mammalian pregnancy. Contact occurs between fetal somatic or placental cells that enter the maternal systemic circulation or between uterine immune cells and the invading extravillous trophoblast. Here we discuss two main types of maternal allo-recognition of the fetus. One depends on avoidance of maternal T cells recognizing and responding to paternally-derived non-self human leukocyte antigens class I and class I allotypes. The other is natural killer allo-recognition where maternally-inherited variable killer immunoglobulin-like receptors expressed by uterine natural killer cells bind to polymorphic fetal human leukocyte antigens-C molecules displayed by extravillous trophoblast. Genetic studies indicate that natural killer cell allo-recognition regulates placentation and the allocation of resources to the fetus. [ABSTRACT FROM AUTHOR]

Several studies described an association between killer-cell immunoglobulin-like receptor (KIR)/HLA gene combinations and clinical outcomes in various diseases. In particular, an important combined role for KIR3DS1 and HLA-B Bw4-I80 in controlling viral infections and a higher protection against leukemic relapses in donor equipped with activating KIRs in haplo-HSCT has been described. Here, we show that KIR3DS1 mediates positive signals upon recognition of HLA-B*51 (Bw4-I80) surface molecules on target cells and that this activation occurs only in Bw4-I80neg individuals, including those carrying particular KIR/HLA combination settings. In addition, killing of HLA-B*51 transfected target cells mediated by KIR3DS1+/NKG2A+ natural killer (NK) cell clones from Bw4-I80neg donors could be partially inhibited by antibody-mediated masking of KIR3DS1. Interestingly, KIR3DS1-mediated recognition of HLA-B*51 could be better appreciated under experimental conditions in which the function of NKG2D was reduced by mAb-mediated blocking. This experimental approach may mimic the compromised function of NKG2D occurring in certain viral infections. We also show that, in KIR3DS1+/NKG2A+ NK cell clones derived from an HLA-B Bw4-T80 donor carrying 2 KIR3DS1 gene copy numbers, the positive signal generated by the engagement of KIR3DS1 by HLA-B*51 resulted in a more efficient killing of HLA-B*51-transfected target cells. Moreover, in these clones, a direct correlation between KIR3DS1 and NKG2D surface density was detected, while the expression of NKp46 was inversely correlated with that of KIR3DS1. Finally, we analyzed KIR3DS1+/NKG2A+ NK cell clones from a HLA-B Bw4neg donor carrying cytoplasmic KIR3DL1. Although these clones expressed lower levels of surface KIR3DS1, they displayed responses comparable to those of NK cell clones derived from HLA-B Bw4neg donors that expressed surface KIR3DL1. Altogether these data suggest that, in particular KIR/HLA combinations, KIR3DS1 may play a role in the process of human NK cell education. [ABSTRACT FROM AUTHOR]

Sclerema neonatorum is a form of panniculitides characterized by diffuse hardening of subcutaneous tissue with minimal inflammation. It usually affects ill and preterm neonates. Prognosis is usually poor in many cases despite aggressive management. Various treatment modalities (antibiotics, intravenous immunoglobulin, steroids, and exchange transfusion) have been explained in literature. Steroids due to its easy availability and low cost can prove to be lifesaving in such cases, especially in resource poor countries. Here, we report a case of sclerema neonatorum in a one-week preterm baby treated successfully with parenteral steroids and antibiotics. [ABSTRACT FROM AUTHOR]

Complement component 3 (C3) presents both slow (C3S) and fast (C3F) variants, which can be locally produced and activated by immune system cells. We studied C3 recipient variants in 483 liver transplant patients by RT- PCR- HRM to determine their effect on graft outcome during the first year post-transplantation. Allograft survival was significantly decreased in C3 FF recipients (C3 SS 95% vs C3 FS 91% vs C3 FF 83%; P=.01) or C3F allele carriers (C3F absence 95% vs C3F presence 90%, P=.02). C3 FF genotype or presence of C3F allele independently increased risk for allograft loss ( OR: 2.38, P=.005 and OR: 2.66, P=.02, respectively). C3 FF genotype was more frequent among patients whose first infection was of viral etiology (C3 SS 13% vs C3 FS 18% vs C3 FF 32%; P=.04) and independently increased risk for post-transplant viral infections ( OR: 3.60, P=.008). On the other hand, C3 FF and C3F protected from rejection events ( OR: 0.54, P=.03 and OR: 0.63, P=.047, respectively). Differences were not observed in hepatitis C virus recurrence or patient survival. In conclusion, we show that, independently from C3 variants produced by donor liver, C3F variant from recipient diminishes allograft survival, increases susceptibility to viral infections, and protects from rejection after transplantation. C3 genotyping of liver recipients may be useful to stratify risk. [ABSTRACT FROM AUTHOR]

HLA-A, -B and -C alleles of 285 individuals, representing three Iranian Lur populations and one Iranian Kurd population were sequenced completely, yielding human leukocyte antigen ( HLA) class I genotypes at high resolution and filling four fields of the official HLA nomenclature. Each population has 87-99 alleles, evenly distributed between the three HLA class I genes, 145 alleles being identified in total. These alleles were already known, named and deposited in the HLA database. The alleles form 316 different HLA A-B-C haplotypes, with each population having between 80 and 112 haplotypes. The four Iranian populations form a related group that is distinguished from other populations, including other Iranians. All four KIR ligands - the A3/11, Bw4, C1 and C2 epitopes - are well represented, particularly Bw4, which is carried by three high-frequency allotypes: HLA-A*24:02, HLA-A*32:01 and HLA-B*51:01. In the Lur and Kurd populations, between 82% and 94% of individuals have the Bw4 epitope, the ligand for KIR3DL1. HLA-B*51:01 is likely of Neandertal origin and associated with Behcet's disease, also known as the Silk Road disease. The Lordegan Lur have the highest frequency of HLA-B*51:01 in the world. This allele is present on 46 Lur and Kurd haplotypes. Present at lower frequency is HLA-B*51:08, which is also associated with Behcet's disease. In the four Iranian populations, 31 haplotypes encode both Bw4+ HLA-A and Bw4+ HLA-B, a dual combination of Bw4 epitopes that is relatively rare in other populations, worldwide. This study both demonstrates and emphasizes the value of studying HLA class I polymorphism at highest resolution in anthropologically well-defined populations. [ABSTRACT FROM AUTHOR]

Huntington's disease (HD) is a hereditary neurodegenerative disorder. The genetic cause is an expansion of CAG repeats located in the IT15 gene. Though the number of CAG repeats ((CAG)n) can largely explain the age at onset (AAO) of symptoms, a percentage of its variation could be attributed to modifier genes and to environmental factors. The study aimed to evaluate the influence of genetic modifiers of the AAO of HD including: (CAG)nand del2642 in the IT15 gene, ADORA2A rs5751876, HAP1 rs4523977, PGC1-α rs7665116 and UCH-L1 rs5030732. Eighteen patients with positive family history and HD-suggestive symptoms were recruited. The (CAG)nand gene polymorphisms were determined by different molecular biology techniques. We observed that the (CAG)ninfluenced in a 64.5% of the variability in the AAO. We also showed that the rs5751876 variant significantly affected this variability. However, the influence of UCH-L1, del2642, HAP1 and PGC1-α gene polymorphisms could not be replicated, perhaps due to small sample size. Genetic studies including the molecular determination of (CAG)n, in addition to other genetic modifiers involved in the variability of the AAO, were first performed in Uruguay. We could replicate in our cohort the anticipation effect on the AAO by the ADORA2A rs5751876. Our results confirm the usefulness of an expanded molecular characterization in HD patients. [ABSTRACT FROM AUTHOR]

Background B factor (BF) from the alternative complement pathway seems to participate in the pathophysiology of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Objective To study the allotypic variability of BF in SLE and their associations with clinical and autoantibodies profile. Methods BF allotypes were determined by high-voltage agarose gel electrophoresis, under constant cooling, followed by immunofixation with anti-human BF antibody, in 188 SLE patients and 103 controls. Clinical and serological data were obtained from medical examination and records. Results No significant differences of BF variants between patients and controls were found, neither in relation to epidemiologic or clinical manifestations. Associations of phenotype BF SS07 and allotype BF*S07 were found with anticardiolipin IgM (aCl-IgM) antibodies (p = 0.014 and p = 0.009 respectively), but not with aCl-IgG, lupus anticoagulant (LA), anti β2GPI or clinical APS. A significant decrease in BF*F allotype (p = 0.043) and BF SF phenotype (p = 0.018) was detected in patients with anti-phospholipid antibodies as a whole (aCl-IgG, aCl-IgM, LA and anti β2GPI). Conclusions There is a link between phenotype BF SS07 and allotype BF*S07 with aCl-IgM in SLE patients; BF*F allotype could be considered a marker of protection against the development of antiphospholipid antibodies in these patients. [ABSTRACT FROM AUTHOR]

Vitamin A supports the induction of immunoglobulin (Ig)A responses at mucosal surfaces in mice, but much less is known about the influence of vitamins on antibody isotype expression in humans. To address this knowledge gap, we examined 46 residual blood samples from adults and children, some of whom were experiencing influenza virus infections of the respiratory tract. Assays were performed for retinol binding protein (RBP, a surrogate for vitamin A), vitamin D (a related vitamin) and antibody isotypes. Results showed that all but two tested samples exhibited RBP and/or vitamin D insufficiencies or deficiencies. Vitamin D correlated with blood IgM and IgG3, while RBP correlated with IgG4 and IgA. RBP also correlated positively with age and with influenza virus-specific antibody neutralization titres. Individuals with low blood RBP levels exhibited the highest frequencies of over-expressed cytokines and growth factors in nasal wash samples, an indication of inflamed mucosal tissues. While cause-effect relationships were not discerned, results support a hypothesis that vitamins directly influence B cell isotype expression in humans, and by so doing may help protect mucosal surfaces from respiratory viral disease. [ABSTRACT FROM AUTHOR]

Our understanding of how equine immunoglobulin genes are organized has increased significantly in recent years. For equine heavy chains, 52 IGHV, 40 IGHD, 8 IGHJ and 11 IGHC are present. Seven of these IGHCs are gamma chain genes. Sequence diversity is increasing between fetal, neonatal, foal and adult age. The kappa light chain contains 60 IGKV, 5 IGKJ and 1 IGKC, whereas there are 144 IGLV, 7 IGLJ, and 7 IGLC for the lambda light chain, which is expressed predominantly in horses. Significant transcriptional differences for IGLV and IGLC are identified in different breeds. Allotypic and allelic variants are observed for IGLC1, IGLC5, and IGLC6/7, and two IGLV pseudogenes are also transcribed. During age development, a decrease in IGLVs is noted, although nucleotide diversity and significant differences in gene usage increased. The following paper suggests a standardization of the existing nomenclature of immunoglobulin genes. [ABSTRACT FROM AUTHOR]

The social amoeba Dictyostelium discoideum integrates into a multicellular organism when individual starving cells aggregate and form a mound. The cells then integrate into defined tissues and develop into a fruiting body that consists of a stalk and spores. Aggregation is initially orchestrated by waves of extracellular cyclic adenosine monophosphate (cAMP), and previous theory suggested that cAMP and other field-wide diffusible signals mediate tissue integration and terminal differentiation as well. Cooperation between cells depends on an allorecognition system comprising the polymorphic adhesion proteins TgrB1 and TgrC1. Binding between compatible TgrB1 and TgrC1 variants ensures that non-matching cells segregate into distinct aggregates prior to terminal development. Here, we have embedded a small number of cells with incompatible allotypes within fields of developing cells with compatible allotypes. We found that compatibility of the allotype encoded by the tgrB1 and tgrC1 genes is required for tissue integration, as manifested in cell polarization, coordinated movement and differentiation into prestalk and prespore cells. Our results show that the molecules that mediate allorecognition in D. discoideum also control the integration of individual cells into a unified developing organism, and this acts as a gating step for multicellularity. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that has been implicated in many diseases. However, there is significant divergence between HCMV seroprevalence and the prevalence of HCMV-associated diseases, implying the presence of host genetic factors that might modulate immunity to this virus. HCMV deploys many sophisticated strategies to evade host immunosurveillance. One strategy involves encoding for proteins that have functional properties of the Fcγ receptor (FcγR). The aim of the present investigation was to determine whether the UL119-UL118-encoded recombinant FcγR ectodomain binds differentially to genetically disparate IgG1 proteins. Results show that mean absorbance values for binding of HCMV UL119-UL118-encoded Fcγ receptor to the immunoglobulin GM (γ marker) 1,17-expressing IgG1 were significantly higher than to the IgG1 expressing the allelic GM 3 allotype (0.225 vs. 0.151; p = 0.039). These findings suggest possible mechanisms underlying the maintenance of immunoglobulin GM gene polymorphism and its putative role in the etiology of HCMV-associated diseases. [ABSTRACT FROM AUTHOR]

The detection and identification of red cell alloantibodies are important processes familiar to all laboratory professionals. A term frequently utilized to describe an alloantibody likely to cause an adverse event is 'clinically significant'. The laboratory usually assesses the clinical significance of alloantibodies based upon specificity, serologic phases of reactivity and cross-match results and make transfusion recommendations accordingly. However, using specificity, reactivity patterns and cross-match results alone cannot always distinguish between clinically significant and nonsignificant alloantibodies. Searches for 'compatible' blood can occur when alloantibodies are identified and 'incompatible' cross-matches occur, leading to inappropriate delays in transfusion and potentially causing patient harm. Cellular assays, such as the monocyte monolayer assay, can be used as an adjunct to predict transfusion outcome. Current routine serology assays will not predict with absolute certainty whether 'incompatible' red cells transfused to a recipient with an alloantibody will be destroyed or whether that recipient will suffer the devastating clinical consequences of a hemolytic transfusion reaction. The monocyte monolayer assay can be of particular assistance when the antibody specificity is of 'variable' clinical significance or the antibody specificity is to a high incidence antigen and rare blood is requested. Finally, it is important to remember that laboratory professionals will be called upon for advice and information by clinicians and patients regarding transfusion recommendations. We are all partners working together to determine the optimal transfusion option. And we must reaffirm to all that transfusion should never be withheld from a patient whose life depends on urgent transfusion. [ABSTRACT FROM AUTHOR]

A high-cell-density transient transfection system was recently developed in our laboratory based on a CHO-GS-KO cell line. This method yields monoclonal antibody titers up to 350 mg/L from a simple 7-day process, in volumes ranging from 2 mL to 2 L. By performing transfections in 24-deep-well plates, a large number of mAbs can be expressed simultaneously. We coupled this new high-throughput transfection process to a semiautomated protein A purification process. Using a Biomek FXp liquid handling robot, up to 72 unique mAbs can be simultaneously purified. Our primary goal was to obtain >0.25 mg of purified mAb at a concentration of >0.5 mg/mL, without any concentration or buffer-exchange steps. We optimized both the batch-binding and the batch elution steps. The length of the batch-binding step was important to minimize mAb losses in the flowthrough fraction. The elution step proved to be challenging to simultaneously maximize protein recovery and protein concentration. We designed a variable volume elution strategy based on the average supernatant titer. Finally, we present two case studies. In the first study, we produced 56 affinity maturation mAb variants at an average yield of 0.33 ± 0.05 mg (average concentration of 0.65 ± 0.10 mg/mL). In a second study, we produced 42 unique mAbs, from an early-stage discovery effort, at an average yield of 0.79 ± 0.31 mg (average concentration of 1.59 ± 0.63 mg/mL). The combination of parallel high-yielding transient transfection and semiautomated high-throughput protein A purification represents a valuable mAb drug discovery tool. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:239-247, 2015 [ABSTRACT FROM AUTHOR]

Life-threatening graft-versus-host disease (GVHD) limits the use of HLA-C-mismatched unrelated donors in transplantation. Clinicians lack criteria for donor selection when HLA-C-mismatched donors are a patient's only option for cure. We examined the role for HLA-C expression levels to identify permissible HLA-C mismatches. The median fluorescence intensity, a proxy of HLA-C expression, was assigned to each HLA-C allotype in 1975 patients and their HLA-C-mismatched unrelated transplant donors. The association of outcome with the level of expression of patients' and donors' HLA-C allotypes was evaluated in multivariable models. Increasing expression level of the patient's mismatched HLA-C allotype was associated with increased risks of grades III to IV acute GVHD, nonrelapse mortality, and mortality. Increasing expression level among HLA-C mismatches with residue 116 or residue 77/80 mismatching was associated with increased nonrelapse mortality. The immunogenicity of HLA-C mismatches in unrelated donor transplantation is influenced by the expression level of the patient's mismatched HLA-C allotype. HLA-C expression levels provide new information on mismatches that should be avoided and extend understanding of HLA-C-mediated immune responses in human disease. [ABSTRACT FROM AUTHOR]

Background Cytomegalovirus ( CMV) reactivation still remains a major problem following allogeneic hematopoietic stem cell transplantation ( HSCT). Patients and methods In this study, we analyzed an immunoglobulin allotype, IgG1m(f), in CMV-seropositive HSCT recipients and their donors to distinguish donor-derived antibody from recipient-derived antibody. Eight donor-recipient pairs were informative regarding the appearance of donor-derived immunoglobulin-G (IgG), as the recipients were homozygous null for the IgG1m(f) allotype and the donors were IgG1m(f) positive. In these patients, total IgG, IgM, and allotype-specific IgG against CMV were measured by enzyme-linked immunosorbent assay. All subjects were monitored for at least 9 months after HSCT with ( n = 5) or without ( n = 3) CMV reactivation. Results Donor-derived CMV IgG tended to be elevated earlier in patients with CMV-seropositive donors than in those with CMV-seronegative donors. In 1 patient with a CMV-negative donor, donor-derived CMV IgG was not detected until late CMV reactivation. In 3 patients without CMV reactivation, donor-derived CMV IgG was also elevated within 1-6 months after HSCT. Conclusion In conclusion, the CMV serostatus of the donor may be related to the timing of the appearance of donor-derived CMV IgG and the reconstitution of humoral immunity against CMV, regardless of the CMV antigenemia level after HSCT. [ABSTRACT FROM AUTHOR]

Antigen recognition by immunoglobulins depends upon initial rearrangements of heavy chain V, D, and J genes. In leporids, a unique system exists for the VH genes usage that exhibit highly divergent lineages: the VHa allotypes, the Lepus sL lineage and the VHn genes. For the European rabbit ( Oryctolagus cuniculus), four VHa lineages have been described, the a1, a2, a3 and a4. For hares ( Lepus sp.), one VHa lineage was described, the a2L, as well as a more ancient sL lineage. Both genera use the VHn genes in a low frequency of their VDJ rearrangements. To address the hypothesis that the VH specificities could be associated with different environments, we sequenced VDJ genes from a third leporid genus, Sylvilagus. We found a fifth and equally divergent VHa lineage, the a5, and an ancient lineage, the sS, related to the hares' sL, but failed to obtain VHn genes. These results show that the studied leporids employ different VH lineages in the generation of the antibody repertoire, suggesting that the leporid VH genes are subject to strong selective pressure likely imposed by specific pathogens. [ABSTRACT FROM AUTHOR]

We report the case of a 13-month-old boy who developed right side parotitis as a first symptom of Kawasaki disease (KD). The data presented herein suggest that physicians should be aware that nonsuppurative parotitis is a possible manifestation of KD. [ABSTRACT FROM AUTHOR]

HLA class I molecules and killer cell immunoglobulin-like receptors (KIR) form a diverse system of ligands and receptors that individualize human immune systems in ways that improve the survival of individuals and populations. Human settlement of Oceania by island-hopping East and Southeast Asian migrants started ~3,500 years ago. Subsequently, New Zealand was reached ~750 years ago by ancestral Māori. To examine how this history impacted KIR and HLA diversity, and their functional interaction, we defined at high resolution the allelic and haplotype diversity of the 13 expressed KIR genes in 49 Māori and 34 Polynesians. Eighty KIR variants, including four 'new' alleles, were defined, as were 35 centromeric and 22 telomeric KIR region haplotypes, which combine to give >50 full-length KIR haplotypes. Two new and divergent variant KIR form part of a telomeric KIR haplotype, which appears derived from Papua New Guinea and was probably obtained by the Asian migrants en route to Polynesia. Māori and Polynesian KIR are very similar, but differ significantly from African, European, Japanese, and Amerindian KIR. Māori and Polynesians have high KIR haplotype diversity with corresponding allotype diversity being maintained throughout the KIR locus. Within the population, each individual has a unique combination of HLA class I and KIR. Characterizing Māori and Polynesians is a paucity of HLA-B allotypes recognized by KIR. Compensating for this deficiency are high frequencies (>50 %) of HLA-A allotypes recognized by KIR. These HLA-A allotypes are ones that modern humans likely acquired from archaic humans at a much earlier time. [ABSTRACT FROM AUTHOR]

The collection of Mantodea of the National Museum of Natural History, Smithsonian Institution, includes 26 holotypes, 7 allotypes, 4 lectotypes, 23 paratypes, and 1 paralectotype. Four type specimens were designated as lectotypes within this work. Highly accurate measurement data, high resolution images of specimens and labels, verbatim label data, georeferenced coordinates, original and newly assigned database codes, and bibliographic data are presented for all primary types. Label data for all paratype specimens in the collection are provide in tabular form. The location of the USNM collection has been moved to the Cleveland Museum of Natural History as a loan under the Off-site Enhancement Program. [ABSTRACT FROM AUTHOR]

Of the five immunoglobulin isotypes, immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3, and IgG4, which are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 domains. These regions are involved in binding to both IgG-Fc receptors (FcγR) and C1q. As a result, the different subclasses have different effector functions, both in terms of triggering FcγR-expressing cells, resulting in phagocytosis or antibody-dependent cell-mediated cytotoxicity, and activating complement. The Fc-regions also contain a binding epitope for the neonatal Fc receptor (FcRn), responsible for the extended half-life, placental transport, and bidirectional transport of IgG to mucosal surfaces. However, FcRn is also expressed in myeloid cells, where it participates in both phagocytosis and antigen presentation together with classical FcγR and complement. How these properties, IgG-polymorphisms and post-translational modification of the antibodies in the form of glycosylation, affect IgG-function will be the focus of the current review. [ABSTRACT FROM AUTHOR]

Highlights: [•] FcγR polymorphisms affect binding to IgG and thereby strength of immune reactions. [•] Likewise, FcγR-IgG binding is affected by which IgG subclasses are involved. [•] Biological differences between IgG allotypes also exist, particularly for IgG3. [•] IgG effector functions are also strongly affected by IgG-Fc glycosylation patterns. [•] IgG-Fc glycan type is antigen dependent, ultimately governed on the B-cell level. [Copyright &y& Elsevier]

Human cytomegalovirus (HCMV), a common herpes virus, has been reported to be a risk factor for many diseases, including malignant diseases such as glioma, neuroblastoma, and breast cancer. Some of the HCMV-associated diseases (e.g., glioma) are rare. The question arises: how could a common virus be associated with uncommon diseases? Interactions between a major gene complex of the human immune system and a viral immunoeva-sion strategy - a probable mechanism of their co-evolutionary adaptation - may shed light on this paradox. To ensure its survival, HCMV has evolved sophisticated immunoevasion strategies. One strategy involves encoding decoy Fcγ receptors (FcγR), which may enable the virus to evade host immunosurveillance by avoiding the Fcγ-mediated effector consequences of anti-HCMV IgG antibody binding. Immunoglobulin G1 proteins expressing GM (γ marker) alleles 3 and 17 have differential affinity to the HCMVTRL11/IRL11-encoded FcγR, and thus act as effect modifiers of HCMV-associated malignancies. The high affinity GM 3 allele has been shown to be a risk factor for neuroblastoma, glioma, and breast cancer. Additional studies involving other viral FcγRs as well as GM alleles expressed on other IgG subclasses are warranted. [ABSTRACT FROM AUTHOR]

Extensive studies have been undertaken to describe naive B cells differentiating into memory B cells at a cellular and molecular level. However, relatively little is known about the fate of memory B cells upon Ag re-encounter. We have previously established a system based on virus-like particles (VLPs), which allows tracking of VLP-specific B cells by flow cytometry as well as histology. Using allotype markers, it is possible to adoptively transfer memory B cells into a naive mouse and track responses of naive and memory B cells in the same mouse under physiological conditions. We have observed that VLP-specific memory B cells quickly differentiated into plasma cells that drove the early onset of a strong humoral IgG response. However, neither IgM+ nor IgG+ memory B cells proliferated extensively or entered germinal centers. Remarkably, plasma cells derived from memory B cells preferentially homed to the bone marrow earlier and secreted increased levels of Abs when compared with primary plasma cells derived from naive B cells. Hence, memory B cells have the unique phenotype to differentiate into highly effective secondary plasma cells. [ABSTRACT FROM AUTHOR]

Immunoevasive proteins ("evasins") of human CMV (HCMV) modulate stability and localization of MHC class I (MHC I) molecules, and their supply of antigenic peptides. However, it is largely unknown to what extent these evasins interfere with recognition by virus-specific CD8 T cells. We analyzed the recognition of HCMV-infected cells by a panel of CD8 T cells restricted through one of nine different MHC I allotypes. We employed a set of HCMV mutants deleted for three or all four of the MHC I modulatory genes US2, US3, US6, and US11. We found that different HCMV evasins exhibited different allotype-specific patterns of interference with CD8 T cell recognition of infected cells. In contrast, recognition of different epitopes presented by the same given MHC I allotype was uniformly reduced. For some allotypes, single evasins largely abolished T cell recognition; for others, a concerted action of evasins was required to abrogate recognition. In infected cells whose Ag presentation efficiency had been enhanced by IFN-γ pretreatment, HCMV evasins cooperatively impared T cell recognition for several different MHC I allotypes. T cell recognition and MHC I surface expression under influence of evasins were only partially congruent, underscoring the necessity to probe HCMV immunomodulation using specific T cells. We conclude that the CD8 T cell evasins of HCMV display MHC I allotype specificity, complementarity, and cooperativity. [ABSTRACT FROM AUTHOR]

GM (γ marker) allotypes, genetic variants of immunoglobulin γ chains, have been reported to be associated strongly with susceptibility to lung cancer, but the mechanism(s) underlying this association is not known. One mechanism could involve their contribution to humoral immunity to lung tumour-associated antigens. In this study, we aimed to determine whether particular GM and KM (κ marker) allotypes were associated with antibody responsiveness to XAGE-1b, a highly immunogenic lung tumour-associated cancer-testis antigen. Sera from 89 patients with non-small cell lung cancer ( NSCLC) were allotyped for eight GM and two KM determinants and characterized for antibodies to a synthetic XAGE-1b protein. The distribution of various GM phenotypes was significantly different between XAGE-1b antibody-positive and -negative patients ( P = 0·023), as well as in the subgroup of XAGE-1b antigen-positive advanced NSCLC ( P = 0·007). None of the patients with the GM 1,17 21 phenotype was positive for the XAGE-1b antibody. In patients with antigen-positive advanced disease, the prevalence of GM 1,2,17 21 was significantly higher in the antibody-positive group than in those who lacked the XAGE-1b antibody ( P = 0·026). This phenotype also interacted with a particular KM phenotype: subjects with GM 1,2,17 21 and KM 3,3 phenotypes were almost four times (odds ratio = 3·8) as likely to be positive for the XAGE-1b antibody as the subjects who lacked these phenotypes. This is the first report presenting evidence for the involvement of immunoglobulin allotypes in immunity to a cancer-testis antigen, which has important implications for XAGE-1b-based immunotherapeutic interventions in lung adenocarcinoma. [ABSTRACT FROM AUTHOR]

An increasingly larger fraction of patients with hematological diseases are treated by hematopoietic stem cells transplantation (HSCT) from HLA matched unrelated donors. Polymorphism of HLA genes represent a major barrier to HSCT because HLA-A,B,C and DRB1 incompatibilities confer a higher risk of aGVHD and mortality. Although >22 million volunteer HLA-typed donors are available worldwide, still a significant number of patients do not find a highly matched HSC donor. Because of the large haplotypic diversity in HLA-B-C associations, incompatibilities occur most frequently at HLA-C, so that unrelated donors with a single HLA-C mismatch often represent the only possible choice. The ratio of HLA-C-mismatched HSCT over the total number of transplants varies from 15-30%, as determined in 12 multicenter studies. Six multicenter studies involving >1800 patients have reported a 21-43% increase in mortality risk. By using in vitro cellular assays a large heterogeneity in T-cell allorecognition has been observed. Yet the permissiveness of individual HLA-C mismatches remains poorly defined. It could be linked to the position and nature of the mismatched residues on HLA-C molecules, but also to variability in the expression levels of the mismatched alleles. The permissive C*03:03-03:04 mismatch is caracterized by full compatibility at residues 9, 97, 99, 116, 152, 156 and 163 reported to be key positions influencing T-cell allorecognition. With a single difference in these key residues the C*07:01-07:02 mismatch might also be considered by analogy as permissive. High variability of HLA-C expression as determined by quantitative RT-PCR has been observed within individual allotypes and shows some correlation with A-B-C-DRB1 haplotypes. Thus in addition to the position of mismatched amino acid residues, expression level of patient's mismatched HLA-C allotype might influence T-cell allorecognition, with patient's low expression-C alleles representing possible permissive mismatches. [ABSTRACT FROM AUTHOR]

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Abstract: Introduction: The stimulatory effects of CRP (C-reactive protein) on endothelial cells are mainly mediated via FcγRIIa. This receptor exists in two different allotypes bearing either arginine (R131) or histidine (H131) at the extracellular amino acid position 131 of the mature protein, but only FcγRIIa-R131 displays high avidity for CRP. This study investigated the role of the FcγRIIa genotype in CRP-stimulated endothelial cells. Materials and Methods: We tested the effects of CRP on expression of the adhesion molecules ICAM-1, VCAM-1, and E-selectin, as well as the endothelial release of pro-inflammatory molecules as a function of the FcγRIIa-genotype (FcγRIIa-H/H131, FcγRIIa-H/R131, FcγRIIa-R/R131) in HUVEC (Human Umbilical Vein Endothelial Cells). HUVEC were grouped according to their FcγRIIa status by genotyping with an allele specific nested-PCR. The expression of ICAM-1, VCAM-1, and E-selectin on HUVEC was detected by flow cytometry. The release of soluble markers (sCD40L, IL-6, IL-8, MCP-1, tPA, sP-selectin, and sVCAM-1) was measured using a multiplex assay for flow cytometry. Results and Conclusions: CRP-stimulated expression of ICAM-1 and E-selectin was dependent on the specific FcγRIIa-genotype, with most pronounced induction in HUVEC with the FcγRIIa-R/R genotype, followed by H/R and H/H. In accordance with this finding, the supernatants of stimulated HUVEC with the R/R genotype showed significantly higher levels of tPA, MCP-1, and IL-6. Our data show that CRP stimulates the expression of adhesion molecules and the release of soluble markers by HUVEC as a function of the FcγRIIa-genotype. These findings could be relevant in the context of risk stratification in patients with cardiovascular disease. [Copyright &y& Elsevier]

Interdomain interactions between the CH3 domains of antibody heavy chains are the first step in antibody assembly and are of prime importance for maintaining the native structure of IgG. For human IgG4 it was shown that CH3-CH3 interactions are weak, resulting in the potential for half-molecule exchange ("Fab arm exchange"). Here we systematically investigated non-covalent interchain interactions for CH3 domains in the other human subclasses, including polymorphisms (allotypes), using real-time monitoring of Fab arm exchange with a FRET-based kinetic assay. We identified structural variation between human IgG subclasses and allotypes at three amino acid positions (Lys/ Asn-392, Val/Met-397, Lys/Arg-409) to alter the strength of inter-domain interactions by>6 orders of magnitude. Each substitution affected the interactions independent from the other substitutions in terms of affinity, but the enthalpic and entropic contributions were non-additive, suggesting a complex interplay. Allotypic variation in IgG3 resulted in widely different CH3 interaction strengths that were even weaker for IgG3 than for IgG4 in the case of allotype G3m(c3c5*/6,24*), whereas G3m(s*/15*) was equally stable to IgG1. These interactions are sufficiently strong to maintain the structural integrity of IgG1 during its normal life span; for IgG2 and IgG3 the inter-heavy chain disulfide bonds are essential to prevent half-molecule dissociation, whereas the labile hinge disulfide bonds favor half-molecule exchange in vivo for IgG4. [ABSTRACT FROM AUTHOR]