Antigen-binding Cleft Research Articles

Atypical sideways recognition of CD1a by autoreactive γδ T cell receptors

CD1a is a monomorphic antigen-presenting molecule on dendritic cells that presents lipids to αβ T cells. Whether CD1a represents a ligand for other immune receptors remains unknown. Here we use CD1a tetramers to show that CD1a is a ligand for Vδ1+ γδ T cells. Functional studies suggest that two γδ T cell receptors (TCRs) bound CD1a in a lipid-independent manner. The crystal structures of three Vγ4Vδ1 TCR-CD1a-lipid complexes reveal that the γδ TCR binds at the extreme far side and parallel to the long axis of the β-sheet floor of CD1a’s antigen-binding cleft. Here, the γδ TCR co-recognises the CD1a heavy chain and β2 microglobulin in a manner that is distinct from all other previously observed γδ TCR docking modalities. The ‘sideways’ and lipid antigen independent mode of autoreactive CD1a recognition induces TCR clustering on the cell surface and proximal T cell signalling as measured by CD3ζ phosphorylation. In contrast with the ‘end to end’ binding of αβ TCRs that typically contact carried antigens, autoreactive γδ TCRs support geometrically diverse approaches to CD1a, as well as antigen independent recognition.

Kinetics of Abacavir-Induced Remodelling of the Major Histocompatibility Complex Class I Peptide Repertoire.

Abacavir hypersensitivity syndrome can occur in individuals expressing the HLA-B*57:01 major histocompatibility complex class I allotype when utilising the drug abacavir as a part of their anti-retroviral regimen. The drug is known to bind within the HLA-B*57:01 antigen binding cleft, leading to the selection of novel self-peptide ligands, thus provoking life-threatening immune responses. However, the sub-cellular location of abacavir binding and the mechanics of altered peptide selection are not well understood. Here, we probed the impact of abacavir on the assembly of HLA-B*57:01 peptide complexes. We show that whilst abacavir had minimal impact on the maturation or average stability of HLA-B*57:01 molecules, abacavir was able to differentially enhance the formation, selectively decrease the dissociation, and alter tapasin loading dependency of certain HLA-B*57:01-peptide complexes. Our data reveals a spectrum of abacavir mediated effects on the immunopeptidome which reconciles the heterogeneous functional T cell data reported in the literature.

HLA allele frequencies and susceptibility analysis in 94 Florida residents with COVID-19 disease

Abstract COVID-19 is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) of suspected zoonotic origin. Although coronaviruses (CoVs) are relatively common across species, mutations can cause severe symptoms in humans. The widespread clinical symptoms encompass a large group of asymptomatic COVID-19 patients, raising a crucial question regarding genetic susceptibility, i.e. whether human leukocyte antigens (HLA) play a role in the patient symptomology. In this study, we hypothesize that “A certain HLA allele or combination of certain alleles can serve as biomarker for the severity of COVID-19”. To test this hypothesis, we genotyped HLAs of 94 patients with confirmed COVID-19 and 89 healthy individuals in Florida, USA, we found certain alleles (HLA-A*74:01, -A*30:01, DPA1*03:01, DPB1*01:01, and DQA1*05:01) were associated with disease susceptibility and some alleles (HLA-DPA1*01:03, DPB1*11:01 and DQA1*02:01) were associated with protection. Furthermore, using in-silico HLA docking modeling, we found that DPA1*01:03 is associated with reduced SARS-CoV-2 infectivity by binding to SARS-CoV-2 spike peptide with high affinity. Also, polymorphism in the antigen binding cleft of HLA-DP has the potential to inhibit binding to peptides derived from SARS-CoV-2 spike protein. The results provided a broader understanding of the genetic HLA association pertaining to the severity of COVID-19. Additionally, the results indicted the importance in performing the HLA genotyping with virus detection to identify high risk individuals.

Structural Characterization of a Minimal Antibody against Human APOBEC3B.

APOBEC3B (A3B) is one of seven human APOBEC3 DNA cytosine deaminases that restrict viral infections as part of the overall innate immune response, but it also plays a major role in tumor evolution by mutating genomic DNA. Given the importance of A3B as a restriction factor of viral infections and as a driver of multiple human cancers, selective antibodies against A3B are highly desirable for its specific detection in various research and possibly diagnostic applications. Here, we describe a high-affinity minimal antibody, designated 5G7, obtained via a phage display screening against the C-terminal catalytic domain (ctd) of A3B. 5G7 also binds APOBEC3A that is highly homologous to A3Bctd but does not bind the catalytic domain of APOBEC3G, another Z1-type deaminase domain. The crystal structure of 5G7 shows a canonical arrangement of the heavy and light chain variable domains, with their complementarity-determining region (CDR) loops lining an antigen-binding cleft that accommodates a pair of α-helices. To understand the mechanism of A3Bctd recognition by 5G7, we used the crystal structures of A3Bctd and 5G7 as templates and computationally predicted the A3B-5G7 complex structure. Stable binding poses obtained by the simulation were further tested by site-directed mutagenesis and in vitro binding analyses. These studies mapped the epitope for 5G7 to a portion of C-terminal α6 helix of A3Bctd, with Arg374 playing an essential role. The same region of A3Bctd was used previously as a peptide antigen for generating a rabbit monoclonal antibody (mAb 5210-87-13), suggesting that this region is particularly immunogenic and that these antibodies from very different origins may share similar binding modes. Our studies provide a platform for the development of selective antibodies against A3B and other APOBEC3 family enzymes.

Impact of HLA-DR Antigen Binding Cleft Rigidity on T Cell Recognition.

The interaction between T cell receptor (TCR) and peptide (p)-Human Leukocyte Antigen (HLA) complexes is the critical first step in determining T cell responses. X-ray crystallographic studies of pHLA in TCR-bound and free states provide a structural perspective that can help understand T cell activation. These structures represent a static “snapshot”, yet the nature of pHLAs and their interactions with TCRs are highly dynamic. This has been demonstrated for HLA class I molecules with in silico techniques showing that some interactions, thought to stabilise pHLA-I, are only transient and prone to high flexibility. Here, we investigated the dynamics of HLA class II molecules by focusing on three allomorphs (HLA-DR1, -DR11 and -DR15) that are able to present the same epitope and activate CD4+ T cells. A single TCR (F24) has been shown to recognise all three HLA-DR molecules, albeit with different affinities. Using molecular dynamics and crystallographic ensemble refinement, we investigate the molecular basis of these different affinities and uncover hidden roles for HLA polymorphic residues. These polymorphisms were responsible for the widening of the antigen binding cleft and disruption of pHLA-TCR interactions, underpinning the hierarchy of F24 TCR binding affinity, and ultimately T cell activation. We expanded this approach to all available pHLA-DR structures and discovered that all HLA-DR molecules were inherently rigid. Together with in vitro protein stability and peptide affinity measurements, our results suggest that HLA-DR1 possesses inherently high protein stability, and low HLA-DM susceptibility.

A different way for γδ T cells to bind

Immunology The ligands bound by γδ T cell receptors (TCRs) are less well characterized than those of their αβ TCR cousins, which are antigens presented by major histocompatibility complex (MHC) and related proteins. Le Nours et al. identified a phenotypically diverse γδ T cell subset in human tissues that reacts to MHC-related protein 1 (MR1), which presents vitamin B derivatives. A crystal structure of a γδ TCR–MR1–antigen complex revealed that some of these TCRs can bind underneath the MR1 antigen-binding cleft instead of recognizing the presented antigen. This work thus uncovers an additional ligand for γδ T cells and reconceptualizes the nature of T cell antigen recognition. Science , this issue p. [1522][1] [1]: /lookup/doi/10.1126/science.aav3900

A class of γδ T cell receptors recognize the underside of the antigen-presenting molecule MR1.

T cell receptors (TCRs) recognize antigens presented by major histocompatibility complex (MHC) and MHC class I-like molecules. We describe a diverse population of human γδ T cells isolated from peripheral blood and tissues that exhibit autoreactivity to the monomorphic MHC-related protein 1 (MR1). The crystal structure of a γδTCR-MR1-antigen complex starkly contrasts with all other TCR-MHC and TCR-MHC-I-like complex structures. Namely, the γδTCR binds underneath the MR1 antigen-binding cleft, where contacts are dominated by the MR1 α3 domain. A similar pattern of reactivity was observed for diverse MR1-restricted γδTCRs from multiple individuals. Accordingly, we simultaneously report MR1 as a ligand for human γδ T cells and redefine the parameters for TCR recognition.

Abrogation of Endogenous Glycolipid Antigen Presentation on Myelin-Laden Macrophages by D-Sphingosine Ameliorates the Pathogenesis of Experimental Autoimmune Encephalomyelitis.

Background: Although myelin is composed of mostly lipids, the pathological role of myelin lipids in demyelinating diseases remains elusive. The principal lipid of the myelin sheath is β-galactosylceramide (β-Galcer). Its α-anomer (α-Galcer) has been demonstrated to be antigenically presented by macrophages via CD1d, a MHC class I-like molecule. Myelin, which is mostly composed of β-Galcer, has been long considered as an immunologically-inert neuron insulator, because the antigen-binding cleft of CD1d is highly α-form-restricted.Results: Here, we report that CD1d-mediated antigenic presentation of myelin-derived galactosylceramide (Mye-GalCer) by macrophages contributed significantly to the progression of experimental autoimmune encephalomyelitis (EAE). Surprisingly, this presentation was recognizable by α-Galcer:CD1d-specific antibody (clone L363), but incapable of triggering expansion of iNKT cells and production of iNKT signature cytokines (IFNγ and IL-4). Likewise, a synthesized analog of Mye-Galcer, fluorinated α-C-GalCer (AA2), while being efficiently presented via CD1d on macrophages, failed to stimulate production of IFNγ and IL-4. However, AA2 significantly exacerbated EAE progression. Further analyses revealed that the antigenic presentations of both Mye-GalCer and its analog (AA2) in α-form via CD1d promoted IL-17 production from T cells, leading to elevated levels of IL-17 in EAE spinal cords and sera. The IL-17 neutralizing antibody significantly reduced the severity of EAE symptoms in AA2-treated mice. Furthermore, D-sphingosine, a lipid possessing the same hydrophobic base as ceramide but without a carbohydrate residue, efficiently blocked this glycolipid antigen presentation both in vitro and in spinal cords of EAE mice, and significantly decreased IL-17 and ameliorated the pathological symptoms.Conclusion: Our findings reveal a novel pathway from the presentation of Mye-GalCer to IL-17 production, and highlight the promising therapeutic potential of D-sphingosine for the human disorder of multiple sclerosis.

BoLA-DRB3 gene as a marker of susceptibility and resistance of the Ukrainian black-pied and red-pied dairy breeds to mastitis

The major histocompatibility complex (MHC) determines the immune response, and the MHC genes are promising candidate genes for identifying associations with diseases. The decisive role in the resistance of cattle to diseases belongs to the major histocompatibility complex of (BoLA). The BoLA system consists of several jointly operating genes that provide antigen presentation by MHC system molecules followed by an immune response to pathogenic microorganisms. The most functional is the BoLA-DRB3 gene. Its exon 2 is highly polymorphic and encodes the peptide antigen-binding cleft. Alleles, for which a close connection with disease susceptibility or disease resistance has been detected, are considered as DNA markers. These play a decisive role in the breeding of cattle to create herds resistant to diseases, including mastitis. This paper presents the results of a study of BoLA-DRB3 gene polymorphism in two commercial cattle breeds: the Ukrainian black-pied dairy (UBPD) and the Ukrainian red-pied dairy (URPD) and its association with mastitis. The UBPD and the URPD cows were genotyped at the bovine lymphocyte antigen DRB3.2 locus by a genotyping system that used polymerase chain reaction and restriction fragment length polymorphisms (PCR-RLFP). In 276 UBPD cows, 32 BoLA-DRB alleles have been found. Six alleles (*03, *08, *10, *22, *24 and *28) were identified with a frequency of more than 5% (total amount of 50.4%). The allele BoLA-DRB3.2*24 was the most frequent (19.2%). In the UBPD population (n = 162), four BoLA-DRB3.2 alleles are truly associated with mastitis: *24 and *26 with susceptibility and *13 and *22 with resistance. In 117 URPD cows, 22 alleles were identified, of which the most frequent were *07, *22, *11, *24, *01, *03 and *16 (total frequency 64.5%). Allele BoLA-DRB3.2*07 (present in 25.6% of cows) was the most commonly found. In the URPD population studied, four alleles truly associated with mastitis were identified. Animals susceptible to the disease had alleles *07 and *08, and resistant animals had alleles *22 and *24. Breeding activities for the creation of cattle resistant to mastitis using alleles of the BoLA-DRB3 gene are much more effective than treatment and special care for animals. Similar research should be carried out for other Ukrainian breeds in relation to various diseases (leukemia, necrobacteriosis, etc.).

Methyldopa blocks MHC class II binding to disease-specific antigens in autoimmune diabetes.

Major histocompatibility (MHC) class II molecules are strongly associated with many autoimmune disorders. In type 1 diabetes (T1D), the DQ8 molecule is common, confers significant disease risk, and is involved in disease pathogenesis. We hypothesized that blocking DQ8 antigen presentation would provide therapeutic benefit by preventing recognition of self-peptides by pathogenic T cells. We used the crystal structure of DQ8 to select drug-like small molecules predicted to bind structural pockets in the MHC antigen-binding cleft. A limited number of the predicted compounds inhibited DQ8 antigen presentation in vitro, with 1 compound preventing insulin autoantibody production and delaying diabetes onset in an animal model of spontaneous autoimmune diabetes. An existing drug with a similar structure, methyldopa, specifically blocked DQ8 in patients with recent-onset T1D and reduced inflammatory T cell responses to insulin, highlighting the relevance of blocking disease-specific MHC class II antigen presentation to treat autoimmunity.

The molecular basis for peptide repertoire selection in the human leukocyte antigen (HLA) C*06:02 molecule

Human leukocyte antigen (HLA)-C*06:02 is identified as the allele associated with the highest risk for the development of the autoimmune skin disease psoriasis. However, the diversity and mode of peptide presentation by the HLA-C*06:02 molecule remains unclear. Here, we describe the endogenous peptide repertoire of ∼3,000 sequences for HLA-C*06:02 that defines the peptide-binding motif for this HLA allomorph. We found that HLA-C*06:02 predominantly presents nonamer peptides with dominant arginine anchors at the P2 and P7 positions and a preference for small hydrophobic residues at the C terminus (PΩ). To determine the structural basis of this selectivity, we determined crystal structures of HLA-C*06:02 in complex with two self-peptides (ARTELYRSL and ARFNDLRFV) and an analogue of a melanocyte autoantigen (ADAMTSL5, VRSRR-abu-LRL) implicated in psoriasis. These structures revealed that HLA-C*06:02 possesses a deep peptide-binding groove comprising two electronegative B- and E-pockets that coincide with the preference for P2 and P7 arginine anchors. The ADAMTSL5 autoantigen possessed a P7-Leu instead of the P7-Arg residue, but nevertheless was accommodated within the HLA-C*06:02 antigen-binding cleft. Collectively, our results provide the structural basis for understanding peptide repertoire selection in HLA-C*06:02.

Shared peptide binding of HLA Class I and II alleles associate with cutaneous nevirapine hypersensitivity and identify novel risk alleles

Genes of the human leukocyte antigen (HLA) system encode cell-surface proteins involved in regulation of immune responses, and the way drugs interact with the HLA peptide binding groove is important in the immunopathogenesis of T-cell mediated drug hypersensitivity syndromes. Nevirapine (NVP), is an HIV-1 antiretroviral with treatment-limiting hypersensitivity reactions (HSRs) associated with multiple class I and II HLA alleles. Here we utilize a novel analytical approach to explore these multi-allelic associations by systematically examining HLA molecules for similarities in peptide binding specificities and binding pocket structure. We demonstrate that primary predisposition to cutaneous NVP HSR, seen across ancestral groups, can be attributed to a cluster of HLA-C alleles sharing a common binding groove F pocket with HLA-C*04:01. An independent association with a group of class II alleles which share the HLA-DRB1-P4 pocket is also observed. In contrast, NVP HSR protection is afforded by a cluster of HLA-B alleles defined by a characteristic peptide binding groove B pocket. The results suggest drug-specific interactions within the antigen binding cleft can be shared across HLA molecules with similar binding pockets. We thereby provide an explanation for multiple HLA associations with cutaneous NVP HSR and advance insight into its pathogenic mechanisms.

CD1a on Langerhans cells controls inflammatory skin diseases.

Abstract In contrast to conventional T cells that recognize peptides on MHC proteins, CD1 molecules present lipid antigens to T lymphocytes. The abundant expression of CD1a hallmarks Langerhans cells in the skin, a subtype of dendritic cell (DC) with antigen-presenting functions. CD1a is able to bind and display a broad spectrum of lipid antigens derived from exogenous sources, such as bacteria, or host origin. The complex immune system of the skin is critically involved in responses to extrinsic insults like allergens, as well as in autoimmune diseases, such as psoriasis. However, the in vivo role of CD1a on Langerhans cells remains enigmatic since CD1a is lacking in mice. Using CD1a-transgenic mice, we show that the lipidic substance urushiol from the plant poison ivy induces severe skin inflammation in a CD1a-dependent fashion. The immune response is driven by CD1a-expressing Langerhans cells that elicit the generation of CD4 T cells, producing the inflammatory cytokines IL-17 and IL-22. Among different urushiol congeners, we identified diunsaturated pentadecylcatechol (C15:2) as dominant antigen for CD1a-restricted T cells. We determined the crystal structure of the CD1a-urushiol (C15:2) complex, demonstrating the molecular basis of urushiol interaction with the antigen-binding cleft of CD1a. In a model for psoriasis, CD1a massively amplified inflammation mediated by Th17 cells reactive with self lipid antigens from skin. Strikingly, treatment with blocking antibodies versus CD1a fully abrogated skin inflammation. Patients suffering from psoriasis showed strong inflammatory T cell activation in response to CD1a. Thus, we propose CD1a as a potential target for future therapeutic strategies against inflammatory skin diseases.

Association of the HLA-B*53:01 Allele With Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Syndrome During Treatment of HIV Infection With Raltegravir.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare, severe adverse event during treatment with raltegravir. The occurrence of DRESS syndrome during treatment with other drugs is strongly associated with particular HLA alleles. We performed HLA testing in 3 of the 5 patients previously reported to have developed raltegravir-induced DRESS syndrome and in 1 previously unreported patient. We then used virtual modeling to visualize interactions between raltegravir and the imputed HLA molecule. Five of the 6 patients who developed raltegravir-induced DRESS syndrome were African, and 1 was Hispanic. HLA typing was performed in 4 patients, all of whom carried both the HLA-B*53 allele and the HLA-C*04 allele to which it is commonly haplotypic. No other HLA alleles were shared by all of the tested patients. Given the approximate prevalence of HLA-B*53 carriage in African (20%) and Hispanic (6%) populations, the probability of all 4 patients being HLA-B*53 carriers, and 2 of 3 African patients being homozygous for HLA-B*53:01, is approximately 0.00002. These data implicate the prevalent African allele HLA-B*53:01 in the immunopathogenesis of raltegravir-induced DRESS syndrome. Although the immunopathogenic mechanisms are currently unknown, virtual modeling suggests that raltegravir may bind within the antigen binding cleft of the HLA-B*53:01 molecule, but not within the closely related HLA-B*35:01 molecule. Further studies are necessary to confirm the strength of the association between carriage of the HLA-B*53:01 allele and raltegravir-induced DRESS syndrome, and the potential utility of HLA screening before raltegravir treatment.

Adverse drug reactions triggered by the common HLA-B*57:01 variant: a molecular docking study

BackgroundHuman leukocyte antigen (HLA) surface proteins are directly involved in idiosyncratic adverse drug reactions. Herein, we present a structure-based analysis of the common HLA-B*57:01 variant known to be responsible for several HLA-linked adverse effects such as the abacavir hypersensitivity syndrome.MethodsFirst, we analyzed three X-ray crystal structures involving the HLA-B*57:01 protein variant, the anti-HIV drug abacavir, and different co-binding peptides present in the antigen-binding cleft. We superimposed the three complexes and showed that abacavir had no significant conformational variation whatever the co-binding peptide. Second, we self-docked abacavir in the HLA-B*57:01 antigen binding cleft with and without peptide using Glide. Third, we docked a small test set of 13 drugs with known ADRs and suspected HLA associations.ResultsIn the presence of an endogenous co-binding peptide, we found a significant stabilization (~2 kcal/mol) of the docking scores and identified several modified abacavir–peptide interactions indicating that the peptide does play a role in stabilizing the HLA–abacavir complex. Next, our model was used to dock a test set of 13 drugs at HLA-B*57:01 and measured their predicted binding affinities. Drug-specific interactions were observed at the antigen-binding cleft and we were able to discriminate the compounds with known HLA-B*57:01 liability from inactives.Conclusions Overall, our study highlights the relevance of molecular docking for evaluating and analyzing complex HLA–drug interactions. This is particularly important for virtual drug screening over thousands of HLA variants as other experimental techniques (e.g., in vitro HTS) and computational approaches (e.g., molecular dynamics) are more time consuming and expensive to conduct. As the attention for drugs’ HLA liability is on the rise, we believe this work participates in encouraging the use of molecular modeling for reliably studying and predicting HLA–drug interactions. Graphical abstract.

In Silico Prediction of HLA-Associated Drug Hypersensitivity

Adverse drug reactions are a leading cause of morbidity and mortality with estimated annual inpatient costs of over $100 billion in the US alone. A growing number of the most severe adverse reactions, termed idiosyncratic drug hypersensitivities, are observed to be immune system mediated with genetic associations to specific human leukocyte antigen (HLA) alleles. However, little is known about the underlying mechanisms of the majority of these associations, which critically hinders preventative action. With combined in silico and in vitro approach we have demonstrated that the antiviral drug abacavir can bind the antigen binding cleft of HLA-B∗57:01 and alter its specificity for self-peptides presented to T cells. This finding, which has been independently reproduced, supports an “altered peptide repertoire model” for HLA-B∗57:01 - abacavir hypersensitivities and explains allele specificity. A critical barrier to examining the generality of this model is our inability to experimentally test the nearly 100 possible combinations between major HLA variants and a single drug. The need for multiple drug assessment further compounds tractability. Computational screening approaches that can better focus experiments are thus highly desired. Here we describe the combined application of molecular docking, molecular dynamics simulation and binding free energy calculations to enable an in silico prediction of HLA-drug associations. The predictive power of our approach is tested on a set of drugs with known HLA-linked hypersensitivity reactions. These include abacavir with B∗57:01, the gout prophylactic allopurinol with B∗58:01, the antiepileptic carbamazepine with B∗15:02, and the antiglaucoma methazolamide with B∗59:01. For these drugs the variant specific residue-wise determinants of HLA-drug interactions are identified. Our studies represent a first step toward the development of a preclinical screening process that aims to identify drugs with a high risk of causing drug hypersensitivity.

Identification of drug- and drug-metabolite immune responses originating from both naive and memory T cells

Identification of drug- and drug-metabolite immune responses originating from both naive and memory T cells

CD1a on Langerhans cells controls inflammatory skin disease.

CD1a is a lipid-presenting molecule abundantly expressed on Langerhans cells. However, the in vivo role of CD1a remains unclear, principally because CD1a is lacking in mice. Using CD1a-transgenic mice, we show that the plant-derived lipid urushiol triggers CD1a-dependent skin inflammation, driven by CD4+ T cells producing IL-17 and IL-22. Human subjects with poison ivy dermatitis showed a similar cytokine signature following CD1a-mediated urushiol recognition. Among different urushiol congeners, we identified diunsaturated pentadecylcatechol (C15:2) as the dominant antigen for CD1a-restricted T cells. We determined the crystal structure of the CD1a-urushiol (C15:2) complex, demonstrating the molecular basis of urushiol interaction with the antigen-binding cleft of CD1a. In a mouse model and psoriasis patients, CD1a amplified inflammatory responses mediated by TH17 cells reactive with self lipid antigens. Treatment with blocking antibodies against CD1a alleviated skin inflammation. Thus, we propose CD1a as a potential therapeutic target in inflammatory skin diseases.

Promiscuous T-cell responses to drugs and drug-haptens

Promiscuous T-cell responses to drugs and drug-haptens

Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model

CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (KD ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC50 typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical.