Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 14.974
Filter
1.
Nat Commun ; 15(1): 5339, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38914562

ABSTRACT

Broadly neutralizing antibodies (bNAbs) are promising candidates for the treatment and prevention of HIV-1 infections. Despite their critical importance, automatic detection of HIV-1 bNAbs from immune repertoires is still lacking. Here, we develop a straightforward computational method for the Rapid Automatic Identification of bNAbs (RAIN) based on machine learning methods. In contrast to other approaches, which use one-hot encoding amino acid sequences or structural alignment for prediction, RAIN uses a combination of selected sequence-based features for the accurate prediction of HIV-1 bNAbs. We demonstrate the performance of our approach on non-biased, experimentally obtained and sequenced BCR repertoires from HIV-1 immune donors. RAIN processing leads to the successful identification of distinct HIV-1 bNAbs targeting the CD4-binding site of the envelope glycoprotein. In addition, we validate the identified bNAbs using an in vitro neutralization assay and we solve the structure of one of them in complex with the soluble native-like heterotrimeric envelope glycoprotein by single-particle cryo-electron microscopy (cryo-EM). Overall, we propose a method to facilitate and accelerate HIV-1 bNAbs discovery from non-selected immune repertoires.


Subject(s)
Antibodies, Neutralizing , Cryoelectron Microscopy , HIV Antibodies , HIV Infections , HIV-1 , Machine Learning , HIV-1/immunology , Humans , HIV Antibodies/immunology , Antibodies, Neutralizing/immunology , HIV Infections/virology , HIV Infections/immunology , CD4 Antigens/metabolism , CD4 Antigens/immunology , Amino Acid Sequence , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp120/chemistry
2.
Biochem Biophys Res Commun ; 725: 150249, 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-38880081

ABSTRACT

The HIV-1 envelope glycoprotein (Env) plays crucial role in viral infection by facilitating viral attachment to host cells and inducing fusion of the virus with the host cell membrane. This fusion allows the HIV-1 viral genome to enter the target cell then triggering various stages of the viral life cycle. The native Env directly interacts with the main receptor CD4 and the co-receptor (CCR5 or CXCR4) in human cell membrane then induces membrane fusion. The elucidation of the structure of Env with CD4 and co-receptors in different HIV-1 subtypes is essential for the understanding of the mechanism of virus entry. Here we report the Cryo-EM structure of the CD4-bound HIV-1 heterotrimeric Env from Asia prevalent CRF07_BC CH119 strain. In this structure, the binding of three CD4 molecules with Env induced extensively conformational changes in gp120, resulting in the transformation of the Env from close state to intermediate open state. Additionally, the conformational shift of V1/V2 loops of the heterotrimeric Env allosterically expose the V3 loop and promoting the further interactions with co-receptor CCR5 or CXCR4. These findings not only illustrate the structural complexity and plasticity of HIV-1 Env but also give new insights how the biological trimeric Env initialize the immune recognition and membrane fusion.


Subject(s)
CD4 Antigens , HIV Envelope Protein gp120 , HIV-1 , HIV-1/metabolism , Humans , CD4 Antigens/metabolism , CD4 Antigens/chemistry , HIV Envelope Protein gp120/metabolism , HIV Envelope Protein gp120/chemistry , HIV Envelope Protein gp120/genetics , Cryoelectron Microscopy , env Gene Products, Human Immunodeficiency Virus/metabolism , env Gene Products, Human Immunodeficiency Virus/chemistry , env Gene Products, Human Immunodeficiency Virus/genetics , Receptors, CCR5/metabolism , Receptors, CCR5/chemistry , Protein Binding , Models, Molecular , Protein Conformation , HIV Infections/virology , HIV Infections/metabolism , Protein Multimerization , Receptors, CXCR4/metabolism , Receptors, CXCR4/chemistry , Asia
3.
Front Immunol ; 15: 1400550, 2024.
Article in English | MEDLINE | ID: mdl-38835756

ABSTRACT

The dog is an important companion animal and also serves as model species for human diseases. Given the central role of T cells in immune responses, a basic understanding of canine conventional T cell receptor (TCR)αß+ T cells, comprising CD4+ single-positive (sp) T helper (Th) and CD8α+ sp cytotoxic T cell subsets, is available. However, characterization of canine non-conventional TCRαß+ CD4+CD8α+ double-positive (dp) and TCRαß+ CD4-CD8α- double-negative (dn) T cells is limited. In this study, we performed a comprehensive analysis of canine dp and dn T cells in comparison with their conventional counterparts. TCRαß+ T cells from peripheral blood of healthy dogs were sorted according to their CD4/CD8α phenotype into four populations (i.e. CD4+ sp, CD8α+ sp, dp, and dn) and selected surface markers, transcription factors and effector molecules were analyzed ex vivo and after in vitro stimulation by RT-qPCR. Novel characteristics of canine dp T cells were identified, expanding the previously characterized Th1-like phenotype to Th17-like and Th2-like properties. Overall, mRNA expression of various Th cell-associated cytokines (i.e. IFNG, IL17A, IL4, IL13) in dp T cells upon stimulation highlights their versatile immunological potential. Furthermore, we demonstrated that the CD4-CD8α- dn phenotype is stable during in vitro stimulation. Strikingly, dn T cells were found to express highest mRNA levels of type 2 effector cytokines (IL4, IL5, and IL13) upon stimulation. Their strong ability to produce IL-4 was confirmed at the protein level. Upon stimulation, the percentage of IL-4-producing cells was even higher in the non-conventional dn than in the conventional CD4+ sp population. Constitutive transcription of IL1RL1 (encoding IL-33Rα) further supports Th2-like properties within the dn T cell population. These data point to a role of dn T cells in type 2 immunity. In addition, the high potential of dn T cells to transcribe the gene encoding the co-inhibitory receptor CTLA-4 and to produce the inhibitory cytokine IL-10 indicates putative immunosuppressive capacity of this population. In summary, this study reveals important novel aspects of canine non-conventional T cells providing the basis for further studies on their effector and/or regulatory functions to elucidate their role in health and disease.


Subject(s)
Receptors, Antigen, T-Cell, alpha-beta , Th2 Cells , Animals , Dogs , Receptors, Antigen, T-Cell, alpha-beta/genetics , Receptors, Antigen, T-Cell, alpha-beta/immunology , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Th2 Cells/immunology , CD8 Antigens/metabolism , CD8 Antigens/immunology , Cytokines/metabolism , CD4 Antigens/metabolism , CD4 Antigens/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Immunophenotyping , Male
4.
Fish Shellfish Immunol ; 150: 109649, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38797336

ABSTRACT

In mammals, CD4 is found to be expressed on T cells and innate immune cells, however, teleost cells bearing CD4 have not been well identified and characterized. In this study, we identified two different CD4-1+ cell subsets in grass carp (Ctenopharyngodon idella): CD4-1+ lymphocytes (Lym) and CD4-1+ myeloid cells (Mye), both of which had the highest proportions in the head kidney. The mRNA expression analysis showed that CD4-1, CD4-2, TCRß, CD3γ/δ, and LCK1 are highly expressed in CD4-1+ Lym and also expressed in CD4-1+ Mye. Furthermore, we found that CD4-1+ Lym have a Lym morphology and highly express T-cell cytokines, suggesting that they are CD4+ T cells equivalent to mammalian Th cells. On the other hand, CD4-1+ Mye were found to have a morphology of macrophage and highly express macrophage marker gene MCSFR, indicating that they are macrophages. In addition, functional analysis revealed that CD4-1+ Mye possess phagocytic ability and great antigen-processing ability. Taken together, our study sheds further light on the composition and function of CD4+ cells in teleost fish.


Subject(s)
Carps , Fish Proteins , Animals , Carps/immunology , Carps/genetics , Fish Proteins/genetics , Fish Proteins/immunology , CD4-Positive T-Lymphocytes/immunology , CD4 Antigens/genetics , CD4 Antigens/immunology , CD4 Antigens/metabolism , Head Kidney/immunology , Head Kidney/cytology , Myeloid Cells/immunology , Immunity, Innate/genetics
5.
EBioMedicine ; 104: 105151, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38728839

ABSTRACT

BACKGROUND: People living with HIV (PLWH) with multidrug-resistant (MDR) viruses have limited therapeutic options and present challenges regarding clinical management. Recent studies have shown that passive transfer of combination broadly neutralizing antibodies (bNAbs) against HIV and anti-domain 1 CD4 antibody UB-421 can sustain virologic suppression in PLWH in the absence of antiretroviral therapy (ART). Yet studies addressing the therapeutic potential of these antibodies and/or detailed characterization of immunologic and virologic parameters in PLWH with MDR HIV are lacking. METHODS: We examined levels of immune activation and exhaustion markers on CD8+ T cells and the intact HIV proviral DNA burden in 11 PLWH with MDR viruses. For comparison purposes, we included a control group consisting of 27 ART-naïve viremic PLWH. In addition, we determined the sensitivity of infectious viral isolates obtained from the participants against eight bNAbs (3BNC117, 10-1074, VRC01, VRC07, N6, 10E8, PGDM1400, and PGT121) and two anti-CD4 antibodies (ibalizumab and UB-421) using a TZM-bl-based neutralization/suppression assay. FINDINGS: The level of intact HIV proviral DNA was comparable between the two groups (P = 0.29). The levels of activation and exhaustion markers PD-1 (P = 0.0019), TIGIT (P = 0.0222), 2B4 (P = 0.0015), CD160 (P = 0.0015), and CD38+/HLA-DR+ (P = 0.0138) were significantly lower in the MDR group. The infectious viral isolates from each study participant with MDR HIV were resistant to at least 2 bNAbs; however, they were sensitive to at least one of the CD4-binding and non-CD4-binding site antibodies. The majority of participants had ibalizumab-sensitive viruses although the isolates from some participants showed reduced sensitivity to ibalizumab. Notably, none of the 93 viral isolates obtained from the participants were resistant to UB-421. INTERPRETATION: Our data suggest that combination therapy with HIV-specific bNAbs and/or UB-421 in the presence of optimized background therapy could potentially provide sustained virologic suppression in PLWH with MDR HIV. However, this therapeutic strategy needs to be evaluated in human clinical trials. FUNDING: Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health.


Subject(s)
Antibodies, Neutralizing , Broadly Neutralizing Antibodies , HIV Antibodies , HIV Infections , HIV-1 , Humans , HIV Infections/immunology , HIV Infections/virology , HIV Infections/drug therapy , HIV-1/immunology , Male , Female , Adult , Antibodies, Neutralizing/immunology , Middle Aged , Broadly Neutralizing Antibodies/immunology , HIV Antibodies/immunology , CD4 Antigens/metabolism , CD4 Antigens/immunology , Drug Resistance, Multiple, Viral , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Viral Load , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism
6.
Cell Mol Biol (Noisy-le-grand) ; 70(5): 155-160, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38814221

ABSTRACT

In order to explore a new mode for the diagnosis of angioimmunoblastic T-cell lymphoma (AITL), 31 cases of AITL and 28 cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) were used as the study subjects. Identifying T follicular helper (TFH) cells with CD4, CD10, Bcl-6, and PD-1, identifying proliferative B cells with CD20 and EZH2, identifying proliferative follicular dendritic cells (FDCs) with CD21 and CD23, and analyzing the value of TFH/B/FDC proliferation and immunolocalization in the diagnosis of AITL. (1) Outside the inherent lymphoid follicles, simultaneous proliferation of TFH/B/FDC (a new diagnostic mode) were observed in AITL [83.87%; 26/31], with their immunolocalizations in the same site [83.87%; 26/31], while this phenomenon was not observed in 28 cases of PTCL-NOS (P<0.05). (2) The sensitivity and specificity of using this new mode to diagnose AITL were both high (83.87%, 100%), which was superior to CD2 (100%, 0%), CD3 (100%, 0%), CD4 (100%, 32.14%), CD5 (100%, 25%), CD10 (61.9%, 100%), Bcl-6 (42.86%, 100%), PD-1 (83.87%, 96.43%), and its Youden Index (0.84) was the highest. The areas under the curve (AUC) of CD10, Bcl-6, PD-1, and new mode to diagnosis AITL were 0.81, 0.71, 0.90, and 0.92, respectively, while the new mode had the highest AUC. The simultaneous proliferation of TFH/B/FDC cells outside the inherent lymphoid follicles can be used to assist in the diagnosis of AITL, and the simultaneous spatiotemporal proliferation of TFH/B/FDC cells is a specific immunomorphology of AITL.


Subject(s)
Proto-Oncogene Proteins c-bcl-6 , Humans , Female , Male , Middle Aged , Aged , Proto-Oncogene Proteins c-bcl-6/metabolism , Neprilysin/metabolism , Immunoblastic Lymphadenopathy/diagnosis , Immunoblastic Lymphadenopathy/pathology , Dendritic Cells, Follicular/pathology , Dendritic Cells, Follicular/metabolism , Programmed Cell Death 1 Receptor/metabolism , Adult , Lymphoma, T-Cell/diagnosis , Lymphoma, T-Cell/pathology , Lymphoma, T-Cell/metabolism , Enhancer of Zeste Homolog 2 Protein/metabolism , Cell Proliferation , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , T Follicular Helper Cells/immunology , T Follicular Helper Cells/metabolism , Receptors, Complement 3d/metabolism , Receptors, Complement 3d/analysis , Antigens, CD20/metabolism , Antigens, CD20/analysis , Lymphoma, T-Cell, Peripheral/diagnosis , Lymphoma, T-Cell, Peripheral/pathology , CD4 Antigens/metabolism , Sensitivity and Specificity , Aged, 80 and over , Immunohistochemistry/methods , ROC Curve
7.
Nat Commun ; 15(1): 4301, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38773089

ABSTRACT

The vaccine elicitation of HIV tier-2-neutralization antibodies has been a challenge. Here, we report the isolation and characterization of a CD4-binding site (CD4bs) specific monoclonal antibody, HmAb64, from a human volunteer immunized with a polyvalent DNA prime-protein boost HIV vaccine. HmAb64 is derived from heavy chain variable germline gene IGHV1-18 and light chain germline gene IGKV1-39. It has a third heavy chain complementarity-determining region (CDR H3) of 15 amino acids. On a cross-clade panel of 208 HIV-1 pseudo-virus strains, HmAb64 neutralized 20 (10%), including tier-2 strains from clades B, BC, C, and G. The cryo-EM structure of the antigen-binding fragment of HmAb64 in complex with a CNE40 SOSIP trimer revealed details of its recognition; HmAb64 uses both heavy and light CDR3s to recognize the CD4-binding loop, a critical component of the CD4bs. This study demonstrates that a gp120-based vaccine can elicit antibodies capable of tier 2-HIV neutralization.


Subject(s)
AIDS Vaccines , Antibodies, Neutralizing , CD4 Antigens , HIV Antibodies , HIV-1 , Humans , AIDS Vaccines/immunology , HIV-1/immunology , HIV Antibodies/immunology , Antibodies, Neutralizing/immunology , CD4 Antigens/immunology , CD4 Antigens/metabolism , Vaccines, DNA/immunology , Antibodies, Monoclonal/immunology , HIV Infections/prevention & control , HIV Infections/immunology , HIV Infections/virology , Cryoelectron Microscopy , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp120/chemistry , Binding Sites , Complementarity Determining Regions/immunology , Complementarity Determining Regions/chemistry
8.
Appl Microbiol Biotechnol ; 108(1): 327, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38717623

ABSTRACT

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats. KEY POINTS: • A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs. • C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity. • The frequency of Treg cells was positively correlated with the viral load during orf virus infection.


Subject(s)
Antibodies, Monoclonal , Flow Cytometry , Goats , T-Lymphocytes, Regulatory , Viral Load , Animals , T-Lymphocytes, Regulatory/immunology , Antibodies, Monoclonal/immunology , Ecthyma, Contagious/diagnosis , Ecthyma, Contagious/immunology , Interleukin-2 Receptor alpha Subunit/immunology , Orf virus/immunology , Fluorescent Antibody Technique/methods , CD4 Antigens/immunology , Goat Diseases/immunology , Goat Diseases/virology , Goat Diseases/diagnosis
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(2): 588-594, 2024 Apr.
Article in Chinese | MEDLINE | ID: mdl-38660871

ABSTRACT

OBJECTIVE: To explore the clinical manifestations, pathological features, immunophenotype, as well as diagnosis, treatment and prognosis of patients with CD4-CD56+ blastic plasmacytoid dendritic cell neoplasm (BPDCN), in order to further understand the rare disease. METHODS: The clinical data, laboratory examinations and treatment regimens of two patients with CD4-CD56+ BPDCN in the First Affiliated Hospital of Wannan Medical College were retrospectively analyzed. RESULTS: The two patients were both elderly males with tumor involved in skin, bone marrow, lymph nodes, etc. Immunohistochemical results of skin lesions showed that both CD56 and CD123 were positive, while CD4, CD34, TdT, CD3, CD20, MPO and EBER were negative. Flow cytometry of bone marrow demonstrated that CD56, CD123, and CD304 were all positive, while specific immune markers of myeloid and lymphoid were negative. Two patients were initially very sensitive to acute lymphoblastic leukemia or lymphomatoid chemotherapy regimens, but prone to rapid relapse. The overall survival of both patients was 36 months and 4 months, respectively. CONCLUSION: CD4-CD56+ BPDCN is very rare and easily misdiagnosed as other hematological tumors with poor prognosis. Acute lymphoblastic leukemia or lymphomatoid therapy should be used first to improve the poor prognosis.


Subject(s)
CD56 Antigen , Dendritic Cells , Aged , Humans , Male , CD4 Antigens/metabolism , CD56 Antigen/metabolism , Hematologic Neoplasms , Immunophenotyping , Prognosis , Retrospective Studies
10.
Rev Alerg Mex ; 71(1): 73, 2024 Feb 01.
Article in Spanish | MEDLINE | ID: mdl-38683090

ABSTRACT

OBJECTIVE: To carry out a preliminary analysis on the Treg lymphocyte counts present in the peripheral blood of allergic asthmatic children from the city of Cartagena, Colombia, compared to healthy controls. METHODS: We compared cytometry counts of ten asthmatic patients (age 7-16 years) and seven healthy controls (6-12 years), recruited in the city of Cartagena. Peripheral blood samples were stained using Cytek's 14-color cFluor Immunoprofiling kit (Cytek® cFluor® Immunoprofiling Kit 14 Color RUO kit), and analyzed on a Northern Lights™ spectral cytometer (Cytek® Biosciences, Fremont, CA, USA), to read 50.000 events per sample. The data obtained were analyzed in SpectroFlo® and FlowJo. The study was approved by the ethics committee of the University of Cartagena (SGR, Grant BPIN2020000100405). RESULTS: The frequency of CD3+, CD4+, CD25+, CD127- Tregs was 11% of all CD4+ T cells, with a range of minimum 8,1% and maximum 17,7%. There was no significant difference in the proportion of Tregs between allergic asthmatic patients and healthy controls (P = 0,2). CONCLUSIONS: With this preliminary sample size, no significant differences were found in the Treg lymphocyte population between allergic asthmatic patients and healthy controls. The 14-color multiplexed panel is a useful tool not only to count CD3+ and CD4+ populations, but also to obtain the percentage of regulatory T cells using cell surface markers.


OBJETIVO: Realizar un análisis preliminar sobre los conteos de linfocitos Tregs presentes en sangre periférica de niños asmáticos alérgicos de la ciudad de Cartagena, comparado con controles sanos. MÉTODOS: Se compararon los conteos de citometría de diez pacientes asmáticos (entre 7 y16 años) y siete controles sanos (entre 6 y12 años), reclutados en la ciudad de Cartagena. La muestra de sangre periférica fue teñida empleando el kit de inmunofenotipo multiplexado de 14 colores de Cytek (Cytek® cFluor® Immunoprofiling Kit 14 Color), y analizada en un citómetro espectral Northern Lights™ (Cytek® Biosciences, Fremont, CA, USA), a lectura de 50.000 eventos por muestra. Los datos obtenidos fueron analizados en SpectroFlo® y FlowJo. El estudio fue aprobado por el Comité de Ética de la Universidad de Cartagena. RESULTADOS: El panel de tinción funcionó apropiadamente y dentro de los parámetros apropiados. Se obtuvo un promedio de células Tregs CD3+, CD4+, CD25+ y CD127- del 11% de todos los CD4+ en las muestras estudiadas, con un rango de mínimo de 8,1% y un máximo de 17,7%. No hubo diferencias significativas en la proporción de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos (P = 0.2). CONCLUSIONES: Con este tamaño de muestra preliminar, no se encontraron diferencias significativas en la población de linfocitos Tregs entre los pacientes asmáticos alérgicos y los controles sanos. El panel multiplexado de 14 colores es una herramienta útil no solo para derivar las poblaciones CD3+ y CD4+, sino también para obtener el porcentaje de células T reguladoras empleando marcadores de superficie celular.


Subject(s)
Asthma , Interleukin-2 Receptor alpha Subunit , Interleukin-7 Receptor alpha Subunit , T-Lymphocytes, Regulatory , Adolescent , Child , Female , Humans , Male , Asthma/blood , Asthma/immunology , CD4 Antigens/analysis , CD4 Antigens/blood , Interleukin-2 Receptor alpha Subunit/blood , Interleukin-2 Receptor alpha Subunit/analysis , Interleukin-7 Receptor alpha Subunit/analysis , Interleukin-7 Receptor alpha Subunit/blood , Lymphocyte Count , T-Lymphocytes, Regulatory/immunology , CD4-Positive T-Lymphocytes/immunology
11.
Elife ; 122024 Apr 19.
Article in English | MEDLINE | ID: mdl-38639990

ABSTRACT

CD4+ T cell activation is driven by five-module receptor complexes. The T cell receptor (TCR) is the receptor module that binds composite surfaces of peptide antigens embedded within MHCII molecules (pMHCII). It associates with three signaling modules (CD3γε, CD3δε, and CD3ζζ) to form TCR-CD3 complexes. CD4 is the coreceptor module. It reciprocally associates with TCR-CD3-pMHCII assemblies on the outside of a CD4+ T cells and with the Src kinase, LCK, on the inside. Previously, we reported that the CD4 transmembrane GGXXG and cytoplasmic juxtamembrane (C/F)CV+C motifs found in eutherian (placental mammal) CD4 have constituent residues that evolved under purifying selection (Lee et al., 2022). Expressing mutants of these motifs together in T cell hybridomas increased CD4-LCK association but reduced CD3ζ, ZAP70, and PLCγ1 phosphorylation levels, as well as IL-2 production, in response to agonist pMHCII. Because these mutants preferentially localized CD4-LCK pairs to non-raft membrane fractions, one explanation for our results was that they impaired proximal signaling by sequestering LCK away from TCR-CD3. An alternative hypothesis is that the mutations directly impacted signaling because the motifs normally play an LCK-independent role in signaling. The goal of this study was to discriminate between these possibilities. Using T cell hybridomas, our results indicate that: intracellular CD4-LCK interactions are not necessary for pMHCII-specific signal initiation; the GGXXG and (C/F)CV+C motifs are key determinants of CD4-mediated pMHCII-specific signal amplification; the GGXXG and (C/F)CV+C motifs exert their functions independently of direct CD4-LCK association. These data provide a mechanistic explanation for why residues within these motifs are under purifying selection in jawed vertebrates. The results are also important to consider for biomimetic engineering of synthetic receptors.


Subject(s)
Lymphocyte Specific Protein Tyrosine Kinase p56(lck) , Placenta , Pregnancy , Animals , Female , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/genetics , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism , Placenta/metabolism , Signal Transduction/genetics , Receptors, Antigen, T-Cell/metabolism , Receptor-CD3 Complex, Antigen, T-Cell/metabolism , Phosphorylation , CD4 Antigens , Mammals/metabolism
12.
mBio ; 15(4): e0032124, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38426750

ABSTRACT

Human immunodeficiency virus type 1 typically requires a high density of CD4 for efficient entry as a mechanism to target CD4+ T cells (T-tropic), with CCR5 being used most often as the coreceptor. When target T cells are limiting, the virus can evolve to infect cells with a low density of CD4 such as macrophages (M-tropic). The entry phenotype is known to be encoded in the viral Env protein on the surface of the virus particle. Using data showing a dose response for infectivity based on CD4 surface density, we built a model consistent with T-tropic viruses requiring multiple CD4 molecules to mediate infection, whereas M-tropic viruses can infect cells using a single CD4 receptor molecule interaction. We also found that T-tropic viruses bound to the surface of cells with a low density of CD4 are released more slowly than M-tropic viruses which we modeled to be due to multiple interactions of the T-tropic virus with multiple CD4 molecules to allow the initial stable binding. Finally, we found that some M-tropic Env proteins, as the gp120 subunit, possess an enhanced affinity for CD4 compared with their T-tropic pair, indicating that the evolution of macrophage tropism can be reflected both in the closed Env trimer conformation on the virion surface and, in some cases, also in the open confirmation of gp120 Env. Collectively, these studies reveal differences in the stoichiometry of interaction of T-tropic and M-tropic viruses with CD4 and start to identify the basis of binding differences at the biochemical level. IMPORTANCE: Human immunodeficiency virus type 1 normally targets CD4+ T cells for viral replication. When T cells are limiting, the virus can evolve to infect myeloid cells. The evolutionary step involves a change from requiring a high surface density of CD4 for entry to being able to infect cells with a low density of CD4, as is found on myeloid lineage cells such as macrophage and microglia. Viruses able to infect macrophages efficiently are most often found in the CNS late in the disease course, and such viruses may contribute to neurocognitive impairment. Here, we examine the CD4 binding properties of the viral Env protein to explore these two different entry phenotypes.


Subject(s)
HIV-1 , Humans , CD4 Antigens/metabolism , CD4-Positive T-Lymphocytes , Gene Products, env/metabolism , HIV-1/physiology , Macrophages/metabolism , Receptors, CCR5/metabolism , Viral Envelope Proteins/metabolism , env Gene Products, Human Immunodeficiency Virus
13.
J Biol Chem ; 300(4): 107133, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38432632

ABSTRACT

Protein mechanical stability determines the function of a myriad of proteins, especially proteins from the extracellular matrix. Failure to maintain protein mechanical stability may result in diseases and disorders such as cancer, cardiomyopathies, or muscular dystrophy. Thus, developing mutation-free approaches to enhance and control the mechanical stability of proteins using pharmacology-based methods may have important implications in drug development and discovery. Here, we present the first approach that employs computational high-throughput virtual screening and molecular docking to search for small molecules in chemical libraries that function as mechano-regulators of the stability of human cluster of differentiation 4, receptor of HIV-1. Using single-molecule force spectroscopy, we prove that these small molecules can increase the mechanical stability of CD4D1D2 domains over 4-fold in addition to modifying the mechanical unfolding pathways. Our experiments demonstrate that chemical libraries are a source of mechanoactive molecules and that drug discovery approaches provide the foundation of a new type of molecular function, that is, mechano-regulation, paving the way toward mechanopharmacology.


Subject(s)
CD4 Antigens , Drug Discovery , Small Molecule Libraries , Humans , CD4 Antigens/metabolism , CD4 Antigens/chemistry , Drug Discovery/methods , High-Throughput Screening Assays/methods , HIV-1/metabolism , HIV-1/chemistry , Molecular Docking Simulation , Protein Stability , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology
14.
BMC Res Notes ; 17(1): 44, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38308298

ABSTRACT

BACKGROUND: Triple-negative breast cancer (TNBC) has been documented as the most aggressive subtype of breast cancer. This study aimed to analyze antitumor and protumor immune activities, and their ratios as significant prognostic biomarkers in metastatic TNBC (mTNBC). METHODS: A multicenter cohort study was conducted among 103 de novo mTNBC patients. The expression of CD8 and CD163 was evaluated using immunohistochemistry staining, CD4 and FOXP3 using double-staining immunohistochemistry, and PD-L1 using immunohistochemistry and RT-PCR. RESULTS: Multivariate analysis revealed that high CD4/FOXP3 (HR 1.857; 95% CI 1.049-3.288; p = 0.034) and the CD8/CD163 ratio (HR 2.089; 95% CI 1.174-3.717; p = 0.012) yield significantly improved 1 year overall survival (OS). Kaplan-Meier analysis showed that high levels of CD4 (p = 0.023), CD8 (p = 0.043), CD4/FOXP3 (p = 0.016), CD8/FOXP3 (p = 0.005), CD8/CD163 (p = 0.005) ratios were significantly associated with higher rate of 1 year OS. Furthermore, 1 year OS was directly correlated with antitumor CD4 (R = 0.233; p = 0.018) and CD8 (R = 0.219; p = 0.026) and was indirectly correlated with protumor CD163 and FOXP3 through CD4/FOXP3 (R = 0.282; p = 0.006), CD4/CD163 (R = 0.239; p = 0.015), CD8/FOXP3 (R = 0.260; p = 0.008), and CD8/CD163 (R = 0.258; p = 0.009). CONCLUSION: This is the first study to demonstrate that high levels of CD4/FOXP3 and CD8/CD163 significantly improved the 1 year OS in de novo mTNBC patients. Thus, we recommend the application of these markers as prognosis determination and individual treatment decision.


Subject(s)
Triple Negative Breast Neoplasms , Humans , B7-H1 Antigen , CD8-Positive T-Lymphocytes/metabolism , Cohort Studies , Forkhead Transcription Factors/genetics , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/pathology , Neoadjuvant Therapy , Triple Negative Breast Neoplasms/pathology , CD4 Antigens , CD8 Antigens
16.
J Virol ; 98(3): e0172023, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38412036

ABSTRACT

The rational design of HIV-1 immunogens to trigger the development of broadly neutralizing antibodies (bNAbs) requires understanding the viral evolutionary pathways influencing this process. An acute HIV-1-infected individual exhibiting >50% plasma neutralization breadth developed neutralizing antibody specificities against the CD4-binding site (CD4bs) and V1V2 regions of Env gp120. Comparison of pseudoviruses derived from early and late autologous env sequences demonstrated the development of >2 log resistance to VRC13 but not to other CD4bs-specific bNAbs. Mapping studies indicated that the V3 and CD4-binding loops of Env gp120 contributed significantly to developing resistance to the autologous neutralizing response and that the CD4-binding loop (CD4BL) specifically was responsible for the developing resistance to VRC13. Tracking viral evolution during the development of this cross-neutralizing CD4bs response identified amino acid substitutions arising at only 4 of 11 known VRC13 contact sites (K282, T283, K421, and V471). However, each of these mutations was external to the V3 and CD4BL regions conferring resistance to VRC13 and was transient in nature. Rather, complete resistance to VRC13 was achieved through the cooperative expression of a cluster of single amino acid changes within and immediately adjacent to the CD4BL, including a T359I substitution, exchange of a potential N-linked glycosylation (PNLG) site to residue S362 from N363, and a P369L substitution. Collectively, our data characterize complex HIV-1 env evolution in an individual developing resistance to a VRC13-like neutralizing antibody response and identify novel VRC13-associated escape mutations that may be important to inducing VRC13-like bNAbs for lineage-based immunogens.IMPORTANCEThe pursuit of eliciting broadly neutralizing antibodies (bNAbs) through vaccination and their use as therapeutics remains a significant focus in the effort to eradicate HIV-1. Key to our understanding of this approach is a more extensive understanding of bNAb contact sites and susceptible escape mutations in HIV-1 envelope (env). We identified a broad neutralizer exhibiting VRC13-like responses, a non-germline restricted class of CD4-binding site antibody distinct from the well-studied VRC01-class. Through longitudinal envelope sequencing and Env-pseudotyped neutralization assays, we characterized a complex escape pathway requiring the cooperative evolution of four amino acid changes to confer complete resistance to VRC13. This suggests that VRC13-class bNAbs may be refractory to rapid escape and attractive for therapeutic applications. Furthermore, the identification of longitudinal viral changes concomitant with the development of neutralization breadth may help identify the viral intermediates needed for the maturation of VRC13-like responses and the design of lineage-based immunogens.


Subject(s)
Broadly Neutralizing Antibodies , HIV Infections , Humans , Amino Acids , Broadly Neutralizing Antibodies/immunology , CD4 Antigens/genetics , env Gene Products, Human Immunodeficiency Virus/genetics , Epitopes , HIV Antibodies , HIV Antigens , HIV Envelope Protein gp120/genetics , HIV Seropositivity , HIV-1/genetics , AIDS Vaccines/immunology
17.
J Virol ; 98(1): e0152223, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38169306

ABSTRACT

Understanding how different amino acids affect the HIV-1 envelope (Env) trimer will greatly help the design and development of vaccines that induce broadly neutralizing antibodies (bnAbs). A tryptophan residue at position 375 that opens the CD4 binding site without modifying the trimer apex was identified using our saturation mutagenesis strategy. 375W was introduced into a large panel of 27 transmitted/founder, acute stage, chronic infection, and AIDS macrophage-tropic and non-macrophage-tropic primary envelopes from different clades (A, B, C, D, and G) as well as complex and circulating recombinants. We evaluated soluble CD4 and monoclonal antibody neutralization of WT and mutant Envs together with macrophage infection. The 375W substitution increased sensitivity to soluble CD4 in all 27 Envs and macrophage infection in many Envs including an X4 variant. Importantly, 375W did not impair or abrogate neutralization by potent bnAbs. Variants that were already highly macrophage tropic were compromised for macrophage tropism, indicating that other structural factors are involved. Of note, we observed a macrophage-tropic (clade G) and intermediate macrophage-tropic (clades C and D) primary Envs from the blood and not from the central nervous system (CNS), indicating that such variants could be released from the brain or evolve outside the CNS. Our data also indicate that "intermediate" macrophage-tropic variants should belong to a new class of HIV-1 tropism. These Envs infected macrophages more efficiently than non-macrophage-tropic variants without reaching the high levels of macrophage-tropic brain variants. In summary, we show that 375W is ideal for inclusion into HIV-1 vaccines, increasing Env binding to CD4 for widely diverse Envs from different clades and disease stages.IMPORTANCESubstitutions exposing the CD4 binding site (CD4bs) on HIV-1 trimers but still occluding non-neutralizing, immunogenic epitopes are desirable to develop HIV-1 vaccines. If such substitutions induce similar structural changes in trimers across diverse clades, they could be exploited for the development of multi-clade envelope (Env) vaccines. We show that the 375W substitution increases CD4 affinity for envelopes of all clades, circulating recombinant forms, and complex Envs tested, independent of disease stage. Clade B and C Envs with an exposed CD4bs were described for macrophage-tropic strains from the central nervous system (CNS). Here, we show that intermediate (clades C and D) and macrophage-tropic (clade G) envelopes can be detected outside the CNS. Vaccines targeting the CD4bs will be particularly effective against such strains and CNS disease.


Subject(s)
HIV Infections , HIV-1 , Viral Tropism , env Gene Products, Human Immunodeficiency Virus , Humans , Broadly Neutralizing Antibodies/immunology , env Gene Products, Human Immunodeficiency Virus/genetics , HIV Antibodies/immunology , HIV Infections/prevention & control , HIV-1/genetics , Mutation , Vaccine Development , Macrophages/virology , CD4 Antigens
18.
Cell ; 187(1): 79-94.e24, 2024 01 04.
Article in English | MEDLINE | ID: mdl-38181743

ABSTRACT

The CD4-binding site (CD4bs) is a conserved epitope on HIV-1 envelope (Env) that can be targeted by protective broadly neutralizing antibodies (bnAbs). HIV-1 vaccines have not elicited CD4bs bnAbs for many reasons, including the occlusion of CD4bs by glycans, expansion of appropriate naive B cells with immunogens, and selection of functional antibody mutations. Here, we demonstrate that immunization of macaques with a CD4bs-targeting immunogen elicits neutralizing bnAb precursors with structural and genetic features of CD4-mimicking bnAbs. Structures of the CD4bs nAb bound to HIV-1 Env demonstrated binding angles and heavy-chain interactions characteristic of all known human CD4-mimicking bnAbs. Macaque nAb were derived from variable and joining gene segments orthologous to the genes of human VH1-46-class bnAb. This vaccine study initiated in primates the B cells from which CD4bs bnAbs can derive, accomplishing the key first step in the development of an effective HIV-1 vaccine.


Subject(s)
AIDS Vaccines , HIV-1 , Animals , Humans , Broadly Neutralizing Antibodies , CD4 Antigens , Cell Adhesion Molecules , HIV-1/physiology , Macaca , AIDS Vaccines/immunology
19.
Med Biol Eng Comput ; 62(2): 423-436, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37889430

ABSTRACT

Human immunodeficiency virus type 1 (HIV-1) is a major global health problem, with over 38 million people infected worldwide. Current anti-HIV-1 drugs are limited in their ability to prevent the virus from replicating inside host cells, making them less effective as preventive measures. In contrast, viral inhibitors that inactivate the virus before it can bind to a host cell have great potential as drugs. In this study, we aimed to design mutant peptides that could block the interaction between gp120 and the CD4 receptor on host cells, thus preventing HIV-1 infection. We designed a 20-amino-acid peptide that mimicked the amino acids of the CD4 binding site and docked it to gp120. Molecular dynamics simulations were performed to calculate the energy of MMPBSA (Poisson-Boltzmann Surface Area) for each residue of the peptide, and unfavorable energy residues were identified as potential mutation points. Using MAESTRO (Multi AgEnt STability pRedictiOn), we measured ΔΔG (change in the change in Gibbs free energy) for mutations and generated a library of 240 mutated peptides using OSPREY software. The peptides were then screened for allergenicity and binding affinity. Finally, molecular dynamics simulations (via GROMACS 2020.2) and control docking (via HADDOCK 2.4) were used to evaluate the ability of four selected peptides to inhibit HIV-1 infection. Three peptides, P3 (AHRQIRQWFLTRGPNRSLWQ), P4 (VHRQIRQWFLTRGPNRSLWQ), and P9 (AHRQIRQMFLTRGPNRSLWQ), showed practical and potential as HIV inhibitors, based on their binding affinity and ability to inhibit infection. These peptides have the ability to inactivate the virus before it can bind to a host cell, thus representing a promising approach to HIV-1 prevention. Our findings suggest that mutant peptides designed to block the interaction between gp120 and the CD4 receptor have potential as HIV-1 inhibitors. These peptides could be used as preventive measures against HIV-1 transmission, and further research is needed to evaluate their safety and efficacy in clinical settings.


Subject(s)
HIV-1 , Humans , HIV-1/genetics , HIV-1/metabolism , CD4 Antigens/genetics , CD4 Antigens/chemistry , CD4 Antigens/metabolism , Peptides/pharmacology , Peptides/chemistry , Binding Sites , Mutation/genetics , HIV Envelope Protein gp120/genetics , HIV Envelope Protein gp120/pharmacology
20.
Immunology ; 171(4): 534-548, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38102962

ABSTRACT

Induction of antibodies (Abs) against the conformational CD4-induced (CD4i) epitope is frequent in HIV-1 infection. However, the mechanism of development of anti-CD4i Abs is unclear. We used anti-idiotypic (aID) monoclonal Abs (mAbs) of anti-CD4i mAbs to isolate anti-CD4i mAbs from infected subjects and track the causative antigens. One anti-aID mAb sorted from infected subjects by aID mAbs had the characteristics of anti-CD4i Abs, including IGHV1-69 usage and ability to bind to HIV-1 Env enhanced by sCD4. Critical amino acid sequences for the binding of six anti-aID mAbs, with shared idiotope to anti-CD4i mAbs, were analysed by phage display. The identified amino acid sequences showed similarity to proteins from human microbiota and infectious agents. Peptides synthesized from Caudoviricetes sp and Vibrio vulnificus based on the identified sequences were reactive to most anti-aID and some anti-CD4i mAbs. These results suggest that anti-CD4i Abs may evolve from B cells primed by microorganisms.


Subject(s)
HIV Infections , HIV-1 , Humans , Epitopes , HIV Antibodies , CD4 Antigens/metabolism , HIV Envelope Protein gp120
SELECTION OF CITATIONS
SEARCH DETAIL
...