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Chella S David - One of the best experts on this subject based on the ideXlab platform.
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Evaluating the role of HLA-DQ polymorphisms on immune response to bacterial superantigens using transgenic mice.
Tissue Antigens, 2007Co-Authors: Govindarajan Rajagopalan, Ginger Polich, B. E. Epstein, Anna K. Lytle, M. S. Rouse, Robin Patel, Manisha Singh, Chella S DavidAbstract:Bacterial superantigens bind directly to human leukocyte antigen (HLA) class II molecules and vigorously activate T cells expressing certain T-cell receptor variable region families. As interaction with HLA class II molecules is the primary step in this process, polymorphic variations in HLA class II can determine the extent of superantigen binding to HLA class II molecules, govern the magnitude of immune activation induced by given superantigens and determine the outcome of superantigen-mediated diseases. As direct assessment of the influence of HLA class II polymorphism in humans is impossible because of expression of more than one HLA class II alleles in a given individual and toxicity of superantigens, transgenic mice expressing HLA-DQ6 (HLA-DQA1*0103 and HLA-DQB1*0601) and HLA-DQ8 (HLA-DQA1*0301 and HLA-DQB1*0302) were used to achieve this goal. HLA-DQ6 and HLA-DQ8 elicited comparable in vitro and in vivo immune response to staphylococcal enterotoxins (SE) A, SEB, SEH and SEK, toxic shock syndrome toxin-1, streptococcal pyrogenic exotoxin (SPE) A and SPEC and streptococcal mitogenic exotoxin Z (SMEZ). However, each superantigen had a unique T-cell receptor activation profile. In vivo challenge with Streptococcus pyogenes, H305, capable of elaborating SPEA and SMEZ, yielded a similar clinical outcome in HLA-DQ6 and HLA-DQ8 transgenic mice. In conclusion, HLA-DQ6 and HLA-DQ8 elicited comparable response to certain bacterial superantigens. Our report highlights the advantages of HLA class II transgenic mice in such studies.
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HLA Transgenic Mice Provide Evidence for a Direct and Dominant Role of HLA Class II Variation in Modulating the Severity of Streptococcal Sepsis
Journal of Immunology, 2007Co-Authors: Mohammed M. Nooh, Nagala El-gengehi, Rita Kansal, Chella S David, Malak KotbAbstract:Our epidemiologic studies on invasive Group A Streptococci (GAS) infections identified specific HLA class II haplotypes/alleles conferring high-risk or protection from streptococcal toxic shock syndrome with a strong protection conferred by the DRB1*15/DQB1*06 haplotype. We used HLA-transgenic mice to provide an in vitro and in vivo validation for the direct role of HLA class II allelic variation in streptococcal toxic shock syndrome. When splenocytes from mice expressing the protective HLA-DQB1*06 (DQ6) allele were stimulated with a mixture of streptococcal superantigens (SAgs), secreted by the prevalent M1T1 strain, both proliferative and cytokine responses were significantly lower than those of splenocytes from mice expressing the neutral DRB1*0402/DQB1*0302 (DR4/DQ8) alleles (p < 0.001). In crisscross experiments, the presentation of SAgs to pure T cells from either the DQ6 or the DR4/DQ8 mice resulted in significantly different levels of response depending on the HLA type expressed on the APCs. Presentation by HLA-DQ6 APCs elicited significantly lower responses than the presentation by HLA-DR4/DQ8 APCs. Our in vitro data were supported by in vivo findings, as the DQ6 mice showed significantly longer survival post-i.v. infection with live M1T1 GAS (p < 0.001) and lower inflammatory cytokine responses as compared with the DR4/DQ8 mice (p < 0.01). The data presented here provide evidence for a direct role of HLA class II molecules in modulating responses to GAS SAgs and underscore the dominant role of HLA class II allelic variation in potentiating the severity of GAS systemic infections.
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Induction of Myasthenia Gravis in HLA Transgenic Mice by Immunization with Human Acetylcholine Receptors
Annals of the New York Academy of Sciences, 2003Co-Authors: Huan Yang, Bianca M. Conti-fine, David K. Okita, Teh-sheng Chan, Mathilde A Poussin, Elzbieta Goluszko, Chella S David, Premkumar ChristadossAbstract:: We utilized HLA transgenic mice to identify the dominant epitopes on the human (H)-AChR alpha subunit. The cytoplasmic H-AChR peptide alpha320-337 was the dominant T cell epitope for DQ8, DR3, and DQ8xDQ6 F1 mice. The H-AChR-immunized HLA-DQ8, DR3, DQ8xDR3 F1 and DQ8xDQ6 F1 mice developed clinical EAMG, whereas HLA-DQ6 mice were less susceptible.
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Cryptic determinants and promiscuous sequences on human acetylcholine receptor: HLA-dependent dichotomy in T-cell function.
Human Immunology, 2002Co-Authors: Raghavanpillai Raju, Eric V Marietta, Bianca M. Conti-fine, Javier Vinasco, Anthony J Infante, Chella S DavidAbstract:Abstract Experimental autoimmune myasthenia gravis can be induced in some strains of mice and rats by immunizing with acetylcholine receptor. Also, epidemiologic studies demonstrate an MHC linkage of myasthenia gravis in the man. In order to obtain direct experimental evidence for the influence of the genes of the MHC complex in the development of myasthenia gravis, we used mice transgenic to individual HLA molecules. We observed an increased susceptibility to the disease in HLA DQ8 transgenic mice compared to HLA DQ6 transgenic mice ( J. Immunol. 160:4169; 1998). These mice lacked endogenous mouse class II molecules. In the present study we mapped the cryptic and dominant sequences on the extra cellular region of human acetylcholine receptor. Although some epitopes ( e.g. , α11-30, α141-160, α171-190) were common between DQ8 and DQ6 transgenic mice, several others were disparately recognized. We also found a functional dichotomy in T cells from mice differing by one MHC molecule (HLA DQ8 or DQ6) when primed by sequences immunodominant in DQ8 and DQ6 tg mice. Differential disease manifestation in the two different HLA transgenic mice could be explained not only by differential recognition of peptides by these antigen presenting molecules, but also by the difference in the functional profile of T cells generated when primed by promiscuous sequence regions.
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HLA-DQ6 transgenic mice resistance to experimental autoimmune myasthenia gravis is linked to reduced acetylcholine receptor-specific IFN-γ, IL-2 and IL-10 production
Journal of Autoimmunity, 2001Co-Authors: Mathilde A Poussin, Elzbieta Goluszko, Juan U Franco, Chella S David, Premkumar ChristadossAbstract:Abstract To comprehend the reduced susceptibility of HLA-DQ6 transgenic mice in comparison with HLA-DQ8 mice, to experimental autoimmune myasthenia gravis (EAMG), we immunized them with acetylcholine receptor (AChR) and examined in vitro, the proliferative and cytokine responses to AChR. When immunized with AChR and examined for AChR-specific lymphocyte responses to AChR, EAMG-resistant DQ6 mice exhibited significantly reduced in vitro lymphoproliferative and cytokine responses to AChR, compared to DQ8 mice. The differences in susceptibility were not linked to a difference in peptide recognition by AChR-specific lymphocytes. AChR T cell epitope mapping showed that both DQ6 and DQ8 responded to the same epitopes, although to varying degrees. Resistance of DQ6 transgenic mice to EAMG was linked to a dramatic suppression of AChR-specific IFN-γ, IL-2 and IL-10 productions by AChR-primed lymph node cells.
Christopher J. Krco - One of the best experts on this subject based on the ideXlab platform.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical Immunology, 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:Abstract HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A o β ) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM ( Dermatophagoides pteronyssinus ) allergen p2. HLA-DQ8 mice responded to p2 peptides 1–20, 41–60, 51–70, 61–80, 91–110, and 101–120. HLA-DQ6 mice responded to peptides 1–20, 11–30, 21–40, 41–60, and 51–70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3–12, 50–70, and 91–120. A synthetic peptide comprising residues 3–12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical immunology (Orlando Fla.), 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A(o)(beta)) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM (Dermatophagoides pteronyssinus) allergen p2. HLA-DQ8 mice responded to p2 peptides 1-20, 41-60, 51-70, 61-80, 91-110, and 101-120. HLA-DQ6 mice responded to peptides 1-20, 11-30, 21-40, 41-60, and 51-70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3-12, 50-70, and 91-120. A synthetic peptide comprising residues 3-12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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Identification of T Cell Determinants on Human Type II Collagen Recognized by HLA-DQ8 and HLA-DQ6 Transgenic Mice
Journal of Immunology, 1999Co-Authors: Christopher J. Krco, Shohei Watanabe, Jerry Harders, Marie M. Griffths, Harvinder S. Luthra, Chella S DavidAbstract:HLA-DQA1*0301 and HLA-DQB1*0302 genes encoding the HLA-DQ8 molecule and HLA-DQA1*0103 and HLA-DQB1*0601 genes encoding the HLA-DQ6 molecule were introduced into H-2Aβo knockout mice. Three lines of transgenic mice were established: HLA-DQ8, HLA-DQ6, and HLA-DQ8β6α. HLA-DQ8 mice are susceptible to collagen-induced arthritis, while HLA-DQ6 mice are resistant. HLA-DQ8β6α mice develop polychrondritis in addition to arthritis. Transgenic mice were primed and challenged with individual synthetic peptides representing human type II collagen. A total of 101 synthetic peptides were tested in each transgenic line of mice. HLA-DQ8 mice responded to 15 synthetic peptides representing all cyanogen bromide fragments. In contrast, HLA-DQ6 mice responded to a subset of the peptides recognized by HLA-DQ8 T cells. HLA-DQ8β6α mice, although exhibiting diminished responses to the majority of HLA-DQ8-restricted determinants, elicited enhanced responses to two peptides. In addition, HLA-DQ8β6α mice respond to two unique peptide determinants contained within cyanogen bromide fragments CB10 and CB11 showing the significance of mixed isotype dimers in the immune response. The determinants recognized by the HLA-DQ transgenic mice are distinct from those previously identified using conventional laboratory mice. These results suggest that human class II transgenic mice offer a means of identifying human class II-restricted epitopes associated with potential human autoantigens.
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HLA-DQ6 and HLA-DQ8 transgenic mice respond to ragweed allergens and recognize a distinct set of epitopes on short and giant ragweed group 5 antigens.
Journal of Immunology, 1998Co-Authors: Svetlana P. Chapoval, Eric V Marietta, Christopher J. Krco, Jerry Harders, Teresa A. Neeno, Chella S DavidAbstract:We have investigated the genetic and molecular basis of immune responsiveness to short ragweed (SRW) ( Ambrosia artemisiifolia ) extract, and group 5 allergens from short and giant ( Ambrosia trifida ) ragweed using transgenic mice expressing DQ6 (HLA-DQA1*0103, HLA-DQB1*0601) and DQ8 (HLA-DQA1*0301, HLA-DQB1*0302) genes in class II knockout (Aβ 0 ) mice. Panels of overlapping peptides spanning the Amb a 5 and Amb t 5 Ags were synthesized. Mice were immunized with whole SRW extract or individual peptides s.c. and lymph node cells (LNC) were challenged in vitro. Strong T cell responses to SRW extract were measured in both HLA-DQ transgenic mice, while control, HLA-DQ6 − /DQ8 − /H-2Aβ 0 , mice were unresponsive. IL-5 and IL-10 were the primary cytokines produced by in vitro challenged LNC of SRW-primed transgenic mice. HLA-DQ6-restricted T cell responses were detected to all three peptides of Amb t 5 and two determinants (residues 1–20 and 11–30) on Amb a 5 . In contrast, LNC of HLA-DQ8 mice did not recognize peptide 11–30 of Amb t 5 Ag, but recognized several Amb a 5 determinants. The immune response in transgenic mice was dependent upon CD4 + T cells and was HLA-DQ restricted. Primed with purified Amb t 5 , both transgenics recognized peptide 21–40, and an additional DQ6-restricted epitope was found within residue 1–20. SRW-immunized HLA-DQ6 mice respond to peptide 11–30 of Amb a 5 , while HLA-DQ8 mice strongly recognize peptide 1–20. These results demonstrate the specificity of HLA class II polymorphism in allergen sensitivity and pave the way for developing antagonistic peptides for desensitization.
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HLA-DQ8 transgenic mice lacking endogenous class II molecules respond to house dust allergens: identification of antigenic epitopes.
Journal of immunology (Baltimore Md. : 1950), 1996Co-Authors: Teresa A. Neeno, Shen Cheng, Christopher J. Krco, Jerry Harders, Jeanine Baisch, Chella S DavidAbstract:We have introduced HLA-DQ8 (HLADQB*0302 and HLA-DQA*0301) genes into A beta 0 knockout mice. Transgenic animals were immunized with a whole body extract of Dermatophagoides pteronyssinus (Der p), one of the causative agents of house dust mite allergy. Transgenic mice expressing HLA-DQ8 genes elicited HLA-DQ8-restricted responses driven by CD4+ T cells. Synthetic-overlapping peptides representing a major allergen of house dust mite (Der p 2) were synthesized and used as immunogens. HLA-DQ8+ mice responded to three peptides: 8 (residues 61-80), 11 (residues 91-110), and 13 (residues 111-129). The mice produced IL-2, IL-4, and IL-6 response to Der p challenge, suggesting a mixed Th1/Th2 response. These mice represent a new model for studies of the immune basis of allergy.
Jerry Harders - One of the best experts on this subject based on the ideXlab platform.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical Immunology, 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:Abstract HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A o β ) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM ( Dermatophagoides pteronyssinus ) allergen p2. HLA-DQ8 mice responded to p2 peptides 1–20, 41–60, 51–70, 61–80, 91–110, and 101–120. HLA-DQ6 mice responded to peptides 1–20, 11–30, 21–40, 41–60, and 51–70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3–12, 50–70, and 91–120. A synthetic peptide comprising residues 3–12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical immunology (Orlando Fla.), 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A(o)(beta)) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM (Dermatophagoides pteronyssinus) allergen p2. HLA-DQ8 mice responded to p2 peptides 1-20, 41-60, 51-70, 61-80, 91-110, and 101-120. HLA-DQ6 mice responded to peptides 1-20, 11-30, 21-40, 41-60, and 51-70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3-12, 50-70, and 91-120. A synthetic peptide comprising residues 3-12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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Identification of T Cell Determinants on Human Type II Collagen Recognized by HLA-DQ8 and HLA-DQ6 Transgenic Mice
Journal of Immunology, 1999Co-Authors: Christopher J. Krco, Shohei Watanabe, Jerry Harders, Marie M. Griffths, Harvinder S. Luthra, Chella S DavidAbstract:HLA-DQA1*0301 and HLA-DQB1*0302 genes encoding the HLA-DQ8 molecule and HLA-DQA1*0103 and HLA-DQB1*0601 genes encoding the HLA-DQ6 molecule were introduced into H-2Aβo knockout mice. Three lines of transgenic mice were established: HLA-DQ8, HLA-DQ6, and HLA-DQ8β6α. HLA-DQ8 mice are susceptible to collagen-induced arthritis, while HLA-DQ6 mice are resistant. HLA-DQ8β6α mice develop polychrondritis in addition to arthritis. Transgenic mice were primed and challenged with individual synthetic peptides representing human type II collagen. A total of 101 synthetic peptides were tested in each transgenic line of mice. HLA-DQ8 mice responded to 15 synthetic peptides representing all cyanogen bromide fragments. In contrast, HLA-DQ6 mice responded to a subset of the peptides recognized by HLA-DQ8 T cells. HLA-DQ8β6α mice, although exhibiting diminished responses to the majority of HLA-DQ8-restricted determinants, elicited enhanced responses to two peptides. In addition, HLA-DQ8β6α mice respond to two unique peptide determinants contained within cyanogen bromide fragments CB10 and CB11 showing the significance of mixed isotype dimers in the immune response. The determinants recognized by the HLA-DQ transgenic mice are distinct from those previously identified using conventional laboratory mice. These results suggest that human class II transgenic mice offer a means of identifying human class II-restricted epitopes associated with potential human autoantigens.
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HLA-DQ6 and HLA-DQ8 transgenic mice respond to ragweed allergens and recognize a distinct set of epitopes on short and giant ragweed group 5 antigens.
Journal of Immunology, 1998Co-Authors: Svetlana P. Chapoval, Eric V Marietta, Christopher J. Krco, Jerry Harders, Teresa A. Neeno, Chella S DavidAbstract:We have investigated the genetic and molecular basis of immune responsiveness to short ragweed (SRW) ( Ambrosia artemisiifolia ) extract, and group 5 allergens from short and giant ( Ambrosia trifida ) ragweed using transgenic mice expressing DQ6 (HLA-DQA1*0103, HLA-DQB1*0601) and DQ8 (HLA-DQA1*0301, HLA-DQB1*0302) genes in class II knockout (Aβ 0 ) mice. Panels of overlapping peptides spanning the Amb a 5 and Amb t 5 Ags were synthesized. Mice were immunized with whole SRW extract or individual peptides s.c. and lymph node cells (LNC) were challenged in vitro. Strong T cell responses to SRW extract were measured in both HLA-DQ transgenic mice, while control, HLA-DQ6 − /DQ8 − /H-2Aβ 0 , mice were unresponsive. IL-5 and IL-10 were the primary cytokines produced by in vitro challenged LNC of SRW-primed transgenic mice. HLA-DQ6-restricted T cell responses were detected to all three peptides of Amb t 5 and two determinants (residues 1–20 and 11–30) on Amb a 5 . In contrast, LNC of HLA-DQ8 mice did not recognize peptide 11–30 of Amb t 5 Ag, but recognized several Amb a 5 determinants. The immune response in transgenic mice was dependent upon CD4 + T cells and was HLA-DQ restricted. Primed with purified Amb t 5 , both transgenics recognized peptide 21–40, and an additional DQ6-restricted epitope was found within residue 1–20. SRW-immunized HLA-DQ6 mice respond to peptide 11–30 of Amb a 5 , while HLA-DQ8 mice strongly recognize peptide 1–20. These results demonstrate the specificity of HLA class II polymorphism in allergen sensitivity and pave the way for developing antagonistic peptides for desensitization.
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HLA-DQ8 transgenic mice lacking endogenous class II molecules respond to house dust allergens: identification of antigenic epitopes.
Journal of immunology (Baltimore Md. : 1950), 1996Co-Authors: Teresa A. Neeno, Shen Cheng, Christopher J. Krco, Jerry Harders, Jeanine Baisch, Chella S DavidAbstract:We have introduced HLA-DQ8 (HLADQB*0302 and HLA-DQA*0301) genes into A beta 0 knockout mice. Transgenic animals were immunized with a whole body extract of Dermatophagoides pteronyssinus (Der p), one of the causative agents of house dust mite allergy. Transgenic mice expressing HLA-DQ8 genes elicited HLA-DQ8-restricted responses driven by CD4+ T cells. Synthetic-overlapping peptides representing a major allergen of house dust mite (Der p 2) were synthesized and used as immunogens. HLA-DQ8+ mice responded to three peptides: 8 (residues 61-80), 11 (residues 91-110), and 13 (residues 111-129). The mice produced IL-2, IL-4, and IL-6 response to Der p challenge, suggesting a mixed Th1/Th2 response. These mice represent a new model for studies of the immune basis of allergy.
Svetlana P. Chapoval - One of the best experts on this subject based on the ideXlab platform.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical Immunology, 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:Abstract HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A o β ) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM ( Dermatophagoides pteronyssinus ) allergen p2. HLA-DQ8 mice responded to p2 peptides 1–20, 41–60, 51–70, 61–80, 91–110, and 101–120. HLA-DQ6 mice responded to peptides 1–20, 11–30, 21–40, 41–60, and 51–70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3–12, 50–70, and 91–120. A synthetic peptide comprising residues 3–12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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HLA-DQ/human CD4-restricted immune response to cockroach allergens in transgenic mice.
Tissue Antigens, 2000Co-Authors: Bettina G. Papouchado, Eric V Marietta, Svetlana P. Chapoval, Catherine R. Weiler, Chella S DavidAbstract:: We investigated the immune response to the German cockroach (Blattella germanica), and one of its major antigens, Blattella germanica group 5 (Bla g 5), in a double-transgenic, double-knockout mouse expressing human HLA-DQ8, HLA-DQ6 and CD4 molecules in the absence of mouse class II and mouse CD4. Transgenic mice were primed and challenged with CR extract or individual synthetic peptides representing Bla g 5. Strong T-cell responses to CR extract were detected in both HLA-DQ/hCD4+ transgenic mice. The responses were two times lower in mice expressing HLA-DQ molecule in the context of mouse CD4. Under similar treatment, no responses were found in the double-knockout Abetadegrees/mCD4degrees mice and in mice expressing human CD4 molecule alone. HLA-DQ/hCD4+ mice produced primarily interleukin (IL)-5, IL-10, and IL-13. Minimal amounts of IL-4 were detected only in HLA-DQ6/ hCD4+ mice. Interferon (IFN)-gamma production was low in both transgenic mouse, suggesting a predominantly T-helper 2 (Th2)-type response. Cockroach allergen extract immunized HLA-DQ8/hCD4+ mice recognized only one of the 20 peptides of Bla g 5 while HLA-DQ6/hCD4+ mice responded primarily to three peptides. Primed with individual peptides, both HLA-DQ/hCD4+ mice responded maximally to peptides 10 (residues 91-110) and 17 (residues 161-180). In addition, HLA-DQ6/hCD4+ mice responded to peptide 16 (residues 151-170). Thus, peptides 10 and 17 contained the major HLA-DQ-restricted hCD4+ T-cell epitopes and could be recognized by both HLA-DQ8 and HLA-DQ6 transgenic mice. Transgenic mice represent a new tool for investigating the immune responses to cockroach allergen. Our results suggest that therapeutic strategies aimed at developing antagonist peptides might be a useful treatment (immunotherapy) for allergic asthma.
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Immune response of HLA-DQ transgenic mice to house dust mite allergen p2: identification of HLA-DQ restricted minimal epitopes and critical residues.
Clinical immunology (Orlando Fla.), 2000Co-Authors: Christopher J. Krco, Svetlana P. Chapoval, Jerry Harders, Chella S DavidAbstract:HLA-DQ8 (HLA-DQA1*0301; HLA-DQB1*0302) and HLA-DQ6 (HLA-DQA1*0103; HLA-DQB1*0602) genes were introduced into mouse class II (H-2A(o)(beta)) knockout mice. Transgenic HLA-DQ8 and HLA-DQ6 mice were individually immunized and challenged using synthetic peptides representing HDM (Dermatophagoides pteronyssinus) allergen p2. HLA-DQ8 mice responded to p2 peptides 1-20, 41-60, 51-70, 61-80, 91-110, and 101-120. HLA-DQ6 mice responded to peptides 1-20, 11-30, 21-40, 41-60, and 51-70. Using single amino acid truncated 30-mer peptides, residues necessary for HLA-DQ8 recognition were identified spanning regions 3-12, 50-70, and 91-120. A synthetic peptide comprising residues 3-12 was synthesized and a series of single alanine substitutions was introduced into the minimal peptide. Introduction of alanine residues at positions 3, 11, and 12 resulted in a significant loss of immune recognition. It was concluded that residues 4, 5, 7, 11, and 12 are critical for immune recognition by HLA-DQ8 mice.
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HLA-DQ6 and HLA-DQ8 transgenic mice respond to ragweed allergens and recognize a distinct set of epitopes on short and giant ragweed group 5 antigens.
Journal of Immunology, 1998Co-Authors: Svetlana P. Chapoval, Eric V Marietta, Christopher J. Krco, Jerry Harders, Teresa A. Neeno, Chella S DavidAbstract:We have investigated the genetic and molecular basis of immune responsiveness to short ragweed (SRW) ( Ambrosia artemisiifolia ) extract, and group 5 allergens from short and giant ( Ambrosia trifida ) ragweed using transgenic mice expressing DQ6 (HLA-DQA1*0103, HLA-DQB1*0601) and DQ8 (HLA-DQA1*0301, HLA-DQB1*0302) genes in class II knockout (Aβ 0 ) mice. Panels of overlapping peptides spanning the Amb a 5 and Amb t 5 Ags were synthesized. Mice were immunized with whole SRW extract or individual peptides s.c. and lymph node cells (LNC) were challenged in vitro. Strong T cell responses to SRW extract were measured in both HLA-DQ transgenic mice, while control, HLA-DQ6 − /DQ8 − /H-2Aβ 0 , mice were unresponsive. IL-5 and IL-10 were the primary cytokines produced by in vitro challenged LNC of SRW-primed transgenic mice. HLA-DQ6-restricted T cell responses were detected to all three peptides of Amb t 5 and two determinants (residues 1–20 and 11–30) on Amb a 5 . In contrast, LNC of HLA-DQ8 mice did not recognize peptide 11–30 of Amb t 5 Ag, but recognized several Amb a 5 determinants. The immune response in transgenic mice was dependent upon CD4 + T cells and was HLA-DQ restricted. Primed with purified Amb t 5 , both transgenics recognized peptide 21–40, and an additional DQ6-restricted epitope was found within residue 1–20. SRW-immunized HLA-DQ6 mice respond to peptide 11–30 of Amb a 5 , while HLA-DQ8 mice strongly recognize peptide 1–20. These results demonstrate the specificity of HLA class II polymorphism in allergen sensitivity and pave the way for developing antagonistic peptides for desensitization.
Jukka Partanen - One of the best experts on this subject based on the ideXlab platform.
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Medium-high resolution electrochemical genotyping of HLA-DQ2/DQ8 for detection of predisposition to coeliac disease
Analytical and Bioanalytical Chemistry, 2014Co-Authors: Hamdi Joda, Noora Alakulppi, Kristina Lind, Linda Strömbom, Jukka Partanen, Valerio Beni, Ioanis Katakis, Daniel Latta, Julian Höth, Ciara K. O'sullivanAbstract:Coeliac disease is a small intestinal disorder, induced by ingestion of gluten in genetically predisposed individuals. Coeliac disease has been strongly linked to human leukocyte antigens (HLA) located on chromosome 6, with almost 100 % of coeliac disease sufferers carrying either a HLA-DQ2 or HLA-DQ8 heterodimer, with the majority carrying HLA-DQ2 encoded by the DQA1*05:01/05:05, DQB1*02:01/02:02 alleles, whereas the remaining carry the HLA-DQ8 encoded by the DQA1*03:01, DQB1*03:02 alleles. In this work, we present the development of a multiplex electrochemical genosensor array of 36 electrodes, housed within a dedicated microfluidic platform and using a total of 10 sequence-specific probes for rapid medium-high resolution HLA-DQ2/DQ8 genotyping. An evaluation of the selectivity of the designed probes was carried out with the target sequences and 44 potentially interfering alleles, including single base mismatch differentiations; good selectivity was demonstrated. The performance of the electrochemical genosensor array was validated, analyzing real human samples for the presence of HLA-DQ2/DQ8 alleles, and compared with those obtained using laboratory-based HLA typing, and an excellent correlation was obtained.
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Low–medium resolution HLA-DQ2/DQ8 typing for coeliac disease predisposition analysis by colorimetric assay
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Hamdi Joda, Deirdre Curnane, Noora Alakulppi, Kristina Lind, Linda Strömbom, Jukka Partanen, Valerio Beni, Ioanis Katakis, Ciara K. O’sullivanAbstract:Coeliac disease is an inflammation of the small intestine, occurring in genetically susceptible individuals triggered by the ingestion of gluten. Human Leukocyte Antigens (HLA) DQ2 and DQ8 gene have been identified as key genetic factors in coeliac disease as they are presented in almost 100 % of the patients. These genes are encoded by the combination of certain alleles in the DQA and DQB region of chromosome 6. Specifically, DQA1*05:01 and DQB1*02:01 alleles for serologically defined leukocyte antigen DQ2 cis, DQA1*05:05 and DQB1*02:02 for DQ2 trans and DQA1*03:01 and DQB1*03:02 alleles for the DQ8. Specific identification of these alleles is a challenge due to the high number of alleles that have been identified so far: 46 in the DQA region and 160 in the DQB region (as of IMGT/HLA Database 10/2011 release). In the reported work, the development of a multiplex colorimetric assay for the low to medium HLA typing of the DQ2 and DQ8 genes is presented. The optimisation of probe design and assay conditions, performed by both surface plasmon resonance and enzyme-linked oligonucleotide assay, are reported. Finally, the performances of the developed typing platform were validated by the analysis of real patient samples and HLA typing, compared with those obtained using hospital based typing technology and an excellent correlation obtained. Figure Example of the results obtained during the colorimetric HLA typing of a real sample
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Low-medium resolution HLA-DQ2/DQ8 typing for coeliac disease predisposition analysis by colorimetric assay.
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Hamdi Joda, Deirdre Curnane, Noora Alakulppi, Kristina Lind, Linda Strömbom, Jukka Partanen, Valerio Beni, Ioanis Katakis, Ciara K. O’sullivanAbstract:Coeliac disease is an inflammation of the small intestine, occurring in genetically susceptible individuals triggered by the ingestion of gluten. Human Leukocyte Antigens (HLA) DQ2 and DQ8 gene have been identified as key genetic factors in coeliac disease as they are presented in almost 100 % of the patients. These genes are encoded by the combination of certain alleles in the DQA and DQB region of chromosome 6. Specifically, DQA1*05:01 and DQB1*02:01 alleles for serologically defined leukocyte antigen DQ2 cis, DQA1*05:05 and DQB1*02:02 for DQ2 trans and DQA1*03:01 and DQB1*03:02 alleles for the DQ8. Specific identification of these alleles is a challenge due to the high number of alleles that have been identified so far: 46 in the DQA region and 160 in the DQB region (as of IMGT/HLA Database 10/2011 release). In the reported work, the development of a multiplex colorimetric assay for the low to medium HLA typing of the DQ2 and DQ8 genes is presented. The optimisation of probe design and assay conditions, performed by both surface plasmon resonance and enzyme-linked oligonucleotide assay, are reported. Finally, the performances of the developed typing platform were validated by the analysis of real patient samples and HLA typing, compared with those obtained using hospital based typing technology and an excellent correlation obtained.
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hla types in celiac disease patients not carrying the dqa1 05 dqb1 02 dq2 heterodimer results from the european genetics cluster on celiac disease
Human Immunology, 2003Co-Authors: Kati Karell, A S Louka, Henry Ascher, Fabienne Clot, Paul J Ciclitira, Ludvig M Sollid, Luigi Greco, Simon J. Moodie, Jukka PartanenAbstract:Abstract Genetic susceptibility to celiac disease is strongly associated with HLA-DQA1*05-DQB1*02 (DQ2) and HLA-DQA1*03-DQB1*0302 (DQ8). Study of the HLA associations in patients not carrying these heterodimers has been limited by the rarity of such patients. This European collaboration has provided a unique opportunity to study a large series of such patients. From 1008 European coeliacs, 61 were identified who neither carry the DQ2 nor DQ8 heterodimers. Fifty seven of these encoded half of the DQ2 heterodimer. The remaining 4 patients had a variety of clinical presentations. Three of them carried the DQA1*01-DQB*05 haplotype as did 20/61 of those carrying neither DQ2 nor DQ8. This may implicate a role of the DQA1*01-DQB*05 haplotype. None of these four patients carried the DQB1*06 allele that has previously been reported in this sub-group of patients. Of the 16 DQ2 heterodimer negative patients without DRB1*04 or DRB1*07 haplotypes, it was inferred that none encoded the previously implicated DRB4 gene as none had a DRB1*09 haplotype. These results underline the primary importance of HLA-DQ alleles in susceptibility to celiac disease, and the extreme rarity of celiac patients carrying neither the DQ2 or DQ8 heterodimers nor one half of the DQ2 heterodimer alone.
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hla dq typing in the diagnosis of celiac disease
The American Journal of Gastroenterology, 2002Co-Authors: Katri Kaukinen, Pekka Collin, Markku Maki, Jukka PartanenAbstract:Abstract OBJECTIVE: More than 95% of celiac patients share the major histocompatibility complex II class human leukocyte antigen (HLA) DQ2 or DQ8 haplotype; patients negative for both types are unlikely to suffer from celiac disease. Our aim was to investigate whether HLA-DQ2 and -DQ8 typing is helpful when diagnosis is uncertain because of the absence of unequivocal small bowel villous atrophy. METHODS: HLA-DQ2 and -DQ8 typing was carried out in 59 patients evincing nondiagnostic small bowel mucosal lesion or positive celiac serology, and in 17 patients maintaining a gluten-free diet without biopsy-proven celiac disease. HLA findings were compared to small bowel mucosal morphology; intraepithelial lymphocytes; and serum endomysial (EmA), reticulin, tissue transglutaminase (anti-tTG) and gliadin antibodies. RESULTS: Of the 59 patients evincing only minor small bowel mucosal changes or positive celiac disease serology, 22 (37%) were negative for DQ2 and DQ8. All EmA-positive patients had celiac-type HLA, but antireticulin antibody, anti-tTg, and antigliadin antibody were also present in HLA-DQ2– and -DQ8–negative individuals. Eleven of 17 patients (65%) observing a gluten-free diet before small bowel biopsy did not share celiac-type HLA. None of the 17 had apparent villous atrophy. Serum EmA and anti-tTG were negative in all. HLA-DQ typing is less expensive than follow-up biopsy in the exclusion of celiac disease. CONCLUSIONS: HLA-DQ2 and -DQ8 determination is useful in exclusion, probably lifelong, of celiac disease in individuals with an equivocal small bowel histological finding. The low specificity of this test must, however, be borne in mind.