Restoration of the antibody response to sheep erythrocytes in thymectomized Xenopus implanted with MHC-compatible or MHC-incompatible thymus

Development ◽  
1984 ◽  
Vol 84 (1) ◽  
pp. 287-302
Author(s):  
A. J. H. Gearing ◽  
Frances A. Cribbin ◽  
J. D. Horton
Keyword(s):  
Major Histocompatibility Complex ◽  
Antibody Response ◽  
Antibody Production ◽  
Blood Cells ◽  
Model System ◽  
T Helper Cell ◽  
T Helper ◽  
Histocompatibility Complex ◽  
Adult Thymus

These experiments make use of an amphibian model system for investigating the role of the thymus in T helper cell education. Clawed toads (Xenopus laevis), thymectomized at 7 days, are unable to mount an antibody response to thymus-dependent antigens, such as sheep red blood cells (SRBC). When thymectomized larvae are implanted with larval thymuses (either irradiated or non-irradiated), incompatible at the major histocompatibility complex (MHC) or with MHC-compatible or -incompatible ‘adult’ thymuses, their splenic plaque-forming cell response and serum haemolytic antibody production to SRBC are both restored, to some extent. However, levels of mercaptoethanol-resistant antibody were extremely poor in those animals implanted with MHC-incompatible ‘adult’ thymus. Larval thymus implants were shown, by ploidy-labelling studies, to become repopulated with host-derived lymphocytes. Whether or not these lymphocytes acquire their MHC restriction specificities in the thymus awaits clarification.

scholarly journals Major histocompatibility complex recombinant R13 antibody response against bovine red blood cells

2020 ◽  
Vol 99 (10) ◽  
pp. 4804-4808
Author(s):  
N.G. Wilkinson ◽  
R.T. Kopulos ◽  
L.M. Yates ◽  
W.E. Briles ◽  
R.L. Taylor
Keyword(s):  
Major Histocompatibility Complex ◽  
Antibody Response ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

scholarly journals Conservation of Babesia bovis Small Heat Shock Protein (Hsp20) among Strains and Definition of T Helper Cell Epitopes Recognized by Cattle with Diverse Major Histocompatibility Complex Class II Haplotypes

2004 ◽  
Vol 72 (2) ◽  
pp. 1096-1106 ◽  
Author(s):  
Junzo Norimine ◽  
Juan Mosqueda ◽  
Guy H. Palmer ◽  
Harris A. Lewin ◽  
Wendy C. Brown
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Small Heat Shock Protein ◽  
Babesia Bovis ◽  
T Helper Cell ◽  
Complex Class ◽  
T Helper ◽  
Histocompatibility Complex

ABSTRACT Babesia bovis small heat shock protein (Hsp20) is recognized by CD4+ T lymphocytes from cattle that have recovered from infection and are immune to challenge. This candidate vaccine antigen is related to a protective antigen of Toxoplasma gondii, Hsp30/bag1, and both are members of the α-crystallin family of proteins that can serve as molecular chaperones. In the present study, immunofluorescence microscopy determined that Hsp20 is expressed intracellularly in all merozoites. Importantly, Hsp20 is also expressed by tick larval stages, including sporozoites, so that natural tick-transmitted infection could boost a vaccine-induced response. The predicted amino acid sequence of Hsp20 from merozoites is completely conserved among different B. bovis strains. To define the location of CD4+ T-cell epitopes for inclusion in a multiepitope peptide or minigene vaccine construct, truncated recombinant Hsp20 proteins and overlapping peptides were tested for their ability to stimulate T cells from immune cattle. Both amino-terminal (amino acids [aa] 1 to 105) and carboxy-terminal (aa 48 to 177) regions were immunogenic for the majority of cattle in the study, stimulating strong proliferation and IFN-γ production. T-cell lines from all individuals with distinct DRB3 haplotypes responded to aa 11 to 62 of Hsp20, which contained one or more immunodominant epitopes for each animal. One epitope, DEQTGLPIKS (aa 17 to 26), was identified by T-cell clones. The presence of strain-conserved T helper cell epitopes in aa 11 to 62 of the ubiquitously expressed Hsp20 that are presented by major histocompatibility complex class II molecules represented broadly in the Holstein breed supports the inclusion of this region in vaccine constructs to be tested in cattle.

scholarly journals Antigen-Specific Signaling by a Soluble, Dimeric Peptide/Major Histocompatibility Complex Class II/Fc Chimera Leading to T Helper Cell Type 2 Differentiation

1999 ◽  
Vol 190 (4) ◽  
pp. 543-554 ◽  
Author(s):  
Sofia Casares ◽  
Cong S. Zong ◽  
Dorel L. Radu ◽  
Alexander Miller ◽  
Constantin A. Bona ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Class Ii ◽  
T Helper Cell ◽  
Helper Cell ◽  
Major Histocompatibility ◽  
T Helper ◽  
Th2 Response ◽  
Histocompatibility Complex

Interaction between a T cell receptor (TCR) and various ligands, i.e., anti-TCR antibodies, superantigens, peptides, or altered peptide ligands in the context of major histocompatibility complex (MHC) molecules can trigger different T helper cell (Th) effector functions. Herein, we studied the T cell response induced by a soluble, dimeric peptide/MHC class II chimera, namely hemagglutinin (HA)110-120/I-Edαβ/Fcγ2a (DEF). We have previously demonstrated that the soluble DEF molecule binds stably and specifically to HA110-120–specific TCRs expressed by a T cell hybridoma. Administration of DEF in vivo induced differentiation of resting and activated peptide-specific T cells toward a Th2 response, as indicated by the increase of interleukin (IL)-4, IL-10, and specific immunoglobulin (Ig)G1 antibodies and decrease of IL-2, specific IgG2a antibodies, and cytotoxic T lymphocyte activity. In contrast to HA110-120 peptide presented by the DEF molecule to T cells, the nominal synthetic peptide induced a predominant Th1 response, and the PR8 virus–derived HA110-120 peptides induced a mixed Th1/Th2 response. Independent of antigen processing, soluble DEF was almost 2 logs more potent in stimulating cognate T cells than the nominal peptide. Polarization of cognate T cells toward the Th2 response occurred upon interaction of soluble DEF with TCR and CD4 molecules followed by early activation of p56lck and ZAP-70 tyrosine kinases, and negative signaling of the signal transducer and activator of transcription (STAT)4 pathway of Th1 differentiation. DEF-like molecules may provide a new tool to study the mechanisms of signaling toward Th2 differentiation and may also provide a potential immunotherapeutic approach to modulate autoreactive T cells toward protective Th2 immune responses.

scholarly journals T cell regulation of b cell activation. Cloned Lyt-1+2-T suppressor cells inhibit the major histocompatibility complex-restricted interaction of T helper cells with B cells and/or accessory cells.

1983 ◽  
Vol 158 (4) ◽  
pp. 1178-1190 ◽  
Author(s):  
Y Asano ◽  
R J Hodes
Keyword(s):  
Major Histocompatibility Complex ◽  
B Cells ◽  
Cell Activation ◽  
Suppressor Cells ◽  
Major Histocompatibility ◽  
T Helper ◽  
Th Cells ◽  
Effector Cells ◽  
Histocompatibility Complex ◽  
Accessory Cells

The present studies have identified cloned Lyt-1+2- T suppressor (Ts) cells that are both antigen specific and major histocompatibility complex (MHC) restricted in their activation requirements and that function to regulate the MHC-restricted activation of B cells by T helper (Th) cells. ParentA-restricted Ts clones suppressed, in antigen-specific fashion, the responses generated by (A X B)F1 Th cells cooperating with parentA (B plus accessory) cells, but did not suppress responses by the same (A X B)F1 Th cell population cooperating with parentB (B plus accessory) cells. Moreover, responses of (A X B)F1 leads to parentA Th cells and (A X B)F1 (B plus accessory) cells were suppressed by parentA-restricted Ts clones but not by parentB-restricted Ts clones. Thus, these findings suggest that the cloned Ts cells that have been characterized here function by specifically inhibiting the MHC-restricted interaction between Th cells and B and/or accessory cells. It was further demonstrated in experiments using cloned Th and Ts populations that these Lyt-1+2-Ts cells act not simply as inducers of suppressor but rather function in a restricted fashion as effector cells in the suppressor pathway.

scholarly journals The major histocompatibility complex-restricted antigen receptor on T cells. II. Role of the L3T4 product.

1983 ◽  
Vol 158 (4) ◽  
pp. 1077-1091 ◽  
Author(s):  
P Marrack ◽  
R Endres ◽  
R Shimonkevitz ◽  
A Zlotnik ◽  
D Dialynas ◽  
...  
Keyword(s):  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell ◽  
Cell Receptor ◽  
Surface Expression ◽  
High Avidity ◽  
Low Doses ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

We have examined the role of the murine homologue of Leu-3 T4, L3T4, in recognition of antigen in association with products of the major histocompatibility complex (Ag/MHC) by murine T cell hybridomas. A series of ovalbumin (OVA)/I-Ad-specific T cell hybridomas were ranked in their sensitivity to Ag/I by measuring their ability to respond to low doses of OVA, or their sensitivity to inhibition by anti-I-Ad antibodies. T cell hybridomas with low apparent avidity for OVA/I-Ad, i.e. that did not respond well to low concentrations of OVA and were easily inhibited by anti-I-Ad, were also easily inhibited by anti-L3T4 antibodies. The reverse was true for T cell hybridomas with apparent high avidity for Ag/MHC. We found that the presence of low doses of anti-L3T4 antibodies caused T cell hybridomas to respond less well to low doses of Ag, and to be more easily inhibited by anti-I-Ad antibodies. These results suggested that the role of the L3T4 molecule is to increase the overall avidity of the reaction between T cells and Ag-presenting cells. In support of this idea was the discovery of several L3T4- subclones of one of our L3T4+ T cell hybridomas, D0.11.10. The L3T4- subclones had the same amount of receptor for OVA/I-Ad as their L3T4+ parent, as detected by an anti-receptor monoclonal antibody. The L3T4- subclones, however, responded less well to low doses of OVA, and were more easily inhibited by anti-I-Ad antibodies than their L3T4/ parent. These results showed that the L3T4 molecule was not required for surface expression of, or functional activity of, the T cell receptor for Ag/MHC. The L3T4 molecule did, however, increase the sensitivity with which the T cell reacted with Ag/MHC on Ag-presenting cells.

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