scholarly journals Analysis of the Role of  Variation of Major Histocompatibility Complex Class II Expression on Nonobese Diabetic (NOD) Peripheral T Cell Response

1998 ◽  
Vol 188 (12) ◽  
pp. 2267-2275 ◽  
Author(s):  
William M. Ridgway ◽  
Hiroaki Ito ◽  
Marcella Fassò ◽  
Chen Yu ◽  
C. Garrison Fathman

The current paradigm of major histocompatibility complex (MHC) and disease association suggests that efficient binding of autoantigens by disease-associated MHC molecules leads to a T cell–mediated immune response and resultant autoimmune sequelae. The data presented below offer a different model for this association of MHC with autoimmune diabetes. We used several mouse lines expressing different levels of I-Ag7 and I-Ak on the nonobese diabetic (NOD) background to evaluate the role of MHC class II in the previously described NOD T cell autoproliferation. The ratio of I-Ag7 to I-Ak expression correlated with the peripheral T cell autoproliferative phenotype in the mice studied. T cells from the NOD, [NOD × NOD.I-Anull]F1, and NOD I-Ak transgenic mice demonstrated autoproliferative responses (after priming with self-peptides), whereas the NOD.H2h4 (containing I-Ak) congenic and [NOD × NOD.H2h4 congenic]F1 mice did not. Analysis of CD4+ NOD I-Ak transgenic primed lymph node cells showed that autoreactive CD4+ T cells in the NOD I-Ak transgenic mice were restricted exclusively by I-Ag7. Considered in the context of the avidity theory of T cell activation and selection, the reported poor peptide binding capacity of NOD I-Ag7 suggested a new hypothesis to explain the effects of MHC class II expression on the peripheral autoimmune repertoire in NOD mice. This new explanation suggests that the association of MHC with diabetes results from “altered” thymic selection in which high affinity self-reactive (potentially autoreactive) T cells escape negative selection. This model offers an explanation for the requirement of homozygous MHC class II expression in NOD mice (and in humans) in susceptibility to insulin-dependent diabetes mellitus.

1998 ◽  
Vol 188 (9) ◽  
pp. 1633-1640 ◽  
Author(s):  
Abdel Rahim A. Hamad ◽  
Sean M. O'Herrin ◽  
Michael S. Lebowitz ◽  
Ananth Srikrishnan ◽  
Joan Bieler ◽  
...  

The interaction of the T cell receptor (TCR) with its cognate peptide–major histocompatibility complex (MHC) on the surface of antigen presenting cells (APCs) is a primary event during T cell activation. Here we used a dimeric IEk-MCC molecule to study its capacity to activate antigen-specific T cells and to directly analyze the role of CD4 in physically stabilizing the TCR–MHC interaction. Dimeric IEk-MCC stably binds to specific T cells. In addition, immobilized dimeric IEk-MCC can induce TCR downregulation and activate antigen-specific T cells more efficiently than anti-CD3. The potency of the dimeric IEk-MCC is significantly enhanced in the presence of CD4. However, CD4 does not play any significant role in stabilizing peptide-MHC–TCR interactions as it fails to enhance binding of IEk-MCC to specific T cells or influence peptide-MHC–TCR dissociation rate or TCR downregulation. Moreover, these results indicate that dimerization of peptide-MHC class II using an IgG molecular scaffold significantly increases its binding avidity leading to an enhancement of its stimulatory capacity while maintaining the physiological properties of cognate peptide–MHC complex. These peptide-MHC–IgG chimeras may, therefore, provide a novel approach to modulate antigen-specific T cell responses both in vitro and in vivo.


1992 ◽  
Vol 176 (1) ◽  
pp. 275-280 ◽  
Author(s):  
M A Blackman ◽  
F E Lund ◽  
S Surman ◽  
R B Corley ◽  
D L Woodland

It has been established that at least some V beta 17+ T cells interact with an endogenous superantigen encoded by the murine retrovirus, Mtv-9. To analyze the role of major histocompatibility complex (MHC) class II molecules in presenting the Mtv-9 encoded superantigen, vSAG-9 to V beta 17+ hybridomas, a panel of nine hybridomas was tested for their ability to respond to A20/2J (H-2d) and LBK (H-2a) cells which had been transfected with the vSAG-9 gene. Whereas some of the hybridomas recognized vSAG-9 exclusively in the context of H-2a, other hybridomas recognized vSAG-9 exclusively in the context of H-2d or in the context of both H-2d and H-2a. These results suggest that: (a) the class II MHC molecule plays a direct role in the recognition of retroviral superantigen by T cells, rather than serving simply as a platform for presentation; and, (b) it is likely that components of the TCR other than V beta are involved in the vSAG-9/TCR/class II interaction.


1995 ◽  
Vol 182 (5) ◽  
pp. 1403-1413 ◽  
Author(s):  
S Morkowski ◽  
A W Goldrath ◽  
S Eastman ◽  
L Ramachandra ◽  
D C Freed ◽  
...  

Peptides from the lumenal portion of invariant chain (Ii) spanning residues 80-106 (class II-associated Ii peptide [CLIP]) are found in association with several mouse and human major histocompatibility complex (MHC) class II allelic variants in wild-type and presentation-deficient mutant cells. The ready detection of these complexes suggests that such an intermediate is essential to the MHC class II processing pathway. In this study, we demonstrate that T cells recognize CLIP/MHC class II complexes on the surface of normal and mutant cells in a manner indistinguishable from that of nominal antigenic peptides. Surprisingly, T cell hybrids specific for human CLIP bound to murine MHC class II molecule I-Ab and a new monoclonal antibody 30-2 with the same specificity, recognize two independent epitopes expressed on this peptide/class II complex. T cell recognition is dependent on a Gln residue (position 100) in CLIP, whereas the 30-2 antibody recognizes a Lys residue-at position 90. These two residues flank the 91-99 sequence that is conserved among human, mouse, and rat Ii, potentially representing an MHC class II-binding site. Our results suggest that the COOH-terminal portion of CLIP that includes TCR contact residue Gln 100 binds in the groove of I-Ab molecule. Moreover, both T cells and the antibody recognize I-Ab complexed with larger Ii processing intermediates such as the approximately 12-kD small leupeptin-induced protein (SLIP) fragments. Thus, SLIP fragments contain a CLIP region bound to MHC class II molecule in a conformation identical to that of a free CLIP peptide. Finally, our data suggest that SLIP/MHC class II complexes are precursors of CLIP/MHC class II complexes.


2017 ◽  
Vol 35 (29) ◽  
pp. 3322-3329 ◽  
Author(s):  
Yong-Chen Lu ◽  
Linda L. Parker ◽  
Tangying Lu ◽  
Zhili Zheng ◽  
Mary Ann Toomey ◽  
...  

Purpose Adoptive transfer of genetically modified T cells is being explored as a treatment for patients with metastatic cancer. Most current strategies use genes that encode major histocompatibility complex (MHC) class I–restricted T-cell receptors (TCRs) or chimeric antigen receptors to genetically modify CD8+ T cells or bulk T cells for treatment. Here, we evaluated the safety and efficacy of an adoptive CD4+ T-cell therapy using an MHC class II–restricted, HLA-DPB1*0401–restricted TCR that recognized the cancer germline antigen, MAGE-A3 (melanoma-associated antigen-A3). Patients and Methods Patients received a lymphodepleting preparative regimen, followed by adoptive transfer of purified CD4+ T cells, retrovirally transduced with MAGE-A3 TCR plus systemic high-dose IL-2. A cell dose escalation was conducted, starting at 107 total cells and escalating at half-log increments to approximately 1011 cells. Nine patients were treated at the highest dose level (0.78 to 1.23 × 1011 cells). Results Seventeen patients were treated. During the cell dose-escalation phase, an objective complete response was observed in a patient with metastatic cervical cancer who received 2.7 × 109 cells (ongoing at ≥ 29 months). Among nine patients who were treated at the highest dose level, objective partial responses were observed in a patient with esophageal cancer (duration, 4 months), a patient with urothelial cancer (ongoing at ≥ 19 months), and a patient with osteosarcoma (duration, 4 months). Most patients experienced transient fevers and the expected hematologic toxicities from lymphodepletion pretreatment. Two patients experienced transient grade 3 and 4 transaminase elevations. There were no treatment-related deaths. Conclusion These results demonstrate the safety and efficacy of administering autologous CD4+ T cells that are genetically engineered to express an MHC class II–restricted antitumor TCR that targets MAGE-A3. This clinical trial extends the reach of TCR gene therapy for patients with metastatic cancer.


1994 ◽  
Vol 180 (5) ◽  
pp. 1911-1920 ◽  
Author(s):  
R S Yeung ◽  
J M Penninger ◽  
T M Kündig ◽  
Y Law ◽  
K Yamamoto ◽  
...  

To reconstitute the human immune system in mice, transgenic mice expressing human CD4 and human major histocompatibility complex (MHC) class II (DQw6) molecules in an endogenous CD4- and CD8-deficient background (mCD4/8-/-), after homologous recombination, have been generated. We report that expression of human CD4 molecule in mCD4/8-/- mice rescues thymocyte development and completely restores the T cell compartment in peripheral lymphoid organs. Upon vesicular stomatitis virus (VSV) challenge, the reconstituted mature T cell population effectively provide T help to B cells in immunoglobulin class switching from IgM to specific IgG-neutralizing antibodies. Human CD4+DQw6+ double transgenic mice are tolerant to DQw6 and the DQw6 molecule functions in antigen presentation, effectively generating a human MHC class II-restricted T cell response to streptococcal M6C2 peptide. These data show that both the hCD4 and DQw6 molecules are functional in mCD4/8-/- mice, fully and stably reconstituting this limb of the human immune system in mice. This animal model provides a powerful in vivo tool to dissect the human CD4-human class II MHC interaction, especially its role in human autoimmune diseases, superantigen-mediated diseases, and acquired immunodeficiency syndrome (AIDS).


1992 ◽  
Vol 175 (6) ◽  
pp. 1493-1499 ◽  
Author(s):  
C R Hewitt ◽  
J R Lamb ◽  
J Hayball ◽  
M Hill ◽  
M J Owen ◽  
...  

The Staphylococcal enterotoxin superantigens stimulate vigorous responses in T cells bearing certain T cell antigen receptor (TCR) V beta regions. In addition to activation, these superantigens also impart negative signals to T cells resulting in a profound state of unresponsiveness or anergy. The Staphylococcus aureus enterotoxins (SE) B and C2 bind to a closely related site on major histocompatibility complex (MHC) human leukocyte antigen (HLA)-DR1 molecules. Only SEB, however, interacts with the TCR V beta 3 region of HA1.7, a human HLA-DR1 restricted T cell clone specific for influenza haemagglutinin. In competition experiments, we demonstrated that the induction of anergy in HA1.7 by SEB is unaffected by the presence of SEC2. These results suggest that SEB-induced anergy is MHC independent and involves a direct interaction between the TCR and SEB. To resolve definitively whether SEB binds directly to T cells in the absence of MHC class II molecules, the cDNAs encoding the HA1.7 TCR were transfected into an MHC class II-negative human T cell line. The addition of SEB to these transfectants resulted in the downregulation of cell surface TCR expression, an increase in the concentration of intracellular calcium ions, the production of lymphokines, and reduced responsiveness to a subsequent challenge with SEB. We conclude that SEB interacts directly with the TCR in the absence of cointeraction with MHC class II molecules, and that this interaction may induce anergy in HA1.7.


1998 ◽  
Vol 187 (11) ◽  
pp. 1871-1883 ◽  
Author(s):  
Laurent Gapin ◽  
Yoshinori Fukui ◽  
Jean Kanellopoulos ◽  
Tetsuro Sano ◽  
Armanda Casrouge ◽  
...  

The positive selection of CD4+ T cells requires the expression of major histocompatibility complex (MHC) class II molecules in the thymus, but the role of self-peptides complexed to class II molecules is still a matter of debate. Recently, it was observed that transgenic mice expressing a single peptide–MHC class II complex positively select significant numbers of diverse CD4+ T cells in the thymus. However, the number of selected T cell specificities has not been evaluated so far. Here, we have sequenced 700 junctional complementarity determining regions 3 (CDR3) from T cell receptors (TCRs) carrying Vβ11-Jβ1.1 or Vβ12-Jβ1.1 rearrangements. We found that a single peptide–MHC class II complex positively selects at least 105 different Vβ rearrangements. Our data yield a first evaluation of the size of the T cell repertoire. In addition, they provide evidence that the single Eα52-68–I-Ab complex skews the amino acid frequency in the TCR CDR3 loop of positively selected T cells. A detailed analysis of CDR3 sequences indicates that a fraction of the β chain repertoire bears the imprint of the selecting self-peptide.


1996 ◽  
Vol 183 (3) ◽  
pp. 1083-1092 ◽  
Author(s):  
R Wen ◽  
G A Cole ◽  
S Surman ◽  
M A Blackman ◽  
D L Woodland

Recent studies have shown that only a subset of major histocompatibility complex (MHC) class II molecules are able to present bacterial superantigens to T cells, leading to the suggestion that class-II associated peptides may influence superantigen presentation. Here, we have assessed the potential role of peptides on superantigen presentation by (a) analyzing the ability of superantigens to block peptide-specific T cell responses and (b) analyzing the ability of individual peptides to promote superantigen presentation on I-Ab-expressing T2 cells that have a quantitative defect in antigen processing. A series of peptides is described that specifically promote either toxic shock syndrome toxin (TSST) 1 or staphylococcal enterotoxin A (SEA) presentation. Whereas some peptides promoted the presentation of TSST-1 (almost 5,000-fold in the case of one peptide), other peptides promoted the presentation of SEA. These data demonstrate that MHC class II-associated peptides differentially influence the presentation of bacterial superantigens to T cells.


2009 ◽  
Vol 77 (11) ◽  
pp. 4953-4965 ◽  
Author(s):  
Justin E. Wilson ◽  
Bhuvana Katkere ◽  
James R. Drake

ABSTRACT The intracellular bacterium Francisella tularensis survives and replicates within macrophages, ultimately killing the host cell. Resolution of infection requires the development of adaptive immunity through presentation of F. tularensis antigens to CD4+ and CD8+ T cells. We have previously established that F. tularensis induces macrophage prostaglandin E2 (PGE2) production, leading to skewed T-cell responses. PGE2 can also downregulate macrophage major histocompatibility complex (MHC) class II expression, suggesting that F. tularensis-elicited PGE2 may further alter T-cell responses via inhibition of class II expression. To test this hypothesis, gamma interferon (IFN-γ)-activated reporter macrophages were exposed to supernatants from F. tularensis-infected macrophages, and the class II levels were measured. Exposure of macrophages to infection supernatants results in essentially complete clearance of surface class II and CD86, compromising the macrophage's ability to present antigens to CD4 T cells. Biochemical analysis revealed that infection supernatants elicit ubiquitin-dependent class II downregulation and degradation within intracellular acidic compartments. By comparison, exposure to PGE2 alone only leads to a minor decrease in macrophage class II expression, demonstrating that a factor distinct from PGE2 is eliciting the majority of class II degradation. However, production of this non-PGE2 factor is dependent on macrophage cyclooxygenase activity and is induced by PGE2. These results establish that F. tularensis induces the production of a PGE2-dependent factor that elicits MHC class II downregulation in IFN-γ-activated macrophages through ubiquitin-mediated delivery of class II to lysosomes, establishing another mechanism for the modulation of macrophage antigen presentation during F. tularensis infection.


1997 ◽  
Vol 186 (8) ◽  
pp. 1223-1232 ◽  
Author(s):  
Thomas Brocker

Thymic T cell development is controlled by T cell receptor (TCR)–major histocompatibility complex (MHC) interactions, whereas a further dependence of peripheral mature T cells on TCR–MHC contact has not been described so far. To study this question, CD4 T cell survival was surveyed in mice lacking MHC class II expression and in mice expressing MHC class II exclusively on dendritic cells. Since neither of these mice positively select CD4 T cells in the thymus, they were grafted with MHC class II–positive embryonic thymic tissue, which had been depleted of bone marrow derived cells. Although the thymus grafts in both hosts were repopulated with host origin thymocytes of identical phenotype and numbers, an accumulation of CD4+ T cells in peripheral lymphoid organs could only be observed in mice expressing MHC class II on dendritic cells, but not in mice that were completely MHC class II deficient. As assessed by histology, the accumulating peripheral CD4 T cells were found to be in close contact with MHC class II+ dendritic cells, suggesting that CD4 T cells need peripheral MHC class II expression for survival and that class II+ dendritic cells might play an important role for the longevity of CD4 T cells.


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