scholarly journals Indirect allorecognition of platelets by T helper cells during platelet transfusions correlates with anti-major histocompatibility complex antibody and cytotoxic T lymphocyte formation [published erratum appears in Blood 1995 Dec 15;86(12):4710]

Blood ◽  
1995 ◽  
Vol 86 (2) ◽  
pp. 805-812 ◽  
Author(s):  
JW Semple ◽  
ER Speck ◽  
YP Milev ◽  
V Blanchette ◽  
J Freedman

To study the cellular immunology of platelet-induced alloimmunization, a murine transfusion model was developed. BALB/c (H-2d) recipient mice were transfused weekly with 2 x 10(8) platelets or 10(3) leukocytes from C57BL/6 (H-2b) donor mice. Recipient antidonor major histocompatibility complex (MHC) class I alloantibodies could be detected in flow cytometric assays by the fifth platelet transfusion. In contrast, when leukocytes only were transfused, alloantibodies were not detected. In vitro assays demonstrated that murine H-2b platelets were positive for MHC class I expression but lacked MHC class II molecules on their membranes and were unable to stimulate proliferation or cytokine production when incubated with naive H-2d spleen cells. In vivo, however, platelet transfusions induced two distinct patterns of cell-mediated reactivity. First, during the initial transfusions and before alloantibody formation, there was induction of T-cell anergy, characterized by the inability of recipient T cells to respond to Concanavalin A (ConA) or to proliferate in an antidonor mixed lymphocyte reaction (MLR), together with suppressed natural killer (NK) cell activity. This unresponsiveness was associated with a transient increase in nitric oxide (NO)-dependent cytotoxicity and interleukin-1 (IL-1) production. Second, once alloantibodies developed, significantly increased antidonor CD8+ cytotoxic T lymphocyte (CTL) and NK cell responses were observed. At this time, when recipient spleen cells were depleted of CD8+ T cells and incubated with only donor platelets in 7- day antigen-presenting cell (APC) assays, enhanced proliferation and IL- 2 production occurred. These cellular responses were not seen when 10(3) allogeneic leukocytes were transfused. Thus, the results suggest that leukoreduced platelet transfusions induce antidonor MHC antibodies and CD8+ CTL responses in recipient mice. At the same time, the transfusions induced recipient CD4+ T-cell activation when incubated with donor platelets in the presence of syngeneic APCs, an indirect recognition pathway that correlates with the time of alloantibody production.

1982 ◽  
Vol 156 (3) ◽  
pp. 810-821 ◽  
Author(s):  
D H Schwartz ◽  
P C Doherty

Thymocytes and spleen cells from C57BL/6 mice (H-2b) neonatally tolerized to H-2k alloantigens do not generate an anti-vaccinia response restricted to H-2Kk when adoptively transferred to appropriate irradiated hosts. This is in sharp contrast to the case for negatively selected C57BL/6 spleen cells acutely depleted of alloreactivity. No evidence for suppression was found in cell mixture experiments. We have shown elsewhere that our neonatally tolerized animals have a centrally induced delection-type tolerance in the absence of obvious suppression.2 We now suggest that in the neonatally tolerized mouse, chronic, central delection of anti-H-2k clones during early T cell ontogeny eliminates the major source of cells able to give rise, via somatic mutation and expansion, to anti-H-2Kk + vaccinia specific cytotoxic T lymphocyte precursors (CTL-P) in the adult. A similar mechanism may operate in the (k + b) leads to b chimera; however, the presence of H-2kxb accessory and presenting cells may permit the eventual generation (via cross-stimulation) of an H-2k-restricted vaccinia-specific repertoire. This would account for our observation of such "aberrant recognition" CTL-P emerging in the spleens of older (k x b) leads to b chimeras.


1981 ◽  
Vol 153 (3) ◽  
pp. 677-693 ◽  
Author(s):  
B Sredni ◽  
LA Matis ◽  
EA Lerner ◽  
WE Paul ◽  
RH Schwartz

The existence of T cells specific for soluble antigens in association with unique F(1) or recombinant major histocompatibility complex (MHC) gene products was first postulated from studies on the proliferative response of whole T cell populations to the antigen poly(Glu(55)Lys(36)Phe(9))(n) (GLφ). In this paper we use the newly developed technology of T lymphocyte cloning to establish unequivocally the existence of such cells specific for GLφ and to generalize their existence by showing that F(1)- specific cells can be isolated from T cell populations primed to poly(Glu(60)Ala(30)Tyr(10))(n) (GAT) where such clones represent only a minor subpopulation of cells. Gl.4b-primed B10.A(5R) and GAT-primed (B10.A × B10)F(1) lymph node T cells were cloned in soft agar, and the colonies that developed were picked and expanded in liquid culture. The GLφ-specific T cells were then recloned under conditions of high-plating efficiency to ensure that the final colonies originated from single cells. T cells from such rigorously cloned populations responded to stimulation with GILφ but only in the presence of nonimmune, irradiated spleen cells bearing (B10.A × B10)F(1) or the syngeneic B 10.A(5R) recombinant MHC haplotype. Spleen cells from either the B10 or B 10.A parental strains failed to support a proliferative response, even when added together. (B10 × B10.D2)F(1) and (B10 × B10.RIII)F(1) spleen cells also supported a proliferative response but (B10 × B10.Q)F(1) and (B10 X B10.S)F(1) spleen cells did not. These results suggested that the T cell clones were specific for GL[phi} in association with the β(AE)(b)-α(E) (k,d,r,) Ia molecule and that recognition required both gene products to be expressed in the same antigen-presenting cells. Support for this interpretation was obtained from inhibition experiments using the monoclonal antibody Y-17 specific for a determinant on the β(AE)(b)-αE Ia molecule. Y-17 completely inhibited the proliferative response of a GLφ-specific clone but had no effect on the response of either a PPD-specific or GAT-specific clone, both of which required the β(A)-α(A) Ia molecule as their restriction element. No evidence could be found for the involvement of suppressor T cells in this inhibition. We therefore conclude that the phenomenon of F(1)-restricted recognition by proliferating T cells results from the presence of antigen- specific clones that must recognize unique F(1) or recombinant Ia molecules on the surface of antigen-presenting cells in addition to antigen in order to be stimulated.


2002 ◽  
Vol 196 (12) ◽  
pp. 1627-1638 ◽  
Author(s):  
Laura Bonifaz ◽  
David Bonnyay ◽  
Karsten Mahnke ◽  
Miguel Rivera ◽  
Michel C. Nussenzweig ◽  
...  

To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal αDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c− cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When αDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4–48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of αDEC-205:OVA to DCs in the steady state initially induced 4–7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with αDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic αCD40 antibody produced large amounts of interleukin 2 and interferon γ, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation.


1991 ◽  
Vol 174 (6) ◽  
pp. 1371-1383 ◽  
Author(s):  
J L Casanova ◽  
P Romero ◽  
C Widmann ◽  
P Kourilsky ◽  
J L Maryanski

We report here the first extensive study of a T cell repertoire for a class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) response. We have found that the T cell receptors (TCRs) carried by 28 H-2Kd-restricted CTL clones specific for a single Plasmodium berghei circumsporozoite nonapeptide are highly diverse in terms of V alpha, J alpha, and J beta segments and aminoacid composition of the junctional regions. However, despite this extensive diversity, a high proportion of the TCRs contain the same V beta segment. These results are in contrast to most previously reported T cell responses towards class II MHC-peptide complexes, where the TCR repertoires appeared to be much more limited. In our study, the finding of a dominant V beta in the midst of otherwise highly diverse TCRs suggests the importance of the V beta segment in shaping the T cell repertoire specific for a given MHC-peptide complex. As an additional finding, we observed that nearly all clones have rearranged both TCR alpha loci. Moreover, as many as one-third of the CTL clones that we analyzed apparently display two productive alpha rearrangements. This argues against a regulated model of sequential recombination at the alpha locus and consequently raises the question of whether allelic exclusion of the TCR alpha chain is achieved at all.


2002 ◽  
Vol 76 (22) ◽  
pp. 11623-11636 ◽  
Author(s):  
Thorsten U. Vogel ◽  
Thomas C. Friedrich ◽  
David H. O'Connor ◽  
William Rehrauer ◽  
Elizabeth J. Dodds ◽  
...  

ABSTRACT It is now accepted that an effective vaccine against AIDS must include effective cytotoxic-T-lymphocyte (CTL) responses. The simian immunodeficiency virus (SIV)-infected rhesus macaque is the best available animal model for AIDS, but analysis of macaque CTL responses has hitherto focused mainly on epitopes bound by a single major histocompatibility complex (MHC) class I molecule, Mamu-A*01. The availability of Mamu-A*01-positive macaques for vaccine studies is therefore severely limited. Furthermore, it is becoming clear that different CTL responses are able to control immunodeficiency virus replication with varying success, making it a priority to identify and analyze CTL responses restricted by common MHC class I molecules other than Mamu-A*01. Here we describe two novel epitopes derived from SIV, one from Gag (Gag71-79 GY9), and one from the Nef protein (Nef159-167 YY9). Both epitopes are bound by the common macaque MHC class I molecule, Mamu-A*02. The sequences of these two eptiopes are consistent with the molecule's peptide-binding motif, which we have defined by elution of natural ligands from Mamu-A*02. Strikingly, we found evidence for the selection of escape variant viruses by CTL specific for Nef159-167 YY9 in 6 of 6 Mamu-A*02-positive animals. In contrast, viral sequences encoding the Gag71-79 GY9 epitope remained intact in each animal. This situation is reminiscent of Mamu-A*01-restricted CTL that recognize Tat28-35 SL8, which reproducibly selects for escape variants during acute infection, and Gag181-189 CM9, which does not. Differential selection by CTL may therefore be a paradigm of immunodeficiency virus infection.


2002 ◽  
Vol 39 (4) ◽  
pp. 512-515 ◽  
Author(s):  
T. Morita ◽  
A. Shimada ◽  
S. Yashiro ◽  
T. Takeuchi ◽  
Y. Hikasa ◽  
...  

A 7-year-old female Labrador Retriever dog showed extreme muscular weakness, muscle wasting, dysbasia, and mild dysphagia. An elevated value of creatine kinase (335 IU/liter) in the serum was detected. Electromyographic findings included increased insertional activity, fibrillation potentials, and bizarre high-frequency repetitive potentials. Histopathologic examination of skeletal muscles revealed myofiber necrosis and phagocytosis, regeneration of myofibers, and perivascular, perimysial, and endomysial infiltrations of lymphocytes, macrophages and plasma cells. Immunohistochemical evaluation demonstrated that infiltrative cells in the early stage of myositis were CD8+ T-cells and that an increased expression of major histocompatibility complex (MHC) class I was apparent on the surface of nonnecrotic muscle fibers. In contrast, many CD3+ cells (T cells) and HLA-DR-positive macrophages and B lymphocytes were found in the severely affected areas. These results suggest that both expression of MHC class I and CD8+ T-cell infiltration may play an important role in initiation of myositis. These histopathologic findings resemble those reported in naturally occurring polymyositis in humans.


1991 ◽  
Vol 174 (5) ◽  
pp. 1059-1071 ◽  
Author(s):  
O Rötzschke ◽  
K Falk ◽  
S Faath ◽  
H G Rammensee

The strong reaction of T cells against foreign major histocompatibility complex (MHC) antigens, commonly termed "alloreactivity", is not only a nuisance for clinical organ transplantation; it also remains a puzzling question for immunologists. By making use of recent technical developments, alloreactive T cells nominally directed against a mutation in a single MHC class I molecule were found to fall into several major categories. One is recognizing peptides whose occurrence is dependent on one particular MHC allele, another is recognizing peptides supported by several MHC alleles, and a third is recognizing peptides occurring independently of MHC alleles. In a fourth category, the binding to MHC of any of a broad range of peptides appears sufficient. In addition, there are T cells for which no peptide involvement could be detected at all. Even within these categories, the heterogeneity of T cells is considerable: among 16 Kb-reactive T cells analyzed, 15 different modes of reactions were found.


1981 ◽  
Vol 153 (6) ◽  
pp. 1517-1532 ◽  
Author(s):  
H Wagner ◽  
C Hardt ◽  
R Bartlett ◽  
H Stockinger ◽  
M Röllinghoff ◽  
...  

To study whether the thymic major histocompatibility complex (MHC) imposes a constraint on the receptor repertoire of maturating cytotoxic T lymphocyte (CTL) precursors, the restriction phenotypes of virus-specific CTL of MHC-compatible and of MHC-incompatible thymus- and bone marrow-grafted (A X B)F1 chimeric mice were compared. Dependent on the mode of in vitro sensitization, thymocytes or splenocytes of both types of chimeric mice generated Sendai virus-specific, self-MHC-or allo-MHC-restricted CTL. By applying the limiting-dilution technique, the CTL-precursor (CTL-P) frequencies of self-MHC-restricted and allo-MHC-restricted virus-specific T cells as well as of alloreactive T cells were determined. The data obtained revealed that independent of MHC differences between thymus and bone marrow, the frequencies of self-MHC-restricted and allo-MHC-restricted CTL-P were comparable, and in the same older of magnitude as those previously determined in conventionally reared mice. Self-MHC-restricted, virus-specific CTL-P were in a three- to fivefold excess over allo-MHC-restricted CTL-P. A segregation analysis revealed that clonally distinct CTL-P give rise to either self-restricted or allo-MHC-restricted, virus-specific CTL. Both sets were found not only in the spleen, but also in the thymus of chimeric mice, formally demonstrating the intrathymic differentiation pathway of self-MHC as well of allo-MHC-restricted CTL-P. These data reveal no major constraint of the thymic MHC on the capacity of T cells to recognize viral antigens either in the context of self-MHC or of allogeneic MHC products.


1997 ◽  
Vol 185 (8) ◽  
pp. 1403-1412 ◽  
Author(s):  
Alice J.A.M. Sijts ◽  
Eric G. Pamer

Association of antigenic peptides with newly synthesized major histocompatibility complex (MHC) class I molecules occurs in the endoplasmic reticulum and is a critical early step for the initiation of cytotoxic T lymphocyte (CTL)-mediated immune defenses. Pathogen-derived peptides compete with a plethora of endogenous peptides for MHC class I grooves. We find that two H2-Kd–restricted peptides, which derive from the Listeria monocytogenes p60 antigen, accumulate in infected cells with different kinetics. Although competition assays suggest that both epitopes are bound with equivalent affinity, they dissociate from MHC class I molecules at markedly different rates. p60 217-225 forms complexes with H2-Kd with a half-life >6 h, while p60 449-457 dissociates from H2-Kd with a half-life of ∼1 h. We find that p60 449-457–H2-Kd complexes retained intracellularly with brefeldin A have a half-life of 30 min, and thus are less stable than surface complexes. While peptide dissociation from retained MHC class I molecules is enhanced, retained H2-Kd molecules maintain a remarkable capacity to bind new T cell epitopes. We find that intracellular H2-Kd molecules can bind new CTL epitopes for up to 3 h after their synthesis. Our studies provide a glimpse of peptide interaction with MHC class I molecules in the endoplasmic reticulum/proximal Golgi complex of intact, infected cells. We propose that the increased intracellular lability of peptide–MHC class I complexes may function to optimize the spectrum of peptides presented to T lymphocytes during cellular infection.


2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Yuzuru Ikehara ◽  
Masahiro Yamanaka ◽  
Takashi Yamaguchi

Both tumor-specificCD4+andCD8+T cells have been identified, and the latter is known as a major effector of adaptive antitumor immune responses. Optimal antitumor immune responses are considered to require the concomitant activation of bothCD8+andCD4+T cells and the additional selective activation ofCD4+T cells with helper, but not regulatory function. As optimal antitumor immune responses are generated by the concomitant activation of both T cell types, it is necessary for vaccine methods involving cytotoxic T-lymphocytes (CTLs) generation to possess a mechanism whereby antigen presenting cells can present administrated exogenous antigens on not only Major histocompatibility complex (MHC) class II, but also MHC class I molecules.


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