scholarly journals Regulation of immune responses by I-J gene products. I. Production and characterization of anti-I-J monoclonal antibodies.

1981 ◽  
Vol 154 (5) ◽  
pp. 1570-1583 ◽  
Author(s):  
C Waltenbaugh
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
Immune Responses ◽  
Biochemical Characterization ◽  
Antigenic Determinants ◽  
Functional Screening ◽  
Gene Products ◽  
Suppressor Factor

Using a novel, two-step functional screening procedure, we have isolated hybridoma B cell lines secreting monoclonal antibodies directed against gene products of the I-Jb and I-Jk subregions of the mouse H-2 complex. These monoclonal antibodies act in vitro by allowing nonresponder spleen cells to respond to normally suppressive quantities of poly(Glu50Tyr50) (GT) (WF8 series of anti-I-Jk monoclonal antibodies) or to suboptimal concentration of poly(Glu60Ala30Tyr10) (WF9 series of anti-I-Jb monoclonal antibodies). Some of the culture supernates that show augmenting activity bind GT-specific T cell-derived suppressor factor (GT-TsF), indicating that some monoclonal antiantibodies display a nonspecific enhancing effect, or, more likely, that anti-I-J monoclonal antibodies have been produced against I-J determinants not found on TsF. It is this last possibility that is most intriguing and that might serve as a means for exploring the heterogeneity of the I-J subregion. It is also possible that some of our monoclonal anti-I-J antibodies might detect antigenic determinants selectively expressed on suppressor T cells, helper T cells, and/or macrophages. In addition, we have demonstrated that monoclonal anti-I-J antibodies should be useful in the biochemical characterization and purification of a monoclonal GT-TsF. These haplotype-specific anti-I-J monoclonal antibodies should prove to be powerful tools for future studies exploring the role of I-J gene products in the regulation of specific immune responses.

scholarly journals Regulation of immune responses by I-J gene products. VI. Recognition of I-E molecules by I-J-bearing suppressor factors.

1986 ◽  
Vol 163 (4) ◽  
pp. 797-811 ◽  
Author(s):  
C Waltenbaugh ◽  
L Sun ◽  
H Y Lei
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Inbred Mouse ◽  
Mouse Strains ◽  
Gene Products ◽  
Suppressor T Cells ◽  
Primary Target ◽  
Suppressor Factor ◽  
B Lymphoma Cells

Poly(Glu50Tyr50) (GT) is not immunogenic in most inbred mouse strains. GT injection produces an I-J--bearing, GT-specific T-cell--derived suppressor factor (GT-TsF1) in H-2b,d,k haplotype mice. GT-TsF1 generates second-order suppressor T cells (Ts2) in H-2a,d,k haplotype mice. Here, we show that in order for GT-TsF1 to act, the recipient strain must express I-E molecules. This suggests that T cells are not the primary target of GT-TsF1. GT-TsF1 can be presented by Ia+ A20-2J B lymphoma cells. GT-TsF1 presentation is blocked by anti-I-E, but not by anti--I-A, mAb, whereas GAT presentation is blocked by anti-I-A, but not by anti--I-E, mAbs. These data suggest that I-J recognizes (or is recognized by) I-E. The existence and role of I-J molecules in immune regulation are discussed in light of these data.

scholarly journals The Generation and Regulation of Tissue-Resident Tregs and Their Role in Autoimmune Diseases

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shuang Wang ◽  
Xueyang Zou ◽  
Yi Zhang ◽  
Xiaoya Wang ◽  
Wei Yang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
T Cells ◽  
Immune Responses ◽  
Autoimmune Diseases ◽  
Hot Spot ◽  
Exploratory Stage ◽  
And Function

Regulatory T cells (Tregs), as an important subset of T cells, play an important role in maintaining body homeostasis by regulating immune responses and preventing autoimmune diseases. In-depth research finds that Tregs have strong instability and plasticity, and according to their developmental origin, Tregs can be classified into thymic-derived Tregs (tTregs), endogenous-induced Tregs (pTregs), which are produced by antigen-stimulated T cells in the periphery in vivo, and induced Tregs (iTregs), which differentiate from naïve T cells in vitro. In recent years, studies have found that Tregs are divided into lymphatic and tissue-resident Tregs according to their location. Research on the generation and function of lymphoid Tregs has been more comprehensive and thorough, but the role of tissue Tregs is still in the exploratory stage, and it has become a research hot spot. In this review, we discuss the instability and plasticity of Tregs and the latest developments of tissue-resident Tregs in the field of biology, including adipose tissue, colon, skeletal muscle, and other Tregs that have been recently discovered as well as their production, regulation, and function in specific tissues and their role in the pathogenesis of autoimmune diseases.

scholarly journals Regulatory mechanisms in cell-mediated immune responses. VIII. Differential expression of I-region determinants by suppressor cells and their targets in suppression of mixed leukocyte reactions.

1979 ◽  
Vol 150 (5) ◽  
pp. 1108-1121 ◽  
Author(s):  
S S Rich ◽  
C S David
Keyword(s):  
T Cells ◽  
Phenotypic Expression ◽  
Suppressor Cells ◽  
Target Cells ◽  
Gene Products ◽  
Suppressor Activity ◽  
Suppressor Factor ◽  
Cytotoxic Studies ◽  
Marked Suppression

The phenotypic expression of I-region determinants on cells producing and responding to MLR suppressor factor (MLR-TsF) was established in these studies. Alloantigen-activated MLR suppressor T cells (MLR-Ts), which produce MLR-TsF bearing gene products of the I-C subregion, were exposed to anti-I subregion sera and complement (C) before in vitro culture for MLR-TsF production. Suppressor activity was prevented by removal of cells bearing I-C determinants, whereas elimination of cells expressing I-A/B determinants had no effect. Interestingly, cytotoxic elimination of cells displaying I-J determinants also prevented MLR-TsF production. Admixture of anti-I-J and I-C antiserum-treated cells for MLR-TsF production failed to reconstitute suppressor activity, indicating that I-C and I-J gene products are expressed on a single population of cells critical to MLR suppression, rather than on distinct interacting subpopulations. Anti-I-C serum activity specific for I-C+ MLR-Ts was removed by adsorption with nylon wool-nonadherent splenic T cells and concanavalin A-activated thymocytes; adsorption with splenic B cells from anti-Thy-1,2 serum and C-treated spleen failed to remove relevant anti-I-C activity. These data suggest that regulatory I-C molecules, like I-J molecules, are preferentially expressed on T lymphocytes. Expression of I-C, or other I-region molecules on responder cell targets of MLR-TsF activity was also investigated. Responder cells were pretreated with anti-I subregion-specific sera in blocking or complement-dependent cytotoxic protocols before addition to MLR with MLR-TsF. Neither blocking nor the cytotoxic removal of cells bearing I-C or other I-region determinants from MLR responder populations interfered with MLR-TsF suppression. Because it has previously been demonstrated that MLR-TsF interacts optimally with activated, I-C syngeneic target cells, blocking and cytotoxic studies with anti-I subregion sera were also performed with responder cells activated by 24 h culture in MLR in the absence of MLR-TsF. Brief MLR-TsF pulse after antiserum treatment generated marked suppression regardless of blocking or absence of cells bearing serologically detected I-region determinants. I-C restricted suppression may thus be mediated not by interaction with I-C-bearing cells, but by target cells which exist in requisite association with populations of I-C+ cells.

scholarly journals Regulation of immune responses by I-J gene products. II. Presence of Both I-Jb and I-Jk suppressor factors in (nonsuppressor x nonsuppressor) F1 mice.

1982 ◽  
Vol 155 (4) ◽  
pp. 955-967 ◽  
Author(s):  
H Y Lei ◽  
M E Dorf ◽  
C Waltenbaugh
Keyword(s):  
Immune Responses ◽  
Suppressor Cells ◽  
Antigenic Determinants ◽  
Gene Products ◽  
Suppressor Factor ◽  
F1 Hybrid ◽  
Gene Complementation ◽  
Specific Suppression ◽  
Hybrid Mice ◽  
Immune Suppressor

Antigen-specific suppression to poly(Glu50-Tyr50) (GT) is under the control of two complementary immune suppressor (Is) genes located in the major histocompatibility (H-2) complex of the mouse. Suppressor strains of mice produce both suppressor T (Ts) cells and Ts-derived suppressor factors (TsF) that bear antigenic determinants of the I-J subregion of the H-2 complex. Nonsuppressor strains of mice, on the other hand, are not suppressed by GT preimmunization. These nonsuppressor mice, however, can be classified according to those that lack the ability to make GT-specific T cell-derived suppressor factor (GT-TsF) after GT injection (i.e., H-2a, I-Jk mice) and those that lack the ability to be suppressed by the appropriate GT-TsF (i.e., H-2b,g2, I-Jb mice). In the present study, we demonstrate that (H-2a x H-2b,g2)F1 hybrid mice produce distinct GT-specific suppressor factors of both parental I-J haplotypes. Moreover, only the I-Jb-bearing GT-TsF derived from these F1 hybrid mice is able to induce second-order suppressor cells (Ts2). This is consistent with the observation that injection of GT-TsF1 derived from C57BL/6 (I-Jb) mice into A/J (I-Jk) mice leads to the production of an antigen-specific I-Jk GT-TsF2. Our results suggest that Is gene complementation occurs through a different cellular mechanism that was previously observed for Ir gene complementation. Further, we show that complementing (non-suppressor X nonsuppressor)F1 hybrid mice produce an I-Jb (and not an I-Jk) GT-TsF1 and an I-Jk (not an I-Jb) GT-TsF2, thus suggesting a heterogeneity of Ia loci within the I-J subregion. Data presented in the present study suggest that there may be even more heterogeneity within the I-J subregion than has has been heretofore reported with regard to I-J expression on Ts.

scholarly journals A Role for CD4 in Peripheral T Cell Differentiation

1997 ◽  
Vol 186 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Daniel R. Brown ◽  
Naomi H. Moskowitz ◽  
Nigel Killeen ◽  
Steven L. Reiner
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Immune Responses ◽  
Cytoplasmic Domain ◽  
T Cell Differentiation ◽  
Th2 Development ◽  
Deficient Mice

Naive CD4+ T helper cells (Th) differentiate into one of two well-defined cell types during immune responses. Mature Th1 and Th2 cells regulate the type of response as a consequence of the unique cytokines that they secrete. CD4 serves a prominent role in potentiating antigen recognition by helper T cells. We have examined the role of CD4 in peripheral T cell differentiation by studying helper T cells from mice with a congenital defect in CD4 expression. After protein immunization or infection with Leishmania major, CD4-deficient mice were incapable of mounting antigen-specific Th2 responses, but retained their Th1 potency. CD4-deficient, T cell receptor transgenic T cells were also incapable of Th2 differentiation after in vitro activation. Expression of a wild-type CD4 transgene corrected the Th2 defect of CD4-deficient mice in all immune responses tested. To investigate the role of the cytoplasmic domain, mice reconstituted with a truncated CD4 molecule were also studied. Expression of the tailless CD4 transgene could not rescue the Th2 defect of CD4-deficient mice immunized with protein or CD4-deficient transgenic T cells activated in vitro, raising the possibility that the cytoplasmic domain of CD4 may influence Th2 generation. Expression of the tailless transgene was, however, capable of restoring Th2 development in CD4-deficient mice infected with L. major or CD4-deficient transgenic T cells activated in the presence of recombinant IL-4, demonstrating that the cytoplasmic domain is not absolutely required for Th2 development. Together, these results demonstrate a previously undescribed role of the CD4 molecule. The requirement for CD4 in Th2 maturation reflects the importance of molecules other than cytokines in the control of helper T cell differentiation.

scholarly journals GENETIC CONTROL OF IMMUNE RESPONSES IN VITRO

1974 ◽  
Vol 140 (1) ◽  
pp. 185-198 ◽  
Author(s):  
Baruj Benacerraf ◽  
Judith A. Kapp ◽  
Carl W. Pierce ◽  
David H. Katz
Keyword(s):  
T Cells ◽  
B Cells ◽  
Immune Responses ◽  
Antibody Responses ◽  
Specific Response ◽  
Gene Products ◽  
Spleen Cells ◽  
Culture Initiation ◽  
Cooperative Interactions

The conditions for cooperative interactions between nonresponder B10.S B cells and GAT-primed irradiated (C57BL/6 x SJL)F1 T cells in the response by cultures of mouse spleen cells to GAT were investigated. GAT-specific antibody responses could be elicited by soluble GAT in cultures of GAT-primed irradiated (C57BL/6 x SJL)F1 T cells with C57BL/6 B cells but not with B10.S B cells. In contrast, when GAT was presented to the cultures on F1 macrophages or as aggregates of GAT with MBSA, GAT-specific PFC responses were observed with both B10.S or C57BL/6 B cells. Irradiated GAT-primed T cells were nevertheless essential for the development of these responses. The GAT-specific response of B10.S B cells in these cultures was inhibited by the addition of soluble GAT at culture initiation. These results indicate that genetic disparity at Ir loci is not an absolute barrier to T-B-cell cooperative interactions in the response to antigens under Ir gene control. The significance of these data for the function of Ir gene products in immunocompetent cells is discussed.

Minimal contribution of cell-bound antibodies to the immunoscintigraphy of inflamed joints with 99mTc-anti-CD4 monoclonal antibodies

2002 ◽  
Vol 41 (03) ◽  
pp. 129-134 ◽  
Author(s):  
A. Wolski ◽  
E. Palombo-Kinne ◽  
F. Wolf ◽  
F. Emmrich ◽  
W. Becker ◽  
...  
Keyword(s):  
T Cells ◽  
Monoclonal Antibodies ◽  
Synovial Membrane ◽  
In Vitro Release ◽  
Peritoneal Macrophages ◽  
Lymphoid Organs ◽  
Whole Body ◽  
Free Form ◽  
Ankle Joints

Summary Aim: The cellular joint infiltrate in rheumatoid arthritis patients is rich in CD4-positive T-helper lymphocytes and macrophages, rendering anti-CD4 monoclonal antibodies (mAbs) suitable for specific immunoscintigraphy of human/ experimental arthritis. Following intravenous injection, however, mAbs are present both in the free form and bound to CD4-positive, circulating monocytes and T-cells. Thus, the present study aimed at analyzing the relative contribution of the free and the cell-bound component to the imaging of inflamed joints in experimental adjuvant arthritis (AA). Methods: AA rat peritoneal macrophages or lymph node T-cells were incubated in vitro with saturating amounts of 99mTc-anti-CD4 mAb (W3/25) and injected i.v. into rats with AA. Results: In vitro release of 99mTc-anti-CD4 mAb from the cells was limited (on average 1.57%/h for macrophages and 0.84%/h for T-cells). Following i.v. injection, whole body/joint scans and tissue measurements showed only negligible accumulation of radioactivity in inflamed ankle joints (tissue: 0.22 and 0.34% of the injected activity, respectively), whereas the radioactivity was concentrated in liver (tissue: 79% and 71%, respectively), kidney, and urinary bladder. Unlike macrophages, however, anti-CD4 mAb-coated T-cells significantly accumulated in lymphoid organs, the inflamed synovial membrane of the ankle joints, as well as in elbow and knee joints. Conclusion: While the overall contribution of cell-bound mAbs to the imaging of arthritic joints with anti-CD4 mAbs is minimal, differential accumulation of macrophages and T-cells in lymphoid organs and the inflamed synovial membrane indicates preferential migration patterns of these 2 cell populations in arthritic rats. Although only validated for 99mTc-anti-CD4 mAbs, extrapolation of the results to other anticellular mAbs with similar affinity for their antigen may be possible.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

scholarly journals Human fetal liver MSCs are more effective than adult bone marrow MSCs for their immunosuppressive, immunomodulatory, and Foxp3+ T reg induction capacity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yi Yu ◽  
Alejandra Vargas Valderrama ◽  
Zhongchao Han ◽  
Georges Uzan ◽  
Sina Naserian ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Immune Responses ◽  
Molecular Mechanisms ◽  
Fetal Liver ◽  
Cytotoxic T Cells ◽  
Cell Contact ◽  
Adult Bone Marrow ◽  
Adult Bone

Abstract Background Mesenchymal stem cells (MSCs) exhibit active abilities to suppress or modulate deleterious immune responses by various molecular mechanisms. These cells are the subject of major translational efforts as cellular therapies for immune-related diseases and transplantations. Plenty of preclinical studies and clinical trials employing MSCs have shown promising safety and efficacy outcomes and also shed light on the modifications in the frequency and function of regulatory T cells (T regs). Nevertheless, the mechanisms underlying these observations are not well known. Direct cell contact, soluble factor production, and turning antigen-presenting cells into tolerogenic phenotypes, have been proposed to be among possible mechanisms by which MSCs produce an immunomodulatory environment for T reg expansion and activity. We and others demonstrated that adult bone marrow (BM)-MSCs suppress adaptive immune responses directly by inhibiting the proliferation of CD4+ helper and CD8+ cytotoxic T cells but also indirectly through the induction of T regs. In parallel, we demonstrated that fetal liver (FL)-MSCs demonstrates much longer-lasting immunomodulatory properties compared to BM-MSCs, by inhibiting directly the proliferation and activation of CD4+ and CD8+ T cells. Therefore, we investigated if FL-MSCs exert their strong immunosuppressive effect also indirectly through induction of T regs. Methods MSCs were obtained from FL and adult BM and characterized according to their surface antigen expression, their multilineage differentiation, and their proliferation potential. Using different in vitro combinations, we performed co-cultures of FL- or BM-MSCs and murine CD3+CD25−T cells to investigate immunosuppressive effects of MSCs on T cells and to quantify their capacity to induce functional T regs. Results We demonstrated that although both types of MSC display similar cell surface phenotypic profile and differentiation capacity, FL-MSCs have significantly higher proliferative capacity and ability to suppress both CD4+ and CD8+ murine T cell proliferation and to modulate them towards less active phenotypes than adult BM-MSCs. Moreover, their substantial suppressive effect was associated with an outstanding increase of functional CD4+CD25+Foxp3+ T regs compared to BM-MSCs. Conclusions These results highlight the immunosuppressive activity of FL-MSCs on T cells and show for the first time that one of the main immunoregulatory mechanisms of FL-MSCs passes through active and functional T reg induction.

scholarly journals Vaccination-induced variation in the 140 kD merozoite surface antigen of Plasmodium knowlesi malaria.

1987 ◽  
Vol 165 (2) ◽  
pp. 359-367 ◽  
Author(s):  
F W Klotz ◽  
D E Hudson ◽  
H G Coon ◽  
L H Miller
Keyword(s):  
Monoclonal Antibodies ◽  
Malaria Infection ◽  
Rhesus Monkeys ◽  
Plasmodium Knowlesi ◽  
Rabbit Antiserum ◽  
Antigenic Determinants ◽  
Partial Protection ◽  
Erythrocyte Invasion ◽  
Merozoite Surface Antigen

Immunity to 143/140 kD schizont antigens of a monkey malaria, Plasmodium knowlesi, provides partial protection to lethal malaria infection in rhesus monkeys challenged with uncloned parasites. To determine the capacity of a cloned parasite to generate variants of the 143/140 kD antigens, immunized monkeys were challenged with a clone of P. knowlesi. Parasites recovered 8 d after inoculation with a cloned parasite retained the 143/140 kD antigens. Parasites recovered 30 d after challenge had undergone changes in the 143/140 kD antigens. Antibodies that block erythrocyte invasion in vitro of the inoculum parasites did not inhibit invasion of erythrocytes by two isolates recovered from the immunized monkeys. An isolate from one monkey recovered on day 30 contained clones expressing new 76/72 kD antigens reactive with rabbit antiserum against the 143/140 kD proteins, and other clones expressing no antigens crossreactive with antisera against the 143/140 kD proteins. An isolate from another monkey obtained 59 d after challenge expressed new antigens of 160/155, 115/113, and 87/85 kD. Using monoclonal antibodies, we found that epitopes were lost from the variant proteins, but we were unable to determine whether new epitopes had appeared. We conclude that clones of P. knowlesi can rapidly vary antigenic determinants on the 143/140 kD proteins in animals immunized with these antigens.

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