Serological analysis of antigen-specific helper factors specific for poly-L(Tyr, Glu)-poly-DLAla--poly-LLys [(T, G)-A--L] and L Glu60-LAla30-LTyr10 (GAT)

Experimental strategies for the study of cellular immunity in renal disease

This overview has examined some of the current experimental options available for the study of cellular immunity in the immunopathogenesis of renal disease. T cell immunity, where it has been examined, seems to have a particularly pivotal role in orchestrating and regulating functional patterns of renal injury. The use of the research methods presented here for the study of cell-mediated interactional events in kidney disease, however, has lagged behind similar efforts in other organ systems. We hope, therefore, this report will serve to stimulate and strengthen further interest in the cell biology of the nephritogenic immune response.

On the molecular basis of T-helper-cell function. IV. B-lymphocyte-promotor factors: on their mode of action, biochemical nature and possible relationship to molecules involved in specific T-helper-cell activity

Some further aspects of B-lymphocyte-promotor factor (B-LPF) activity have been studied. This activity was present in the supernatants of certain helper-T-cell lines, and it induced polyclonal activation of Ig+ B cells into Ig-secreting cells. It was found that B-LPF induced polyclonal, terminal B-cell differentiation (1) in T-cell- and macrophage-depleted spleen cell populations, (2) in both Lyb-5- and Lyb-5+ cells as well as in small and blast-like splenic B cells, and (3) in normal rather than memory B cells. B-LPF function was neither restricted to major histocompatibility complex gene products nor to immunoglobulin allotypes. B-LPF-like activity was also produced by some B-cell lymphomas/hybrids and by the P388-D1 macrophage line. B-LPF activity was found in three MW fractions: (I) greater than 180,000 (pI greater than 7.0 and 4.5-5.5); (II) 50,000-70,000 (pI greater than 7.0; 6.0-6.5, and 4.5-5.5); and (III) 10,000-15,000 (pI greater than 7.0). All three MW forms of B-LPF activity carried antiserum 6036-defined and AB-1.9.3 monoclonal antibody-defined determinants, and they reacted with chicken gammaglobulin (CGG)-Sepharose but not with human serum albumin-Sepharose. These data indicate that the three MW forms of B-LPF activity are associated/dissociated forms of a 10,000-15,000 MW form (subunit) rather than three different molecular species with B-LPF activity. A comparative study between antigen-specific helper factors and B-LPF was hampered by the finding that the helper-T-cell hybridomas used (e.g., T85-109-45/1) only produced B-LPF in our hands. Previously, it has been described that these helper-T-cell hybrids produced CGG-specific, I-Ak-restricted helper factors. However, one surprising observation was that B-LPF produced by both T85 hybrid cells and L12 T lymphoma cells was absorbed and could be eluted from CGG-Sepharose columns. The relationship of B-LPF to other nonspecific and apparently specific T-helper-cell products is discussed in particular in the light of the observations that many immunologically active molecules are built up from 10,000-12,000 molecular weight domain-like polypeptide structures.

Detection of helper and suppressor T cell lines to soluble antigens using a modified ELISA system

Helper and suppressor activity of T cell lines were investigated using an assay system which is based on measurement by the enzyme-linked immunosorbent assay (ELISA) of the antibody produced in vitro. T cell lines were established from spleens of BALB/c mice immunized with ovalbumin and human serum albumin. The T cells were expanded in culture with irradiated spleen cells and antigen or concanavalin A supernatant. The culture system used for assay of T cell activities contained antigen (Ag)-primed unfractionated spleen cells or Ag-primed B cells. Ag-primed cells and cultured T cells were incubated together with Ag (0.05 ng/ml-100 micrograms/ml) for various times, washed at varying intervals, and supernatants assayed for specific antibody activity by an ELISA adapted for this purpose. A total incubation time of 9 days was required for significant antibody production. Complete reconstitution of the antibody response was observed with Ag-primed B cells and Ag-primed T cells were combined. In one experiment, a helper cell line was shown to restore specific antibody production to approximately 50% of the normal response while a suppressor cell line suppressed antibody production by 90%. A linear response of between 0.2 and 1.4 OD units was observed in the ELISA allowing easy detection of help or suppression. As little as 80 ng of specific antibody could be detected. This technique allows quantitative determination of antibody production for a large number of individual microcultures.

Inhibition of secondary IgG responses by monosaccharides: evidence for I-region control

Certain monosaccharides selectively inhibit secondary IgG responses in vitro. Genetic analyses described in this report revealed that the inhibitory sugars differed between mouse strains and these differences mapped to the I-J and I-C subregions of the murine MHC. These results imply that interaction between T and B lymphocytes can involve the recognition of I-region controlled carbohydrate structures.

Regulation of delayed-type hypersensitivity to pathogens and alloantigens

Recent studies reinforce the notion that delayed-type hypersensitivity plays a key role in the host defence against microbial and intracellular parasitic infection, and in the rejection of skin allografts. F. Y. Liew reviews these studies and discusses the observation that this T-cell mediated immunity is profoundly regulated by antigen-specific suppressor T cells, some of which are restricted by products of the I-J subregion of the MHC.

Regulation of delayed-type hypersensitivity. VII. The role of I-J subregion gene products in the inhibition of delayed-type hypersensitivity to major histocompatibility antigens by specific suppressor T cells

Suppressor T cells for delayed-type hypersensitivity (DTH) to alloantigens are induced by injecting mice intravenously with a high dose of X-irradiated allogenic cells. Using the same protocol, suppression of DTH directed against H-2 subregion products could also be induced, provided that the H-2 incompatibility between the cells used for the induction of suppression and the recipients includes the I-J subregion genes. Thus, the I-J subregion difference is both necessary and sufficient for the induction of suppression of DTH to the whole or part of the H-2 gene products. The suppression appears to be mediated by antigen-specific suppressor T cells which recognize the allo-I-J molecules and are able to suppress the DTH response to other H-2 subregion gene products in an associative recognition manner. T cells from (B10 x BALB/c)F1 mice suppressively primed against B10.A(5R) cells (directed against JkEk antigens), when adoptively transferred to normal syngeneic recipients, were capable of suppressing the hosts' DTH response to B10.A(4R) cells (KkAk antigens) when the recipients were challenged with [B10.A(4R) x B10.A(5R)]F1 cells (KkAk x JkEk). The recipients express normal DTH reactivity to B10.A(4R) cells when challenged with a mixture of B10.A(4R) cells (KkAk + JkEk). These results provide direct evidence that when functioning as alloantigens, the I-J determinants preferentially induce suppressor T cells which specifically impair the immune response to the I-J molecules as well as other H-2 gene products if they are physically associated with the I-J determinants. The role of I-J subregions as the suppressor genes is discussed in terms of the possible application in transplantation immunity and the host's defence against infectious diseases.

Analysis of antigen-specific, Ig-restricted cell-free material made by I-J+ Ly-1 cells (Ly-1 TsiF) that induces Ly-2+ cells to express suppressive activity

A set of T cells defined by a unique profile of cell surface alloantigens (phenotype Ly-1+2-; Qa-1+; I-J+) produces biologically active cell-free material(s) (Ly-1 TsiF) which induces another T cell set (cell surface phenotype Ly-1,2+; I-J/; Qa-1+) to participate in the suppression of primary immune responses to heterologous erythrocytes. The suppression is specific for the inducing antigen, and the Ly-1 TsiF binds antigen in a specific way. The activity of Ly-1 TsiF can be removed by anti-I-J immunosorbents and will not be expressed if the functional producer and acceptor cells do not share gene products that are encoded in or are tightly linked to the VH portion of the Ig complex. There is no requirement for the Ly-1 TsiF and its acceptor cell(s) to share major histocompatibility complex gene products. Thus, for optimal induction of antigen-specific suppression by cell-gree materials from Ly-1 T cells, three necessary conditions must be met: (a) antigen recognition by Ly-1 TsiF; (b) the expression of I-J gene products and (c) identify of VH-linked Ig locus gene products (or other products influenced by those genes) on both the inducer molecule and its acceptor cell. The role of the Ig-linked restriction is particularly intriguing, and its possible meaning is considered in detail.

Rabbit antisera with specificity for isolated mouse T-lymphocyte receptors

Rabbit antibodies obtained after immunization of mouse immunoglobulin (MIg)-tolerant rabbits with B6 anti-CBA IgG and having specificity for B6 anti-CBA IgG and T-cell receptors (antiserum 5936) were used to isolate 5936-reactive molecules from B6 anti-CBA mixed lymphocyte culture supernatants. Such 5936-reactive molecules were produced by the B6 T cells, and they did not react with rabbit anti-MIg antisera. They had a mol. wt of 50,000-75,000, and were single-chain polypeptides that did not react with concanavalin A (Con A)--Sepharose. These molecules were in turn injected into rabbits, and the antisera thus obtained had the following characteristics: (1) they reacted against B6 anti-CBA T-cell receptor material but not against B6 anti-CBA IgG; (2) they reacted with about 35% of B6 (H-2b, Ig-1b) anti-CBA T cells, 25% of B6 Con A blasts and 0-10% of normal B6 T cells but not with B6 lipopolysaccharide (LPS) blasts, C3H.B10 (H-2b, Ig-1j) anti-CBA or CBA anti-B6 T cells, CBA Con A blasts or normal CBA T cells; and (3) they reacted with the same 50,000-75,000 mol. wt, T-cell-derived molecules as did antiserum 5936. The implications of these findings are discussed in relation to the nature of T-cell receptors.

Contrasuppression. A novel immunoregulatory activity

We have described an interaction between two T cells subsets that results in interference with the expression of Ly-1-, 2+ (Ly-2) T cell-mediated suppression. We refer to this novel immunoregulatory activity as contrasuppression. The T cell responsible for the induction of contrasuppression (inducer cell) expresses the phenotype Ly-1-, 2+;I-J+;Qa-1+. This phenotype distinguishes it from the suppressor effector cells which we find to be I-J-2.3. An I-J+ soluble mediator from the contrasuppressor inducer cell acts on another cell (acceptor cell) that expresses the phenotype Ly-1+, 2+; I-J+; Qa-1+. This phenotype distinguishes it from T helper cells. Both the inducer cell (or its biologically active mediator) and its acceptor cell are required for the expression of contrasuppression. Because contrasuppressor cells can block the suppressive activity of cell-free mediators released by Ly-2 suppressor T cells, the mechanism of contrasuppression is either separated from or in addition to the inactivation of suppressor cells themselves. The potential importance of contrasuppressor activity in the regulation of suppressor T cell activity in allowing immunologic memory to be expressed and in permitting microenvironmental immune regulation is discussed.

Inhibition of secondary IgG responses by N-acetyl-D-galactosamine

A range of monosaccharides were tested for their ability to inhibit a variety of in vitro immune response. The most striking specific inhibition was produced by N-acetyl-D-galactosamine (GalNAc). This sugar strongly inhibited the secondary IgG antibody response to two different hapten-carrier systems, but had no effect on primary and secondary IgM responses, generation of cytotoxic T cells to alloantigens and mixed lymphocyte reactions. By exposing secondary antibody cultures to GalNAc for varying periods of time, it was observed that GalNAc only exerted its inhibitory effect on day 4 of the culture, the day when IgG plaque-forming cells first appeared. Furthermore, GalNAc could override the action of T helper factor in T cell-depleted cultures. Collectively, these data indicate that GalNAc inhibits the initiation of IgG synthesis probably by blocking the interaction of a helper factor for IgG synthesis with its target cell.

A non-T:non-B cell bears I-A, I-E, I-J, and Tla (Qa-1?) determinants

A non-T:non-B accessory cell in peritoneal washout or spleen-cell suspensions facilitates T-cell proliferative responses to the mitogen, concanavalin A. Utilizing monoclonal antibody, we show that this accessory cell bears the same I-A- and I-E-subregion controlled determinants as found on B cells. In addition, the same accessory cell bears a Tla(Qa-1?)-region and an I-J-subregion controlled determinant. This I-J determinant is also present on splenic accessory cells involved in in vitro antibody responses to sheep red blood cells. Data in a companion paper show that not all anti-I-J sera contain antibody reactive with the accessory cell, and suggest that T cells involved in the generation of suppressor activity and accessory cells bear different I-J-subregion controlled determinants.

Ly-1 inducer and Ly-1,2 acceptor T cells in the feedback suppression circuit bear an I-J-subregion controlled determinant

An I-J-subregion controlled determinant is expressed on Ly-1 inducer and Ly-1,2 acceptor T cells in the feedback suppression circuit. Ly-1 T cells absorb the I-J antibody reactive with the Ly-1,2 acceptor T cell, suggesting that both inducer and acceptor T cells have the same I-J determinant. Since less than 10 percent of Ly-1 or Ly-1,2 T cells are killed by anti-I-J plus complement treatment, the I-J determinant demarcates functionally distinct subsets of both the Ly-1 and Ly-1,2 T-cell sets. This I-J determinant is not expressed on a detectable number of Ly-1 helper T cells which induce B lymphocytes to produce anti-sheep red cell antibody in tissue culture.

Intra-H-2 recombination in the mouse. III. I-Region characterization of haplotypes H-2at2, H-2at3 and H-2a2

Serological characterization of three K-S interval recombinant strains, TBR2 (H-2at2), TBR3 (H-2at3) and AIR 1 (H-2a2) was performed using anti-H-2, Ia, Ss and Slp antisera. The data presented here reveal that the crossover events in both TBR2 and TBR3 occurred between the I-A and I-E subregions. In both cases, the H-2K and I-A subregions were derived fron the H-2t1 of chromosome, while the I-E, S and H-2D regions were derived from the H-2b chromosome (KsAkEbSbDb). The H-2a2 chromosome resulted from a crossover event between the H-2a1 and H-2i9 chromosomes. Ia and Ss typing of AIR 1 suggested that the K to I-E regions originated from H-2a1 and the S and D regions originated from H-2i9 (KkAkEkSbDd).

Demonstration of carbohydrate- and protein determined Ia antigens by monoclonal antibodies

Ten monoclonal alloantibodies were examined by submitting each antibody to five independent tests in order to determine whether they reacted primarily with the glycoprotein or glycolipid class of Ia antigens. The tests employed were as follows: (1) the ability to participate an Ia-like protein from the cell surface as detected by SDS-PAGE; (2) inhibition by protein-Ia extracts free of CHO-Ia; (3) inhibition by CHO-Ia extracts free of protein-Ia; (4) neuraminidase sensitivity of the antigen and (5) inhibition by simple sugars. Using these tests, three of the ten monoclonal antibodies were shown to recognize a CHO-Ia antigen while seven recognized the protein class of Ia antigens. The three CHO-Ia-specific monoclonal antibodies recognized Ia specificities 2, 9 and 17. Monoclonal antibodies recognizing protein-defined Ia.2 and 17 specificities were also characterized. These results imply that some Ia specificities, as defined by genetic testing, can occur both as carbohydrate-defined and protein-defined determinants.--Sugar inhibition studies showed that CHO-Ia.2 has D-glucosamine as its immunodominant sugar while CHO-Ia.17 shows preference for a beta-linked galactose. Furthermore, studies with neuraminidase demonstrated that sialic acid plays a role in the antigenic determinants of CHO-Ia.9 and CHO-Ia.17. Finally, it is noteworthy that CHO-Ia.2, the private specificity of the k haplotype, appears to be expressed only on cells and not in serum. These studies clearly demonstrate the existence of the two Ia antigen classes and emphasize the complexity of the murine I region.

Antigen-specific T-cell factors

Antigen-specific T-cell factors are mediator molecules which are produced by helper and suppressor T cells and which can perform the function of those cells in an antigen-specific manner. They probably play an important part in immunoregulation. The major histocompatibility complex has a controlling influence on their structure and activity, while their antigen-recognition properties may be conferred by immunoglobulin V regions. Interest in the factors derives from three related areas of research, namely (i) the problem of T-cell recognition of antigen; (ii) the mechanisms of cellular interactions in antibody production and cell-mediated immunity; and (iii) the genetic control of immune responses. This review discusses the literature up to June 1980 on their production, structure, genetic restriction and mechanism of action.

Production and main characteristics of a fetal calf serum-specific cell line that induces T and B cell differentiation

Spleen cells from B6 mice injected with fetal calf serum (FCS) could be kept proliferating as a continuous cell line in vitro provided they were culture in the presence of irradiated syngeneic spleen cells and FCS. Cells in this cell line showed a strong proliferative response when stimulated with concanavalin A (Con A), and they were able to mediate the following functions: (1)they helped the generation of alloantigen-specific cytotoxic T lymphocytes (CTL) from thymocyte-spleen cell mixed lymphocyte cultures (MLC), (2)they induced the generation of CTL from normal syngeneic spleen cells in the absence of allogeneic stimulator cells, and (3)they induced normal spleen cells to differentiate into anti-sheep erythrocyte (SRBC) plaque-forming cells (PFC), in the absence of SRBC in the cultures. The use of this cell line (called line 12) may thus provide an interesting approach for the study of cellular and molecular requirements for cell-cell interactions and for the differentiation of T and B effector functions.

Antigen specific T cell factors

Antigen specific helper and suppressor factors have a similar structure, with two major sections, a 'variable region', determining antigen specificity which is likely to be controlled by Immunoglobulin VH genes, with which it shares idiotype and framework determinants. Specific factors also have a 'constant region' which does not vary between strains and minimally between species or with the antigenic specificity of the factors, which are defined by rabbit anti-helper or anti-suppressor antisera. This region determines the biological function of the molecule. Anti-Ia antisera react with factors, but the nature and function of Ia molecules on T cell factors is still unclear. The model of specific factor structure, with C and V regions resembles that of immunoglobulin, and it is thus possible that the C region of factors, like the V region is Ig linked. Because there are multiple T cells, helping and suppressing antibody responses specifically, it seems improbable that all of these cells could interact directly with rare antigen-specific B cells. Thus we propose that macrophage presenting cells are the key to the integration of signals for immune induction and regulation for T and B cells. Since Ir genes have been identified in the macrophage presenting cells interacting with both T and B cells, this suggests that macrophage Ia antigens are of importance in the integration of triggering signals for the lymphoid pool.

Major histocompatibility gene complex (MHC)-coded determinants on antigen-specific suppressor factor for delayed-type hypersensitivity and surface phenotypes of cells producing the factor

Antigen-specific suppressor factor for delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC) was obtained by incubating in vitro spleen cells from CBA mice (H-2k) injected intravenously 3 days previously with 1 x 10(9) SRBC. The suppressor factor was characterized for major histocompatibility gene complex (MHC)-coded antigenic determinants by passing the factor through immunosorbents coupled with appropriate alloantisera. The suppressor factor was absorbed by anti-H-2k, anti-Iak and anti-I-Jk immunosorbents but was not retained by anti-Ias, anti-I-Js, anti-I-Ak, anti-I-E/Ck or anti-H-2Kk immunosorbents. In addition, the factor bound to an immunosorbent coupled with rabbit antibodies against carbohydrate-defined Ia antigens. Furthermore, the suppressive activity that was absorbed was quantitatively recovered in the acid eluates from the immunosorbents. Treatment of the spleen cells with anti-Lyt-1.1 antiserum and complement completely abrogated their ability to elaborate the suppressor factor in vitro. In contrast, treatment with anti-Lyt-2.1 or anti-Iak antiserum and complement had no effect. Thus, it appears that the suppressor factor for DTH to SRBC bears I-J subregion-coded determinants, and its production is dependent on cells which have the Lyt-1+,2- and Ia- phenotype.

Genetic control of the immune response to the terpolymer L-glutamic acid 60-L-alanine 30-L-tyrosine10 (GAT). III. Restricted heterogeneity of the anti-GAT response from BALB/c responder mice

The heterogeneity of the anti-GAT [terpolymer poly(Glu60, Ala30, Tyr10)] response of GAT responder mice has been analyzed. Purified anti-GAT antibodies from BALB/c mice belong only to the gamma 1 kappa subclass. The isoelectric focusing pattern obtained indicates that the anti-GAT antibodies are particularly basic and restricted. These results have been confirmed by two-dimensional polyacrylamide gel electrophoresis; by this technique, we have shown that the gamma 1 chain and the corresponding kappa chain of anti-GAT antibodies are restricted. All the anti-GAT antibodies from 10 BALB/c mice bear the cross-reactive GAT idiotype previously defined (J. Thèze and G. Sommé, Eur. J. Immunol. 1979, 9: 924). The present results indicate that the anti-GAT repertoire expressed in BALB/c mice is very limited.