p-Azobenzenearsonate-L-tyrosine-mediated helper function in immune responses of guinea pigs and rats

Mode of antigen presentation required for triggering of T cell response: analysis by use of azobenzenearsonate-tyrosine derivatives as antigens and L cells transfected with I-Ak genes as antigen presenting cells

Our previous study demonstrated (1) that the presence of charged groups (amino and carboxyl groups) at the alpha-carbon of tyrosine is essential for activation of azobenzenearsonate-L-tryosine (ABA-L-Tyr specific T cells, and (2) that T cells recognizes ABA-L-Tyr in association with macromolecules on syngeneic spleen cells used as antigen presenting cells (APC). The present study was undertaken to confirm that the macromolecules on APC are Ia molecules, by using L cells transfected with A beta k and A alpha k genes as APC. I-Ak restricted ABA-L-Tyr specific cloned T cells, and T hybridoma cells were activated by ABA-L-Tyr in the presence of the L cell transfectants, of which expression of I-Ak molecules had been proven by specific binding of anti-I-Ak monoclonal antibody (MAb) 10.2.16 on the cell surface. The pattern of responses of I-Ak restricted ABA-L-Tyr specific T cells to various ABA-Tyr derivatives presented by the I-Ak expressing L cell transfectants was similar to the pattern obtained by using H-2k spleen cells as APC. Thus, ABA-L-Tyr and ABA-Tyr derivatives, which have both amino and carboxyl groups at the alpha-carbon of Tyr, presented by the L cell transfectants triggered good response of I-Ak restricted ABA-L-Tyr specific T cells. By contrast, ABA-Tyr derivatives, which lack the amino or carboxyl group, or both groups, at the alpha-carbon of Tyr, presented by the L cell transfectants could not activate the ABA-L-Tyr specific T cells at all. Furthermore, anti-I-Ak MAb, but not anti-I-Ek MAb, inhibited completely the response of I-Ak restricted ABA-L-Tyr specific T cells to ABA-L-Tyr presented by the L cell transfectants. These results indicate strongly that the macromolecules on APC which associate with ABA-L-Tyr are A beta k A alpha k gene products, i.e., I-Ak molecules.

Augmentation of the antibody response by hapten help. II. Determination by many genes outside the MHC

The purpose of the present work was to characterize the immune response (Ir) genes that influence augmentation of the antibody response by help with the hapten azobenzene-arsonate (ABA). Hapten help was measured as the augmentation in the plaque-forming cell (PFC) response to bovine gamma globulin (BGG) after priming mice with ABA conjugated to ovalbumin (OVA) and challenging subsequently with ABA-BGG. The first approach involved inbred mouse strains that were matched for H-2 but differed in their non-H-2 genetic backgrounds. B10.D2 mice were low responders even though they shared the H-2d haplotype with BALB/c and DBA/2 mice, which were high responders. C57BL/10 mice were high responders even though they shared the H-2b haplotype with C57BL/6, C3H.SW, and A.BY mice, all of which were strains that were low responders. The second approach was to identify any segregation of H-2 with the gene(s) encoding susceptibility to hapten help in the backcross generation. (BALB/c X C57BL/6) F1 hybrids were backcrossed to C57BL/6. The results showed no association with the major histocompatibility complex (MHC).

ABA-specific helper T cells in A/J mice bear the major cross-reactive idiotype

Attempts were made to induce azobenzenearsonate (ABA)-specific helper cell responses in A/J mice. These were measured by an increase in TNP plaque-forming cells following administration of the double hapten conjugate ABA-bovine serum albumin-TNP. Immunization with ABA coupled homologous immunoglobulin or spleen cells produced ABA-specific help only when the same carrier was used to boost. Hapten-specific help was achieved by two injections of ABA-N-acetyltyrosine in complete Freund's adjuvant 5 weeks apart. This help was passively transferable by T cells as shown by its elimination with anti-Thy 1.2 serum and complement treatment. The presence of the major ABA cross-reactive idiotype (CRI) on these T helper cells could be similarly shown by the elimination of help when the cells were treated with rabbit anti-CRI antibody and complement prior to passive transfer. The same treatment did not effect ABA-specific helper activity of CBA/J mice.

Hapten-specific T cell response to azobenzene-arsonate-N-acetyl-L-tyrosine (ABA-tyr) in Lewis rats. II. Induction and suppression of ABA-specific helper cell activity for antibody production

Immunization of Lewis rats with azobenzenearsonate-N-acetyl-L-tyrosine (ABA-tyr) in complete Freund's adjuvant (CFA), produces a hapten-specific helper T cell response measured by an increase in plaque forming cells (PFC) against a different hapten. The response seen is primarily direct (IgM) PFC unless B cells are primed by injection of trinitrophenylated keyhole limpet hemocyanin (TNP-KLH) prior to immunization with ABA-tyr. The response requires both ABA and TNP to be on the same carrier molecule which can be as diverse as bovine serum albumin (BSA), poly L-glutamine-lysine-tyrosine (L-GLT); however, a D-amino acid polypeptide does not work. The in vitro demonstration of such help was successful only with peritoneal exudate lymphocytes, not spleen or lymph node cells. Repeated pretreatment of rats by intraperitoneal injection of ABA-tyr in incomplete Freund's adjuvant (IFA) induced an unresponsiveness for helper activity to subsequent immunization with the same antigen in CFA. Passive transfer of lymphoid cells from spleens and lymph nodes from rats pretreated with ABA-tyr in IFA followed by boosting with ABA-tyr in CFA induced unresponsiveness to subsequent induction of hapten-specific help.

Lack of heterogeneity in antihapten antibodies of a phylogenetically primitive shark

Individual mammals have the capacity to express at least one million distinct antigen binding specificities, implying a high degree of structural heterogeneity in the variable heavy and light chain (VH and VL) portions of the antibody molecules. Studies of higher vertebrate species suggest that this heterogeneity is created both through a sizeable repertoire of germ-line VH and VL genes and through random rearrangements of V and joining genes. Additional somatic mechanisms probably also contribute to the ultimate heterogeneity; one-third of murine plasmacytomas producing lambda 1 immunoglobulin carry a somatically mutated Ig1-V gene. The relative contributions of these various mechanisms to the overall imunoglobulin variability are difficult to evaluate. The production of different antibodies to a defined determinant in different individuals of an inbred mouse strain [for example, (3-iodo-4-hydroxy-5-nitrophenyl) acetyl (NIP) in CBA mice] suggests the involvement of somatic mutations or rearrangement but does not rule out the possibility that each individual CBA mouse expresses only a small random fraction from a large germ-line repertoire of V genes determining different anti-NIP binding sites. The opposite finding, that different individuals produce nearly identical antibodies to a defined determinant, would suggest the presence and expression of a limited number of germ-line genes without somatic alterations. Data presented here suggest that primitive sharks (Heterodontus fransisci) produce such antibodies to the hapten furyloxazolone.

Immunological methods based on antigen-coupled bacteriophages

Simple chemicals, many proteins, nucleic acids or polysaccharides can be coupled to bacteriophages without completely destroying their infectivity. The coupled phages are then sensitive to inactivation by the relevant antibodies. Thus it is possible to construct phage inactivation assays for antibodies or inactivation inhibition assays for antigens. The advantages of the bacteriophage methods include superior sensitivity and good stability of the reagents. The phage inactivation method detects preferably high-affinity antibodies, but what really matters is a high avidity. Because of the polyvalency IgM antibodies can have a high avidity associated with moderate affinity, and therefore low amounts of IgM class antibody, for instance natural antibody, are often measurable by this test. The chemical conjugation inactivates a proportion of the bacteriophages. If the antigen can be made chemically reactive (self-coupling), approximately 10% of the phage particles escape this inactivation and can serve as indicators of antibody action. When the antigen cannot be made chemically reactive, this inactivation is more complete and the phage assay is less satisfactory.

Effect of prior sensitization with hapten on the antibovine IgG antibody response to hapten-conjugated tolerogen of mice tolerized by low doses of bovine IgG

Mice tolerized by low doses of bovine IgG (BGG), immunized with arsanilated (ARS) conjugates and challenged with ARS-BGG show an augmented anti-BGG antibody response compared with controls immunized with nonconjugated carrier. Conditions optimal for generating hapten help are explored and suggest that the phenomenon is mediated by hapten-specific helper T cells. During exploration of these conditions it became apparent that the response was suppression rather than augmentation with ARS, under certain circumstances, and with 2,4-dinitrophenyl, 4-hydroxy-5-iodo-3-nitro-phenylacetyl (NIP) and sulfanilic acid, under all conditions tested. Especially important in determining the outcome of the interaction was the type of adjuvant used for hapten priming. The significance of these observations is discussed in relationship to the balance between negative and positive cooperation.

Inheritance of antibody specificity. III. A new VH gene controls fine specificity of anti-p-azobenzenearsonate coupled to the carbon atom 5 of hydroxyphenylacetic acid in the mouse

Mice of 10 inbred strains were immunized with a protein conjugate of a hapten of p-azobenzenearsonate coupled to the carbon atom 5 of hydroxphenylacetic acid (ABA-HOP), and anti-ABA-HOP titers were determined by the haptenated phage inactivation. Mean titers of C57BL/6 and BALB/c mice were significantly lower than those of A/J and CBA strains. The titers were under a polygenic control and did not correlate with allotypes in backcross mice. Fine specificity of the anti-ABA-HOP was characterized by inhibiting the haptenated phage inactivation reaction with five chemically related compounds including ABA-HOP (Fig. 1). This antibody was genetically more polymorphic than any other antibody studied. Three distinct idiotypes could be demonstrated and the number is probably greater. The idiotypes of the A/J and C57BL/6 were inherited as allotype-linked dominant Mendelian traits, the former in two and the latter in three different backcrosses. Condominance of the two alleles was shown since approximately equal amounts of the two idiotypes were produced by the population of heterozygous mice. There were many individual heterozygotes, however, in which only one parental idiotype could be detected. In other individuals of the same genotype the other parental idiotype was predominant. In many mice a mixture of the two idiotypes was indicated by doubly sigmoid inhibition curves. The causes for the variation in the expression of the two alleles in genotypically identical mice is discussed.

Concentrations of three hapten-binding immunoglobulins in pooled normal human serum

The amount of natural anti-DNP-cap, anti-NIP-cap or anti-ABA-TYR in human IgM was measured by using immunoabsorbents and hapten elution. We found that 1.0% of pooled human IgM is specific for DNP-cap, 0.2% for NIP-cap and 0.02% for ABA-TYR. Haptens NIP and DNP were found to be cross-reactive when tested with natural antibodies even though they were not cross-reactive when tested with immune antibodies.