Cellular localization of anti-DNP-PLL and anticonveyor albumin antibodies in genetic nonresponder guinea pigs immunized with DNP-PLL albumin complexes

A speculative view of immune recognition

The speculation that immunologically reactive haptens must be those attached to carriers' immunodominant epitopes suggests a clearer mechanism by which the mysterious hapten-carrier phenomena are generated. This review focuses on the molecular biological nature of immune recognition of hapten-protein antigens both by the T-cell and the B-cell. T and B lymphocytes specifically recognize one determinant of the same antigen molecule in two different ways and in different circumstances. The B-cell recognizes an antigen by the preliminary antigen receptors on the cell's surface, at the time it is still intact, interiorizes it and presents the processed antigenic peptide after an antigen processing procedure. In contrast, the T-cell recognizes a hidden antigenic determinant, together with portions of the MHC on the presenting cell. The immune memory is mainly directed to the hidden internal determinant of an antigen. Some aspects of the clonal selection theory of antibody formation are also discussed at the modern molecular level.

Histocompatibility type and immune responsiveness in random bred Hartley strain guinea pigs

Outbred Hartley strain guinea pigs capable of responding immunologically to 2,4-dinitrophenylated poly-L-lysine were shown to display a histocompatibility specificity in common with inbred strain 2 guinea pigs. This histocompatibility specificity was not detected in guinea pigs unable to respond immunologically to DNP-PLL. The result suggests that the poly-L-lysine specific immune response gene is very closely linked or even identical with a gene determining a major histocompatibility antigen in guinea pigs.

The immune response to (3-amino, 5-succinylaminobenzoyl)-p-aminophenylarsenic acid. Immunofluorescent studies of cells making anti-arsanilic acid antibody or anti-m-aminosuccinanilic acid antibody

The cells synthesizing antibodies in response to immunization with (3-diazo, 5-succinylaminobenzoyl) p-aminophenylarsenic acid—bovine gamma globulin (3A, 5S-BGG) and related antigens have been studied using fluorescent anti-arsanilic acid (anti-Ars), anti-m-aminosuccinanilic acid (anti-Suc) and anti-BGG antibodies, all fluorescent reagents having been prepared from specific precipitates. In the primary response, 1.6 per cent of all cells staining with anti-hapten antibodies after treatment of the smears with a mixture of Ars-rabbit gamma globulin (Ars-RGG) and Suc-RGG stain with both (1.9 per cent of cells staining with anti-Ars; 9.5 per cent of cells staining with anti-Suc). In the secondary response, 12.8 per cent of all cells staining with antihapten antibody stain with both (17.1 per cent of cells staining with anti-Ars; 50.6 per cent of cells staining with anti-Suc). No differences are noted in the percentages of cells staining with both anti-Ars and anti-Suc in animals given a mixture of Ars-BGG and Suc-BGG compared to animals given 3A, 5S-BGG or a doubly conjugated Ars-Suc-BGG (AS-BGG). Comparable numbers of doubly staining cells are present in controls given only Ars-BGG or only Suc-BGG. This is interpreted as indicating that most and probably all of the doubly staining cells noted in the experimental groups are related to an antigenic cross reaction rather than to the synthesis of two antibodies by a single cell. Evidence that this is a cross reaction of intracellular antibody is presented. No cells staining with both antihapten and anticarrier protein (BGG) antibodies have been observed.

Selective immune reactivity to DNP-poly-L-lysine in randomly bred guinea-pigs

The specific immune response towards the synthetic antigen DNP—p(Lys) in randomly bred guinea-pigs has been investigated. A full immunological response, namely delayed hypersensitivity, PCA reactive, complement fixing and mercaptoethanol sensitive antibodies was obtained in nearly half the animals. The other half also showed an immune response restricted, however, to complement fixing and mercaptoethanol sensitive antibodies. Genetic heterogeneity of these animals with respect to immunization to DNP—p(Lys) was thus found to be reflected in the type of immune response induced rather than in an all or none reactivity.

Distribution of antibody-forming cells of different specificities in the lymph nodes and spleens of guinea pigs

The distribution of antibody-forming cells of different specificities in the lymph nodes and spleens of guinea pigs immunized with two separate antigens or with antigens bearing two determinants was studied. When animals were immunized with two soluble protein antigens or antigens in which the two antigenic determinants were on the same molecule, antibody-forming cells of different specificities were always randomly intermixed. However, when animals were immunized with two heat-aggregated particulate protein antigens and then boosted with soluble protein antigens, cells of different specificities were often seen to occur in groups. These results suggest that antibody-forming cells may not arise by the antigen-stimulated proliferation of precommitted antibody-forming cells, but rather antibody-forming cells arise by a transformation of uncommitted precursor cells as the result of their interactions with a locally produced material derived from the processing of antigen.

Hapten carrier relationships in the DNP-PLL foreign albumin complex system: induction of tolerance and stimulation of cells in vitro

Genetic nonresponder guinea pigs made tolerant to BSA and then immunized with DNP-PLL.BSA failed to make anti-DNP-PLL antibodies. Thus, tolerance to a carrier protein renders animals unresponsive to the hapten which it bears. The addition in vitro of DNP-PLL or DNP-GL to lymph node cell cultures derived from genetic responder animals immunized with these materials led to a significant stimulation of (3)H-thymidine incorporation into DNA. However, the addition of DNP-PLL or DNP-GL to lymph node cell cultures from nonresponder animals immunized with these materials failed to produce any stimulation of DNA synthesis. Furthermore, the addition of DNP-PLL to lymph node cell cultures from nonresponder animals immunized with DNP-PLL.BSA or DNP-PLL.OVA also failed to stimulate cell proliferation in spite of the fact that the lymph node cells of these animals were producing anti-DNP-PLL antibodies. The above facts suggest that the function of the PLL gene product is to act at an early crucial step in the immune mechanism to form an antigen-inducer complex. The specificity of this early step may be of a simple order and different than that of the antibody which is later produced in the immune response.

Antigenic competition: cellular or humoral

The injection of one antigen into mice inhibited the response to a second when 1 to 10 days separated the two injections. When the same type of inhibition was attempted in gamma-irradiated mice reconstituted with normal spleen cells, the inhibition was greater in mice receiving 50 million spleen cells than in those receiving 10 million. The results are interpreted as favoring a humoral mechanism of inhibition.

The immune response to a hybrid protein molecule; specificity of secondary stimulation and of tolerance induction

Upon immunization with LDH-III (subunit composition AABB) rabbits produce anti-A and anti-B antibodies in comparable amounts. These antibodies fit equally well to the hybrid enzyme and to LDH-V (AAAA) or LDH-I (BBBB) respectively, as tested by passive hemagglutination inhibition. No antibodies reacting with both LDH-I and LDH-V were detected. A minority of hybrid-specific antibodies was, however, present in the sera. Animals primed with LDH-III respond regularly to a boosting injection of LDH-V with the production of large amounts of anti-A (but not anti-B) antibodies. A similar injection of LDH-I stimulates (if it has any effect at all) the production of anti-B antibodies only. Stimulation with one of the pure types does not impair a subsequent response to the other. The majority of the animals primed with LDH-III responded not at all or weakly to a boosting injection of LDH-I, though antibodies to LDH-I were present in the sera at the time of stimulation. This effect can hardly be explained on the basis of serological sepcificity. Hyporesponsiveness to LDH-III can be induced by injection of LDH-V into the newborn. Both anti-A and anti-B titers are equally depressed. Within the dose range tested, LDH-I does not exert any tolerogenic action with respect to LDH-III. The carrier property of subunit A is evident in the induction of both immunity and tolerance to LDH-III. The early phase of the immune response to the hybrid enzyme may be carrier-specific, and receptors for the haptenic subunit B may not exist at that stage.