The mode of interaction with macrophages of two ordered synthetic polypeptides which differ in their thymus dependency.

The mode of interaction with macrophages of two ordered synthetic polypeptides (Tyr-Tyr-Glu-Glu)-poly(DLAla)--poly(Lys), (T-T-G-G)-A--L, and (Tyr-Glu-Tyr-Glu)-poly(DLAla)--poly(Lys), (T-G-T-G)-A--L, which differ in their requirements for T-B cell co-operation in the process of antibody production, was compared. The binding of the two radiolabelled antigens to the surface of peritoneal adherent cells, their uptake by the cells and the rate of their degradation were investigated. Macrophages were found to be capable of degrading both poly-peptides with the same efficiency.

Expression of T cell suppressor activity in the immune response of newborn mice to a T-independent synthetic polypeptide.

One and two day old mice responded to the T-independent synthetic polypeptide poly (DTyr,DGlu)-poly(DPro)--poly(DLys) with high antibody production, whereas a dramatic decrease was observed in the immune response of 3 day old injected animals. The presence and expression of suppressor T cells in the 3 day old newborn mice spleens was demonstrated by transferring spleens of 3 day old mice into either thymectomized, irradiated recipients together with bone-marrow cells, or into 1--2 day old newborn recipients. In both cases a significantly lower antibody response was observed in recipients of the 3 day old newborn spleen cells as compared to recipients of the same number of adult spleen cells.

Specificity and crossreactivity of idiotypes of murine antibodies induced by poly(Tyr,Glu)-poly(DLAla)-poly(Lys) and poly(Phe,Glu)-poly(DLAla)-poly(Lys).

Antibodies elicited against the two synthetic polypeptides, poly(Tyr,Glu)-poly(DLAla)-poly(Lys) [(T,G)-A-L] and poly(Phe,Glu)-poly(DLAla)-poly(Lys) [(Phe,G)-A-L], are crossreactive although the humoral responses to these immunogens are under different genetic controls. The fine specificity of the antibodies elicited by the two polypeptides was studied in the present work. Antisera against (Phe,G)-A-L bind both (125)I-labeled (T,G)-A-L and iodinated modified (Phe,G)-A-L.

The effect of a water soluble adjuvant on the immune response to synthetic polypeptides.

The effect of a water soluble adjuvant (WSA) extracted from mycobacteria on the immune response to synthetic polypeptides has been studied in rabbits and inbred mice. WSA increased the antibody response of rabbits to the synthetic polypeptide poly(Tyr,Glu)-poly(DLAla)--poly(Lys) designated (T,G)-A--L when injected together with either incomplete or complete Freund's adjuvants (FIA or FCA). As compared to the respective controls, the effect of WSA was more pronounced when injected with FIA.

The nature and functions of specific immune response genes and their products.

Antibodies produced by inbred mouse strains immunized with the random synthetic polypeptide poly (Tyr,Glu)-poly(DLAla)--polyLys denoted (T,G)-A--L were found to be specific mainly to the ordered peptide Tyr-Tyr-Glu-Glu. Low responder H-2k mice, upon immunization with either the random (T,G)-A--L or the ordered (T-T-G-G)-A--L coupled to methylated bovine serum albumin (MBSA), produce antibodies with comparable titers to those observed in high responder H-2b mice following immunization with the antigens alone or with their complexes with MBSA. A comparison of the above antibodies have led to the conclusion that low responder mice, upon immunization with the synthetic antigens complexed with MBSA, produce antibodies of the same specificity and quality as those of high responders (as shown by the isoelectric focusing technique) and they also have the same affinity and heterogeneity as antibodies of H-2b mice (measured by equilibrium dialysis and antigen binding capacity assay).

In vitro studies on H-2 linked unresponsiveness. 1. Normal helper cells to (T,G)-A-L and GAT in low and non-responder mice.

Lymphoid cells from unprimed high responder (C57BL/10) and low responder mice (B10.Br, B10.A, CBA) to (T,G)-A-L and high responder (B10, B10.

Lymphocytes alloantigens associated with X-chromosome-linked immune response genes.

A new polymorphic alloantigen system controlled by loci on the X-chromosome has been identified by using antisera from F1 hybrid mice differing in their X-chromosome. These alloantigens are associated with the X-chromosome. These alloantigens are associated with the X-linked immune response genes controlling the immune response to the so-called "thymus independent antigens" such as type III pneumococcal polysaccharide, poly(I)-poly(C), and denatured DNA.

Antigen-specific T cell factors: a fine analysis of specificity.

The specificity of T cell factors produced in presence of synthetic polypeptide antigens was studied. Factors prepared with either one of the three antigens: poly(Tyr,Glu)-poly(DLALa)--poly(Lys), (T,G)-A--L, poly(Phe,Glu)-poly(DLALa)--poly(Lys), (Phe,G)-A--L, and poly(His,Glu)-poly(DLALa)--poly(Lys), (H,G)-A--L, successfully cooperated with B cells for antibody production to the homologous as well as to the other two immunogens. Furthermore, the activity of a (T,G)-A--L-specific factor was removed after passage through immunoadsorbents built of Sepharose coupled to: (T,G)A--L, (Phe-G)-A--L and poly(Glu)-poly(DLAa)--poly(Lys), (G)-A--L, but not to poly (DLALa)--poly(LLys),A--L.

Genetic control of immune responsiveness to poly (LPro)--poly (LLys)-derived polypeptides by histocompatibility-linked immune response genes in the rat.

In rats responsiveness to branched synthetic polypeptides carrying a Pro--L backbone, such as (T,G)-Pro--L or (Phe,G)-Pro-L and to Pro--L itself is controlled by Ir genes which are linked to the major histocompatibility genes. The level of antibody production to these polypeptides does not fall into strict high or low responder categories but covers the range in between. (T,G)-pro--L and Pro--L elicit a very similar response pattern which, however, differs from that obtained with (Phe,G)-Pro--L.

Role of antigenic structure in cell to cell cooperation.

Two synthetic polypeptides which differ only in the order of amino acids in their NH2-terminal side chains, namely, (Tyr-Tyr-Glu-Glu)-poly(DLAla)- -poly(LLys) and (Tyr-Glu-Try-Glu)-poly(DLAla)- -poly(LLys), were found to be under different genetic control. By three different in vivo systems for thymus-derived cell depletion, it was demonstrated that (Tyr-Tyr-Glu-Glu)-poly(DLAla)- -poly(LLys), which represents the random poly(Tyr,Glu)-poly(DLAla)- -poly(Lys) in the pattern of immune responses and in the quality of antibodies they elicit, is thymus-dependent whereas (Tyr-Glu-Tyr-Glu)-poly(DLAla)-poly(LLys) does not require thymus-derived cell help for efficient antibody production. Therefore, the two ordered polypeptides which are similar chemically differ in parameters, not yet determined, which affect their capability to trigger bone marrow-derived cells.

Reconstitution of genetically regulated responses against random and ordered synthetic polypeptides by methylated bovine serum albumin as analyzed by isoelectric focusing.

In previous publications it was shown by avidity measurements, cross-reactivity patterns and genetic analyses, that the tetrapeptide T-T-G-G is the immuno-dominant epitope of the synthetic polypeptide (T, G)-A--L. In the present study this close immunological relationship between the random multichain copolymer (T, G)-A--L and the ordered analogue (T-T-G-G)-A--L is extended by two additional criteria. First, the immune response against (T-T-G-G)-A--L in H-2k nonresponder mouse strains can be reconstituted to high antibody levels by complexing this antigen to methylated bovine serum albumin, as was tested earlier for (T,G)-A--L.

Analysis of the role of different cell types in the genetic regulation of antibody production to the thymus-independent synthetic polypeptide poly (DTyr, DGlu)-poly (DPro)--poly (DLys).

The immune response potential of mice to the thymus-independent synthetic polypeptide poly (DTyr, DGlu)-poly(DPro)--poly(DLys)[D(T,G)-Pro--L] is genetically regulated. The defect in the ability of low responder mice to mount an immune response to this antigen appears to be expressed in their B cell population since the presence of thymocytes, or addition of "educated T cells" or supernatant of T cells after stimulation with the antigen neither enhanced, nor suppressed the level of antibodies produced in both low and high responder mice. Low responsiveness could not be enhanced either by stimulation of macrophages or by injection of poly(A) - poly(U) in contrast to the significant effect of these agents on low responses to the thymus-dependent poly(LTyr, LGlu)-poly(LPro)--poly(LLys) [L(T,G)-Pro--L].

Comparison of the immune response potential of newborn mice to T-dependent and T-independent synthetic polypeptides.

Newborn mice do not, in general, produce antibodies during the 1st week of life; this inability to respond immunologically has been attributed to lack of functional macrophages and T cells. To determine whether B cells of newborn mice are functionally mature and therefore capable of producing antibodies to thymus (T) independent antigens, the response of 1-9-day-old C3H/HeJ mice injected with a thymus-independent polypeptide, poly(DTyr,DGlu)-polyDPro- -polyDLys was compared to that of their littermates injected with a thymus-dependent immunogen, poly(LTyr,LGlu)-polyLPro- -polyLLys. No antibodies were detected in 1- or 2-day-old mice immunized with the T-dependent antigen, as revealed by haemagglutination and haemolytic plaque-forming cell assays, performed 6 days after injection of the antigen.

In vitro proliferative reactions by lymphocytes from both responder and "low" responder mice to (T,G)-A--L.

In summary (T,G)-A--L can induce specific in vitro lymphoproliferative reactions in LNC from immunized mice. From 3-8 weeks after immunization lymphocytes from responder mice react to a much greater degree than from low responders. These proliferative reactions are not specifically enhanced by supernatants of "educated" T cells.

Varied effects of polyadenylic-polyuridylic acid on immune responses.

The effect of the double-stranded synthetic polynucleotide, poly(A).poly(U), on the immune response of inbred mouse strains to multichain synthetic polypeptides was studied. Poly(A).

Lack of inverse relationship between the net charge of T-independent immunogens and the responding spleen cells.

Previous studies have demonstrated an inverse relationship between the net electrical charge of immunogens and the antibodies they elicit. This correlation was found to be expressed at the cellular level. It has been shown that thymus-derived cells may recognize immunogens on the basis of their overall electrical charge.