Production of antisera specific for idiotype(s) of murine anti-(T,G)-A--L antibodies.

Antibodies to the synthetic polypeptide (T,G)-A--L were raised in C57BL/10 and C3H.SW mice. For each strain, the anti-(T,G)-A--L antibodies from 10 animals were pooled, affinity purified on a (T,G)-A--L-Sepharose column, and used to immunize Lewis rats. The resulting rat antisera were adsorbed with insolubilized normal mouse globulin in order to remove anti-isotypic and anti-allotypic antibodies. The residual antibodies specifically inhibited the binding of (T,G)-A--L by anti-(T,G)-A--L as measured by a radioimmunoassay. The specificity of this inhibition was demonstrated as follows: 1) failure of the anti-(T,G)-A--L anti-idiotype to inhibit the binding of nuclease to anti-nuclease antibody of the same allotype; 2) failure of Lewis anti-[B10 anti-(T,G)-A--L] to inhibit C3H.SW anti-(T,G)-A--L and vice versa; 3) ability to absorb anti-C3H.SW anti-idiotypic activity on insolubilized C3H.SW anti-(T,G)-A--L but not on B10 anti-(T,G)-A--L. The same or cross-reactive idiotype(s) was present in the majority of individuals of each of these strains.     

Xid and normal mice express a light chain-associated cross-reactive idiotype in response to (T,G)-A--L and (T,G)-A--L-mBSA

Rabbit anti-idiotypic (Id) antibodies were prepared against purified ascites anti-(T,G)-A--L antibodies (TGB5) that had been absorbed to remove A--L-specific antibodies and were specific for (T,G)-side chain determinants. Purified rabbit anti-TGB5 Id antibodies detected an allotype-independent, light chain-associated cross-reactive Id expressed by the majority of individual mice immunized with (T,G)-A--L, (T,G)-A--L coupled to methylated bovine serum albumin (mBSA), or the linear terpolymer GAT. Primary and secondary monoclonal hybridoma protein (HP) antibodies from X/Xxid heterozygous (wild-type) mice immunized with (T,G)-A--L and/or (T,G)-A--L-mBSA were analyzed for isotypy and were grouped into eight antibody fine specificity sets defined by the patterns of direct binding to the antigens (T,G)-A--L, (Phe,G)-A--L, (T,G)-Pro--L, GT, and A--L. Analysis of these primary and secondary HP for TGB5 idiotypy showed a preferential expression of the TGB5 Id among GT+-binding HP (antibody fine specificity sets 1 through 3). All of the primary GT+-binding HP and the majority of secondary GT+-binding HP (sets 1 through 3) were TGB5 Id+. Most but not all of the TGB5 Id+ HP bound GAT. Of the side-chain-specific HP (sets 1 through 7), 78% of primary HP vs 49% of secondary HP bound GT. By these criteria, the primary HP response appears more restricted than the secondary HP response, consistent with the idea that Id diversification and antibody heterogeneity are regulated and selected events occurring during memory B cell generation. Although xid mice produce less antibody than wild-type mice to (T,G)-A--L, the TGB5 Id was produced early in the primary response by both xid and wild-type mice immunized with (T,G)-A--L or (T,G)-A--L-mBSA, and was maintained as a detectable Id in equivalent amounts in their secondary serum antibody responses. These results support the idea that distinct B cell subsets, including the xid B cell subset, share the same immunoglobulin gene repertoire.     

Idiotypic analysis of hybridoma antibodies to branched synthetic polymer (Tyr, Glu)-Ala-Lys: idiotypic relationship with antibodies to linear random polymer (Glu60, Ala30, Tyr10)

The expression of three anti-GAT idiotypes, CGAT, Gte, and GA-1, on 17 C57BL/10 and four C3H.SW hybridoma anti-(T,G)-A--L antibodies was analyzed. These hybridoma anti-(T,G)-A--L antibodies exhibited two patterns of fine antigen binding specificity. The majority of the hybridoma antibodies bound the (T,G)-A--L, GT, and GAT polymers but not the GA polymer, and were designated as GT-reactive hybridoma antibodies. A minor population of hybridoma anti(T,G)-A--L antibodies bound to (T,G)-A--L but not to GT, GAT, or GA, i.e., (T,G)-A--L-specific. A complete correlation between fine antigen binding pattern and the expression of CGAT idiotype was demonstrated. None of the 21 hybridoma anti-(T,G)-A--L antibodies expressed the GA-1 idiotype. All of the GT-reactive and none of the GT-nonreactive hybridoma anti-(%,G)-A--L antibodies expressed the CGAT idiotype. Furthermore, the Gte idiotype was found on the majority of CGAT+-bearing C57BL/10 hybridoma anti-(T,G)-A--L antibodies. These results indicate that C57BL/10 anti-(T,G)-A--L antibody repertoire can be grouped into a minimum of three families; i.e., CGAT+ Gte+, CGAT+ Gte-, and CGAT- Gte- families, with the CGAT+ Gte+ family as the major compartment. This is confirmed by the high percentage idiotype binding of serum anti-(T,G)-A--L antibodies with anti-CGAT idiotypic antisera. Finally, anti-idiotypic antisera made against CGAT+ hybridoma anti-GAT or anti-(T,G)-A--L antibodies crossreact extensively with other CGAT+ hybridoma anti-GAT and anti-(T,G)-A--L antibodies. However, additional experiments demonstrated that CGAT+ hybridoma anti-(T,G)-A--L antibodies also possess private idiotypes.     

Trypanosoma cruzi specific antibody response in immunized C3H(He) mice during infection

C3H(He) mice previously immunized with live culture derived Corpus Christi strain T. cruzi are significantly protected (up to 100% survival) against challenge by Brazil strain blood trypanosomes. The antibody response, directed against the Brazil strain or the Corpus Christi strain, in these mice has been observed by comparing sera from mice immunized only, infected only, or immunized and infected. The anti- T. cruzi titers determined by both direct agglutination (DA) and indirect fluorescence (IFA) were routinely found to be highest for immunized and infected mice with immunized mice and infected mice following in decreasing order. The use of mercaptoethanol treatment of sera (DA) and isotope specific second antibody (IFA) showed that IgG is the major parasite specific immunoglobulin response through infection. Evidence of cross-reacting antigens on the two parasite strains was found. By both DA and IFA, 11 of 18 anti-Brazil strain monoclonal antibodies were found to react (IFA titers of 320 or greater) with both parasite strains. No evidence of localization of cross-reacting antigens (using mouse antisera) or antigenic determinants (using monoclonal antibodies) was found in that uniform fluorescence over the parasite was observed in all IFA tests.     

Specificity of H-2-linked Ir gene control in mice: demonstration of T helper cells recognizing branched synthetic polypeptides in low responder mice

This report provides evidence for the presence of T helper cells capable of recognizing the polypeptide antigens T6-A--L and (H,G)-A--L in low responder mice of H-2k and H-2b haplotypes, respectively. Mice were primed in vivo with the T6-A--L-avidin-(H,G)-A--L complex or, in the case of T6-A--L in H-2k mice, with the cross-reactive and permissive antigen T6-S--L. T helper cells cooperating with DNP-primed B cells could be rechallenged in vitro with the DNP-conjugates of T6--A--L or (H,G)-A--L, although the cells were of low responder type with respect to these antigens. This implies that T cell-macrophage interaction required for restimulation is apparently not defective in these low responders. The implications of these results for the concept of Ir gene control are discussed.     

Cross-reactive idiotypic determinants on antibodies and antigen-specific helper T cell continuous lines

Anti-idiotypic antibodies produced in C57BL/6 mice (H-2b, Igh-1b) against (T,G)-A--L-specific antibodies of C3H.SW mice (H-2b, Igh-1j) were used to probe (T,G)-A--L-specific helper T cell lines and clones for the expression of idiotypic determinants on the cell surface of the monoclonal functional T cells. By using the fluorescence-activated cell sorter (FACS II), anti-idiotypic sera of individual mice that specifically bind C3H.SW anti-(T,G)-A--L antibodies were shown to stain significantly cells of the E-9M(+) continuous T helper line originated from C3H.SW (T,G)-A--L "educated" T cells. The same antisera did not react with a helper T cell line of C3H.SW origin specific to human gamma-globulin. They also did not stain a (T,G)-A--L-specific helper T cell line derived from CWB (H-2b, Igh-1b) mice, which differ from C3H.SW mice only in their heavy chain allotypes. Thus, the expression of the idiotypic determinants on the T cell lines appears to be antigen-specific and linked to the heavy chain allotypic marker as shown for the specific antibodies. Different clones derived from the E-9 M(+) line were tested their reactivity with the individual anti-idiotypic sera. All clones but one (1.11) were stained significantly. The clones were tested for their biologic activity and all of them except clone 1.11 were found to exert helper activity specific to (T,G)-A--L. Thus, individual anti-idiotypic sera against C3H.SW anti-(T,G)-A--L antibodies recognize cross-reactive idiotypic structures on the surface of antigen-specific monoclonal helper T cells.     

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. Anti-(T,G),Pro--L antibodies do not cross-react with (T,G)-A--L, but do so extensively with Pro--L. Anti-(Phe,G)-Pro--L antibodies show cross-reactivity to (Phe,G)-A--L only when the antibody-producing strain is a high responder to (Phe,G)-A--L. These results when considered in view of data obtained in mice on genetic control of the immune response to (T,G)-Pro--L suggest that at least two unlinked Ir genes are involved in controlling anti-Pro--L responsiveness.     

Anti-idiotype stimulation of antigen-specific antigen-independent antibody responses in vitro. II. Triggering of B lymphocytes by idiotype plus anti-idiotype in the absence of T lymphocytes

Antibodies specific for the idiotypes of B10 anti-(T,G)-A--L antibodies (anti-id) induced B lymphocytes to secrete anti-(T,G)-A--L antibodies in vitro in the absence of both antigen and T lymphocytes, provided either that the B lymphocytes were previously primed in vivo with (T,G)-A--L or that id specific for (T,G)-A--L was added to the cultures. These antigen- and T lymphocyte-independent responses were antigen specific and appeared not to require accessory cells. The results suggested that B lymphocyte activation occurred via the formation of id-anti-id complexes, and evidence was obtained that this activation involved two separate interactions between the B lymphocytes and the id-anti-id complexes. These studies document a previously undescribed regulatory function of anti-idiotype antibodies.     

Antigen-Specific T-cell factors in the immune response to poly(Tyr,Glu)-poly(Pro)-poly(Lys)

The production by T cells of an antigen-specific factor capable of replacing the T-cell function in specific antibody formation was used as a tool for studying the cellular aspects of the genetic control of immune responses. The ability of different T-cell populations to produce a cooperative signal and the ability of B-cell populations to react to this signal were studied in different mouse strains. The antigen used was the synthetic polypeptide poly(LTyr,LGlu)-poly-(LPro) —poly(lXys), (T,G)-Pro -L, the response to which was found not to beH-2-linked. It was found that the SWR strain of mice, a low responder to (T,G)-Pro -L, is not capable of producing a T-cell factor specific to this antigen, but its B cells react normally to an active factor produced in a high responder strain. In the DBA/1 strain, also a low responder to (T,G)-Pro -L, the bone marrow cells are not able to cooperate with an active T-cell factor to produce anti-(T,G)-Pro —L-specific antibodies, while their T cells do produce a (T,G)-Pro -L-specific factor. The SWR (low responder) B cells can be triggered by DBA/1 (low responder) T cells factor specific to (T,G)-Pro —L to produce an antibody response to this immunogen. These results suggest that the immune response to (T,G)-Pro -L is controlled by two genes which are expressed in different lymphocyte populations.     

Antigen-specific T-cell factor in cell cooperation and genetic control of the immune response.

Cell interactions between thymus-derived (T) and bone marrow-derived (B) lymphocytes in the antibody response appear to involve soluble T-cell mediators known as 'factors.' This paper describes the properties of a T-cell factor that has specificity for the inducing antigen, a synthetic polypeptide (T, G)-A--L, and is able to replace T cells in the thymus-dependent antibody response to (T, G)-A--L. Besides antigen specificity, the main features of the molecule are that it is nonimmunoglobulin; it has a molecular weight of about 50,000; and it is a product of the I-A subregion of the H-2 complex (the mouse major histocompatibility complex). These properties suggest that the factor is closely related to the T-cell receptor, which may, by inference, also be a product of the H-2 complex. The factor cooperates well with allogeneic B cells. It can also be absorbed by bone marrow cells and B cells. Studies on the genetic control of the immune response to (T, G)-A--L using the T-cell factor indicate that two immune response genes in the H-2 complex are involved in genetic control, one expressed in T cells and the other in B cells. This two gene hypothesis has been confirmed by showing that an F1 between two low responders to (T, G)-A--L can be a high responder.     

In vitro T-lymphocyte proliferative response to mouse thyroglobulin in experimental autoimmune thyroiditis

The in vitro lymphocyte proliferative response to mouse thyroglobulin (MTg) was studied in good and poor responder mice in relationship to in vivo antibody formation and thyroid infiltration. CBA(H-2^k) and BALB/c(H-2^d) mice were immunized in the hind footpads with MTg incorporated into complete Freund's adjuvant (CFA). At weekly intervals up to 28 days, groups of mice were sacrificed. Their popliteal lymph nodes were cultured in vitro for proliferative response to MTg and their antibody levels and thyroid involvement determined. In good responder CBA mice, the proliferative responses to MTg were strongest on Days 8 to 14, where they were 9- to 14-fold over control levels, depending on the day of harvest. The response declined to 2- to 4-fold over background on Days 21 to 28, although high antibody levels were present throughout this period. The proliferative response was abrogated by anti-Thy-1 treatment, indicating its dependence on T cells. In poor responder BALB/c mice, no significant proliferative responses to MTg were observed at any time, although the animals displayed moderate levels of MTg antibody. The responses to PPD, in contrast, were similar in both strains, usually being 4- to 7-fold above background. Thyroid infiltration, like the proliferative response to MTg, was observed only in CBA mice. Thus lymphocyte proliferation at 8 to 14 days represents a reliable, early in vitro correlate of autoimmune thyroiditis induced with CFA as adjuvant.     

RNA conversion of lymphoid cells to synthesize allogeneic immunoglobulins in vivo

Ribonucleic acid extracts (“5 day immune” and “nonimmune”-RNA) obtained from lymph nodes and spleens of rabbits homozygous for the b⁴ or b⁵ allele of light chain immunoglobulin allotypes were injected iv into nonimmunized rabbits homozygous for the alternate allele. The recipient rabbits were then given multiple iv injections of sheep red blood cells (SRBC). The spleens were assayed 13, 21, and 37 days following the RNA injection for “direct” IgM and “indirect” IgG plaque forming cells (PFC) specific for SRBC. The b4 or b5 light chain allotype and the a1, a2, and a3 heavy chain allotype of the antibody in the plaques was identified by radioautography and by inhibition of plaque formation using anti-allotype antibodies. The b light chain allotype of the RNA donor was identified in 22–32% of the IgM plaques and in 25–42% of the IgG plaques. The allotype of the host rabbit b light chain allotype was identified in 56–67% of the IgM plaques and in 57–71% of the IgG plaques. Likewise the a heavy chain allotype of the RNA donor was identified in 10–19% of the IgM plaques and in 12–19% of the IgG plaques. The allotype of the host rabbit a heavy chain allotype was identified in 51–60% of the IgM plaques and in 55–63% of the IgG plaques. The concentrated lysates of spleen and lymph node cells were also analyzed for immunoglobulins of each light chain allotype by immunodiffusion with radiolabeled antibody. The allotype of both the RNA donor rabbit and host rabbit were found in most of the lysates of lymphoid tissues and in some of the IgG isolated from the serum and concentrated.     

From cell biology to immunology--a short trip

Immunologic memory and immunoglobulin allotype suppression are discussed as problems in Cell Biology. Memory, the ability of an animal after a first antigenic exposure to give a heightened and faster immune response upon a second exposure to the same antigen, is shown to be a property of bone marrow-derived cell lines. Expression of this memory depends on interaction with thymus-derived cells from either non-immunized or immunized mice. Chronic allotype suppression is described for the first time. It is initiated by in utero or neonatal exposure of (SJL × BALB/c)F₁ mice, allotype a/b, to anti b antibody. Suppression lasts for long periods and continues in irradiated recipients which have received lymphoid cells from suppressed donors. Selection against b allotype producing cell precursors can explain suppression.     

Plasmodium berghei and Eperythrozoon coccoides: Antibody and immunoglobulin synthesis in germfree and and conventional mice simultaneously infected

The immune response to Eperythrozoon coccoides and the malaria parasite Plasmodium berghei was evaluated in germfree (GF) and conventionally reared (CV) mice infected with both parasites. Following infection, the mice showed significant changes in the levels of the immunoglobulins IgM, 7Sγin1, 7Sγ2a, and 7Sγ2b, but no detectable changes in IgA. Increases in immunoglobulin levels were first observed in GF mice, but by the twelth day both GF and CV mice had comparable levels. 7Sγ2a globulin had a bimodal distribution in both groups of mice which probably was due to heterogeneity in the allotype of this immunoglobulin. IgM levels closely paralleled the antibody responses to P. berghei suggesting that most of the antibody to this parasite was IgM. Relatively low levels of antibody to both parasites, in comparison to the large immunoglobulin response, were detected in GF and CV mice. The possible causes for the low titers are discussed.     

Heligmosomoides polygrus (equals nematospiroides dubius): humoral and intestinal immunologic responses to infection in mice

Measurements of serum IgG₁, IgG_2a, IgM, and IgA levels and antibody titers in these immunoglobulin classes were made at intervals after initial infection and challenge infection of mice immunized by two or three previous infections. Identical measurements were made on the content of the small intestine in mice which had been exposed to the same infection schedule. Sections of small intestine taken after initial infection and challenge infection were examined by the fluorescent antibody technique for changes in populations of immunoglobulin-containing cells and by routine histologic procedures for histopathologic changes.In serum, only IgG₁ was consistently increased after initial infection, and antibody in IgG₁ was detected within the first 2 wk of infection. In immunized animals, only IgG₁ and antibody of this class always responded to challenge infection, although antibody in other immunoglobulin classes was detected.IgA concentration of the intestinal content did not differ significantly after initial infection or challenge infection of immunized mice. Immunized mice had about twice the IgG₁ concentration in intestinal content as singly infected animals. No intestinal antibody was detected after initial infection; only IgG₁ antibody was detected in the intestinal content of immunized and challenged mice.Cell infiltrates in the intestinal mucosa and submucosa of immunized animals contained numerous IgG₁-containing cells. Mast cells and globular leukocytes were observed in the intestine of immunized animals.     

Alteration in lymphocyte recognition repertoire during aging: II. Changes in the expressed T-cell receptor repertoire in aged mice and the persistence of that change after transplantation to a new differentiative environment

Changes in the T-lymphocyte alloreceptor repertoire associated with aging by exploring the frequency of cytotoxic T-lymphocyte precursors (CTLp) available for activation by various major histocompatibility complex (MHC) haplotypes in mice of different ages have been investigated. There was no consistent pattern of change in CTLp frequencies. Thus, for instance, while the frequency of responder C57Bl/6 CTLp for ATH alloantigen decreased with age, the frequency for C3H alloantigen increased. There was no significant change in the overall frequency of splenic CTLp (assessed irrespective of antigen specificity). No evidence was found that CTL produced by activated CTLp of aged mice were less specific in their lytic capacity that CTL produced by CTLp of young mice. However, by assaying responder CTLp cultures at limiting dilution we obtained evidence that the “burst size” (mean lytic capacity per responder well assayed at limiting dilution) was diminished with age of the donor of the CTLp pool. Furthermore, we obtained evidence that the apparent affinity of CTL for their target antigen was consistently decreased when those effector cells were derived from a pool of CTLp of aged mice. All of these changes reflected in mature T cells derived from aged mice were already apparent in the bone marrow stem cell pool of aged individuals and were not due to environmental influences alone, as assessed by the phenotype of T cells derived from young or old bone marrow stem cells transplanted to young or aged recipient mice. A final study has examined evidence for more subtle changes in the T-cell alloreceptor repertoire, reflecting heterogeneity in young or aged mice in the recognition repertoire associated with a given antigenic specificity. By preparing F₁ anti (parent anti-F₁)-suppressor cells directed against CTL from young parental mice (a, b, c), or aged parental mice (x, y, z), we have explored the heterogeneity in the anti-C3H alloreceptor repertoire in individual young or aged C57Bl/6 mice. Suppression by immunized F₁ animals was assessed in tissue culture (inhibition of mixed lymphocyte culture (MLC) responses) or in vivo (inhibition of lethal GvHD induced by inoculation of parental lymphocytes into sublethally irradiated F₁ hybrid mice). Irrespective of the assay system used, the data suggests that the receptor repertoire of aged T lymphocytes uses recognition structures different from those of young individuals, and that there is less individual-to-individual variation in the receptor repertoire of aged mice than in young mice.     

Clonal analysis of the primary and secondary B cell responses of neonatal, adult, and xid mice to (T,G)-A--L

The splenic focus assay was used to clone B cells from neonatal, adult and xid mice in order to examine their primary and secondary responses to (T,G)-A--L. Adult precursor cell frequencies to (T,G)-A--L were achieved late in neonatal ontogeny. Primary xid B cells responded to DNP-HY but not to (T,G)-A--L in the splenic focus assay. The frequency of secondary B cells from (T,G)-A--L-primed xid mice was less than or equal to 10% that of secondary B cells from wild-type (non-xid or X/Xxid heterozygous) mice. Although xid B cells were poorly responsive to (T,G)-A--L in the splenic focus assay, (T,G)-A--L-primed xid mice could provide help as recipients for stimulation of wild-type primary and secondary B cells. It seems likely that the B2 subset contributes most of the splenic focus response to (T,G)-A--L. The fine specificities of antibodies produced by neonatal, xid, and adult (wild-type) B cell clones were analyzed using analogues of (T,G)-A--L. A specificity shift was observed between the adult primary and secondary antibody responses to (T,G)-A--L. Less than 10% of adult primary clones produced antibodies cross-reactive on (Phe,G)-A--L (recognizing A--L determinants or Phe,Glu determinants), whereas more than 70% of primary clones produced Tyr,Glu side-chain specific antibodies cross-reactive on GT. The percentage of clones producing GT-binding antibodies diminished in the secondary response, while the percentage of clones producing antibodies cross-reacting on (Phe,G)-A--L increased. Neonatal clones also produced mostly GT-binding antibodies but gave a higher percentage of (Phe,G)-A--L-cross-reacting antibodies than adult primary clones. The specificities of secondary antibodies produced by xid and wild-type B cell clones were dissimilar. First, xid secondary clones were "primary-like" in that no anti-A--L antibodies were detected. Second, clones whose antibodies bound side-chain determinants but not GT were produced in higher frequency by xid than by wild-type secondary B cells. The differential responsiveness of B cell subsets to antigen and regulatory signals may influence memory B cell generation and the specificity of antibodies produced in the primary vs secondary response.     

Control of the immune reaction: T cells in immunized mice which depress the in vivo DNA synthesis response in the lymph nodes to skin painting with the contact sensitizing agent picryl chloride.

This paper describes the properties of a suppressor population in immune mice which specifically depresses DNA synthesis in vivo in normal mice. Mice were immunized by painting the skin with the contact sensitizing agent picryl chloride—an agent which causes contact sensitivity and antibody production. Five days later the regional lymph nodes or spleens were taken and injected into normal recipients which were then immunized by painting the skin with the same agent. The injection of the immune cells depressed the DNA synthesis response to picryl chloride in the regional lymph nodes when assessed 4 days later by the incorporation of radioactive iododeoxyuridine. The cells in the transferred population responsible for this depression were T cells as shown by the effect of anti-θ serum, their failure to adhere to nylon wool and antiimmunoglobulin columns and their appearance in the fraction of cells lacking receptors for C3(EAC^? cells) on resetting with sheep cells coated with antibody and complement. The cells were large and their activity was destroyed by 2500 R in vitro. Their production was prevented by treatment with cyclophosphamide before exposure to antigen but was unaffected by adult thymectomy. In these two aspects they differed from the T cells which suppress contact sensitivity which occur in mice injected with picryl sulphonic acid—an agent which causes unresponsiveness.     

Genetic and other effects on antibody and cell mediated immune response in swine leucocyte antigen (SLA)-defined miniature pigs

Miniature pigs of eight swine leucocyte antigens (SLA) haplotypes were immunized with sheep erythrocytes (SRBC), hen egg white lysozyme (HEWL) and the synthetic peptide (T, G)-A--L to induce antibody. Bacillus Calmette Geurin (BCG) and dinitrochlorobenzene (DNCB) were used to induce cell mediated immune response (CMI). Analysis of variance by least squares was used to assess the effects of SLA haplotype, sire, dam, litter and sex of pig on the magnitude of the primary and secondary antibody response and on dermal delayed type hypersensitivity induced by purified protein derivative of tuberculin (PPD) and DNCB-induced contact hypersensitivity. The statistical model accounted for 43.50-77.30% of the observed variability in antibody and CMI at various times after immunization or challenge. While SLA had a significant effect on both antibody and CMI to some antigens at some, but not all times, sire, dam and litter were more frequently significant and to a greater degree. Haplotypes dd, dg and gg produced more antibody to SRBC and (T, G)-A--L while dg and gg had higher primary, but not secondary antibody response to HEWL. Delayed hypersensitivity to PPD was most marked in pigs of dd, dg and gg haplotypes while contact hypersensitivity to DNCB was expressed least in the dg and gg haplotype pigs. Heritability estimates were high for response to (T, G)-A--L and HEWL indicating feasibility of selective breeding for these traits.     

Is genetically related macrophage factor (GRF) a soluble immune response (Ir) gene product?

The possibility that the antigen-presenting "macrophages" interacting with helper cells either directly or via the intermediary action of a soluble factor consisting of Ia antigen and a fragment of immunogen, termed GRG (genetically related factor), are a site of Ir gene action was investigated by using the synthetic polypeptide antigen (T,G)-A--L. It was found that T cells from (responder x nonresponder) F1 mice were stimulated by responder "macrophages" or GRF derived from these cells but not by the nonresponder macrophages of GRF from these cells. This suggests that the defect in helper cell induction in nonresponders is at the level of the presenting cell and that the macrophage factor GRF is a soluble Ir gene product. This conclusion was supported by the observation that there was normal presenting cell and GRF function in nonresponders, mouse strains such as CBA that yield helper cells and helper factor with (T,G)-A--L and have defects elsehwere.