Studies on the immune response to a characterized antigenic determinant of the tobacco mosaic virus protein

The compartmentalization of antigen-reactive lymphocytes in desensitized guinea pigs

A single injection of ε,DNP-Lys_7–10 can render previously sensitized guinea pigs specifically unreactive to subsequent intradermal challenge with that antigen. Antigen-reactive lymphocytes, as assayed by macrophage-migration in-inhibition or thymidine incorporation, were depleted from the peritoneal exudates of those animals. In contrast, it was intriguing to find that lymph node lymphocytes from such animals responded normally in the antigen-induced thymidine incorporation assay. These studies demonstrate a compartmentalization of antigen-reactive lymphocytes in desensitized animals which may account for the short-lived nature of this phenomenon.

Cell-mediated immune responses to chlamydial antigens in guinea pigs injected with inactivated chlamydiae

Cell-mediated immunity (CMI) to chlamydial antigens was readily induced in guinea pigs by a single injection of Betaprone-inactivated chlamydiae in complete Freund adjuvant. The CMI was measured in vivo by delayed hypersensitivity skin tests, and in vitro by inhibition of migration of peritoneal exudate cells and by proliferation of lymph node lymphocytes. There was an overall correlation between in vivo and in vitro responses. Of the in vitro assays, migration inhibition reflected the state of sensitization, as judged by skin tests, more uniformly than lymphocyte stimulation. Extensive inter- and intra-species cross-reactivity was noted between LB-1, a strain of C. trachomatis, and three strains of C. psittaci, 6BC, GPIC, and 562F. Cross-reactivity between LB-1 and 6BC was one-way only, by all three parameters: LB-1 elicited strong cross-reactions in 6BC-immunized animals but not vice versa. Antichlamydial antibodies could not be demonstrated in any of the animals by microimmunofluorescence.

Immunobiology and species distribution of Mycobacterium tuberculosis antigen 5

The immunobiology and mycobacterial species distribution of immunoabsorbent affinity chromatography-purified Mycobacterium tuberculosis antigen 5 have been studied. In delayed hypersensitivity skin tests, antigen 5 was nearly equipotent with tuberculin-purified protein derivative in sensitized guinea pigs. In vitro, antigen 5 was capable of stimulating the production of migration inhibitory factor by cultured lymphocytes from sensitized guinea pigs and humans. Antigen 5 stimulated thymidine incorporation by cultured guinea pig lymphocytes but did not stimulate thymidine incorporation by cultured human lymphocytes. Although erythrocytes were readily sensitized with antigen 5 for passive hemagglutination, their use did not offer any advantage over previous hemagglutination techniques for the serodiagnosis or evaluation of patients with tuberculosis. By immunoelectrophoresis and immunodiffusion, antigen 5 was readily identified in culture filtrates of 10 strains of M. tuberculosis and M. bovis but not in those of 30 strains of 12 other myobacterial species.

Characterization of immunologically active peptides from the cell wall of T. mentagrophytes

A low molecular weight fraction from chitinase digested cell walls of T. mentagrophytes containing both polysaccharide and peptide moieties was found to have immunological reactivity at both the cellular and humoral level. This fraction (UM2(a)) was further degraded by treatment with either a combination of pronase and carboxypeptidase A or with trypsin. Peptides were separated from the carbohydrate-rich fraction by ultrafiltration. The carbohydrate-rich fraction retained the ability to induce both immediate and delayed skin reactions in sensitized guinea pigs and to stimulate the proliferation of sensitized lymphocytes in vitro. The peptide moieties retained reactivity in that they caused delayed reactions and lymphocyte proliferation but were unable to induce immediate or Arthus reactions in sensitized animals. Tryptic peptides from UM2(a) were purified by ion exchange chromatography. A high proportion of these peptides demonstrated immunological activity at both the cellular and humoral level since they were capable of inducing delayed reactions and/or lymphocyte transformation, as well as being capable of blocking the complement fixation reaction between UM2(a) and specific antiserum.

Mycobacterial antigens: a review of their isolation, chemistry, and immunological properties

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Immunochemical studies on the tobacco mosaic virus protein

The decapeptide having the amino acid sequence Thr-Thr-Ala-Glu-Thr-Leu-Asp-Ala-Thr-Arg has been shown to be a major antigenic determinant of the tobacco mosaic virus protein in rabbits, mice and guinea pigs. The antigenic specificity of the decapeptide is attributed to its C-terminal tripeptide Ala-Thr-Arg. Although this tripeptide has no demonstrable binding with antibodies to the protein, its N-octanoylated derivative exhibits specific binding with antibodies as well as the capacity to elicit delayed skin reactions in guinea pigs immunized with the protein. The latter results suggest that both B cells and T cells have antigen receptors of identical specificities. Although all mouse strains tested responded equally to TMVP, with the production of anti-protein, the response to the decapeptide was shown to be correlated (albeit not absolutely) with Ig allotype Iga exhibiting generally high responsiveness while Igb exhibiting generally low responsiveness. The low responsiveness could not be attributed to suppression of the secondary immune response.

Studies of cellular sensitization to myelin antigens in multiple sclerosis. Dissociation of MIF and LBT production in response to a peptide encephalitogenic in rhesus monkeys

The macrophage migration inhibitory factor (MIF) assay and the lymphoblastic transformation (LBT) technique were utilized simultaneously to measure immune responses to peptide Y, the 17 amino acid C-terminal fragment of basic myelin protein, in patients with multiple sclerosis (MS). Ten normals and 67 MS patients from the Montreal Neurological Hospital and affiliated institutions were examined. A prospective attempt was made to correlate the measured responses with phasic clinical activity of the disease. The LBT results indicate some degree of cellular sensitization to peptide Y which parallels the clinical course of the illness, and resembles earlier positive findings obtained with the whole basic myelin protein molecule. These findings, however, are in contrast to a negative MIF response to the Y peptide used in the present study and further contrast the positive MIF results obtained earlier using the whole protein. It is not evident from the results of the present study whether sensitization may be of any pathogenetic significance, but the findings show that differing portions of the basic myelin protein molecule may selectively stimulate specific lymphokine elaboration by sensitized lymphocytes.

Autoimmune disease antigens

The first step towards understanding the cellular interaction which results in autoimmune disease is to determine what triggers the recognition between a specific autoimmune antigen determinant and the cellular receptor. In this review, we have focused on the antigen inducing experimental allergic encephalitis (EAE) because the antigen has been characterized and a relatively large body of information on its biological activities has been accumulated. Clearly, a specific allergic encephalitis-producing determinant is present and is represented on a relatively small portion of the molecule. The determinant induces a wide variety of biological reactivities, some of which are classed as cellular mediated. An attempt is made to dissect activities such as blast transformation (BT), migration inhibitory factor (MIF), in vivo delayed type hypersensitivity reaction (DTH) and EAE and to relate them to the structural requirements which the determinants possess. The complexities which arise indicate that subpopulations of cells with different receptor activities may respond selectively and that recognition of the receptor is produced by an EAE determinant consisting of three amino acids in a specific linear sequence. Furthermore, under experimental circumstances the EAE activity can be dissociated from the other activities (BT, MIF, DTH), indicating that while these tests are used generally to follow various human autoimmune disease activities, they may represent the reaction of a broad spectrum of cells.

The immune response to oxidized ferredoxin. I. Specificity of the response to the amino terminal determinant

Several synthetic peptide analogues of the amino terminal antigenic determinant (ala-tyr-lysile-ala-asp-ser) of oxidized ferredoxin (O-Fd) were tested for their ability to inhibit the complement fixation reaction between O-Fd and homologous rabbit antiserum, and to inhibit the migration of spleen cells from guinea-pigs immunized to O-Fd or to a conjugate of the amino terminal heptapeptide (N7) and bovine serum albumin (N7-BSA). The results of the migration inhibition assay suggest that the tetrapeptide and longer peptides of the native sequence were all recognized and stimulated the production of migration inhibition factor. Peptides modified at the aspartic residue were partially active while the serine modified peptide was not. Modification at the amino end of the heptapeptide had no effect on migration inhibition. As specificity controls, it was shown that the N7-BSA conjugate inhibited migration in O-Fd immunized animals, while O-Fd inhibited migration in N7-BSA immunized animals. The hexa-, hepta-, aspartic-deleted and serine-modified peptides were able to inhibit the complement fixation reaction with O-Fd and specific rabbit antiserum. Inhibition found with the serine-modified peptide and the lack of inhibition with the amino-modified peptide or the di-, tri-, tetra- and pentapeptides indicates the determinant recognized by the rabbit antibodies is either larger or is located nearer the middle of the heptapeptide than the determinant which induced the production of MIF.

Hapten-specific responses to contact sensitizers. Use of fluorodinitrobenzene to elicit migration inhibition and macrophage agglutination factors from lymph node cells of contact-sensitive guinea-pigs

Hapten-specific sensitivity of guinea-pigs sensitized to dinitrophenyl (DNP) contactants and to DNP-protein conjugates was investigated by skin test and by antigen-induced elaboration of migration inhibition (MIF) and macrophage agglutination factors (MAF) From lymph node cells. The delayed contact reaction was highly specific for low doses of contactant and markedly less so for conjugates; lymph node cells elaborted both lymphokines in response to brief exposures to dinitrofluorobenzene (DNFB) or prolonged exposures to DNP conjugates. Elicitation of MAF by DNFB or DNP conjugate was inhibited in the presence of DNP glycine; the activity of MAF induced by DNP conjugate (but not that induced by DNFB) was inhibited in the presence of DNP-glycine as well. These results suggest that contact sensitivity to DNP conjugates reflect two different types of hapten-specific cellular sensitivity mediated by populations of cells with different antigen receptors and possibly, functionally different lymphokines.

Induction of T cell response to haptens coupled to mycobacteria

A new method for the induction of cellular immune response to commonly used haptens in the absence of detectable antibody response is described. Different haptens were convalently coupled to Mycobacteria and they were injected into guinea pigs in incomplete Freund's adjuvant. Humoral and cellular immune response to haptens were examined at weekly intervals for 5 weeks. Our results show that a significant anti-hapten cellular response was induced and subsequently elicited by both in vivo (skin test) and in vitro (Lymphocyte transformation and macrophage migration inhibition) assays.

Cell-mediated immunity in the rheumatoid diseases. I. Skin testing and mitogenic responses in sero-negative arthritides

Cellular immunity has been investigated in patients with various kinds of sero-negative arthritis. The incidence of cutaneous response to recall antigen streptokinase-streptodornase (SK-SD), and the ability to mount a primary cutaneous response to dinitrochlorobenzene (DNCB) have been examined in patients with ankylosing spondylitis and psoriatic arthritis. The results were not significantly different from normal. In vitro lymphocyte transformation in the presence of phytohaemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) has been measured using peripheral blood lymphocytes from patients with ankylosing spondylitis, psoriatic arthritis and Reiter's disease. In comparison with a control group, significantly reduced responses were found to a low dose of PHA in the ankylosing spondylitis and Reiter disease patients. Significant increase in response occurred to a high dose of PHA, in patients with psoriatic arthritis and Reiter's disease, and to PWM in Reiter's disease patients. The in vitro results in the ankylosing spondylitis, psoriatic arthritis and Reiter's disease patients suggest some abnormality in the T-cell population in sero-negative arthritis.

Multiple antigenic sites on an eicosapeptide. I. Precipitin studies in the goat

Purified peptide 105-124, an antigenic determinant from the carboxy terminus ribonuclease, was found to form an immune precipitate with antibody to that region prepared by affinity chromatography from goat hyperimmune antiserum to reduced carboxymethylated ribonuclease (CM-RNase). Cm-rnase also gave an immune precipitate with the antibody. Purified antibody to another region of similar size (40-61) did not form a precipitate with CM-RNase but did co-precipitate in the presence of antibody to peptide 105-124 and CM-RNase. The precipitin reaction between antibody to peptide 105-124 and CM-RNase was inhibited by two synthetic derivatives, peptides 118-124 and ala114-RNase 114-124. Stoichiometry of the precipitin reactions of antibody to 105-124 with CM-RNase or peptide 105-124 suggested an antigen valency of three or more. Consistent with this both peptides 105-124 and ala114-RNase 114-124 elicited immediate cutaneous reactions but 118-124 did not. These findings suggest that the eicosapeptide 105-124 is multivalent since at least three antibodies can react simultaneously with it.

Cellular immunity and circulating antibody to herpes simplex virus in subjects with recurrent herpex simplex lesions and controls as measured by the mixed leukocyte migration inhibition test and complement fixation

Cellular immune responses and circulating antibody levels to herpes simplex virus were examined in patients with recurrent herpes simplex (HSV) infections and controls. Mixed leukocyte migration inhibition by herpes simplex antigen was less in affected patients than in controls but serum antibody levels were higher. There was no significant difference in leukocyte migration between patients with active or recent lesions and other herpes subjects, and the response in the mixed leukocyte migration test to phytohaemagglutinin (PHA) was similar in patients and controls. The data presented suggest that a localized defect in cell mediated immunity to herpes simplex virus may exist and be responsible for recurrent herpes simplex infections.

Lymphocyte response to autologous tumor antigen(s) and phytohemagglutinin in ovarian cancer patients

Peripheral blood lymphocytes from 11 patients with ovarian carcinoma were incubated several times with autologous tumor extract as well as phytohemagglutinin (PHA) at different concentrations. Lymphocytes from 10 normal, healthy, age-matched females were also studied similarly. Tritiated thymidine incorporation into DNA of transformed lymphocytes was measured. No significant response was obtained with lymphocytes from ovarian cancer patients or normal individuals in the presence of tumor extracts. Of 6 tumor extracts tested, 5 did not have any cytotoxic effect on autologous or on homologous normal healthy lymphocytes. Hence, with this test system employed, no evidence for a cell-mediated immunity to autologous tumor in ovarian cancer patients was observed. PHA, on the other hand, induced vigorous blastogenic response in several ovarian cancer patient's lymphocytes, as well as in all normal healthy lymphocytes, indicating no inherent defect in the T-lymphocyte system of ovarian cancer patients. Only 2 of the patients, when tested for delayed hypersensitivity reaction against a battery of recall antigens and keyhole limpet hematocyanin, were completely anergic. None of the patients responded when skin tested with their own tumor extracts.

Alloantiserum-induced inhibition of migration inhibition factor production in immune response gene-controlled immune systems

We have previously demonstrated that alloantisera prepared by reciprocal immunization of strain 2 and strain 13 guinea pigs specifically block stimulation of in vitro DNA synthesis in genetically controlled systems. In order to determine whether this blockade extends to other T-lymphocyte functions, we examined the effect of alloantisera on the production of migration inhibition factor (MIF). (2 x 13)F(1) guinea pigs were immunized with a DNP derivative of the copolymer of L-glutamic acid and L-lysine (DNP-GL) and with DNP guinea pig albumin (GPA). The response to the former is controlled by a 2-linked Ir gene while that to the latter is mainly controlled by a 13-linked Ir gene. MIF production was assayed by an indirect procedure in which the migrating cell population lacked the histocompatibility antigen against which the alloantiserum was directed. Our results showed that anti-2 serum blocked MIF production by F(1) cells in response to DNP-GL but not DNP-GPA while anti-13 serum had the opposite effect. These experiments show that expression of a second major T-cell function is specifically blocked by alloantisera and suggest that Ir-gene products may act as antigen recognition substances on more than one type of T cell.

Demonstration of a blocking factor in the plasma and spinal fluid of patients with subacute sclerosing panencephalitis. I. Partial characterization

Conflicting reports on the immune responsiveness of patients with subacute sclerosing panencephalitis (SSPE) have been reported. This report shows that the leucocytes from four SSPE patients exhibited strong sensitivity to both measles and SSPE virus preparations as measured by the macrophage migration inhibition test, mixed lymphocyte virus infected cell culture test, and the lymphotoxin assay. Earlier suggestions that a factor may be operating to suppress cellular reactivity are confirmed by the demonstration that the response of lymphocytes from SSPE patients could be blocked by the addition of SSPE spinal fluid or plasma. It was determined that the blocking factor was stable at -20 degrees C, heat labile at 56 degrees C for 30 minutes, trypsin and neuraminadase sensitive, and had a mol wt greater than 150,000 as determined by Sephadex G-200 gel chromatography. The blocking factor appeared to be specific for SSPE virus and did not block the response of lymphocytes to nonspecific mitogenic agents and other viral and bacterial agents.

The Wiskott-Aldrich syndrome. Results of transfer factor therapy

12 patients with Wiskott-Aldrich syndrome were treated with therapeutic doses of transfer factor in an attempt to induce cellular immunity. Clinical improvement was noted after transfer factor therapy in 7 of the 12 patients treated. Because this disease has a variable course and temporary spontaneous improvement can occur, the observed improvement cannot necessarily be attributed to the transfer factor. However, in two patients repeated remissions consistently followed transfer factor administration on repeated occasions. This included freedom from infections, regression of splenomegaly, and clearing of eczema. An unexpected finding was a decrease in bleeding in 3 of the 10 patients who had bleeding. Conversion of skin reactivity was obtained in all seven patients who clinically seemed to respond to transfer factor. In vitro studies performed after the administration of transfer factor demonstrated that the lymphocytes of the patients now produced migration inhibitory factor in response to appropriate test antigens, but did not undergo increased radioactive thymidine incorporation in response to the same antigens. A defect in the monocyte IgG receptors has been found in certain patients with the disease, and the current study shows that all patients with defective monocyte IgG receptors responded to transfer factor, whereas only one patient with normal receptors showed any response. This test may thus prove to be useful in predicting the results of transfer factor therapy in patients with Wiskott-Aldrich syndrome, although evaluation of a larger series of patients will be necessary to confirm this point. We conclude that cellular immunity can be induced, that there appears to be clinical benefit in certain patients with Wiskott-Aldrich syndrome by the use of transfer factor, and that this mode of therapy warrents trial in these patients and others with defects of cellular immunity.

Experimental allergic encephalitis. Dissociation of cellular immunity to brain protein and disease production

The encephalitogenic determinant of brain protein, a nonapeptide having the amino acid sequence Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys, has been characterized and synthesized. In a previous study, analogues of this encephalitogenic peptide were synthesized and some were shown to be encephalitogenic while others were not. Guinea pigs were immunized with encephalitogenic peptides having amino acid sequences different from that in the native protein. These guinea pigs did not show cellular immunity in vivo (skin reactivity) or in vitro (lymphocyte stimulation or macrophage migration inhibition) to the encephalitogenic brain protein (EP) although they did show cellular immunity to the immunizing antigenic peptide. Guinea pigs immunized with an encephalitogenic peptide having the same amino acid sequence as the brain protein, or with a nonencephalitogenic peptide having the same amino acid sequence as the native protein but lacking the terminal lysine, did develop cellular immunity to the EP. Animals immunized with EP showed cellular immunity to this protein, but not to the encephalitogenic peptides. Animals immunized with nonencephalitogenic protein (NEP), prepared by altering the tryptophan residue of EP, did not develop disease but did show cellular immunity in vitro and in vivo to the EP. Animals protected from disease by immunization with NEP similarly showed cellular immunity to EP. Thus, the results suggest a dissociation between cellular immunity to EP and the production of experimental allergic encephalitis (EAE). Animals immunized with the encephalitogenic peptides develop EAE, but do not show cellular immunity to EP, and animals immunized with NEP show cellular immunity to EP but do not develop EAE. A fresh approach to the examination of the pathogenesis of EAE is now possible through the use of these well-characterized antigens.