Genetic determinants of immunological responsiveness

Genetic control of acquired resistance to visceral leishmaniasis in mice

A series of H-2 and non-H-2 congenic resistant (CR) strains on a C57BL/10Sn background were infected with 10(7) amastigotes of Leishmania donovani. Non-H-2 congenic strains B10.LP-H-3b and B10.CE(30NX) and (B10.LP-H-3b x B10)F1 hybrids showed a very rapid decrease in liver-parasite burdens beyond day 21. Parasite counts for these strains at day 35 were significantly lower than for all other strains tested. The rapid decrease in parasite numbers, massive lymphocellular infiltration into the liver and strong delayed hypersensitivity reactions to parasite antigens in strains congenic for a portion of chromosome 2 indicated that acquired immunity to L. donovani was controlled by a dominant gene at or near the Ir-2 locus. In addition, B10.129(10M) mice, which differ from C57BL/10Sn at the H-11 locus, showed highly significant increases in parasite numbers at day 35. Other observations supporting the absence of acquired immunity in B10.129(10M) included negative delayed hypersensitivity tests to parasite antigens and the absence of lymphocellular infiltrate into the liver. Although the differences were not as pronounced, H-2 CR strains with H-2b, H-2a, and H-2k haplotypes also showed significantly greater decreases in parasite numbers by day 35 as compared to other H-2 CR strains.

Selected immune responses of adult cotton rats (Sigmodon hispidus) to dietary restriction

1. We examined the influence of moderate to severe dietary restriction on immune system function in adult cotton rats. Animals (N = 80) were fed ad lib. (controls) or restricted [moderate = 80% ad lib. for 1 or 2 weeks; severe = 80% ad lib. for 1 or 2 weeks followed by 40% ad lib. for one (week 3) or two (week 4) additional weeks] amounts of food for 1-4 weeks. 2. Average body weight loss for severely restricted animals in week 4 was 17%; dietary treatments had no measurable effect on hematological parameters (hematocrit, white blood cell count), lymphoid organ weights (thymus gland, spleen, popliteal lymph nodes), and mononuclear cell yields from lymphoid organs. 3. Cell-mediated immune function was assessed in vitro by a lymphoproliferative response assay and in vivo by a delayed-type hypersensitivity response assay. 4. Proliferative responses of spleen cell cultures stimulated with concanavalin A (Con A, Canavalia ensiformis) and pokeweed (PWM, Phytolacca americana) were normal or significantly greater among moderately restricted than control cotton rats during week 1 and week 2. 5. Lymphoproliferative responses of severely restricted animals were normal or reduced during week 3 and week 4. 6. Delayed-type hypersensitivity responses to the contact antigen oxazolone were significantly depressed among severely restricted animals in week 4 compared to controls. 7. In comparison with laboratory rodent strains, our initial results indicate that immune system function in adult cotton rats is not as sensitive to short term (1-4 weeks) periods of dietary restriction. 8. Immune system function was related to changes in body weight as a result of feed restriction.

T-cell receptor and autoimmune disease

Since the genes encoding the TCR have been cloned, their structure, organization, pattern of rearrangement, diversification and expression in ontogeny have been classified. However, there are still many important questions to be addressed, such as the nature of thymic education, tolerance, the mechanism of MHC-restricted antigen recognition and the relation between TCR repertoire and autoimmunity. In the future, new approaches to study these issues, such as transgenic mice, X-ray crystallography, and severe combined immune deficiency mice reconstituted with human hematopoietic cells will lead to a more profound understanding of these questions. This will hopefully allow us to manipulate the immune response in different and more effective ways than are currently available.

Analysis of the serum antibody responses to type 1 and type 2 fimbriae in mice immunized with Actinomyces viscosus T14V

The antibody responses of inbred mice immunized with Actinomyces viscosus T14V cells were analyzed using enzyme-linked immunoabsorbent assays (ELISAs) for measuring serum antibodies reactive with A. viscosus T14V cells and type 1 and type 2 fimbriae. In A/J mice immunized intraperitoneally on days 0 and 14, the serum antibody responses approached peak levels during d 19-35, and a dose of 10(8) cells/injection elicited optimal responses. Analysis of the responses of three genetically diverse strains of inbred mice indicated striking variations in the amounts of anti-type 1 (6.5-fold) and anti-type 2 (14.3-fold) antibodies elicited. The observed variations in the magnitude of the anti-fimbrial antibody responses are theoretically of sufficient magnitude to account for significant differences between mouse strains in their ability to inhibit adherence of A. viscosus T14V to saliva-coated hydroxyapatite and other bacteria. These studies provide a model with which the effects of variations in anti-fimbrial antibody responses on bacterial adherence may be analyzed.

Seronegative virus carriers in the infection of rabbits with human T lymphotropic virus type I

Six HTLV-I-transformed T cell lines were prepared from PBL of three rabbits each of B/J and Chbb:HM strains, and were inoculated into newborn rabbits of these two strains, and of their F1 hybrid. None of three B/J cell lines induced anti-HTLV-I antibody response in newborn B/J rabbits, whereas all three Chbb:HM cell lines did induce a response in newborn Chbb:HM rabbits. These B/J cell lines however could induce antibody response in adult B/J as well as newborn Chbb:HM rabbits, and a Chbb:HM cell line could induce a response in a newborn B/J rabbit. Similar unresponsiveness was observed in (B/J x Chbb:HM)F1 hybrids neonatally inoculated with B/J cells. Unresponsiveness was abrogated by reinoculation of some but not other cell lines. Viral antigen-positive cell lines harboring HTLV-I provirus genomes were established from such seronegative B/J and F1 rabbits. Simultaneous inoculation of HTLV-I-transformed cells and SPV resulted in the induction of papilloma and antibody against SPV, but not antibody against HTLV-I. The present findings thus reveal that neonatal infection of HTLV-I could result in immunological tolerance to the virus antigens, thereby leading to a persistent infection without antibody induction.

Sex ratio and sibship size in juvenile rheumatoid arthritis kindreds

In a study of sibship size and sex ratio in juvenile rheumatoid arthritis, the anticipated sex ratios, including a marked female predominance in early onset pauciarticular disease and in polyarticular disease, were found. The size of the sibship showed a progressive increase with increasing age of the proband at onset of disease. In addition, the sex ratios of the sibs deviated from expected, among families where the proband's disease was characterized as either early onset pauciarticular or polyarticular in its presentation.

Genetics of resistance to African trypanosomes: role of the H-2 locus in determining resistance to infection with Trypanosoma rhodesiense

Susceptibility and resistance to Trypanosoma rhodesiense infections in inbred and H-2 congenic strains of mice were studied. Mean survival times and patterns of parasitemia were examined. C3HeB/FeJ mice were highly susceptible; CBA/J, A/J, and BALB/cByJ mice displayed an intermediate level of susceptibility; whereas C57BL/10 mice were highly resistant. H-2 congenic strains with the BL/10 background resembled the BL/10 parental type, thereby suggesting that the major histocompatibility complex does not play a major role in regulating resistance and susceptibility to infection with T. rhodesiense.

A one-receptor view of T-cell behaviour

The discovery of T cells and their behaviour has forced a re-evaluation of the immunological relationship between self and not-self. T cells seem to respond against foreign antigens only when the latter are in some form of association with self molecules encoded by the major histocompatibility complex. This has raised the question of whether T-cell recognition may depend on two separate receptors. I present here the case for a model of T-cell behaviour based on a single receptor.

Immunogenetic control of experimental type II collagen-induced arthritis. I. Susceptibility and resistance among inbred strains of rats

Seven inbred rat strains were tested for susceptibility to experimental type II collagen-induced arthritis and for development of cellular immunity to type II collagen by delayed hypersensitivity skin testing. WF (RT1u), LEW (RT1l), and DA (RT1a) were the most susceptible of the strains tested with respect to incidence (greater than 95%) and severity of disease. LEW and DA were strongly skin test reactive to calf type II collagen. BUF (RT1b) developed moderate skin test responses to calf type II collagen and showed low susceptibility to collagen arthritis (1/8). MAXX (RT1n), LEW.B3 (RT1nvl), and AUG (RT1c) were not susceptible to collagen arthritis and showed negative to very weak skin test responses to type II collagen. Disease susceptibility was inherited as a dominant trait in the F1 progeny of (WF X LEW.B3) matings. These data suggest that clinical expression of experimental collagen-induced arthritis and immune responsiveness to type II collagen are controlled in part by genes within or closely linked to the rat major histocompatibility complex--RT1.

Genes in mice that affect susceptibility to cortisone-induced cleft palate are closely linked to Ir genes on chromosomes 2 and 17

Inbred and congeneic strains of mice have been examined for susceptibility to cortisone-induced cleft palate, and the role of genes linked to H-2 on chromosome 17 has been confirmed. Increasing degrees of susceptibility were associated with the H-2d, H-2b, H-2k, and H-2a haplotypes, respectively, with H-2q and H-2s also being associated with fairly high levels of susceptibility. Evidence was obtained that suggests that one gene maps within the B region of H-2, and that a second H-2 linked gene which acts by complementation maps to the right of E. Another gene affecting this trait is closely linked to the H-3 and Ir-2 loci on the second chromosome.

An unusual symmetric recombinant between adenovirus type 12 DNA and human cell DNA

On purification of human adenovirus type 12 (Ad12) by equilibrium sedimentation in CsCl density gradients, two bands of particles, Ad12-3 and Ad12-3a, are observed. The particles from band Ad12-3a contain a recombinant of human host cell DNA and of Ad12 DNA. The human cell DNA sequences contain repetitive DNA recurring 200 to 500 times in cellular DNA. Ad12 DNA and the recombinant genomes exhibit the same or similar lengths. This finding suggests that a constant amount of DNA is packaged into complete Ad12 particles. On cleavage of KB cellular DNA with EcoRI, BamHI, HinfI, Msp I, Mbo I Pst I, or Bgl II, the (32)P-labeled cellular DNA from Ad12-3a particles hybridizes on Southern blots to distinct bands of KB DNA. There is also less-specific background hybridization that is not observed in the control. The cellular DNA from Ad12-3a particles is not methylated, whereas the same cellular sequences in KB cell DNA appear to be extensively methylated. On denaturation and renaturation, the recombinant DNA molecules are converted to molecules half as long as Ad12 DNA, as determined by gel electrophoresis and electron microscopy. The recombinant DNA molecules were terminally labeled by exonuclease III treatment and subsequent refilling of the depleted segments with [(32)P]dNTPs by using DNA polymerase I (Klenow fragment). When these molecules were cleaved with EcoRI, BamHI, Msp I, or Pst I, only one terminal DNA fragment was found to be labeled. The results of partial digestion experiments using Msp I, HinfI, or Mbo I are consistent with a model in which 700-1150 base pairs from the left terminus of Ad12 DNA are linked to host cell DNA containing repetitious sequences, and this structure is symmetrically duplicated as a large inverted repeat of the type ABCDD'C'B'A'. The Ad12 DNA sequences are flanking the entire molecule, which consists mainly of human KB cell DNA. The recombinants appear to be stable on serial passage of the virus preparation for many years, although variations in the sequence of the recombinants occur. These symmetric recombinant (SYREC) molecules suggest a way to use adenovirus DNA as a eukaryotic vector. Their occurrence provides further evidence for the generation of virus-host DNA recombinants and may help elucidate the role this interaction may have in adenovirus replication and oncogenesis.

The brain and subarachnoid space as possible sites for endocrine tissue transplantation

Immunological rejection has been the major problem limiting the successful transplantation of tissue from one animal to another. Recent technological developments, combined with the use of the central nervous system as an immunologically privileged site, suggest that it might be possible to achieve long-term survival of hormone-secreting tissues, between two gentically dissimilar animals, if these tissues are transplanted to the brain and subarachnoid space of the host. The physiological parameters that should be considered in the clinical application of a transplant of this type are discussed.

Immune response deficiency of BSVS mice. II. Generalized deficiency to thymus-dependent antigens

BSVS mice gave abnormally low IgG responses to 5 thymus-dependent antigens as well as a weak delayed-type hypersensitivity (DTH) response to sheep red blood cells. In contrast to IgG, the IgM antibody responses of these mice were normal to three T-independent antigens as well as to all five T-dependent antigens. The low immune responsiveness of BSVS mice was also reflected in the low levels of IgG(2)a, IgG(2)b and IgG(3) in their normal serum. The low T-dependent immune responses may result from BSVS mice having been selectively bred for susceptibility to infection with St. Louis encephalitis virus and Salmonella. C57BL/6J mice, which are also highly susceptible to Salmonella, gave low immune responses similar to, but genetically distinct from, those of BSVS mice. The levels of Ig-positive and theta-positive cells were normal in BSVS and C57BL/6J mice.

Genetic control of anti-DNP response to DNP-BSA given by continuous infusion technique

Ten inbred strains of mice were administrated with dinitrophenyl-bovine serum albumin (DNP-BSA) at a dose of 30 or 300 microgram/day by continuous infusion technique. Anti-DNP plaque-forming cells (PFC) in their spleens were assayed 10 to 12 days after the beginning of the infusion. NZB, BALB/c, C3H/He and NC strains were high responders to both doses of DNP-BSA. KK, SII and TES strains were low responders at both doses. SJL/J, C57B1/6 and DDD strains were intermediate responders: the antibody response was low to the dose of 30 microgram/day, and high to the dose of 300 microgram/day. Breeding tests between high responder BALB/c and intermediate responder DDD mice indicated that the immune response was largely controlled by a gene linked to the H-2 complex. Similar studies with high responder NZB and low responder TES mice suggested an involvement of a few genes: at least one of the controlling genes may be linked to the H-2 complex.

Autoimmunity, histocompatibility, and aging

The immunologic theory of aging proposes that the normal process of aging in man and all animals is pathogenetically related to faulty immunological processes and may be analogous to a type of autoimmune phenomena ultimately involving all body tissues. It may be said that the sharply increased incidence in elderly humans of the autoimmune and immunodeficiency "diseases of age" are thought to be greatly potentiated by the age-related decline in immune surveillance mechanisms particularly involving self/non-self discriminatory abilities. The major histocompatibility complex has emerged as a complex of "supergenes" coding for antigens whose ultimate biological function may be to serve as recognition units allowing lymphocytes to recognize self from non-self on an immunological basis. Also, recent data are consistent with our supposition that differences in age-specific peaks of various immune functional parameters in genetically homozygous mice may be influenced by genes linked to the major histocompatibility complex. These differences may account, at least in part, for the highly strain-dependent, age-specific incidence of certain diseases, including autoimmune and malignant diseases in the mouse. Heightened susceptibility to develop a particular disease in a susceptible animal occurs when a certain balance is reached between the interplay of immune functional parameters which mature, differentiate, or decline at different rates in the same animal. The age-specificity of this balance may be under partial control of H-2 or HLA-linked genes.

Strong and weak immune responses across the same major histocompatibility barrier in rats

Inbred rat strains, Fischer 344 (F-344) and Lewis (LEW), share the serologicalAg-Bl allele and react very weakly in mixed lymphocyte culture (MLC). Despite this apparent identity atAg-B, these strains differ markedly in their immune responses to anAg-B disparate third strain Marshall 520 (M-520) (Ag-B6). F-344 recipients allowed M-520 heart grafts an extended survival, whereas LEW recipients rejected them rapidly. F-344 and M-520 showed a weak response in MLC in contrast to a strong response for LEW and M-520. F-344 produced antisera in response to injection of M-520 cells that had a relatively high antibody titer but low cytotoxic activity. F-344 responded to another strain, Buffalo (BUF) (alsoAg-B6), in a similar fashion. F-344 apparently can produce a strong allogeneic response, as it was able to rapidly reject heart grafts from (LEW x Brown-Norway) F(1) donors (LBN) (Ag-B 1/3). The low response of F-344 to M-520 probably was not due to shared antigens between the two strains because M-520 heart grafts underwent rapid rejection in LEW hosts highly tolerant to F-344. To explain the contrasting response of F-344 and LEW to theAg-B6 disparity, we propose that it is controlled by an immune-response gene(s); that F-344 has a low-responding allele and LEW has a high-responding allele. The data do not reveal a location for this proposed gene. The high-responding allele appears to be dominant, as M-520 hearts were rejected rapidly by (F-344 x LEW) F(1) recipients.

Failure to find H-2-associated susceptibility to LCM disease

Nine strains of mice bearing five distinct H-2 genotypes were inoculated intracerebrally with LCMV. There was no association found between particular K or D allotypes and susceptibility to acute LCM disease.

In vitro immune responsiveness to vaccinia virus and HLA

Because several lines of evidence suggest that HLA products might have an important function in the immune response to infectious agents, we studied the possible relation between immune response to vaccinia virus and HLA phenotype in 79 soldiers who received a primary vaccination. A low in vitro response to vaccinia virus was associated with HLA-Cw3 both in 49 subjects tested three to four weeks after vaccination (P less than 0.001) and in the remaining 30 subjects tested five to 11 weeks after vaccination (P = 0.035). Responses to unrelated antigens and phytohemagglutinin of lymphocytes tested before, three to four weeks and five to 11 weeks after vaccination indicated that this association was specific for vaccinia virus and suggested that differences in immune response to vaccinia were reflected in temporarily altered immune responsiveness to unrelated antigens. Our results indicate that HLA-Cw3 or an HLA product associated with Cw3 is involved in the cellular immune response to vaccinia virus.

The kinetics of IgG and IgM antibody-forming cells in ACI and F344 rats immunized with poly(glu52lys33tyr15)

The cellular kinetics of antibody production in high and low responder rats immunized with poly(Glu52Lys33Tyr15) or with poly(Glu52Lys33Tyr15)/MeBSA were characterized: serum antibody and IgG and IgM antibody-forming cells in the spleen and in selected lymph nodes were assayed in male and female rats following immunization by several routes. Aggregation of the antigen with MeBSA enabled the poorly responding F344 rats to produce antibody, which was almost exclusively IgG. High responder ACI rats, under the same conditions, produced antibody of both IgG AND IgM classes. These data suggest that in low responders one defect, possibly at the T-cell level, can be overcome by aggregation but that a second defect, involving the regulation of IgM production, still exists.

Codominant inheritance in immunogenetic (IR-gene) systems

Immunogenetic (IR-gene) systems consist of animals showing different quantitative antibody responses when immunized with similar doses of a given antigen. Strains of animals giving high and low antibody titres are described as high and low responders, respectively. The degree of dominance in F1 hybrid strains, obtained from a cross between high and low responder parents, can readily be calculated using the dominance index formula, which takes the value of +1 for complete dominance, -1 for complete recessivity and the value of zero for no dominance. In reviewing 1527 F1 animals, obtained from ninety-one immunogenetic systems, the degree of diminance (d) was found to be: +0-0076 +/- 0-1053 (mean +/- s.e.), which is close to a value of zero and this is consistent with codominant inheritance. It is suggested that in immunogenetic systems, both alleles are expressed as codominant genes.

Experimental autoimmune encephalomyelitis in mice: genetic control of susceptibility

Experimental autoimmune encephalomyelitis (EAE) was induced in inbred and congenic strains of mice by injection of mouse spinal cord homogenate (MSCH) in Freund's complete adjuvant (FCA) with pertussis vaccine. Genetic analyses showed that susceptibility to EAE in mice was inherited as a dominant trait and was in part controlled by genes located in the centromeric half of the H-2 complex. Mice with EAE developed cell-mediated immune responsiveness to basic protein of myelin (BPM), as judged by the macrophage migration inhibition assay, using peritonealyexudate cells; this was not observed with mice of resistant strains. However, the migration of peritoneal exudate cells of both susceptible and resistant strains was significantly inhibited in the presence of purified protein derivative (PPD) of M. tuberculosis. Thus, the genes involved in the control of susceptibility to EAE also influence T cell responsiveness to BPM. Antibody to BPM, as judged by radioimmunoassay, was detected in susceptible and resistant strains but there was no correlation between the presence or levels of antibody and susceptibility or resistance to EAE. It is suggested that resistance to EAE is associated with failure of T cells to recognize and/or respond to the encephalitogenic determinant of the BPM molecule.

Controversies in current immunization policy and practices: one physician's viewpoint

Immunization offers the best available method preventing diseases which exact huge tolls in terms of comfort, life and economic stability of humans. However, immunization is a mixed blessing because of unavoidable risks to recipients of almost any biologic product. Only by careful attention to the balance of risks between an immunization procedure and its corresponding disease will we achieve a rational, sound and appropriate policy and practice. This report details the author's analysis and opinion concerning some current controversies in immunization policy and practice. The reader is cautioned that the report represents one viewpoint; others report differing or even contradictory interpretations of the data presented, leading to different or even opposing views. The purpose of this report will be ably served if the reader considers the data himself (herself) and reaches an independent, informed opinion.

The genetic control of the antibody response in inbred rats

The antibody response of genetically inbred rats to poly(Glu52Lys33Tyr15) is controlled by a complex polygenic system which includes at least two autosomal genes and a sex influence, which may also be genetically determined. The genetic control of the quantity, binding constants, and specificity of the antibody formed linked to the major histocompatibility locus. Factors other than the major genetic ones and the sex influence also affect the quantity of antibody formed, since animals of the same genotype can make significantly different amounts of antibody, depending upon the crosses by which they acquire the major histocompatibility alleles. After immunization with poly(Glu52Lys33Tyr15) the low responders make fewer antibody-producing cells, are not capable of mounting a delayed hypersensitivity reaction to the polypeptide and appear to be deficient in their ability to produce the specific IgM antibody. Immunization of the low responders with antigen aggregated with methylated bovine serum albumin enhances the quantity of antibody formed, increases the binding constants and crossreactivity of the antibody and enhances the delayed hypersensitivity response. In contrast to the findings with the L-amino acid polypeptide, there does not appear to be any genetic control over the antibody response to the D-amino acid enantiomorph poly(DGlu52DLys33DTyr15), which is minimal in all strains.

Genetic control of susceptibility to experimental allergic encephalomyelitis in rats

Rats of the inbred strains Lewis and DA are highly susceptible to the induction of experimental allergic encephalomyelitis (EAE) while Brown Norway rats are resistant to this disease. Evidence has been obtained which suggests that a single dominant gene is associated with susceptibility to EAE. The locus controlling EAE susceptibility is closely linked to the Ag-B histocompatibility locus but is not identical to it.