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W R Levis

Publications and source records attributed to W R Levis.

At least 55 records · Page 3Linked to original sources
PubMed1980

Specific and nonspecific immunoregulatory events in the clonal response of human lymphocytes in vitro.

Stimulation of sensitive leucocyte populations with near optimal concentrations of soluble microbial antigens results in vigorous lymphocyte proliferation when 3H-thymidine incorporation is measured after 4-8 days. Lymphoblasts in these cultures revert to small lymphocytes after 10-14 days, at which time they are often refractory to any stimulant including the original incubating antigen. When these primed lymphocytes are irradiated with 500-1000 R to block their proliferation and added to fresh leucocyte culture from the same individual (autologous), they usually, but not invariably, reduce the proliferation of the unirradiated fresh leucocyte cultures. Exposure to 6000 R reduced the suppressor activity. Reduction was specific for the microbial antigen with which they were originally generated, but, more often, a combination of both specific and nonspecific suppression was observed. These data provide good evidence, with reciprocal specificity, for the generation of antigen specific suppression in vitro.

Cells, Cultured↗
PubMed1979

Studies on the contact sensitization of man with simple chemicals: V. Clonal priming allows direct in vitro assessment of autologous HLA-associated factors required for immune response to dinitrochlorobenzene.

Human lymphocytes from dinitrochlorobenzene (DNCB)-sensitized human subjects primed in first culture with dinitrophenylated-antigens yield a population of cells which respond in an accelerated manner to the same or similar antigen in second culture. Using this "clonal priming" approach, we have demonstrated that such a primed population showed maximal proliferative response to dinitrophenylated autologous cells. These DNP primed clones also showed responses to some dinitrophenylated allogeneic leukocytes. The magnitude of the accelerated blastogenic response with allogeneic leukocytes varied in most instances in relation to the degree of sharing of HLA-A, B, and DRw antigens with the original autologous stimulator. These findings show that the self-specific factors recognized in conjunction with the dinitrophenyl antigen are closely but not invariably associated with established major histocompatibility (MHC)-associated serologic typing results. While DNP primed clones fail to respond to unmodified autologous leukocytes, they often show significant responses to unmodified allogeneic leukocytes. If such accelerated responses to unmodified allogeneic leukocytes are not the result of nonspecific activation of allogeneic responding lymphocyte clones, these findings further indicate that DNP modified self can resemble some alloantigens.

Dermatitis, Contact↗
PubMed1979

Selective defects in T cell function in ataxia-telangiectasia.

We have studied three patients with ataxia-telangiectasia (AT) and found two of them to have a normal mixed leucocyte culture stimulating and responding ability. However, all three patients and one parent had defective cell-mediated lympholysis (CML), even in the face of a potent proliferative response to allogeneic leucocytes. None of these patients showed significant proliferative responses to common microbial antigens (tetanus toxoid, Candida albicans, purified protein derivative (PPD), diphtheria toxoid, influenza). Our studies indicate tha the T cell defect in AT preferentially affects certain T cell functions associated with antigen recognition and the generation of allogeneic CML, while sparing the allogeneic proliferative response. The selective deficiency of specific lymphocyte functions in a thymic immunodeficiency with a known defect in DNA repair is consistent with the concept that DNA modulating enzymes are important for T cell function.

Antigens↗
PubMed1978

Extreme insulin resistance in ataxia telangiectasia: defect in affinity of insulin receptors.

The syndrome of ataxia telangiectasia is associated with glucose intolerance and insulin resistance. We examined the status of insulin receptors on circulating monocytes and on cultured fibroblasts from two siblings with ataxia telangiectasia and severe insulin resistance. 125I-insulin binding to monocytes of the two patients consistently demonstrated an 80 to 85 per cent decrease in receptor affinity. In contrast, the defect in receptor affinity was not expressed on the patients' cultured fibroblasts or on monocytes or fibroblasts obtained from unaffected family members. Whole plasma and immunoglobulin-enriched fractions of plasma from the patients inhibited the normal binding of insulin to its receptors on cultured human lymphocytes (IM -9 line) and on human placental membranes. We conclude that the insulin resistance in the two siblings with ataxia telangiectasia was associated with defects in the affinity of the receptors for insulin, probably caused by circulating inhibitors of insulin binding.

Acanthosis Nigricans↗
PubMed1978

Clonal priming of human lymphocytes with soluble microbial antigens: high-dose paralysis, restoration, and autologous leukocyte preference.

Lymphocytes stimulated in appropriate leukocyte cultures undergo blastogenesis and proliferation for a finite period of time. With specific antigens the proliferative response peaks usually between 4 and 8 days, after which the blastoid cells revert to small lymphocytes. Lymphocytes "primed" in this manner can be restimulated to proliferate only by the same antigen with which they were incubated and only with an adequate amount of a self-specific, autologous, somatic product(s). First or "primary" leukocyte cultures stimulated by optimal or supraoptimal concentrations of soluble protein antigens (purified protein derivative (PPD), tetanus toxoid, Candida albicans) will undergo proliferation in the first culture, but the increased number of small lymphocytes that can be visualized after 10--14 days often fail to respond to any stimulus in second (secondary) or "primed" cultures. However, when fresh X-irradiated autologous cells are re-added in appropriate amounts, vigorous accelerated proliferation takes place. Addition of allogeneic cells to antigen-primed populations has one of three effects: (1) no effect (complete restriction); (2) in some instances allogeneic cells restore a significant response to the specific antigen but almost never to the same degree as autologous cells; and (3) allogeneic cells can also induce high levels of accelerated responsiveness without added antigen. These findings are discussed in the context of a working hypothesis that self-specific factors are involved in all specific immune responses. The combination of antigen and self-specific factors may lead to a quantitatively unique immune response to all antigens in each individual. The preferential response to antigen in conjunction with autologous rather than allogeneic leukocytes suggests that self-specific products are required for recognition of soluble microbial antigens.

Antigens, Bacterial↗
PubMed1978

Specificity of human cytotoxic responses to chemically modified autologous cells.

Human PBML can generate cytotoxic responses to autologous cells that have been chemically modified with TNP or DNP. The cytotoxic effectors have precise hapten specificity. The DNP-specific effectors recognize DNP in association with cell surface alloantigens, which appear to be at least partially associated with HLA-A and -B. The TNP-specific effectors recognize TNP in association with several classes of determinants--some of which are HLA-linked alloantigens that are incompletely associated with HLA-A and -B, while other determinants are widely shared among humans.

Cross Reactions↗
PubMed1977

Clonal priming of human lymphocytes: Specificity and cross-reactivity of cellular immune reactions.

Clonal priming in response to chemical and microbial antigens which defines the specificity of cellular immune reactions, was demonstrated by culture techniques. Human leucocyte cultures stimulated with specific antigens typically show peak levels of D.N.A. synthesis after 5 to 7 days in culture. Such primary leucocyte cultures were incubated for 10-20 days, then the cells were gently centrifuged and resuspended in fresh RPMI 1640 with 20% plasma. These secondary or primed cultures typically showed less than 1000 c.p.m. after 48 hours. However, if the original antigenic stimulant was added, specific accelerated responses were seen by 48 hours in the secondary cultures. Lymphocyte clones in these sceondary cultures primed with dinitrophenylated (D.N.P.) antigens (from subjects sensitised to dinitrochlorobenzene) showed enhanced D.N.A. sythesis in response to the same dinitrophenylated antigens and showed varible accelerated responses to related chemically modified antigens. However, D.N.P.-activated clones in these secondary cultures did not show enhanced responses to microbial antigens even though the lymphocytes had been highly responsive to tetanus toxoid and other microbial antigens in primary cultures. The specificity of this clonal activation was further demonstrated by the enhanced response of secondary cultures of tetanus-toxoid-activated clones to tetanus toxoid but not to dinitrophenylated antigens. The abiltty to detect specificity and cross-reactivity of cellular immune reaction has broad implications for investigations of cellular immunity as well as many potential applications in the diagnosis and understanding the patogenesis of inflammatory and neoplastic diseases in which cellular immune discrimination may be involved.

Antibody Formation↗
PubMed1977

HLA and other immunogenetic approaches to the study of diseases in man.

We have attempted to focus on several areas that can be practically explored to elucidate the mechanisms accounting for the polymorphism of the human major histocompatibility complex and attendent disease predispositions. In addition to widespread serologic HLA typing of specific populations, diseases, and families, it is important to improve discriminating methods for expoloration of other areas of the HLA supergene, especially those involved in specific immune responsiveness. It may also be necessary to take into account possible modulating effects of the MHC on other recognized human genes. Application of these improved methods to the study of infertile couples, recognized genetic syndromes, and human malignancies may assist in unraveling the immunogenetic enigma of these diseases.

Allergy and Immunology↗
PubMed1976

Mixed cultures of sperm and leukocytes as a measure of histcompatibility in man.

Human peripheral blood leukocyte cultures containing varying numbers of washed fresh sperm were cultured for 4 days. [3H] Thymidine incorporation was used as a measure of lymphocyte transformation. Human sperm cells induce a 4- to 250-fold increase in [3H] thymidine incorporation in allogeneic leuocyte cultures, but no increase was demonstrated in autologous leukocyte cultures. The response was dose-dependent with maximum stimulation obtained at 2 x 10(6) sperm per milliliter of culture. Seminal plasma was inhibitory in a dose-dependent fashion and as little as 0.2 microliter per 200 microliters of culture was inhibitory. The data indicate that tissues other than leukocytes can express the portion of the major histocompatibility complex responsibile for allospecific lymphocyte transformation, and thus have application in transplantation and reproductive biology.

HLA Antigens↗
PubMed1976

Specific blastogenesis and lymphokine production in DNCB-sensitive human leucocyte cultures stimulated with soluble and particulate DNP-containing antigens.

A soluble hapten (dinitrobenzene sulphonic acid (DNBSO3)) and particulate antigens consisting of DNCB, DNFB or DNBSO3 complexed with erythrocytes, all induce a specific blastogenic response and lymphokine production in leucocyte cultures from human subjects topically sensitized to dinitrochlorobenzene (DNCB). While low concentrations (50-100 mug/ml) of DNBSO3 could be left in human leucocyte cultures the entire 4 or 5 days of culture and result in reasonable levels of blastogenesis, it was found that consistently higher degrees of blast transformation resulted when DNCB-sensitive leucocytes were exposed to high concentrations of DNBSO3 (500 mug/ml) for a short period (2 hr). Cell-free supernatants from DNCB-sensitive leucocyte cultures harvested after 48 hr induced blastogenesis and DNA synthesis in secondary target leucocyte cultures from subjects not sensitized to DNCB. Such a blastogenic factor or lymphokine appeared to stimulate even in the absence of any residual antigen, since DNCB complexed to erythrocytes was removed by simple filtration through a 0-45 mum Millipore filter. In contrast to DNCB complexes, the antigenic activity of DNBSO3 complexed with erythrocytes was not removed by such filtration. Thus, several DNP-containing haptens (DNCB, DNFB, DNBSO3) induce specific lymphocyte transformation and lymphokine production when exposed in several different manners to leucocytes from humans sensitized to DNCB. The ability to use either a particulate or soluble stimulant in vitro offers a versatile system for studying cell-mediated immunity in humans with a broad range of potential applicability in both investigate and clinical medicine.

Antigens↗
PubMed1975

Studies on the contact sensitization of man with simple chemicals. III. Quantitative relationships between specific lymphocyte transformation, skin sensitivity, and lymphokine activity in response to dinitrochlorobenzene.

Dinitrochlorobenzene (DNCB) coupled to peripheral blood erythrocytes or leukocytes forms a particulate complex, DNCB-antigen. The addition of DNCB-antigen induced blastogenesis and DNA synthesis in leukocyte cultures from DNCB-sensitized human subjects and not in leukocyte cultures from nonsensitized controls. In general, sensitized subjects who displayed a higher degree of cutaneous reactivity to DNCB, as manifested by duration and intensity of dermatitis, also showed a greater blastogenic response to DNCB-antigen in vitro. This quantitative correlation, however, was not invariant. Certain soluble factor(s), or lymphokines are released following the addition of DNCB-antigen to leukocyte cultures prepared from some sensitive subjects who were rechallenged one or more times with DNCB. These lymphokines induce blastogenesis in secondary target leukocyte populations from nonsensitized subjects. Extended studies are presented which slow little or no lymphokine activity in peripheral blood leukocyte cultures during a primary immune response, despite high degrees of blastogenic activity in response to DNCB-antigen. Significant lymphokine activity was observed only following additional rechallenge with DNCB. Blastogenesis and skin reactivity specific for DNCB have been shown to develop at about the same time during a primary immune response. This, along with the quantitative correlation shown in this communication, suggests that both processes probably reflect thymic-dependent cellular immunity. The appearance of lymphokine activity following rechallenge with DNCB suggests that DNCB-induced lymphokines may represent an amplifying mechanism of the cellular immune response that involves recruitment of previously uncommitted lymphocytes.

Antigens↗
PubMed1975

Studies on the contact sensitization of man with simple chemicals. IV. Timing of skin reactivity, lymphokine production, and blastogenesis following rechallenge with dinitrochlorobenzene using an automated microassay.

An automated microassay was adapted to the sutdy of specific in vitro lymphocyte transformation to dinitrochlorobenzene (DNCB) erythrocyte complexes (DNCB-antigen). Studies of culture conditions indicated that in flat-bottomed microtiter culture plates, 0.2ml culturese containing 4x105 leukocytes and a total culture time of 4 or 5 days yeild satisfactory results for the relatively low responses seen with specific antigens such as DNCB-antigen. Culture were incubated for 3 hr with tritiated thymidine and harvested with the Multipe Automated Sample Harvester(MASH II). The effect of DNCB rechallenge on in vitro lymphocte transformation was stuided using this automated microassay. DNCB rechallenge boosted the in vitro response to DNON 25 TO 31 MM Hg; four patients (hypercapnic, group II) at a co2 from 54 to57 mm Hg. AH 8165 0.25 mg/kg (one quarter of the dose required for intubation) was given by rapid central venous injection. Haemodynamic responses were similar in the two groups; these were increase in heart rate ranging from 45 to 60 percent, increases in mean arterial pressure of 17-20 pre cent, and increases in cardiac output of 22-32 per cent. The intensity of neuromusclar blockade of the forearm muscles after AH 8165 was similar in the two groups, and there was no significant difference in recovery rates; roup I patients were 80 per cent recovered in 36.6 min, group II patinets in 47.3 min. It was concluded that the activity of AH 8165 was not influenced by moderate changes in respiratory acid-base status.

Antigens↗