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Biomedical subjects

J B Lindblom

Publications and source records attributed to J B Lindblom.

At least 19 recordsLinked to original sources
PubMed1982

Surface Ia-like expression and MLR-stimulating capacity of human leukemic myeloblasts: implications for immunotherapy and prognosis.

Surface Ia-positive cells were found to vary from 0 to 100% in initial blood specimens from 37 adults with acute myelogenous leukemia (AML). When myeloblasts from 19 patients were tested against panels of lymphocytes from 5 to 19 normal donors, mean stimulation indices ranged from 1 to 60. Some leukemic myeloblasts strongly stimulated most allogenic responder lymphocytes whereas others produced almost no stimulation. The addition of antibody against human Ia to 28 mixed leukocyte reaction (MLR) combinations resulted in significant inhibition (p less than 0.001) of 3H-thymidine incorporation. Testing of myeloblastic Ia may have clinical relevance because patients with greater than 50% Ia-positive myeloblasts had a significantly longer survival than patients with fewer Ia-positive myeloblasts (p less than 0.04).

Adult↗
PubMed1978

Reactivity of a rabbit antiserum against highly purified HLA-DR antigens.

A rabbit antiserum has been raised against highly purified, detergent-solubilized HLA-DR antigens. Externally or internally labelled surface glycoproteins from B-lymphocytes, epidermis, macrophages, and B-lymphoma cell lines reacted with the antiserum which precipitated polypeptide chains with the molecular weights 28,000 and 34,000. Such polypeptide chains were not observed when the antiserum was reacted with T-lymphocytes, T-cell lymphoma lines, kidney, brain, thymus and spermatozoa. Fab-fragments of the antiserum completely abolished the cytotoxic action of HLA-DR allantisera but had no effect on the cytotoxicity mediated by HLA-A,B and C loci antisera. Moreover, the rabbit antiserum reacted with the same molecules as the HLA-DR alloantisera. Fab-fragments of the rabbit antiserum completely abolished the MLR response and from the kinetics of the inhibition it is concluded that the Fab-fragments may interfere primarily with the initial recognition phase of the MLR.

Animals↗
PubMed1978

HLA-A, -B, -C and -D antigens in male patients with myasthenia gravis.

HLA-A, -B, -C and -D antigens were determined in 54 male Myasthenia Gravis patients. A significant increase of the B8 antigen frequency was found among patients with an onset of the disease before the age of 35. No significant increase was found among the D antigens. In a combined male and female material with an early age at onset, thymic hyperplasia was correlated to the presence of HLA-B8.

Adult↗
PubMed1976

Structural and immunological similarities between HLA antigens from three loci.

HLA antigens are coded for by three closely linked loci. The gene products of the first and second locus are known to be very similar in overall structure. Antigens coded for by the third locus were examined with regard to their chemical and immunological relationship to the first and second loci gene products. It is demonstrated that the third locus antigens are composed of two types of polypeptide chains, the smaller of which is identical to beta2-microglobulin. The alloantigenic polypeptide chain has an apparent molecular weight of 48 000 when solubilized by detergen treatment and about 35 000 when released from the cell membrane by proteolysis. These data together with size and shape analyses by gel chromatography and sedimentation velocity determinations show that HLA antigens from the three subloci are indistinguishable with the techniques employed. Suggestive evidence was obtained that the third locus antigens are more sensitive to proteolysis than the first and second locus antigens. The similarity between the three gene products was also evident on cyanogen bromide fragmentation of the polypeptide chains. Furthermore, rabbit antibodies against antigens coded for by the first locus cross-reacted extensively with antigens from the second and third locus. This study therefore lends strong credence to the view that the three HLA antigen subloci have arisen by gene duplications of a common ancestral gene.

Cross Reactions↗
PubMed1976

Beta2-microglobulin on the cell surface. Specificity of inhibition of the mixed leukocyte reaction and mitogenic properties of antibodies against the two HLA antigen polypeptide chains.

Intact antibodies, and F(ab')2, and Fab' fragments thereof directed against beta2-microglobulin (beta2m) and the HLA alloantigenic polypeptide chain impede the mixed leukocyte culture reaction (MLR). The Fab' fragments are effective only when bound to the responder cell population. The kinetics of their inhibiting action suggest that they interfere with the recognition phase of the MLR. Thus, it seems possible that beta2m may be part of or closely associated with those structures on the responding cells which recognize the stimulatory alloantigens. Antibodies against beta2m or the other HLA antigen polypeptide chain are mitogenic for peripheral blood lymphocytes. The antibodies against beta2m caused greater stimulation than those against the HLA alloantigenic polypeptide chain. Only bivalent antibodies against beta2m were mitogenic and promoted blast transformation of 1 to 2% of the lymphocytes. Although only B lymphocytes were triggered, the mitogenic response of cultures containing various proportions of B and T cells suggests that cooperation of the two cell types is necessary to obtain optimal mitogenic stimulation.

Antigen-Antibody Reactions↗
PubMed1976

HL-A frequencies in Crohn's disease and ulcerative colitis.

Sixty-two patients with Crohn's disease and 51 with ulcerative colitis were HL-A typed. Phenotype frequencies were calculated and compared with those of a control group of 335 individuals. A higher frequency of HL-A17 was found among the Crohn's disease patient but this was not significant. However, HL-A17 has been included in two studies on Crohn's disease and the combined relative risk is 3.24 which significantly deviates from 1 unity. No statistically significant differences in the HL-A antigen distribution were found among the patients with ulcerative colitis.

Adult↗
PubMed1974

Highly purified papain-solubilized HL-A antigens contain beta2-microglobulin.

HL-A antigens comprising 11 different antigenic specificities were isolated after papain solubilization of spleen-cell membrane constituents. During the entire purification procedure, beta(2)-microglobulin appeared together with the HL-A antigens. The highly purified antigens were composed of two polypeptide chains. The large subunit carried the antigenic specificity whereas the small polypeptide chain was very similar, if not identical, to beta(2)-microglobulin. The two HL-A antigen polypeptide chains were held together by noncovalent interactions only, and beta(2)-microglobulin, isolated from urine, could replace the small subunit in forming a complex with the large polypeptide chain. The topographical relationship in the cell membrane between beta(2)-microglobulin and the large HL-A antigen polypeptide chain is unknown. The two polypeptide chains may be fortuitously bound as a result of the solubilization procedure.

Antibody Specificity↗