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Peripheral B lymphocytes obtained from three healthy individuals who had been immunized against peripheral blood lymphocytes from appropriate HLA-incompatible donors were transformed by the use of Epstein-Barr virus. The transformed blastoid B cells were repeatedly subcultured by means of "cluster picking," and the HLA antibody-producing cultures were identified by testing the culture supernatants by means of the cytotoxicity assay, using the corresponding donor cells. Thus far, four cell lines that secrete cytotoxic HLA antibodies (MP1, 3, 4, and 5) have been established. Specific immunoabsorption experiments revealed that the antibody activity is carried by lambda-type IgM for MP1, by kappa-type IgM for MP3 and MP5, and by both for MP4. Specificity analysis of a panel of HLA-pretyped cells indicated that MP1 detects DQw2, whereas MP5 recognizes B7. The specificity of MP3 was similar to a DQ specificity termed DC5 (probably equivalent to TA10) but not the same. In the case of MP4, both of the lambda-type and kappa-type antibodies appeared to be directed toward new HLA class II determinants.

We are reporting the production and characterization of a human monoclonal antibody recognizing antigen HLA-25. The antibody was developed by a line transformed in vitro by the Epstein-Barr virus. The immune B lymphocytes for transformation were generated by planned immunization of a volunteer with repeated doses of allogenic peripheral blood lymphocytes of one donor over the course of 7 years. The antibody showed correlation with A25 antigen on a panel of 244 individuals tested by microcytotoxicity. The antibody showed neither cytotoxic reactivity nor CYNAP phenomenon with antigens of HLA-10 CREG.

IgM molecules were purified by the use of anti-IgM antibody-coupled Sepharose from the culture supernatant of an Epstein-Barr-virus-transformed lymphoblastoid cell line, MP1, that secretes alloantibodies possessing HLA-DQw2 specificity as defined by the cytotoxicity assay. The obtained IgM preparation was labeled with radioactive iodine-125I and fractionated by gel filtration. It contained pentameric IgM and smaller oligomeric IgMs. When tested by the direct cellular binding assay against a panel of HLA-typed cell lines, they all showed the DR3 and DR7 association pattern characteristic of DQw2. A weak but significant binding was detected for DR1, DR6, and DR9. On isoelectrofocusing, MP1 pentameric IgM gave a restricted banding pattern comparable to monoclonal IgM obtained from a patient with Waldenström's syndrome. Moreover, the pattern was identical to that of IgM purified from the culture supernatant of a defined hybrid clone, 162, that was generated by fusing MP1 cells with heteromyeloma D33 cells. The target class II molecules showed the dimeric structure that conforms to DQw2 molecules.

T cells recognize protein antigens as fragments (peptides) held in a defined binding site of class I or class II major histocompatibility (MHC) molecules. The formation of complexes between various immunologically active peptides and different MHC molecules has been demonstrated directly in binding studies between the peptides and solubilized, purified molecules of class II MHC. Studies with intact cells, living or fixed, have not directly demonstrated the binding of the peptides to MHC molecules on antigen-presenting cells, but the formation of such complexes has been shown indirectly through the capacity of antigen-presenting cells to stimulate specific T cells. Here we report evidence that supports directly the binding of radiolabelled influenza matrix peptide 17-29 to products of the human class II MHC locus HLA-DR, on living homozygous B-cell lines, and we show that the kinetics of such binding is much faster with living cells than with fixed cells. Furthermore, whereas the peptide reacts with HLA-DR molecules of all alleles, it binds preferentially to DR1, the restricting element in antigen presentation.

Sixty patients with celiac disease were typed by radioimmunoassay for the specificities HLA-DR3, HLA-DR7, and for an allelic specificity, DC3, of the HLA-associated DC locus. We found that celiac disease is primarily associated with the DC determinant. The previously described associations with DR3, DR7, B8, B13, and A1 can be explained by decreasing degrees of linkage disequilibrium with DC3.

This study was carried out to assess the diagnostic accuracy of a new gastrointestinal cancer antigen ( GICA ) defined by a monoclonal antibody. Its sensitivity and specificity were assayed in a group of patients with different pancreatic diseases (10 acute pancreatitis, 27 chronic pancreatitis, 22 cancers of the pancreas) and in 29 normal individuals. The concentration of GICA was always inferior to 37 units/ml (our discriminant limit between cancer and noncancer patients) both in cases with chronic pancreatitis and in healthy subjects. Increased levels of the antigen were found in 16/22 (72.7%) pancreatic cancer patients and in 3/10 (33.3%) cases with acute pancreatitis. The assay was within the normal range in 2 (28.6%) out of 7 cancers judged resectable. The test is simple and rapid, but its relative sensitivity and the frequent elevation of GICA in other adenocarcinomas of the gastrointestinal tract make it unsuitable for screening programs in pancreatic cancer. Even its use for early diagnosis of cancer of the pancreas does not seem promising. The major finding of our study is the lack of false-positives in patients with chronic pancreatitis and therefore the usefulness of this test in differentiating preoperatively between chronic inflammation and cancer of the gland. Frequent increase of the marker in patients with acute pancreatitis is not yet clear.

Allelic sequence variation of the HLA DP-alpha and DP-beta genes has been analyzed in a panel of 34 DP-typed cell lines. The polymorphic second exon of these genes was specifically amplified in vitro by the polymerase chain reaction method, using the thermostable DNA polymerase of Thermus, aquaticus. The analysis of M13 clones containing the amplified DP-beta sequences revealed a total of 14 allelic variants. In general, specific allelic DP-beta sequences were associated with each of the defined DPw1-w6 types, with beta allele subtypes revealed for the DPw2 and DPw4 specificities. An additional six DP-beta alleles which did not correlate with any of the T cell-defined specificities (DP "blanks") were also identified. Only the two previously characterized alleles of DP-alpha were detected. These observations suggest that the T cell-defined DP specificities are determined by polymorphic residues on the beta-chain. The sequence polymorphisms in DP-beta are clustered in a few specific regions, and can be detected using sequence-specific oligonucleotide probes and polymerase chain reaction amplified DNA in a rapid dot-blot format. This approach provides a simple and informative method of DP typing. The DP-beta sequences derived from four DP-typed celiac disease patients were compared with the distribution of DP-beta alleles in control individuals.

A standardized procedure is proposed for deliberate immunizations against human major histocompatibility complex determinants. The data presented demonstrate its effectiveness and, by using a number of necessary precautions, this procedure has proven to be very safe. The following points are especially important: (1) exclusive utilization of regular blood donors as immunizers; (3) use of whole blood as an immunizing agent; and (3) use of small immunizing stimuli rather than large transfusions. This procedure can be recommended for the production of monospecific anti-HLA antisera and it may be useful if and when a deliberate transfusion policy for prospective kidney recipients is adopted.

Human peripheral blood lymphocytes respond in vitro to sheep red blood cells (SRBC) with the appearance of numerous specific plaque-forming cells, if the Epstein-Barr virus (EBV) is added to the cultures together with the antigen. However, it was found that when polyethylene glycol (mol. wt. 6000) is included in the culture medium at a final concentration of 4%, antigen alone is able to induce an anti-SRBC response, with clear hemolytic plaques of regular size. Addition of EBV causes a further increase in the antigen-specific antibody response.

Investigation of an informative family including two probands with male multiplex retinitis pigmentosa revealed that the putative disease susceptibility loci were not linked to those of HLA. In addition, analysis of immunological data obtained yielded evidence suggestive of X-linked inheritance of susceptibility to cell-mediated immune aberration in this family.

Peripheral mononuclear cells (MNC) of patients with autoimmune thyroid disease have been shown to proliferate when cultured with human thyroglobulin (hTg). In addition, such a phenomenon is apparent in a certain number of healthy individuals. In this study we have attempted to correlate hTg-induced MNC proliferation, occurrence of anti-hTg autoantibodies and HLA phenotype (including Class II DR and DQ loci) in a population of HLA-typed normal blood donors. Fourteen out of 56 subjects showed a significant MNC proliferation to hTg. Three of them had anti-hTg autoantibodies in the serum, while none of the hTg-unresponsive subjects showed such antibodies. No correlation with HLA phenotype (including Class II DR5 specificity, referred as associated with Hashimoto's thyroiditis, and DQ alleles) was observed.

Human Ia molecules were isolated from cells of LG-38, an HLA-homozygous lymphoid cell line of DR5 specificity. Three Ia subsets could be distinguished and separated by using specific alloantisera and a monoclonal antibody with polymorphic reactivity. These subsets carried the specificities DR5 and MT2, MT2 alone and MB3 alone. The structure of the three molecular species was analyzed by microfingerprinting. The subset carrying only MT2 was similar, in both the component alpha and beta chains, to the major subset carrying DR5 and MT2, whereas the subset carrying MB3 was distinct in both chains from the other two subsets. These data are compatible with our previous findings obtained for the products of two Ia loci closely linked to the DR locus and provisionally called DC and BR; they also support the conclusion that the subset carrying only MT2 is an allelic product of the BR locus, whereas the MB3 subset is an allelic product of the DC locus. MT2 appears to be a shared specificity of DR and BR loci products.

A DP serological allospecificity was identified using 125I-labeled preparations of HLA class II molecules isolated from cells of HLA homozygous typing cell lines, SLE (DRw6, DQw1, DPw3) and WT46 (DRw6, DQw1, DPw2), and depleted of DR molecules by absorption with an anti-DR monoclonal antibody. The specificity, provisionally called WT, was carried by class II molecules possessing the characteristics of DP molecules on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and detected primarily in DPw1, DPw3 and DPw5 cells and exceptionally in some DPw2 cells including WT46 and DPw4 cells on a large panel of DP-pretyped B cell lines mostly derived from the 10th International Histocompatibility Workshop B cell reference panel. It was apparently allelic to another DP serological specificity BUT previously defined on DP molecules isolated from cells of DPw2+ HLA deletion mutant cell line LCL 721.82. On the same cell panel; the BUT specificity was negative in all DPw1, DPw3 and DPw5 cells, and positive in all DPw2 and DPw4 cells and also in DPw2B and DPw4B cells except the cells typed WT+. This DP association pattern was similar to that of the known allelic sequences, GGPM and DEAV, in DP beta F segment, one of the six variable segments in the second exon of DP beta gene. Thus, genomic DNA from 22 B cell lines pretyped for BUT and WT specificities were enzymatically amplified for the second exon of DP beta gene by the use of locus-specific oligonucleotide primers and hybridized with 32P-labeled oligonucleotide probes corresponding to the F segment sequence variations. This oligonucleotide typing showed perfect one-to-one correlation with the BUT and WT serological typing. The typing also revealed that WT46 cells, although typed DPw2, have the DEAV sequence common to DPw1, DPw3 and DPw5.

Knowledge of the tumor content of estrogen (ER) and progesterone (PgR) receptors has proved to be of significant value in human breast cancer. Relative determinations were performed in 589 specimens in our laboratory. The positivity of ER and PgR is correlated with the patients' age at diagnosis, tumor size and relative grade. In particular, the significance of PgR versus ER status and the possible prognostic role of these receptors are investigated.

HLA class II molecules were partially purified from cells of an HLA deletion mutant cell line, LCL721.82, that lost DR and DQ expression but retained DPw2 specificity and labeled with radioactive 125I. The radioiodinated preparation bound to DP-specific monoclonal antibody B7/21 as well as rabbit anti-HLA class II antiserum. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the component involved in these bindings gave, unlike known HLA class II molecules, a sharp and dense band of approximately 60 kDa under nonreducing conditions and a single but diffuse band of approximately 30 kDa under reducing conditions. By screening 401 anti-HLA class II alloantisera, including those distributed in the 9th International Histocompatibility Workshop and also those locally available, eight were found to possess significant binding activity. Specificity analysis of these eight binding-positive antisera on a panel of DP-pretyped HLA homozygous typing cells revealed the presence of two clusters, one corresponding to an allodeterminant associated with DPw1, 2 and 3 and the other to that associated with DPw2 and 4. These two determinants were shown by the sequential binding test to reside on the B7/21-defined HLA class II molecules. Thus, two major conclusions were drawn: two distinct allodeterminants are carried by a single DP molecule; and these serologically detected DP allodeterminants are supertypic to cellularly defined DP allospecificities.

Coeliac disease is an autoimmune disease of the intestinal mucosa, elicited by ingestion of wheat gluten in genetically susceptible individuals. Susceptibility to coeliac disease has been associated with the serologically defined variants DR3 and DR7 of the class II antigens encoded by the HLA-D region. Three related class II antigens, each consisting of an alpha and a beta glycoprotein chain, have been identified and are designated HLA-DR, HLA-DQ, and HLA-DP. These highly polymorphic transmembrane proteins bind peptides derived from the processing of foreign antigens and present them to T lymphocytes; they also influence the specificity of the mature T-cell repertoire. The role of HLA-DP polymorphism in susceptibility has not been as fully explored as that of the other class II antigens because of the complexity of the primed lymphocyte typing (PLT) method for determining DPw specificities. Here we use a new DNA-based method of HLA-DP typing to analyse the distribution of DP beta alleles in a group of coeliac disease patients and healthy controls. Two specific DP beta alleles (DPB4.2 and DPB3) are increased in the patient population. Comparison of the DP beta sequences suggests that the polymorphic residues at position 69 and at 56 and 57 may be critical in conferring susceptibility. Further, the contribution of the susceptible DP beta alleles appears to be independent of linkage to the previously reported DR3 and DR7 markers for coeliac disease. The distribution of DQ alpha and beta alleles in patients suggests that a specific DQ heterodimer may be responsible for the observed DR associations. Individuals with both this DQ antigen and a specific DP beta allele are at increased risk for coeliac disease.

Antisera recognizing subsets of human T lymphocytes can be produced by planned immunizations involving HLA-A and HLA-B compatible donors. The reactivity of these antisera against some individuals of a population, but not others, show that they recognize a polymorphic cell surface component. The study of informative families shows the HLA linkage of at least some of these alloantigenic determinants.

Using two alloantisera produced by planned immunization of blood donor volunteers, a new specificity was defined residing on human Ia molecules. The specificity is possessed by the following human lymphoid cell lines: Reh, NALM-1, B89, KM-3 and BJAB, and appears to be the same as the DRw13 specificity discovered in the 8th International Histocompatibility Workshop. A radioimmunoassay for typing w13 on peripheral blood lymphocytes was established. A population and family study supports the genetic control by the HLA-DR locus. The phenotypic frequency in an Italian population was 3.7 percent. The relationship between w13 and the MT2 supertypic specificity was confirmed at the molecular level and the papain sensitivity of w13-carrying molecules was determined.

Sera obtained from planned immunizations between unrelated donors and recipients, identical or compatible at HLA-A and B, were assessed for their capacity to alter the in vitro response of a test panel of lymphocytes to PHA and a purified streptococcal antigen (PAS). In the case of PHA, no serum effects were apparent. The response to PAS, however, significantly inhibited by two sera. When tested for their complement-dependent cytotoxicity on enriched populations of T and B lymphocytes, none of the sera manifested cytotoxicity against T cells nor did serological inhibition correlate with the capacity to lyze B cells. The data suggest that inhibition of the PSA response is mediated by blocking antibodies specific for a subset of lymphocytes, possibly T cells. While the precise mechanism governing the response to PSA is not known, the data are compatible with the idea that an HLA-linked Ir gene, expressed on a subset of T lymphocytes, controls immune responsiveness to PSA.

Human Ia(-like) specificities controlled by gene loci other than HLA-DR were searched for at the molecular level in cells of human B-cell-type cell lines which carry two established DR specificities. Chevalier cells of DRw3 and 7 and U698M cells of DRw2 and 4 were used. Their Ia molecules were partially purified, radioiodinated and analyzed for Ia specificities by the direct binding and sequential binding assays with a selected panel of human Ia alloantisera. It was possible in both the cell lines to define a third subset of Ia molecules carrying a new specificity in addition to two Ia subsets carrying the established DR specificities. The new specificity was detected by putative anti-DRw4 and anti-DRw7 antisera and was closely associated with DRw4 and DRw7 at population level. It was thus designated provisionally as BR4X7. These results suggest that the BR4X7 specificity is coded for by a separate Ia locus closely linked to HLA-DR locus. The determinant(s) responsible for BR4X7 was located on the small subunit of Ia molecules.

The polymorphism of HLA-DR antigens has been studied by Southern blot hybridization under conditions specific for the detection of the DR beta chain genes. Haplotype-specific patterns were defined with DNA from DR1, 2, 3, 4, 7, w8, w11, w12, and W13 homozygous typing cells, with restriction enzymes Eco RI, Bgl I, and Pvu II. Certain serological specificities, such as DR2, DR3, and DR7, can be encoded by distinct allelic forms of DR beta chain genes. The procedure of "DNA typing" was applied to family analysis of individuals expressing only a single DR specificity upon serological typing. Three cases are described here: (1) in family GR, phenotypic DR 7 homozygotes correspond to genomic heterozygotes, and a novel DR7 allele is described: (2) in family RU, the genes corresponding to a serologically undetected (blank) DR allele were identified by restriction fragment length polymorphism (RFLP); this novel DR haplotype has an RFLP pattern similar to those of the DRw52 family, even though this specificity was not expressed on the DR-blank lymphocytes; (3) in family RG, there is no blank allele, but a homozygote RFLP situation at the DR subregion.

On the basis of reactions with a chronic lymphatic leukemia cell panel, evidence for 6 new specificities of the Merrit B-cell alloantigenic system in man is presented, bringing the number of provisionally defined specificities to 19. These can be roughly divided into two segregant series. The system is well represented on both homozygous and heterozygous B-type lymphoblastoid cell lines. In the cell lines some specificities show a suggestive but inexact correlation with HLA-D locus factors. This correlation is represented also on peripheral blood B cells, on the non-T variety of acute lymphatic leukemia cells, and on acute myeloid leukemia cells. Although great similarities exist, each of the cell populations may manifest differences other than or in addition to mere differences in B-cell antigen frequencies.

This paper describes the in vitro production of the human alloantibody 454A.C5 with HLA-DQw2 specificity produced by a stable EBV-transformed cell line. Immune B cells for transformation were generated by planned immunization of a blood donor volunteer with repeated HLA-immunizations over the course of 9 yr. Reactivity of 454A.C5 was in exact concordance with the presence of the DQw2 antigen as defined by microcytotoxicity assay on a panel of 21 B lymphoblastoid cell lines with well-characterized HLA antigens. Family studies showed the segregation according to the HLA-DQw2 haplotype; thus we demonstrate by serological and formal genetics criteria, that the alloantibody is specifically directed against the DQw2. 454A.C5 antibody may be employed as a monospecific HLA typing reagent.

Polymorphism of mitochondrial DNA has been studied in two highland (Desulo, Tonara) and in two lowland (Galtellì, Orosei) Sardinian isolates, formerly subjected to different selective pressure due to malaria, and in 103 individuals from Northern Italy (Bergamo area), where malaria never appeared to be endemic. Two mitochondrial restriction endonuclease patterns (morphs) never described before have been found, one in the Bergamo and Orosei samples, and the other one only in Orosei. Four new mitochondrial types (mitotypes) due to different combinations of morphs have been identified; two of them have been found only in Sardinia, but with such a low frequency that they cannot be defined as typical Sardinian mitotypes. One mitotype (BamHI-morph 3, MspI-morph 4, AvaII-morph 9 and HaeII-morph 1) showed a significantly higher frequency in the highland rather than in the lowland Sardinian villages or in the Bergamo area. Since this mitotype has been found at a relatively high frequency in Central and Southern Italy, while it has been reported to be rare in Caucasians of Central European origin and absent in other ethnic groups (Africans, Chinese, Japanese and Israeli Jews), we suggest it may represent an ancient Mediterranean type. The analysis of these data suggests that drift or other evolutive forces different from malaria might be the major cause of mitochondrial DNA variation in Sardinia.

Analysis by the indirect fluorescence test followed by fluorescence-activated cell sorter (FACS) analysis has shown that antisera recognizing subsets of human T lymphocytes can be produced by planned immunizations involving HLA-A and HLA-B compatible donors. The reactivity of these antisera against some individuals of a population but not others shows that they recognize a polymorphic cell surface component. The reactive subpopulation largely overlaps with the JRA+ subset, which was previously shown to possess regulatory properties in functional assays. The specificity of the antisera for a T cell subset and the unrelatedness of the anti-B cell activity of the same antisera has been confirmed by two-color fluorescence tests.

Some human B-lymphoblastoid cell lines are shown to express at least two types of Ia-like antigens. One antigen is defined by alloantisera to HLA-DR, and the other antigen is defined by alloantisera and a monoclonal antibody to the specificities DC1, MT1 (MB1), and LB12, which are in linkage disequilibrium with HLA-DR. The subunits of the DC1 molecule differ from those of the DR molecule. The light chains of both molecules are structurally polymorphic.

Antiserum 8w670 which had been classified as anti-DR5 in the Workshop analysis was found by the direct binding test to react with about 40% of Ia molecules in an Ia preparation from LG38 cells (DR5,5) that was deleted of DR molecules and DR-like molecules we call BR and enriched in DC molecules by pretreatment with a rabbit antiserum raised against alpha-subunits of DR and BR molecules. The specificity involved in the binding reaction was shown by the binding inhibition assay to be present in 100% of DR5-positive cases (53 out of 53) and 8w13-positive cases (2 out of 2) and in 23% of DR4-positive cases (4 out of 17). This association pattern did not correspond to any of the known supertypic specificities including the DC beta 4 and DC alpha 3, both of which had been found on DR5-associated DC molecules. Yet sequential binding analysis revealed that the 8w670-defined specificity was indeed present on the same molecules carrying DC beta 4 and DC alpha 3 specificities. This specificity was designated DC5.

DNA hybridization with synthetic oligonucleotide probes was used to assess engraftment in 19 thalassemic patients who received bone marrow grafts from their respective healthy HLA-identical siblings. Three oligomers complementary to the tandem repetitive sequences of different hypervariable regions of human DNA were designed so as to produce simple RFLP (restriction fragment length polymorphism) patterns. Each probe hybridizes to one or two bands in HinfI-digested genomic DNA. The combined use of these three probes allowed a discrimination between all the HLA-identical siblings tested. Both donor-specific and recipient-specific DNA fragments existed in 18 out of the 19 sibling pairs studied. One pair possessed only a donor-specific fragment. DNA analysis at an early stage after the graft detected donor-specific fragments in 15 out of 19 patients, recipient-specific fragments in three patients and a mix of recipient and donor fragments in one patient. At a later stage this patient possessed donor-specific fragments only. Follow-up DNA analysis confirmed these findings. Thus 16 patients continued to display donor-specific fragments over 60 days post-transplant. These DNA data showed strong correlation with the clinical status of the patients as well as with other markers of engraftment including cytogenetics and hemoglobin synthesis. The patients who showed donor-specific fragments over 60 days have been free of thalassemic symptoms for over 300 days. Moreover, in 11 cases it was possible to predict the fate of the graft within 15 days after transplantation. In conclusion, the use of the three synthetic oligonucleotide probes provides a powerful tool in documenting engraftment in bone marrow transplantation.

HLA-DP genotyping was performed using dot-blot analysis with synthetic oligonucleotide probes. Fourteen probes were designed based on the known sequence variations in the polymorphic segments of the DP beta second exon. Each probe was tested against genomic DNA amplified by the polymerase chain reaction, using DP beta-specific primers. A total of 45 HLA homozygous B-cell lines, selected from the Tenth International Histocompatability Workshop and pretyped for the known DP omega specificities, were analyzed. Different hybridization patterns were found for each DP omega specificity. The oligonucleotide hybridization performed on DP omega-negative B-cell lines gave a pattern distinct from those of known DP omega specificities, indicating the presence of novel DP allelic sequences. The use of sequence-specific oligonucleotides combined with DNA amplification allows a simple and reliable genotyping of DP antigens.