Activated monocytes prime naïve T cells against autologous cancer: vigorous cancer destruction in vitro and in vivo.

It has not been considered so far that antigen-presenting cells (APC) may phagocytose immunogenic material from autologous cancer cells. Assuming the presence of cancer-immunogenic material in APC, we developed a novel autologous priming method that does not require tumour cells or identified peptides. Cancer-immunogenic information came from CD14+ monocytes. When stimulated with CD3-activated T cells, monocytes primed CD3+ CD4+ and CD3+ CD8+ resting/naïve T cells to become powerful effector cells within 24 h. During priming, depletion of CD14+ monocytes but not CD1a+ CD83+ dendritic cells prevented T cell priming. During cancer cell destruction, dendritic cells, but not monocytes, enhanced cancer cell lysis. The cascade-primed (CAPRI) immune cell quartet comprising monocytes, dendritic cells, CD4+ T and CD8+ T cells induced a significant decrease in the number of suppressive CD25(high) FoxP3+ CD4+ T cells. CAPRI cells induced a marked upregulation of MHC class I and class II expression in cancer cells, which is crucial for autoimmune-like lysis. We show in vivo evidence of the CAPRI cell concept in nude mice. In humans, we present circumstantial clinical evidence showing the efficacy of CAPRI cells in an adjuvant treatment attempt for breast cancer patients with metastasis (N = 42). Compared to patients at the Munich Tumor Center (no CAPRI treatment N = 428), almost double the expected number of patients survived 5 years (P =1.36 × 10⁻¹4). The CAPRI method is a safe procedure without negative side effects. High numbers of cancer-specific CAPRI cells can be obtained within a week against different cancer types for efficient adoptive cell therapy.

Identification of two cis-encoded HLA-DQ molecules that carry distinct alloantigenic specificities.

The monoclonal antibodies Genox 3.53, S1, and R1 define polymorphic epitopes localized to DQ molecules. All three antibodies showed a strong association with the HLA-DR antigens 1, 2, and w6 when tested on a panel of 68 unrelated individuals, suggesting that they all recognized the DQw1 allospecificity. However, segregation analysis and binding studies with a panel of HLA-D/DR homozygous cells indicated that these monoclonal antibodies defined two different alloantigens. Cells homozygous for DR 1, 2, or w6 expressed the epitopes defined by all three antibodies (i.e., S1, R1, and Ge) while cells homozygous for DR4 and DRw8 expressed only the S1 and R1 epitopes. Sequential immunoprecipitation analyses in S1+/R1+/Ge+ individuals, in which the three epitopes were shown by segregation analysis to be encoded by the same chromosome, revealed two distinct DQ-like molecules. While R1 and S1 appeared to reside on the same molecule, the epitope defined by Genox 3.53 was on a different molecule. Identical results were obtained with DR1-, DR2-, or DRw6-bearing cells. Thus it appears that DQw1-bearing individuals express two cis-encoded DQ-like molecules that carry distinct alloantigenic specificities.

Direct demonstration of an HLA-DR allotypic determinant on the low molecular weight (beta) subunit using a mouse monoclonal antibody specific for DR3.

A murine monoclonal antibody directed against a human B cell surface antigen with the characteristics of HLA-DR is described. The antigen detected is tightly linked to HLA and is correlated with the alloantigen HLA-Dw/DR3. Reactivity with a fraction of Dw/DRw6 cells is also observed. The determinant recognized by this antibody has been shown to be present on the smaller molecular weight beta subunit of the HLA-DR antigen.

HL-A LD (lymphocyte defined) typing: a rapid assay with primed lymphocytes.

When human lymphocytes are cultured for 9 to 14 days with stimulating cells of a family member differing by a single HL-A haplotype they become "primed" to recognize specific HL-A LD (mixed lymphocyte culture) antigens. These primed lymphocytes respond specifically and rapidly when "restimulated" with cells of a person that contain the same LD antigens as those of the priming haplotype. Specific HL-A LD antigens can be detected within 24 hours by this primed LD typing.

Identification of naturally processed T cell epitopes from glutamic acid decarboxylase presented in the context of HLA-DR alleles by T lymphocytes of recent onset IDDM patients.

Glutamic acid decarboxylase (GAD) has been defined as a major target antigen in insulin-dependent diabetes mellitus (IDDM). To identify the molecular ligands triggering a T cell response to GAD, a panel of human GAD65-specific T lymphocyte lines was generated from peripheral blood of three recent onset IDDM patients. All lines derived from a patient expressing the high-risk-conferring HLA-DR*0301/ *0401 haplotypes recognized a single epitope localized between amino acid positions 270 and 283 of GAD65, a stretch that is located in close proximity to the homology region shared with Coxsackie virus P2-C protein. All lines with this specificity were restricted to the DRA, B1*0401 product of the DR4 haplotype. Analysis of the GAD-specific T cell response in a second patient homozygous for DR4 haplotypes demonstrated that the same DRA, B1*0401 allele selected T cells specific for a different determinant. The T cell response profile in a third patient showed that DR*1501/ *1601-encoding haplotypes could present at least three different epitopes to GAD65-specific T lymphocytes. One of these epitopes was presented by a DR allele associated with the resistance-conferring DRB1*1501 haplotype. GAD-specific T cell lines could not be isolated from HLA class II-matched normal individuals. Our data reveal that (a) the T cell response to GAD65 is quite heterogenous in recent onset IDDM patients; (b) HLA-DR, not DQ, seems to be the principal restriction element used by T cells present at the onset of the disease; and (c) T cells responding to epitopes containing identical sequences to Coxsackie virus P2-C protein were not detected.

Improved cognitive and memory abilities in a patient with Alzheimer's disease treated with activated immune cells: Immune cell therapy may benefit more AD patients.

So far, the pathogenesis of Alzheimer's disease (AD) has not been clarified, nor has patient therapy been satisfactory. Although inheritance dominates the less frequent early-onset AD in young and middle-aged individuals, environmental and immunogenetic factors have been identified in the most frequently occurring late-onset AD of higher-aged individuals, comprising 90% of AD patients. Thorough investigations have detected a prevalence of certain microbes which are known to affect brain activities in the brains of AD patients. This microbial prevalence suggests failing immune responses by immune gene variants against specific microbes. In fact, some immune gene variants have been detected significantly more often in AD patients. Failing immune responses can be corrected by activating immune cells outside the body ("in vitro") for the subsequent therapeutical injections. Activated immune cells digest and present microbial peptides better and differentiate naïve/resting immune cells to powerful effector cells, which can be used for therapy. The patient's activated immune cells can pass the blood-brain barrier and overcome chronic infections in the brain. Furthermore, activated immune cells can secrete a series of neurotrophins for the restoration of neuronal circuits. Based on the encouraging results of immunotherapy in a patient with late-onset AD, we hypothesize that therapy with the patient's activated immune cells would safely benefit many AD patients.

Do dogs harbour risk factors for human breast cancer?

We ask consulting patients regularly whether they keep pets in order to identify zoonotic factors. It became apparent that patients with breast carcinoma (N=69) owned significantly more often dogs but not cats compared to age matched female controls. We compared the frequencies of dog and pet ownership with data from public available statistics on women (N=1320) of the same age group in Bavaria. The most striking result was that more than twice the number of patients kept dogs permanently in the last 10 years and at the time of interrogation as compared to control individuals at the time of interrogation (p=0.0000003, relative risk 3.5). Further internet search on the morbidity of breast carcinoma showed in dogs a protracted course of disease and metastases into lung, liver and bones, resembling the course of disease in human breast cancer. In contrast with this, breast cancer presented in cats a dramatically short course and the main but unusual location of metastasis presents in the hind legs. A recent publication in Norway reported on a high frequency (53.3%) of breast carcinomas in 14,401 investigated dogs. Which transmissible factor or factors come into question? Variants of the mouse mammary tumor virus (MMTV) can productively replicate in human cells and in different animals, including dogs. Many investigators, but not all, could identify MMTV-like sequences in sporadic human breast cancer. MMTV or MMTV-like sequences have not been investigated in canine breast carcinomas until now. It is also conceivable that other microbes from the dog, for example bacteria, could participate in the first steps of carcinogenesis in human. It was recently shown that bartonella species promote vascularization and prevent apoptosis of infected cells with the same methods as helicobacter pylori. Our considerations require further research. Epidemiologic cohort studies and identification of potential carcinogenic microbial factors will prove or disprove our hypothesis that risk factors from dogs could contribute to the carcinogenesis of human breast cancer.

Production of human T cell growth factor.

We provide here a protocol for production of T cell growth factor (TCGF) using cells isolated from defibrinated blood. Whether combined in allogeneic pools or tested as single donors, these cells consistently yield high activity TCGF, following PHA stimulation. Protocols using cells isolated from heparinized blood have often included addition of indomethacin or removal of adherent cells, or both, to overcome the problem of frequent nonproducing cultures. Our failure to find nonproducing cultures using this source of cells suggests that inhibitory cells or factors are removed by the blood clot formed during defibrination. A distinct economic advantage is gained by using these cells, not only because of the reliability of obtaining active supernatants, but also because the same blood can be used for preparation of a serum pool for cell cultures and the erythrocytes are useful for absorption of contaminating PHA present in the TCGF-containing media. Not only can defibrinated blood leukocytes be stimulated by PHA to release TCGF, but when cultured in allogeneic mixtures containing no PHA, they also release active TCGF.

Biochemical dissection of DRw6 related epitopes using monoclonal antibodies.

Three monoclonal antibodies (MoAbs) directed against polymorphic epitopes of Ia antigens were used as tools for a serological and biochemical dissection of the class II products encoded by the HLA-DRw6 haplotype. MoAb 16.23 defines an epitope common to DRw13 and DR3 haplotypes, MoAb S5 defines an epitope common to DRw13 and DR2 haplotypes, and MoAb S2 defines an epitope apparently restricted to DRw13. Not all DRw13 cells express these epitopes. Analysis of 16 DRw6 homozygous typing cells showed that expression of all three epitopes was restricted to those DRw13 cells that carried the Dw18 antigen, the DRw13 Dw19 cells being negative. The relationships among the molecules bearing these epitopes were investigated using sequential immunoprecipitation in lymphoblastoid cell lines derived from genetically characterized individuals. In both DRw13 and DR2 bearing cells, the DR2 + w13 epitope was localized to a population of DQ molecules which also carried the DQw1 specificity defined by MoAb Genox 3.53. The S5 epitope is therefore a private specificity that distinguishes the DQw1 antigens encoded by the DR2 and DRw13 haplotypes from the DQw1 antigens encoded by other haplotypes. The DRw13 and the DR3 + w13 epitopes were both shown to be expressed on DR molecules that also carried a DRw52-like specificity. In a DRw13 haplotype encoding both the S2 and 16.23 epitopes, the epitopes appeared to be located on separate molecules. The antibodies described here can distinguish between DRw13 cells which carry different Dw antigens, identify a private specificity on the DQw1 antigen, and define two distinct DR molecules encoded by some DRw13 haplotypes.

Noncodominant expression of target antigens recognized by human cytotoxic T lymphocytes.

Human CTL that recognized MHC-controlled determinants distinct from HLA-A. B, C, and D/DR antigens were tested in a family with nine siblings. Segregation analysis of positive CML reactions showed strong lysis of target cells of three HLA-identical siblings, inheriting the b and c MHC haplotypes (blc), but not of the parents or siblings inheriting only one of these haplotypes. Some cytotoxicity was seen against parental target cells, although it seemed to be qualitatively distinct from that directed against the b/c targets. Studies using the competitive inhibition technique showed that cells inheriting only the b or c haplotypes were not effective in decreasing the specific cytotoxicity. Furthermore, simultaneous inclusion of inhibitor cells of both the b and c haplotypes did not hinder the specific cytotoxicity. Induction of CTL recognizing this new determinant did not occur when either antigens of the b or c haplotypes were used as MLC stimulating cells, or when antigens of both haplotypes were presented simultaneously, but on separate stimulating cells, in a three-cell MLC. These results suggest that the target determinant recognized by these unusual CTL is complex; it may be formed through interactions of two surface molecules or by genetic complementation yielding a hybrid antigen.

Isolation of HLA-haplotype-specific human T-lymphocyte clones.

Human T-lymphocyte clones showing proliferative and cytotoxic responses specific for HLA antigens were isolated. To obtain enriched numbers of functionally active colonies, the cells were first sensitized in vitro in a tertiary mixed lymphocyte culture (MLC), using 10 stimulating cells for each responding cell. To assess quickly the genetic specificity of the clones, the cells used in the priming MLC and later as screening cells were prepared from an HLA-typed family. Using this approach, 75% of the colonies seeded at 1 cell/well showed functional activity specific for HLA.

Cell-growth kinetics and karyotype analysis of human memory lymphocytes responding to alloantigen and mitogen.

Peripheral-blood lymphocytes were primed in vitro with the mitogen phytohemagglutinin (PHA) or with allogeneic cells and their memory responses studied following sequential restimulation with either mitogen or alloantigen. Chromosome preparations were made every 24 hours following exposure to the stimulating agents. Cultures were labeled with BUdR for sister-chromatid staining of the chromosomes which provided information about the kinetics of cell growth and rates of sister chromatid exchange. Cultures containing n BUdR were used for the investigation of cell karyotypes after chromosome-banding. Following PHA as well as alloantigen restimulation, an earlier reaction of the responding cells was observed. The peak response after the first stimulation was found at 120 h with allogeneic stimulation and at 60 h with mitogen stimulation. In the second round of stimulation, the peak occurred after 48 h (allogeneic) and 36 h (PHA) and following the third stimulation after 36 h (allogeneic) and 24 h (PHA). The speed of cell growth was decreased following restimulation with either alloantigen and mitogen. In contrast to the allogeneic restimulation, the number of cells responding after PHA restimulation was decreased. No systematic numerical or structural aberration of the karyotype was detected following repeated stimulation with either alloantigen or mitogen. In this sense, the lymphocyte subpopulations selected by repeated stimulation did not differ from the starting material. On the other hand, the sister-chromatid exchange (SCE) frequency was increased following allogeneic restimulation, whereas it remained constant with PHA restimulation.

Lack of protection from HIV infection by the mutant HIV coreceptor CCR5 in intravenously HIV infected hemophilia patients.

The CCR5 chemokine receptor is an important coreceptor for macrophage-tropic HIV strains. Homozygous carriers of the mutated CCR5 receptor with a 32 bp deletion (delta 32-CCR5) are highly protected against HIV infection. A protective effect has also been described for heterozygous individuals carrying both mutated and wildtype CCR5 receptors. We compared the frequency of the mutated delta 32-CCR5 HIV coreceptor in HIV positive patients infected by sexual contact (N = 160) with intravenously HIV infected hemophilic patients (N = 84) and HIV negative individuals (N = 421). We found no protective effect of delta 32-CCR5 HIV coreceptor in hemophilic patients (p = 0.0134). If proteins of plasma concentrates would be responsible for facilitating the entry of HIV macrophages by upregulation of the CCR5 wildtype receptor it would be of therapeutical interest to identify the responsible plasma proteins.

The multifactorial nature of MHC-linked susceptibility to insulin-dependent diabetes.

Several lines of evidence suggest that major histocompatibility complex (MHC)-linked susceptibility to insulin-dependent diabetes mellitus (IDDM) is not restricted to the presence or absence of any single gene product. The existence of population-specific haplotypes associated with IDDM supports the concept that distinct combinations of MHC alleles interact synergistically to induce disease when other environmental and genetic factors are present. MHC-controlled peptide transport and binding to MHC molecules as well as the levels of MHC class I and class II expression in the thymus and pancreatic beta cells may also play significant roles in the outbreak of IDDM. These intrinsic factors shape the T-cell receptor (TCR) repertoire during T-cell ontogeny in the thymus and later influence the efficiency of potentially autoreactive T cells in the periphery. Several extrinsic factors, such as viruses or dietary proteins, may be directly involved in the TCR/MHC interaction at the cell surface; furthermore viruses can alter the regulatory mechanisms of peptide/MHC interaction and expression. We propose that these intrinsic and extrinsic factors need not be mutually exclusive and might even be interdependent: a given virus may act deleteriously only when certain autoreactive T cells and combinations of MHC alleles are present in the individual. IDDM would develop if pathogenic T-cells are activated and an appropriate target MHC/peptide is expressed in pancreatic beta cells. Future knowledge of the host-virus relationships influenced by the MHC genes, the function of their encoded proteins and the polymorphic gene structure of well-established susceptibility MHC haplotypes will help delineate an overall picture of this issue.

Cessation of immunosuppression after renal transplantation.

Five recipients of successful living related donor kidney transplants stopped azathioprine and prednisone against medical advice. Two recipients who were nonidentical by human leukocyte (HL-A) serotyping and mixed leukocyte culture (MLC) became uremic again after cessation if immunosuppression for periods of 2 and 6 months. Both patients died while refusing to reinstitute iunosuppression and their kidneys showed severe rejection histologically. Three recipients of MCL and HL-A identical kidneys were off azathioprine and prednisone for periods of 7, 12, and 30 months, respectively. None developed changes in renal function. Two patients currently are back on immunosuppression. The third recipient remains stable although off immunosuppression for 36 months; her cessation of immunosuppression was elicited by a mailed questionnaire sent to all recipients following detection of the first four. In addition to these five patients, three recipients of cadaver kidneys lost graft function after lapses in immunosuppression. This represents a 4% incidence of major lapses in immunosuppression (excluding known cessation during sepsis). The clinical outcome depended on degree of histocompatibility as best measured by MLC.

Association of herpes simplex virus-induced erythema multiforme with the human leukocyte antigen DQw3.

We studied the genetic markers in human leukocyte antigen (HLA) region HLA-A, -B, -C, -DR, -DQ, C2, Bf, C4A, and C4B of 31 patients with erythema multiforme (EM) and their families. In contrast to the complement allotypes, which showed no deviation from the distribution in the normal population, two HLA class II antigens occurred in much higher frequency in patients with EM. The frequency of HLA-DQw3 (77.4%) increased with high significance compared with normal Caucasian control individuals (41.2%). An even stronger DQw3 association was found in the patient group with postherpetic EM (88.8%; relative risk, 9.41). Interestingly, all patients suffering from frequently recurrent EM were found to have the DQw3 allele (relative risk 44.2). The previously reported association to HLA-B15 was also seen and may be due to a linkage disequilibrium with the HLA-DR4 allele (66.6% in recurrent EM). Our data provide further evidence that classic recurrent EM is related to herpes simplex virus infection and should be regarded as a distinct entity within the enigmatic EM syndrome. DQw3 may serve as a helpful marker for distinguishing this entity from other diseases with EM-like lesions.

Cultured human T lymphocyte lines and clones as immunogenetic tools.

Human T lymphocytes were sensitized in vitro to allogeneic determinants encoded by the HLA region and subsequently cloned by limiting dilution in the presence of human T cell growth factor. An in vitro priming protocol entailing multiple rounds of allostimulation in mixed lymphocyte culture, using a disparate stimulating to responding cell ratio (10:1), enabled a high frequency of functionally active clones to be isolated. The specificity of the proliferative and cytotoxic reactivities was ascertained directly by screening in an HLA characterized family.

The isolation and characterization of murine monoclonal antibodies directed to polymorphic epitopes on HLA antigens.

Twenty-two murine monoclonal antibodies directed to distinct polymorphic epitopes on HLA class I or class II antigens have been isolated and characterized using a simple protocol for fusion and hybridoma selection. Thirteen MAbs directed to class I antigens are reported here for the first time. The majority of these MAbs reacted with multiple specificities, often revealing a surprising sharing of epitopes. MAbs directed against single classically defined alloantigenic specificities were also obtained.