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The suitability of blood collected on filter papers in comparison with corresponding conventional serum samples in the diagnosis of bovine anaplasmosis was studied using the Complement Fixation Test (CFT), DOT-ELISA, Western immunoblot and Rapid Card Agglutination Test (RCAT). Dried blood on Whatman filter paper no. 1 was eluted in 1.8 ml of PBS 0.05% Tween 20 given an initial dilution of 1:100. The reactivity in both DOT-ELISA and Western immunoblotting was similar to that obtained with the sera diluted 1:100. Filter paper samples gave lower reactivity in all the tests as compared with corresponding serum samples. There was no significant difference in the reactivity between the eluates from filter papers stored at room temperature and those stored at 4°C. Storage at room temperature did not significantly affect reactivity for up to 6 months. Eluates from filter papers stored for 6 months at room temperature continued to give similar reactivity to those from freshly prepared filter papers in both DOT-ELISA and Western blot, and in the Rapid Card Agglutination Test. It is concluded that collecting blood on filter papers is a suitable technique for large-scale screening and for seroepidemiological studies on anaplasmosis, and offers many advantages especially in developing countries where transport and cold chain facilities are a major constraint. [ABSTRACT FROM AUTHOR]

The prevalence of bovine anaplasmosis was studied in 320 Zebu cattle randomly selected from three regions of Uganda (central, south-western and north-western) using DOT-ELISA, Western immunoblotting. Rapid Card Agglutination Test (RCAT), Capillary Tube Agglutination Test (CAT), Complement Fixation Test (CFT), and parasitological techniques. Dried blood on Whatman filter paper no. 1 was eluated in PBS 0.05% Tween 20 prior to testing at an initial dilution of 1.25. The incidence of parasitaemia ranged from 25% in the central region to 35% in the northwestern region and the serological prevalence was lower in the central region and highest in the north-west. Prevalence rates assayed by DOT-ELISA and Western immunoblotting were 1.5-fold greater than those tested with RCAT and 3-fold greater than in CAT. The overall prevalence rates by DOT-ELISA and Western immunoblotting compared favourably with CFT data. The present data utilizing dried blood on filter papers indicate that there is a high prevalence of anaplasmosis in those regions of Uganda surveyed and it confirms our observations and those of others that collecting blood on filter papers is a suitable technique for large-scale screening and for seroepidemiological studies. [ABSTRACT FROM AUTHOR]

Our understanding of immunity to filarial infection is enigmatic and continues to be passionately debated. The mechanisms whereby filarial nematodes are killed in vivo and how these parasites avoid these mechanisms are poorly understood. Although vaccination studies in permissive animals took off seven decades ago, the exact mechanisms driving protective immunity are extensively being investigated. Currently, little is known regarding the collective functions or counter-regulatory mechanisms of the antibody isotypes in filarial infection with respect to protective immunity. Establishing the functional role of antibody isotypes and cytokines in the various infection phenotypes can contribute immensely to current knowledge in filarial immunology. This paper reviews insight into protective immunity in filarial infection with focus on humoral and cellular responses from animal models and human studies. [ABSTRACT FROM AUTHOR]

Protective immunity against mycobacteria is dependent on antigen-specific T cells. The antibodies induced upon immunization with mycobacteria have no apparent role in host protection, Serological techniques have detected some antigens that are also recognized by human T cells but may fail to recognize others. Potentially, there may be differences in the epitopes seen by the T and B cell anti-mycobacterial antigen repertoires. We have screened the different components of sonicated BCG or Mycobacterium leprae that were separated according to their molecular weight (MW) by SDS-PAGE and then electroblotted on nitrocellulose paper. The blots were cut into squares and tested directly in a T cell proliferation assay. Our results indicate that peripheral T cells of healthy leprosy patient contacts respond preferentially to the lower MW (<70,000) and not the higher MW fractions of M. leprae and BCG, in contrast to the humoral response of these same individuals. The most important fractions in inducing a lymphoproliferative response were in the regions of 11-16 kDa of BCG and M. leprae and to the 22-26 kDa region of M. leprae. These fractions appeared to represent molecular weight regions that were in some instances clearly distinct from previously defined antigens. It was further shown that lymphoproliferation in response to mycobacterial fractions correlated with the production of gamma interferon, a lymphokine required for macrophage activation and elimination of mycobacteria. These studios allow the direct assessment of antigens involved in protective T cell-mediated immunity, and should be helpful in selecting relevant antigens for skin testing and immunization. [ABSTRACT FROM AUTHOR]

The antibody response to a hapten conjugated to a protein can, in a number of situations, be suppressed by prior immunization with the carrier protein alone. The study of this finding appears to have been handicapped by previous literature on the subject having been consistently misquoted. It is to be hoped that recognition of this will allow a better understanding of the limitations to such suppression, and hence the mechanism by which it may act, [ABSTRACT FROM AUTHOR]

Two main ideas have been put forward lo explain the unexpectedly low anti-hapten antibody titres which can result from pre-priming a mouse with carrier before hapten-carrier immunization. The first involves the interaction of a network of idiotype-specific suppressor T cells, the second instead arguing for the role of intrinsie B-cell anergy. This paper proposes that the data available can equally be interpreted as reflecting the suboptimal interaction between T and B cells at differing stages of maturity, provided that memory B cells can be divided into two subsets. Further, it is suggested that these considerations must be taken into account in the analysis of B-cell anergy in receptor transgenic mice. [ABSTRACT FROM AUTHOR]

This paper describes studies of genetic markers and immune functions in the first Icelandic family identified with X-linked agammaglobulinaemia (X-L,A). including three affected brothers. The eldest brother was diagnosed at the age of 9 in 1963. He suffered repeated infections and died at the age of 23. The other two affected brothers, diagnosed al 6 years and 1 year of age, are alive and well on immunoglobulin replacement therapy at the ages of 32 and 24. All were typed for HLA, complement, and various other markers. Pedigree analysis suggests an X-linked segregation of the disease. Their serum IgG is maintained at normal levels on therapy. Several parameters of immune function were studied. The following results were obtained for the X-LA brothers: B cells are absent in their peripheral blood samples, T-cell numbers arc normal, but monocytes are increased in numbers and activity. No immunoglobulin production could be elicited in vitro with PWM and no cells containing cytoplasmic Ig were detectable among PWM-stimulated blasts. Nevertheless the proliferative response was particularly vigorous, but the responding cells were shown to be exclusively T cells. No blast transformation could be achieved with EB virus. NK-cell activity was normal/high normal. Other cell-mediated immune functions were normal, In conclusion our data indicate that the differentiation of B cells is blocked in the two surviving XLA brothers. They have survived for a longer time and in better health than is generally reported- Early diagnosis and adequate replacement treatment with Ig is clearly crucial. Vigorous nonspecific immune mechanisms may help to compensate for the defective specific immune mechanisms may help to compensate for the defective specific immunity. [ABSTRACT FROM AUTHOR]

Antigen 60 (A60), a member of the thermostable macromolecular antigen family (TMA) and main component of old tuberculin and purified protein derivative (PPD), has been purified from the cytoplasm of Mycobacterium bovis BCG; its structure and metabolism have already been described. In the present paper, the action of A60 on humoral immunity has been analysed by an ELISA type immunoassay, and that on cellular immunity by the mouse footpad swelling test. Injection of very low A60 doses into unprimed mice produced an undetectable level of anti-A60 antibodies: the effect or a booster inoculation was not appreciable in the absence of incomplete Freund's adjuvant, but was evident when the latter was added. Higher doses of the antigen produced an appreciable primary response, and a sharp and long-lasting secondary response, which had a 10-fold higher intensity in the presence of incomplete adjuvant. No detectable delayed hypersensitivity reactions were observed in unprimed mice after footpad injection of A60, whereas clear responses were elicited in primed mice. This effect was more pronounced when the footpad was injected after a secondary response than after a primary response, and it was invariably magnified by incomplete adjuvant. It is concluded that A60 is a powerful immunogen, which is able to induce primary and secondary responses and delayed hypersensitivity reactions, effects that are adjuvant-modulated and develop concurrently. [ABSTRACT FROM AUTHOR]

Optimal proliferative response of T lymphocytes to purified protein derivative of tuberculin (PPD) in vitro requires that antigen be presented by autologous macrophages or allogeneic macrophages sharing HLA-D/DR determinants with the T cell donor. In some cases, however, T cells may respond to a limited extent to PPD in association with macrophages expressing different HLA-D/DR determinants. In this paper experiments are presented where various combinations of T cells and HLA-D/DR disparate macrophages were stimulated with PPD. We often found a strong PPD-specific response in HLA-D/DR-incompatible combinations in which the macrophages carried HLA-DR antigens known from serological studies to be cross-reactive with those of the T cell donor than in combinations in which this was not the case. Thus, the cross-reactions detected by serology may sometimes be reflected on a functional level in T lymphocyte/macrophages cooperation. [ABSTRACT FROM AUTHOR]

Virus neutralization at respiratory mucosal surfaces is important in the prevention of infection. Mucosal immunity is mediated mainly by extracellular secretory immunoglobulin A (sIgA) and its role has been well studied. However, the protective role of intracellular specific IgA (icIgA) is less well defined. Initially, in vitro studies using epithelial cell lines with surface expressed polymeric immunoglobulin receptor (pIgR) in transwell culture chambers have shown that icIgA can neutralize influenza, parainfluenza, HIV, rotavirus and measles viruses. This effect appears to involve an interaction between polymeric immunoglobulin A (pIgA) and viral particles within an intracellular compartment, since IgA is transported across the polarized cell. Co‐localization of specific icIgA with influenza virus in patients' (virus culture positive) respiratory epithelial cells using well‐characterized antisera was initially reported in 2018. This review provides a summary of in vitro studies with icIgA on colocalization and neutralization of the above five viruses. Two other highly significant respiratory infectious agents with severe global impacts viz. SARS‐2 virus (CoViD pandemic) and the intracellular bacterium—Mycobacterium tuberculosis—are discussed. Further studies will provide more detailed understanding of the mechanisms and kinetics of icIgA neutralization in relation to viral entry and early replication steps with a specific focus on mucosal infections. This will inform the design of more effective vaccines against infectious agents transmitted via the mucosal route. [ABSTRACT FROM AUTHOR]

It has been 25 years since we first described long‐lived memory plasma cells of the bone marrow, 13 years since we identified bone marrow resident memory T cells and 2 years since we showed that the bone marrow is also a preferred location of resident memory B cells. The bone marrow is increasingly recognized as a fundamental component of long‐lasting immunological memory, not only providing protective immunity but also fuelling chronic inflammation. We now understand that the bone marrow functions as the 'backbone' of immunological memory, hosting the memory plasma cells which provide not only humoral immunity but also memory B and T cells, which constitute 'reactive memory'. This knowledge now allows us to define true cellular 'correlates of protection' for systemic immunity, its quality and duration, as induced by infection and vaccination, something that has never been more important given the recent SARS‐CoV‐2 pandemic. While memory plasma cells of the bone marrow indicate long‐lasting humoral protection, memory T (and B) cells mobilized into the blood in secondary immune reactions indicate the strength of reactive memory. In this review, we have contextualized many of our own findings from the last two decades that have contributed to our understanding of how bone marrow‐resident memory cells provide local and systemic immunity. [ABSTRACT FROM AUTHOR]

World Health Organisation recommends the practice of BCG vaccination at birth in countries which have a high incidence of tuberculosis and/or high leprosy burden. The BCG vaccination is considered safe for a competent immune system. However, in children with weakened immune systems cause of which can be primary or secondary, the vaccine may lead to side effects which can be localized or disseminated. In this study, we report a spectrum of inborn errors of immunity (IEI) commonly referred to as primary immunodeficiency disorders (PIDs) diagnosed in a large cohort of patients presenting with complications to BCG vaccination from India. Retrospective data analysis of patients referred to ICMR‐ National Institute of Immunohematology (ICMR‐NIIH) for IEI workup between 2007 and 2019 was done. IEI was identified in n = 52/90 (57.7%) patients presenting with BCG complications. Of these, n = 13(14.4%) patients were diagnosed with severe combined immune deficiency, n = 15(16.7%) with chronic granulomatous disease, n = 19(21.1%) with Inborn errors of IFN‐γ immunity, n = 4(4.4%) with Combined immunodeficiency and n = 1(1.1%) with Leucocyte Adhesion Deficiency type1. Majority of cases with BCGosis (88%) had an underlying IEI. This study strongly highlights the need for evaluation of patients with BCG complications for underlying IEI. While disseminated BCGosis strongly predicts underlying IEI, even localized persistent adenitis may be a warning sign of underlying IEI. It is also strongly recommended to record a family history of previous sibling death prior to administration of this live vaccine and deferring live vaccine till the diagnosis of IEI is ruled out in cases with a positive family history. [ABSTRACT FROM AUTHOR]

Intrasplenic immunization with antigen immobilized on nitrocellulose (NC) paper results in an immune response with nanogram amounts of antigen without the use of Freund's adjuvant. Comparing the sensitivity of the intrasplenic immunization with intraperitoneal or subcutaneous administration, we found that the intrasplenic method resulted in more positive animals with higher titres than did the other techniques with the smallest amount of antigen (70 ng of bovine serum albumin). With larger amounts of albumin the intraperitoneal method yielded the highest titres. No loss of antigenicity was observed when we immunized with equal amounts of protein separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotted and stained with either Coomassie brilliant blue R 250 or Amido black 10 B. [ABSTRACT FROM AUTHOR]

The article discusses ligands and receptors in autoimmune systems. Brief information regarding ligands and receptors; Theories of idiotype network; Lists of diseases that involves autoimmunity to receptors; Utilization of the cellular receptor repertoire.

Primed LD typing cells were prepared against single HLA baplotypes within families and used to type a random panel of 48 individuals. PLT cells could be grouped on the basis of highly correlated responses with the panel test cells; the 21 different PLT cells could be used to define 6 different PL antigens. One of these, PL 3, was split by the responses of two of the 21 PLT cells which measured an antigen called PL 3.1. [ABSTRACT FROM AUTHOR]

The recognition and neutralization of tumour cells is one of the big challenges in immunity. The immune system has to recognize syngeneic tumour cells and has to be primed and respond in an adequate manner. Priming of a leukaemia-specific immune response is a crucial step in tumour immunology that can mislead to tumour tolerance either by T cell ignorance, deletion or Treg induction. To resemble the situation of acute lymphoblastic leukaemia ( ALL) in patients, we used the murine BALB/c model with syngeneic BM185 tumour cells. We established a tumour cell line that expresses the neo-antigen ovalbumin ( BM185- OVA/ GFP) to allow the application of T cell receptor transgenic, antigen-specific CD4+ T cells. Here, we demonstrate that effective anti- ALL immunity can be established by in vivo priming of CD4+ T cells that is sufficient to differentiate into effector cells. Yet they failed to control tumour alone, but initiated a Th1 response. An efficient tumour clearance was dependent on both antigen-specific CD4+ T cells and CD8+ effector T cells from the endogenous repertoire. The tolerogeneic milieu was characterized by increased Tregs numbers and elevated IL-10 level. Tregs hamper effective antitumour immune response, but their depletion did not result in reduced tumour growth. In contrast, neutralization of IL-10 improved median mouse survival. Future therapies should focus on establishing a strong CD4+ T cells response, either by adjuvant or by adoptive transfer. [ABSTRACT FROM AUTHOR]

The complement system is a major part of the innate immunity. The first component of the classical pathway of complement activation, C1q, plays a crucial role in the clearance of immune complexes and apoptotic bodies from the organism. Autoantibodies against C1q (anti-C1q) have been found in a number of autoimmune and infectious diseases. They have been best described in patients with systemic lupus erythematosus, where they are thought to play a pathogenic role in lupus nephritis (LN). Their high negative predictive value for the occurrence of active proliferative LN, as well as their possible ability to indicate a renal flare as soon as 6 months in advance, have rendered anti-C1q antibodies a novel non-invasive tool in the detection of active LN. [ABSTRACT FROM AUTHOR]

The need of a specific defence mechanism against intracellular pathogens is proposed to have arisen very early in evolution, perhaps already in protozoa, e.g. amoebae. The phagocytic machinery of amoebae lends itself as a possible starting point for the evolution of such a mechanism. The hypothetical evolutionary pathway described here has been constructed to demonstrate the feasibility of developing a defence system against pathogens in the amoeba, which bears resemblances to contemporary cell-mediated immunity, and can thus be considered as its ancestor. [ABSTRACT FROM AUTHOR]

This study was aimed to assess the prevalence of naturally acquired humoral immune responses and their association with reduced susceptibility to malaria in children and adults with differential clinical conditions from an Indian zone where malaria is endemic. The study was undertaken in an eastern province of India (Keonjhar, Orissa) in a group of 341 children (both younger and older) and 98 adults living in two different areas, Town area and Forest area. They were studied for their parasitological and immunological profiles. Sera from different age-matched groups were screened by ELISA to measure IgG reactivities for characterizing humoral immune responses to the B-cell epitopes of Plasmodium falciparum MSP1, AMA1, RAP1 and EBA175 peptides and P. falciparum-infected erythrocyte lysate. In Town area, overall P. falciparum cases were 5.5%, whereas those in Forest area were 26.7%. We observed an age-wise increasing trend of immunity in these two populations. It was also noticed that the frequency of responders to stage-specific antigens was higher in individuals from the Town area where the frequency of malaria was lower. The naturally acquired humoral immune responses to different stage-specific antigens of P. falciparum reflect the reduced risk of malaria in the study groups. The higher frequency of seroresponders showed correlation with lower risk of developing malaria. [ABSTRACT FROM AUTHOR]

In Credo 2004, Zinkernagel and Hengartner (Z&H) have continued their challenge to the immunological community to reconsider assumptions regarding the most fundamental aspects of adaptive immunity. They have appropriately championed the role of persistent, widely distributed antigen in tolerance induction, parameters that do not figure prominently in most other models. The global theory of immunity they have developed is predominately based on observations from studies with viruses and tumours. I suggest here that a more successful approach to generating a theory of the default rules of immunity can be obtained through the study of immunity versus tolerance in the setting of transplantation. Transplantation studies lack the confounding variable of competing evolution present in responses to specific infectious agents and tumours and, therefore, more clearly elucidate default rules of immunity. The geographical model in Credo 2004, primarily a one-signal model regulated by antigen, is contrasted with (1) Cohn's time-based two-signal model and (2) a development–context model that postulates distinct central and peripheral tolerance mechanisms. [ABSTRACT FROM AUTHOR]

An ideal immune system should provide each individual with rapid and efficient responses, a diverse repertoire of recognition and effector molecules and a certain flexibility to match the changing internal and external environment. It should be economic in cells and genes. Specific memory would be useful. It should not be autoreactive. These requirements, a mixture of innate and adaptive immunity features, are modulated in function of the dominant mode of selection for each species of metazoa during evolution (K or r). From sponges to man, a great diversity of receptors and effector mechanisms, some of them shared with plants, are articulated around conserved signalling cascades. Multiple attempts at combining innate and adaptive immunity somatic features can be observed as new somatic mechanisms provide individualized repertoires of receptors throughout metazoa, in agnathans, prochordates, echinoderms and mollusks. The adaptive immunity of vertebrates with lymphocytes and their specific receptors of the immunoglobulin superfamily, the major histocompatibility complex, developed from innate immunity evolutionary lines that can be traced back in earlier deuterostomes. [ABSTRACT FROM AUTHOR]

Common variable immunodeficiency, CVID, is a primary antibody deficiency characterized by decreased levels of serum immunoglobulin G (IgG), decreased IgA and/or IgM and recurrent infections. It is assumed to be heterogeneous group of disorders caused by different genetic defects. Some patients have decreased levels of class switched memory B cells and/or decreased levels of somatic hypermutation which points to defects in the germinal centre (GC) reactions as cause of the disease in these patients. The inducible costimulator, ICOS, and its' ligand, ICOSL, are both involved in and necessary for the GC reaction and so is activation-induced cytidine deaminase, AID. Therefore, we sequenced the ICOS, ICOSL and AID genes in a cohort of 34 Danish CVID patients. We found 13 new single nucleotide polymorphisms (SNP) in the intron regions of the ICOSL gene as well as one SNP in exon 3. However, none of these polymorphisms were associated with CVID. We did not find a previously reported CVID-causing ICOS gene deletion or any other unique mutations in the ICOS or AID genes. [ABSTRACT FROM AUTHOR]

Discusses the Danger model of immunity in its historical context. Similarity between Danger model and models based on self-nonself discrimination (SNSD); Assumption of the classical SNSD model about an individual's immune system; Essential elements of the Danger model.

This article focuses on symposium held at Weitenburg Castle, West Germany, 19-20 June 1976. The symposium dealt with the increasingly important field of genetic markers available for the HLA-D region. Since the early recognition some years ago of la-like antigens that could be detected serologically in man separate from the SD antigens, there has been a rapid development in this area. The present volume contains several reports bringing the field up to its present state of knowledge.

Comments on the views of Melvin Cohn and R. E. Langman on immunology. Conceptual horizon on immunology; Understanding of tolerance and immunity; Difference between an antigen-sensitive and an effector lymphocyte.

Mycobacterium bovis infection in cattle continues to be a problem in several regions, partly due to inadequate diagnostic tests. The aim of this study was to use an experimental model of the natural disease to identify T-cell epitopes from the mycobacterial 38kDa antigen as potentially specific diagnostic reagents. A panel of overlapping synthetic peptides (16-mers with a five-residue overlap) were produced from the published amino acid sequence. It was found that peripheral blood lymphocytes from at least three of four experimentally infected animals, which were considered to be in either Th1-or Th1/Th2-dominated stages of anti-mycobacterial immunity, proliferated in response to five epitopes (residues 1-27, 88-107, 122-138, 243-260 and 307-328). However, in vitro production of IFN-γ was detected only in response to epitope 122-138, indicating a role in protective immunity. The peptides were not recognized by control, uninfected animals, but all epitopes showed various degrees of recognition by animals which were field reactors to intradermal tuberculin testing. Furthermore, epitopes 1-27, 88-107 and 122-138 were recognized by four breeds of cattle and by animals from separate herds, suggesting genetic permissiveness in recognition which would be essential in the development of a diagnostic test. [ABSTRACT FROM AUTHOR]

Somatic mutation activity in immunoglobulin Vκ genes during the response to the hapten 2-phenyl-5-oxazolone was measured in lymph node B-cell populations at various timepoints after footpad immunization. When the VκOx1 genes rearranged to the Jκ5 segment were amplified from genomic DNA using the polymerase chain reaction and sequenced, somatic mutations could be detected as early as day 4 after immunization. Somatic mutations were also detected after sequencing RNA from oxazolone-specific hybridomas derived from lymph node cells at day 4 after immunization. These early mutations were found mostly in cells with a germinal centre phenotype. No indication of selection at the population level by apoptosis was detected until day 7 after immunization. These results suggest somatic mutations can be induced very early during the immune response in lymph node cells, prior to the peak of clonal expansion and selection with regard to antigen binding. [ABSTRACT FROM AUTHOR]

Patients with defects of terminal complement components are particularly exposed to the risk of developing neisserial infections and seem to respond poorly to meningococcal capsular polysaccharide (PS) C via natural immunization. The sole meningococcal PSC is, on the other hand, an excellent immunogen in normal people. Considering the great importance of vaccine prophylaxis for the prevention of meningococcal infections in patients with complement defects, it is crucial to study the antibody response to the sole meningococcal PS in these patients. We therefore analysed the levels of anti- PSA and PSC antibodies in the members of four families including patients with homozygous and heterozygous defects of C7, C8 or factor H, before and after vaccination with the sole PSA + C. Surprisingly, we found the highest levels of antibodies before vaccination In homozygous subjects, followed by heterozygous and normal controls, whereas, after vaccination, homozygous subjects showed the lowest increase of specific antibodies, indicating their relative incapability to respond to sole meningococcal PS. In conclusion, this study demonstrates (I) the capacity to respond to meningococcal PS via natural immunization by patients with total complement defects, and (2) the low responsiveness to meningococcal PS via vaccine immunization by the same patients. We propose that vaccination should be given to patients lacking specific antibodies and their serological response should be assessed. In addition this study confirms previous observations on a likely lower immunogenic power of meningococcal serogroup C via natural immunization compared with the better immunogenicity of the sole PSC. [ABSTRACT FROM AUTHOR]

Flow cytometry with the specific monoclonal antibody (MoAb) L31 was used to analyse the expression of HLA class I heavy chains not bound with β2-microglobulin (β2m) by neuroblastoma (NB) cell lines IMR- 32 and LA-N-1. The cells, which express barely detectable amounts of β2m-free (L31-positive molecules) and β2m-complexed HLA class I antigens(W6.32-and BBM.1-reactive molecules), expressed MHC class I molecules not bound to light chains upon differentiation with either retinoic acid or serum starvation. The expression was not accompanied by an increase of surface heterodimers. Conversely, recombinant interferon-γ (rIFN-γ) treatment led IMR-32 and LA-N-1 cells to almost exclusively express β2m-complexed HLA class I heavy chains. Surface β2m-free MHC class I molecules displayed a molecular mass of ∼45 kDa and did not bind exogenously added β2m. No changes in the synthesis of either HLA class I and β2m mRNAs or of L31 proteins were observed in differentiated NB cells, thus suggesting that the surface exposure of unusual HLA class I antigens is regulated post-translationally. These findings indicate that, in addition to activated lymphocytes, the surface expression of β2m-free class I heavy chains is a feature of other cell types, such as NB cells. [ABSTRACT FROM AUTHOR]

We have determined the specificity of the classes of anti-leishmanial antibodies which are delectable in serum from patients with active cutaneous leishmaniasis. On immunoblots. differences exist in the patterns of antigen recognition by IgG, IgM, IgA and IgE antibodies present in localized cutaneous leishmaniasis (LCL) and diffuse cutaneous leishmaniasis (DCL) patient serum. Each class of antibody showed differing patterns of banding to the various molecular species of parasite antigens. There was significant variation in the specificities of the IgG antibody reactivities between individual patients. The patterns of IgM binding were generally homogeneous and restricted to antigens with Mr > 40 kDa. The only class anti-Leishmania antibodies which showed shared patterns of common antigen recognition by all of the patients studied were IgA antibodies. The reactivities of IgE antibodies encompassed two antigens of Mr 36 and 46-48 kDa which were not recognized by any of the other isotypes. Such antibody class associated reactivity may be useful in the design of serodiagnostic assays for the detection of Leishmania infection or other infectious agents. [ABSTRACT FROM AUTHOR]

A review is given of the problems and challenges in using immunological techniques in and for developing countries. [ABSTRACT FROM AUTHOR]

Intravenous injection of 106 to 107 non-fractionated spleen cells (SC) from C57BL/6 (B6, H-2b) mice into completely allogeneic, immunodeficient H-2d severe combined immuno deficiency (scid) mice leads to engraftment of allogeneic donor T cells. Mice analysed in the tenth week post-transfer had engrafted donor-type CD4+ and CD8+ T cells in the spleens but showed no clinical evidence of graft-versus-host disease (GVHD). Transfer of allogeneic T cells engrafted in scid recipients did not induce GVHD upon i.v. injection into secondary scid recipients and lead in most recipients to engraftment of a pure CD4+ T-cell population. Experiments were carried out to investigate the reason(s) for the lack of GVHD in recipient scid mice. i.e. the presence of allotolerance in the engrafted donor T cells. Scid spleen cells (SC) efficiently stimulated alloreactive responses of B6 T cells: scid SC stimulated H-2d-specific cytotoxic responses in a B6 anti-scid mixed lymphocyte culture in vitro, and scid SC injected i.v. into B6 mice efficiently primed splenic cytotoxic lymphocyte precursors against H-2d alloantigens. Moreover when assayed in vitro, no veto activity or natural suppressor activity was detectable in scid SC. These data demonstrate that tolerizing mechanisms currently believed to operate in vivo can not explain the fact that allogeneic T cells injected i.v. into immunodeficient scid mice become tolerized against host-type alloantigens. Our results are discussed in the tight of clinical experience of allogeneic T-cell transfer in scid infants. [ABSTRACT FROM AUTHOR]

We have characterized CD4-CD8- double-negative (DN) αβTCR+ T cells from a patient with immunodeficiency, lymphocylosis, lymphadenopathy, and hepatospletiomegaly. The majority of peripheral blood lymphocytes were DN αβTCR+ T-cells as evaluated by FACS and biochemical analysis. The DN T cells showed the following phenotype: αβTCR+. γδTCR- . CD2+ , CD3+. CD4-. CD5+ CD7- CD8- , CD16-, CD25-, CD26-, CD28-, CD45RO- , CD45RA+, CD57+, and HLA-DR+. Both southern blot analysis of TCR genes and FACS analysis applying a panel of Vβ and Vβ monoclonal antibodies (MoAbs) indicated a polyulonal T-cell expansion. Thymic biopsy showed normal histology, whereas lymph node biopsy samples showed altered histological anti immunohistological patterns with markedly expanded paracortical areas containing the DN T cells of the same phenotype as found in periphernl blood T cells. In functional studies. The DN T cells showed a profoundly reduced proliferative response upon stimulation with mitogens as well as MoAbs against the TCR/CD3 complex, CD2, and CD28, respectively. Addition of exogenous interleukin-2 (IL-2) only minimally augmented the proliferative response. In contrast, the addition of a combination of Ca2+ ionophore and phorbol 12-myristate M-acetate (PMA) restored the proliferative response of the DM T cells to almost normal levels. This observation strongly suggests that the protein kinase C activity of the DN T cells was intact, but that the normal mechanism for transmembrane signal transduction was impaired in these unusual DN T cells. [ABSTRACT FROM AUTHOR]

Expression of HLA class I antigens on the cell surface requires the association of heavy chain. endogenous peptide and β-microglobulin (β2m). We have studied the expression of free class I heavy chain and β2m in cryostatic sections of 51 HLA class I negative human tumours of different origin. Selective low expression of β2m was observed only on the 9 colorectal adenocarcinomas. In contrast, simultaneous under-expression of heavy chain and β2m was detected in the rest of the tumours studied. Our results suggest that the accumulation in the cytoplasm of HLA heavy chain in HLA negative colorectal careinomas is a particular mechanism that cannot be applied to all HLA negative tumours. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated that anti-DNA antibodies share important genetical features with antibodies lo exogenous antigens, suggesting that anti-DNA antibody responses may be (auto-) antigen driven. We have earlier defined three out of five rabbits as anti-dsDNA antibody responders based on reactivity with calf thymus (CT) dsDNA after inoculation with the human dsDNA virus BK. In the present study we demonstrate that all five animals that received BK virus inoculations produced antibodies to BK virus dsDNA, These antibodies did not cross-react with CT dsDNA. as shown by inhibition experiments. The anti-BK dsDNA antibodies persisted over time, in contrast to the anti-CT dsDNA antibodies that decreased shortly after a peak following the first boost of BK virus. While the anti-CT dsDNA antibodies decreased, the anti-BK dsDNA antibodies remained elevated, this supporting the results of the inhibition experiments which showed that two independent antibody populations are produced after BK virus inoculations. In the three animals producing anti-mammalian dsDNA antibodies, antibodies recognizing CT dsDNA reappeared after intravenous administration of a complex of CT dsDNA and methylated bovine serum albumin (MBSA) without adjuvant. The later anti-CT dsDNA antibodies did not cross-read with BK dsDNA, In contrast to earlier studies we conclude that mammalian dsDNA may be immunogenic, and that discrete molecular differences in DNA antigens from different sources may induce anti-dsDNA antibodies specific for dsDNA molecules of different origin. [ABSTRACT FROM AUTHOR]

Mycobacterium w, an atypical cultivable mycobacterium. is undergoing phase III clinical trials as a vaccine against leprosy in India, It has brought about lepromin conversion and histopathological upgradation in a significant number of patients studied so far. It is important to identify antigens of M, w that trigger T-cell responses in leprosy patients vaccinated with this organism. In the present study the peripheral T-cell repertoire of 12 M. w-vaccinated leprosy patients. 10 unimmunized leprosy patients. 8 tubereuloid and 5 healthy contacts was analysed with fractionated antigens of M. w. The lepromatous leprosy patients who are in general anergic to antigens of M. leprae did not respond to antigens of M. w. However, peripheral blood mononuclear cells obtained from leprosy patients who had been vaccinated with M. w responded lo many antigens. These responses were frequently directed against low molecular weight entities of 14-45 kDa, T cells from tuberculoid leprosy patients and healthy contacts also responded predominantly to a number of low molecular weight antigens of M. w. The study also identified an immunodominant 28-31 kDa antigenic fraction carrying T- as well as B-cell activating determinants. [ABSTRACT FROM AUTHOR]

CD40 and CD43 arc two cell-surface glycoproteins that appear to be functionally involved in the growth stimulation of human B cells. Whereas CD40 is structurally similar to the NGF receptor and is present on all resting B cells. CD43 displays no homology to other known proteins and is expressed only on a subpopulation of these cells. To further understand the extra- and intracellular signals regulating these molecules and in which stage of activation they may play a role, we used various activation strategies and studied their expression on tonsillar B cells. As expected, activation of protein kinase C by TPA increased both CD40 and CD43. In contrast, a rise in intracellular Ca-2+. e.g. by ionomycin, did not influence the expression of these antigens. However, in the presence of TPA, ionomycin further up-regulated CD41 but not CD40. Anti- IgM behaved similarly to ionomycin suggesting that the effect of this reagent was due primarily to its ability to increase intracellular Ca2+. Of three interleukins(IL-2, IL-4 and IL-6) only IL-4 had a significant effect when used alone in that it up-regulated CD40 but not CD43. However, in the presence of anti-IgM, both IL-2 and IL-4 synergistically up-regulated the two antigens. Complementation of antigen receptor stimulation with TPA or IL-4 increased CD4U during the first 24 h, whereas up-regulation of CD43 did not occur until 24 to 4S h after stimulation. With regard both to up-regulation in response to different stimuli and to kinetics, CD40 expression paralleled that of the early activation antigen CD23, whereas CD43 was induced in parallel with the transferrin receptor (CD71). Taken together, our results suggests that the expression of CD40 and CD43 is regulated by different intracellular signals and that CD40 may be important during early activation, whereas CD43 may have its major function during later stages of B-cell differentiation. These assumptions are in line with the observations that CD4U antibodies can directly activate resting B cells and that CD43 are retained on plasma cells. [ABSTRACT FROM AUTHOR]

Interleukin 6 (IL-6) is a cytokine with multiple biological activities on various tissues and cells. We have investigated the effect of recombinant human IL-6 (rnIL-6) on growth and differentiation of U937, Recombinant human IL-6 induced a dose-dependent growth inhibition, apparent around day 4. of up to 50%, by day 8 of culture. Concomitant with this, changes in cytochemical activities were observed, indicative of differentiation, A panel of U937 antigens was analysed after culture with rhIL-6, Expression of the majority of these membrane antigens was unaffected, with the exception of two classes. First, rhIL-6 had a profound effect on members of the leucouytic cell adhesion molecules (Leu CAM) family. Expression of the a-chain of CR3 (complement receptor 3; CD11b) was enhanced in a dose-dependent fashion, with maximal expression around day 7, Parallel to this a simultaneous increase in β-chain (CD18) expression was found. Furthermore, enhanced expression of CR3 was accompanied by increased rosetting with sheep erythrocytes sensitized with C3bi, A much lower, but significant, enhancement was observed for the a-chain of the p 150.95 antigen (CD11c). Expression of leucocyte function-associated antigen-1, (LFA-1). (CD11a/CD18) remained unchanged. Remarkably, however, expression of a ligand of LFA-1. intercellular adhesion molecule-1 (ICAM-1; CD54), was enhanced with similar kinetics as CR3 and p150.95. A specific anti-rnIL-6 antiserum completely inhibited the IL-6 effect. These observations provide further support for an important role of IL-6 in the regulation of myeloid cell development in man. [ABSTRACT FROM AUTHOR]

We do not agree with the analysis of Langman and Cohn on the function of Ig receptors. We have reviewed the available literature regarding anti-Ig activation of B cells and found it contradictory and unconvincing. We have presented experimental evidence on the inability of Ig receptors on B cells to mediate activation or tolerogenic signals. We suggest that the Ig receptors serve to focus antigen to specific B cells so the B cells can be activated by TI antigens or helper T cells. The Ig molecules also bind foreign antigen and thereby initiate internalization and antigen processing. The processed peptides are exported to the membrane, where they associate with MI-IC class!! antigens, thus transforming B cells into efficient antigen-presenting cells. [ABSTRACT FROM AUTHOR]

The article presents information on a study related to the reaction of the blood serum and the erythrocytes of different human subjects with one another. The result was only to some extent as expected. With many samples there was no noticeable change, that is, the result was exactly the same as if an individual's blood cells had been mixed with his own serum. Frequently, however, there occurred a phenomenon known as agglutination, in which the serum caused the cells of the alien individual to group into clusters. The surprising finding was that agglutination, when it occurred at all, was just as pronounced as the already familiar reactions, which take place during the interaction between serum and cells of different animal species. However, in the other cases there seemed to be no difference between the blood of different individuals.

Immunological phenotyping of acute leukaemias is important for a more precise diagnosis with respect lo both cell lineage and maturation level. We have developed a rapid and reliable method for immunophenotyping, based on the use of magnetic monodisperse beads coated with monoclonal antibodies. After only a l0-min incubation of immunomagnetic beads (1MB) with mononuclear cells isolated from bone marrow or peripheral blood, the percentage of rosetting cells can be counted in the microscope. A panel of 16 monoclonal antibodies against haematopoietic cell-surface antigens was applied on 29 cases of acute myelogenic (AML) or lymphocytic (ALL) leukaemias, in order to compare immunological typing by immunomagnetic beads with Immunofluorescence staining (IF), in all the cases tested, the two methods showed a virtually identical antigen distribution. The procedure described offers the advantages of being fast and simple to perform. Moreover, it has a high specificity and is easy to interpret in cases with low antigen expression, [ABSTRACT FROM AUTHOR]

We have studied lepromatous leprosy (LL) as a human model disease for T-cell non-responsiveness to specific mycobacterial antigens and studied the effect of rlL-4. rIL-2, rlFN-γ and rTNF-α thereon, T-cell non-responsiveness to Mycobacterium bovis bacillus Calmette- Guerin (BCG) or purified protein derivative of M. tuberculosis (PPD) antigens could be overcome in 5 out of 8 non-responder patients by rlL-2 and in 2 out of 8 by rlL-4. The ability of rIL-4 to overcome BCG/PPD non-responsiveness was strongly dose-dependent. When rIL-2 and rIL-4 were added simultaneously, they seemed to synergize in their effect- T-cell non-responsiveness to M. leprae could be overcome only in 2 out of 18 non-responders by rIL-2 but not by rIL-4 alone. The ability of rlL-2 to overcome T-cell non-responsiveness to M, leprae antigens became particularly marked when the recombinant 65-kDa heat shock antigen of M. leprae was used instead of whole bacilli. Exogenously added rIL-4, and Io a lesser extent rlL-2. strongly enhanced existing T-ceil responses to BCG or M. leprae in the majority (8 out of 11) of responders. These findings may have implications for the in vivo manipulation of the immune response by recombinant lymphokines and vaccines. [ABSTRACT FROM AUTHOR]

Focuses on the public lecture from Elie Metchnikoff, winner of the Nobel Prize for Medicine in Stockholm, Sweden about immunity theory. Discussion on the resistance of the body to diseases; Development of the theory of bacterial action of the humours in opposition to the phagocyte theory; Comparison on the concept of benign role of the inflammatory reaction in general and of the phagocytic reaction in particular.

In a previous study we observed that human epidermal cell (EC) suspensions containing HLA- DR-expressing keratinocytes showed an amplified T-cell response to purified protein derivative (PPD). To evaluate further the possible immunological importance of class II transplantation antigens on keratinocytes we have compared the T-cell response to PPD in the presence of the following stimulator cells: EC suspensions from normal skin, or EC from tuberculin- reactive skin with or without removal of Langerhans' cells. The proliferation of purified T lymphocytes from peripheral blood in response to PPD in the presence of various concentrations of autologous EC was measured by [3H]thymidine incorporation on day 6. In 3 experiments out of 4 the EC from tuberculin-reactive skin, containing 28–76% HLA-DR-expressing cells as judged by immunocytochemistry (which also revealed fairly numerous HLA-DQ/ -DP-expressing keratinocytes and a slight increase in CD36- and CD4- but not CD1-expressing cells), induced a more pronounced T-cell response to PPD than did normal EC. This was not the case in the fourth experiment, in which a small number of HLA-DR- (15%) and few if any HLA-DQ-/-DP-expressing keratinocytes were found. Immunomagnetic removal of CD1-reactive Langerhans' cells from the tuberculin-reactive EC suspensions resulted in a reduction of the T-cell response to PPD, in most cases down to background level (T cells alone + PPD). This study does not support the hypothesis that HLA-DR-expressing keratinocytes can in themselves act as antigen-presenting cells. [ABSTRACT FROM AUTHOR]

A murine monoclonal antibody (MoAb) F101.01 reacting with the T cell receptor (TCR)-T3 complex is presented. Immunobistological studies showed that F101.01 specifically stains T-zone lymphocytes in lymph nodes, tonsils and splenic tissue. Two-colour immunofluorescence and flow cytometry demonstrated co-expression of the antigen defined by F101.01 and the pan-T cell antigens defined by CD2. CD3. CD5, and CD7 antibodies. Cells stained with CD4 and CD8 antibodies were both included in the F101.01-positive population, whereas CD16-positive natural killer cells (NK). B cells (CD19 and CD21)), and myeloid cells (CD 13 and CD.13) were excluded. The target antigen of F101.01 co-modulated with the CD3-defined antigen (T3) and the TCR recognized by the MoAb WT-31. CD3 antibody and WT-31 both blocked binding of F101.01, F101.01 precipitated the TCR-T3 complex From lysates of 125M-labelled peripheral blood mononuclear cells (PBMC) and HPB-ALL, when the lysate was prepared with a detergent (digitonin) that conserves the TCR-T3 complex, FACS analysis of T cells from a patient with a T cell immunodeficiency demonstrated that A-TCS- 1-CD3+ CD4+ and δ-TCS-1-CD3+ CD8+ cells were brightly F101.01+, whereas a large subpopulation of δ-TCS-l+CD3+CD4-CD8 cells were weakly F101.01, We conclude that F101.01 recognizes a conformational epitope of the TCR-H complex and that it reacts with the αβ TCR-T3 and the γ δ TCR-T3 complexes with different intensities. [ABSTRACT FROM AUTHOR]

Heterogeneity in antigen recognition of an alloreactive helper T-cell line was studied by repealed limiting dilution cloming. Analysis of the fine specificities of these clones showed that the gain of reactivity to new antigens by the T-cell line included the generation of non-crossreactive T cells specific to new major histocompatibility (MHC) antigens. Analysis of function revealed that all the T-cell clones studied had similar cell surface antigens and secreted interieukin 4 (IL-4)and IL-5/IL-3 but not IL-2 or gamma interferon (IFN-7gamma;). The T-cell clones served as helper cells for B cells expressing the appropriate MHC antigens lo both clonal proliferation and differentiation into antibody-producing cells. [ABSTRACT FROM AUTHOR]

Immunization of female Lewis rats with bovine type II collagen induces a severe polyarthritis with an incomplete penetration. Castration of the rats increased the incidence to 94% compared with 50% among sham-operated controls. When castrated female rats were implanted with silicone capsules containing/β-oestradiol they developed arthritis with a delayed onset and a decreased severity compared with castrated rats implanted with empty Silastic capsules. The levels of anti-type II collagen auto-antibodies were not affected by castration or oestrogen treatment. These findings show that oestrogen suppresses the development of collagen arthritis in rats and that this effect is mediated by mechanisms other than anti type II collagen autoantibodies. [ABSTRACT FROM AUTHOR]

Dendritic cells (DC) were isolated from synovial tissue and synovial fluids of patients with rheumatoid arthritis and from peripheral blood of healthy donors. The cells were analysed for various surface antigens in indirect immunofluorescence by means of monoclonal antibodies. Surface antigen expression and accessory activity of the DC during short-term cultures were also investigated. Both the rheumatoid synovial and the normal blood DC were strongly positive for panleucocyte antigen and class II major histocompatibility complex (MHC) antigens (HLA-DP, HLA-DQ, and HLA-DR). The DC suspensions (purity ∼80-85%) showed very low percentages of cells staining for various other cell membrane markers, including B cell, T cell, natural killer (NK) cells, and various monocyte/macrophage markers as well as markers specific for dendritic reticulum cells and Reed Sternberg cells. Moreover, neither rheumatoid nor normal DC reacted with the RFD1 monoclonal antibody, which is specific for interdigitating cells of human thymus. In contrast to Langerhans' cells, the DC lacked the thymocyte (T6) marker. The various DC expressed neither complement receptors (CR1, CR3) transferring receptors, nor Fc receptors. They also lacked enzyme markers like peroxidase and nonspecific esterase. The DC formed clusters with autologous T cells. Cluster formation was readily inhibited by anti-HLA-DR and anti-CD2 (TII) monoclonal antibodies. After 3 to 5 days in culture the DC still expressed class II MHC antigens and were potent stimulators in allogeneic mixed lymphocyte reactions (MLR). Only a small number of cells in the DC suspensions from synovial tissue expressed fibroblast antigens before and after culture. [ABSTRACT FROM AUTHOR]

Spontaneous and pokeweed mitogen-induced production of specific autoantibodies were studied in cultures of peripheral blood mononuclear cells from patients with different clinical stages of myasthenia gravis. Receptor antibody-related idiotypes and anti-idiotypic antibodies were defined by binding to mouse monoclonal anti-idiotypic and anti-receptor antibodies, respectively. Patients with severe disease had a more complete spectrum of idiotypes in serum, and cells from such patients spontaneously produced more antibody species and higher concentration of both idiotypes and anti-idiotypes than patients with mild disease. The frequencies of antibody specificities in tissue culture supernatants more closely reflected disease activity than those in serum. Tissue culture for (he study of different species of autoantibodies has proved to be a useful tool for monitoring the disease and the effects of treatment. [ABSTRACT FROM AUTHOR]

A comparison of murine monoclonal IgG subclass antisera with rabbit polyclonal IgG subclass antisera restriction of the monoclonal antisera and further antigenic heterogeneity within the IgG subclasses of at least two antigenic variants of IgG1, two of IgG2, two of IgG3 and a third subtype of IgG4. [ABSTRACT FROM AUTHOR]